Public Service Co Of New Hampshire 10-K 14 Feb 25 2024 FY Annual report Financial data

COVER PAGE

COVER PAGE - USD ($)	12 Months Ended
	Dec. 31, 2024	Jan. 31, 2025	Jun. 30, 2024
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2024
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity Registrant Name	EVERSOURCE ENERGY
Entity Incorporation, State or Country Code	MA
Entity Address, Address Line One	300 Cadwell Drive
Entity Address, City or Town	Springfield
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01104
City Area Code	800
Local Phone Number	286-5000
Entity File Number	001-05324
Entity Tax Identification Number	04-2147929
Title of 12(b) Security	Common Shares, $5.00 par value per share
Trading Symbol	ES
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 20,096,384,968
Entity Common Stock, Shares Outstanding		366,785,030
Documents Incorporated by Reference	Documents Incorporated by Reference Portions of the Eversource Energy and Subsidiaries 2023 combined Annual Report on Form 10-K and portions of the Proxy Statement relating to the Annual Meeting of Shareholders to be held on May 1, 2025, are incorporated by reference into Parts II and III of this Report.
Entity Central Index Key	0000072741
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Amendment Flag	false
The Connecticut Light and Power Company
Entity Information [Line Items]
Current Fiscal Year End Date	--12-31
Entity Registrant Name	THE CONNECTICUT LIGHT AND POWER COMPANY
Entity Incorporation, State or Country Code	CT
Entity Address, Address Line One	107 Selden Street
Entity Address, City or Town	Berlin
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06037-1616
City Area Code	800
Local Phone Number	286-5000
Entity File Number	000-00404
Entity Tax Identification Number	06-0303850
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		6,035,205
Entity Central Index Key	0000023426
NSTAR Electric Company
Entity Information [Line Items]
Current Fiscal Year End Date	--12-31
Entity Registrant Name	NSTAR ELECTRIC COMPANY
Entity Incorporation, State or Country Code	MA
Entity Address, Address Line One	800 Boylston Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02199
City Area Code	800
Local Phone Number	286-5000
Entity File Number	001-02301
Entity Tax Identification Number	04-1278810
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		200
Entity Central Index Key	0000013372
Public Service Company of New Hampshire
Entity Information [Line Items]
Current Fiscal Year End Date	--12-31
Entity Registrant Name	PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE
Entity Incorporation, State or Country Code	NH
Entity Address, Address Line One	Energy Park
Entity Address, Address Line Two	780 North Commercial Street
Entity Address, City or Town	Manchester
Entity Address, State or Province	NH
Entity Address, Postal Zip Code	03101-1134
City Area Code	800
Local Phone Number	286-5000
Entity File Number	001-06392
Entity Tax Identification Number	02-0181050
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		301
Entity Central Index Key	0000315256

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2024
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut
CL&P
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut
NSTAR Electric
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut
PSNH
Auditor [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Hartford, Connecticut

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current Assets:
Cash	$ 26,656	$ 53,873
Receivables, Net (net of allowance for uncollectible accounts)	1,651,325	1,431,531
Unbilled Revenues	242,169	225,325
Materials, Supplies, Natural Gas and REC Inventory	594,568	507,307
Regulatory Assets	2,189,660	1,674,196
Current Assets Held for Sale	56,327	0
Prepayments and Other Current Assets	315,368	355,762
Total Current Assets	5,076,073	4,247,994
Property, Plant and Equipment, Net	40,986,578	39,498,607
Deferred Debits and Other Assets:
Regulatory Assets	4,880,974	4,714,970
Goodwill	3,571,333	4,532,100
Investments in Unconsolidated Affiliates	168,652	660,473
Prepaid Pension and PBOP	1,336,633	1,028,207
Marketable Securities	320,272	337,814
Long-Term Assets Held for Sale	2,611,145	0
Other Long-Term Assets	642,869	592,080
Total Deferred Debits and Other Assets	13,531,878	11,865,644
Total Assets	59,594,529	55,612,245
Current Liabilities:
Notes Payable	2,042,793	1,930,422
Long-Term Debt – Current Portion	1,003,150	824,847
Rate Reduction Bonds – Current Portion	43,210	43,210
Accounts Payable	1,736,880	1,869,187
Accrued Interest	341,558	260,577
Regulatory Liabilities	632,282	591,750
Current Liabilities Held for Sale	52,593	0
Other Current Liabilities	868,491	821,404
Total Current Liabilities	6,720,957	6,341,397
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,411,206	5,303,730
Regulatory Liabilities	4,032,564	4,022,923
Asset Retirement Obligations	590,890	505,844
Accrued SERP and PBOP	95,400	123,754
Long-Term Liabilities Held for Sale	398,859	0
Other Long-Term Liabilities	1,123,999	1,029,238
Total Deferred Credits and Other Liabilities	11,652,918	10,985,489
Capitalization:
Long-Term Debt	25,701,627	23,588,616
Rate Reduction Bonds	324,072	367,282
Noncontrolling Interest - Preferred Stock of Subsidiaries	155,568	155,569
Common Shareholders' Equity:
Common Shares	1,878,622	1,799,920
Capital Surplus, Paid In	9,428,905	8,460,876
Retained Earnings	3,929,141	4,142,515
Accumulated Other Comprehensive Income/(Loss)	(26,472)	(33,737)
Treasury Stock	(170,809)	(195,682)
Common Shareholders' Equity	15,039,387	14,173,892
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	$ 59,594,529	$ 55,612,245

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Allowance for uncollectible accounts, current	$ 556,164	$ 554,455

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME/(LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Operating Revenues	$ 11,900,809	$ 11,910,705	$ 12,289,336
Operating Expenses:
Purchased Power, Purchased Natural Gas and Transmission	3,736,078	5,168,241	5,014,074
Operations and Maintenance	2,012,926	1,895,703	1,865,328
Depreciation	1,433,503	1,305,840	1,194,246
Amortization	342,864	(490,117)	448,892
Energy Efficiency Programs	671,828	691,344	658,051
Taxes Other Than Income Taxes	997,901	940,359	910,591
Loss on Pending Sale of Aquarion	297,000	0	0
Total Operating Expenses	9,492,100	9,511,370	10,091,182
Operating Income	2,408,709	2,399,335	2,198,154
Interest Expense	1,111,336	855,441	678,274
Losses on Offshore Wind Investments	464,019	2,167,000	0
Other Income, Net	410,482	348,069	346,088
Income/(Loss) Before Income Tax Expense	1,243,836	(275,037)	1,865,968
Income Tax Expense	424,664	159,684	453,574
Net Income/(Loss)	819,172	(434,721)	1,412,394
Net Income Attributable to Noncontrolling Interests	7,519	7,519	7,519
Net Income/(Loss) Attributable to Common Shareholders	$ 811,653	$ (442,240)	$ 1,404,875
Basic Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.27)	$ 4.05
Diluted Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.26)	$ 4.05
Weighted Average Common Shares Outstanding:
Basic (in shares)	357,482,965	349,580,638	346,783,444
Diluted (in shares)	357,779,408	349,840,481	347,246,768

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS)/INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net Income/(Loss)	$ 819,172	$ (434,721)	$ 1,412,394
Other Comprehensive Income, Net of Tax:
Qualified Cash Flow Hedging Instruments	20	20	20
Changes in Unrealized Gains/(Losses) on Marketable Securities	0	1,252	(1,636)
Changes in Funded Status of Pension, SERP and PBOP Benefit Plans	7,245	4,412	4,470
Other Comprehensive Income, Net of Tax	7,265	5,684	2,854
Comprehensive Income Attributable to Noncontrolling Interests	(7,519)	(7,519)	(7,519)
Comprehensive Income/(Loss) Attributable to Common Shareholders	$ 818,918	$ (436,556)	$ 1,407,729

CONSOLIDATED STATEMENTS OF COMM

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Shares	Capital Surplus, Paid In	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2021		344,403,196
Beginning balance at Dec. 31, 2021	$ 14,599,844	$ 1,789,092	$ 8,098,514	$ 5,005,391	$ (42,275)	$ (250,878)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)	1,412,394			1,412,394
Dividends on Common Stock	(883,113)			(883,113)
Dividends on Preferred Stock	(7,519)			(7,519)
Issuance of Common Shares (in shares)		2,165,671
Issuance of Common Shares	199,905	$ 10,828	189,077
Capital Stock Expense	(2,847)		(2,847)
Long-Term Incentive Plan Activity	8,335		8,335
Issuance of Treasury Shares (in shares)		949,724
Issuance of Treasury Shares	71,172		53,822			17,350
Issuance of Treasury Shares for Acquisition (in shares)		925,264
Issuance of Treasury Shares for Acquisition	72,133		54,830			17,303
Other Comprehensive Loss	2,854				2,854
Ending balance (in shares) at Dec. 31, 2022		348,443,855
Ending balance at Dec. 31, 2022	15,473,158	$ 1,799,920	8,401,731	5,527,153	(39,421)	(216,225)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)	(434,721)			(434,721)
Dividends on Common Stock	(942,398)			(942,398)
Dividends on Preferred Stock	(7,519)			(7,519)
Long-Term Incentive Plan Activity	1,375		1,375
Issuance of Treasury Shares (in shares)		1,096,411
Issuance of Treasury Shares	78,313		57,770			20,543
Other Comprehensive Loss	$ 5,684				5,684
Ending balance (in shares) at Dec. 31, 2023	349,540,266	349,540,266
Ending balance at Dec. 31, 2023	$ 14,173,892	$ 1,799,920	8,460,876	4,142,515	(33,737)	(195,682)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)	819,172			819,172
Dividends on Common Stock	(1,025,027)			(1,025,027)
Dividends on Preferred Stock	(7,519)			(7,519)
Issuance of Common Shares (in shares)		15,740,294
Issuance of Common Shares	1,000,089	$ 78,702	921,387
Capital Stock Expense	(10,642)		(10,642)
Long-Term Incentive Plan Activity	(6,557)		(6,557)
Issuance of Treasury Shares (in shares)		1,327,492
Issuance of Treasury Shares	88,714		63,841			24,873
Other Comprehensive Loss	$ 7,265				7,265
Ending balance (in shares) at Dec. 31, 2024	366,608,052	366,608,052
Ending balance at Dec. 31, 2024	$ 15,039,387	$ 1,878,622	$ 9,428,905	$ 3,929,141	$ (26,472)	$ (170,809)

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Dividends on Common Shares (in dollars per share)	$ 2.86	$ 2.70	$ 2.55
Par value of Common Shares (in dollars per share)	$ 5	$ 5	$ 5

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Activities:
Net Income/(Loss)	$ 819,172	$ (434,721)	$ 1,412,394
Adjustments to Reconcile Net Income/(Loss) to Net Cash Flows Provided by Operating Activities:
Depreciation	1,433,503	1,305,840	1,194,246
Deferred Income Taxes	435,889	85,405	346,779
Uncollectible Expense	74,069	72,468	61,876
Pension, SERP and PBOP Income, Net	(73,564)	(90,706)	(160,857)
Pension and PBOP Contributions	(5,915)	(6,860)	(83,148)
Regulatory Under Recoveries, Net	(919,359)	(151,548)	(205,294)
Gain (Loss) from Litigation Settlement	0	0	(72,041)
Amortization	342,864	(490,117)	448,892
Cost of Removal Expenditures	(294,984)	(315,699)	(303,755)
Payment in 2022 of Withheld Property Taxes	0	0	(78,446)
Losses on Offshore Wind Investments	464,019	2,167,000	0
Loss on Pending Sale of Aquarion	297,000	0	0
Other	(102,450)	(53,026)	(39,192)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(432,620)	(124,393)	(470,593)
Taxes Receivable/Accrued, Net	55,502	36,357	18,358
Accounts Payable	47,082	(287,637)	377,657
Other Current Assets and Liabilities, Net	19,529	(66,202)	(45,583)
Net Cash Flows Provided by Operating Activities	2,159,737	1,646,161	2,401,293
Investing Activities:
Investments in Property, Plant and Equipment	(4,480,529)	(4,336,849)	(3,441,852)
Proceeds from Sales of Marketable Securities	268,164	395,604	457,612
Purchases of Marketable Securities	(242,959)	(336,779)	(424,174)
Investments in Unconsolidated Affiliates	(929,688)	(1,680,473)	(742,496)
Proceeds from Unconsolidated Affiliates	862,713	1,090,662	0
Other Investing Activities	(13,365)	(2,897)	20,420
Net Cash Flows Used in Investing Activities	(4,535,664)	(4,870,732)	(4,130,490)
Financing Activities:
Issuance of Common Shares, Net of Issuance Costs	989,447	0	197,058
Cash Dividends on Common Shares	(1,001,488)	(918,995)	(860,033)
Cash Dividends on Preferred Stock	(7,519)	(7,519)	(7,519)
Increase/(Decrease) in Notes Payable	(94,959)	695,552	(78,170)
Repayment of Rate Reduction Bonds	(43,210)	(43,210)	(43,210)
Issuance of Long-Term Debt	4,501,623	5,198,345	4,045,000
Retirement of Long-Term Debt	(1,949,995)	(2,008,470)	(1,175,000)
Other Financing Activities	(57,082)	(46,466)	(48,185)
Net Cash Flows Provided by Financing Activities	2,336,817	2,869,237	2,029,941
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	(39,110)	(355,334)	300,744
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	166,418	521,752	221,008
Cash, Cash Equivalents and Restricted Cash - End of Year	$ 127,308	$ 166,418	$ 521,752

THE CONNECTICUT LIGHT AND POWER

THE CONNECTICUT LIGHT AND POWER COMPANY BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current Assets:
Cash	$ 26,656	$ 53,873
Receivables, Net (net of allowance for uncollectible accounts)	1,651,325	1,431,531
Unbilled Revenues	242,169	225,325
Materials, Supplies, Natural Gas and REC Inventory	594,568	507,307
Regulatory Assets	2,189,660	1,674,196
Prepayments and Other Current Assets	315,368	355,762
Total Current Assets	5,076,073	4,247,994
Property, Plant and Equipment, Net	40,986,578	39,498,607
Deferred Debits and Other Assets:
Regulatory Assets	4,880,974	4,714,970
Prepaid Pension and PBOP	1,336,633	1,028,207
Other Long-Term Assets	642,869	592,080
Total Deferred Debits and Other Assets	13,531,878	11,865,644
Total Assets	59,594,529	55,612,245
Current Liabilities:
Long-Term Debt – Current Portion	1,003,150	824,847
Accounts Payable	1,736,880	1,869,187
Regulatory Liabilities	632,282	591,750
Other Current Liabilities	868,491	821,404
Total Current Liabilities	6,720,957	6,341,397
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,411,206	5,303,730
Regulatory Liabilities	4,032,564	4,022,923
Other Long-Term Liabilities	1,123,999	1,029,238
Total Deferred Credits and Other Liabilities	11,652,918	10,985,489
Capitalization:
Long-Term Debt	25,701,627	23,588,616
Noncontrolling Interest - Preferred Stock of Subsidiaries	155,568	155,569
Common Shareholders' Equity:
Capital Surplus, Paid In	9,428,905	8,460,876
Retained Earnings	3,929,141	4,142,515
Accumulated Other Comprehensive Income/(Loss)	(26,472)	(33,737)
Stockholders' equity	15,039,387	14,173,892
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	59,594,529	55,612,245
The Connecticut Light and Power Company
Current Assets:
Cash	1,093	10,213
Unbilled Revenues	59,759	57,403
Materials, Supplies, Natural Gas and REC Inventory	217,316	156,467
Regulatory Assets	638,529	480,369
Prepayments and Other Current Assets	51,688	94,789
Total Current Assets	1,700,279	1,418,684
Property, Plant and Equipment, Net	13,002,193	12,340,192
Deferred Debits and Other Assets:
Regulatory Assets	1,687,029	1,662,778
Prepaid Pension and PBOP	182,483	129,801
Other Long-Term Assets	267,861	298,169
Total Deferred Debits and Other Assets	2,137,373	2,090,748
Total Assets	16,839,845	15,849,624
Current Liabilities:
Notes Payable to Eversource Parent	280,000	249,670
Long-Term Debt – Current Portion	2,944	0
Obligations to Third Party Suppliers	63,840	75,753
Regulatory Liabilities	124,122	102,239
Derivative Liabilities	71,090	81,944
Other Current Liabilities	170,854	127,703
Total Current Liabilities	1,398,100	1,394,090
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	2,052,806	1,860,122
Regulatory Liabilities	1,395,883	1,315,928
Other Long-Term Liabilities	204,801	258,185
Total Deferred Credits and Other Liabilities	3,653,490	3,434,235
Capitalization:
Long-Term Debt	5,108,173	4,814,429
Noncontrolling Interest - Preferred Stock of Subsidiaries	116,200	116,200
Common Shareholders' Equity:
Common Stock	60,352	60,352
Capital Surplus, Paid In	3,684,265	3,384,265
Retained Earnings	2,819,107	2,645,868
Accumulated Other Comprehensive Income/(Loss)	158	185
Stockholders' equity	6,563,882	6,090,670
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	16,839,845	15,849,624
The Connecticut Light and Power Company | Nonrelated Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	663,171	558,993
Current Liabilities:
Accounts Payable	548,100	622,055
The Connecticut Light and Power Company | Related Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	68,723	60,450
Current Liabilities:
Notes Payable to Eversource Parent	280,000	457,000
Accounts Payable	$ 137,150	134,726
Capitalization:
Long-Term Debt		$ 207,300

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Allowance for uncollectible accounts, current	$ 556,164	$ 554,455
CL&P
Allowance for uncollectible accounts, current	$ 279,108	$ 296,030

THE CONNECTICUT LIGHT AND POW_2

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Revenues	$ 11,900,809	$ 11,910,705	$ 12,289,336
Operating Expenses:
Purchased Power and Transmission	3,736,078	5,168,241	5,014,074
Operations and Maintenance	2,012,926	1,895,703	1,865,328
Depreciation	1,433,503	1,305,840	1,194,246
Energy Efficiency Programs	671,828	691,344	658,051
Taxes Other Than Income Taxes	997,901	940,359	910,591
Total Operating Expenses	9,492,100	9,511,370	10,091,182
Operating Income	2,408,709	2,399,335	2,198,154
Interest Expense	1,111,336	855,441	678,274
Other Income, Net	410,482	348,069	346,088
Income/(Loss) Before Income Tax Expense	1,243,836	(275,037)	1,865,968
Income Tax Expense	424,664	159,684	453,574
The Connecticut Light and Power Company
Operating Revenues	4,614,977	4,578,804	4,817,744
Operating Expenses:
Purchased Power and Transmission	1,836,911	2,612,949	2,110,253
Operations and Maintenance	815,345	733,287	707,162
Depreciation	406,540	376,904	355,511
Amortization of Regulatory Assets/(Liabilities), Net	104,446	(500,367)	335,636
Energy Efficiency Programs	171,690	133,453	134,222
Taxes Other Than Income Taxes	419,575	401,135	384,746
Total Operating Expenses	3,754,507	3,757,361	4,027,530
Operating Income	860,470	821,443	790,214
Interest Expense	231,004	193,361	169,348
Other Income, Net	77,591	61,560	83,252
Income/(Loss) Before Income Tax Expense	707,057	689,642	704,118
Income Tax Expense	194,459	170,909	171,198
Net Income/(Loss)	$ 512,598	$ 518,733	$ 532,920

THE CONNECTICUT LIGHT AND POW_3

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Other Comprehensive Income, Net of Tax:
Comprehensive Income/(Loss) Attributable to Common Shareholders	$ 818,918	$ (436,556)	$ 1,407,729
The Connecticut Light and Power Company
Net Income/(Loss)	512,598	518,733	532,920
Other Comprehensive Income, Net of Tax:
Qualified Cash Flow Hedging Instruments	(27)	(26)	(26)
Changes in Unrealized Gains/(Losses) on Marketable Securities	0	42	(56)
Other Comprehensive Income/(Loss), Net of Tax	(27)	16	(82)
Comprehensive Income/(Loss) Attributable to Common Shareholders	$ 512,571	$ 518,749	$ 532,838

THE CONNECTICUT LIGHT AND POW_4

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus, Paid In	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	The Connecticut Light and Power Company	The Connecticut Light and Power Company Common Stock	The Connecticut Light and Power Company Capital Surplus, Paid In	The Connecticut Light and Power Company Retained Earnings	The Connecticut Light and Power Company Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2021		344,403,196					6,035,205
Beginning balance at Dec. 31, 2021	$ 14,599,844	$ 1,789,092	$ 8,098,514	$ 5,005,391	$ (42,275)	$ 5,299,501	$ 60,352	$ 3,010,765	$ 2,228,133	$ 251
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						532,920			532,920
Dividends on Preferred Stock	(7,519)			(7,519)		(5,559)			(5,559)
Dividends on Common Stock	(883,113)			(883,113)		(292,400)			(292,400)
Capital Contributions from Eversource Parent						250,000		250,000
Other Comprehensive Loss, Net of Tax						(82)				(82)
Ending balance (in shares) at Dec. 31, 2022		348,443,855					6,035,205
Ending balance at Dec. 31, 2022	15,473,158	$ 1,799,920	8,401,731	5,527,153	(39,421)	5,784,380	$ 60,352	3,260,765	2,463,094	169
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						518,733			518,733
Dividends on Preferred Stock	(7,519)			(7,519)		(5,559)			(5,559)
Dividends on Common Stock	$ (942,398)			(942,398)		(330,400)			(330,400)
Capital Contributions from Eversource Parent						123,500		123,500
Other Comprehensive Loss, Net of Tax					5,700	16				16
Ending balance (in shares) at Dec. 31, 2023	349,540,266	349,540,266					6,035,205
Ending balance at Dec. 31, 2023	$ 14,173,892	$ 1,799,920	8,460,876	4,142,515	(33,737)	6,090,670	$ 60,352	3,384,265	2,645,868	185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						512,598			512,598
Dividends on Preferred Stock	(7,519)			(7,519)		(5,559)			(5,559)
Dividends on Common Stock	$ (1,025,027)			(1,025,027)		(333,800)			(333,800)
Capital Contributions from Eversource Parent						300,000		300,000
Other Comprehensive Loss, Net of Tax					7,200	(27)				(27)
Ending balance (in shares) at Dec. 31, 2024	366,608,052	366,608,052					6,035,205
Ending balance at Dec. 31, 2024	$ 15,039,387	$ 1,878,622	$ 9,428,905	$ 3,929,141	$ (26,472)	$ 6,563,882	$ 60,352	$ 3,684,265	$ 2,819,107	$ 158

THE CONNECTICUT LIGHT AND POW_5

THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Adjustments to Reconcile Net Income/(Loss) to Net Cash Flows Provided by Operating Activities:
Depreciation	$ 1,433,503	$ 1,305,840	$ 1,194,246
Deferred Income Taxes	435,889	85,405	346,779
Uncollectible Expense	74,069	72,468	61,876
Pension, SERP and PBOP Income, Net	(73,564)	(90,706)	(160,857)
Pension Contributions	(5,915)	(6,860)	(83,148)
Regulatory (Under)/Over Recoveries, Net	(919,359)	(151,548)	(205,294)
Gain (Loss) from Litigation Settlement	0	0	(72,041)
Cost of Removal Expenditures	(294,984)	(315,699)	(303,755)
Other	(102,450)	(53,026)	(39,192)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(432,620)	(124,393)	(470,593)
Taxes Receivable/Accrued, Net	55,502	36,357	18,358
Accounts Payable	47,082	(287,637)	377,657
Other Current Assets and Liabilities, Net	19,529	(66,202)	(45,583)
Net Cash Flows Provided by Operating Activities	2,159,737	1,646,161	2,401,293
Investing Activities:
Investments in Property, Plant and Equipment	(4,480,529)	(4,336,849)	(3,441,852)
Other Investing Activities	(13,365)	(2,897)	20,420
Net Cash Flows Used in Investing Activities	(4,535,664)	(4,870,732)	(4,130,490)
Financing Activities:
Cash Dividends on Common Shares	(1,001,488)	(918,995)	(860,033)
Cash Dividends on Preferred Stock	(7,519)	(7,519)	(7,519)
Increase (Decrease) in Notes Payable To Eversource Parent	(94,959)	695,552	(78,170)
Issuance of Long-Term Debt	4,501,623	5,198,345	4,045,000
Retirement of Long-Term Debt	(1,949,995)	(2,008,470)	(1,175,000)
Other Financing Activities	(57,082)	(46,466)	(48,185)
Net Cash Flows Provided by/(Used In) Financing Activities	2,336,817	2,869,237	2,029,941
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	(39,110)	(355,334)	300,744
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	166,418	521,752	221,008
Cash, Cash Equivalents and Restricted Cash - End of Year	127,308	166,418	521,752
The Connecticut Light and Power Company
Operating Activities:
Net Income/(Loss)	512,598	518,733	532,920
Adjustments to Reconcile Net Income/(Loss) to Net Cash Flows Provided by Operating Activities:
Depreciation	406,540	376,904	355,511
Deferred Income Taxes	175,424	184,037	45,381
Uncollectible Expense	17,190	11,675	15,578
Pension, SERP and PBOP Income, Net	(12,019)	(18,316)	(28,971)
Regulatory (Under)/Over Recoveries, Net	(257,561)	157,200	(144,793)
Gain (Loss) from Litigation Settlement	0	0	(72,041)
Amortization of Regulatory Assets/(Liabilities), Net	104,446	(500,367)	335,636
Cost of Removal Expenditures	(60,536)	(80,479)	(71,596)
Other	(47,680)	(16,194)	(25,927)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(175,162)	(100,684)	(256,338)
Taxes Receivable/Accrued, Net	64,914	25,633	897
Accounts Payable	4,232	(88,040)	207,698
Other Current Assets and Liabilities, Net	(48,973)	(20,535)	(24,308)
Net Cash Flows Provided by Operating Activities	683,413	449,567	869,647
Investing Activities:
Investments in Property, Plant and Equipment	(978,532)	(1,093,121)	(876,740)
Other Investing Activities	0	173	591
Net Cash Flows Used in Investing Activities	(978,532)	(1,092,948)	(876,149)
Financing Activities:
Cash Dividends on Common Shares	(333,800)	(330,400)	(292,400)
Cash Dividends on Preferred Stock	(5,559)	(5,559)	(5,559)
Increase (Decrease) in Notes Payable To Eversource Parent	(177,000)	457,000	0
Issuance of Long-Term Debt	650,000	800,000	0
Retirement of Long-Term Debt	(139,800)	(400,000)	0
Capital Contributions from Eversource Parent	300,000	123,500	250,000
Other Financing Activities	(8,856)	(9,244)	0
Net Cash Flows Provided by/(Used In) Financing Activities	284,985	635,297	(47,959)
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	(10,134)	(8,084)	(54,461)
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	12,243	20,327	74,788
Cash, Cash Equivalents and Restricted Cash - End of Year	$ 2,109	$ 12,243	$ 20,327

NSTAR ELECTRIC COMPANY AND SUBS

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current Assets:
Cash	$ 26,656	$ 53,873
Receivables, Net (net of allowance for uncollectible accounts)	1,651,325	1,431,531
Unbilled Revenues	242,169	225,325
Materials, Supplies, Natural Gas and REC Inventory	594,568	507,307
Regulatory Assets	2,189,660	1,674,196
Prepayments and Other Current Assets	315,368	355,762
Total Current Assets	5,076,073	4,247,994
Property, Plant and Equipment, Net	40,986,578	39,498,607
Deferred Debits and Other Assets:
Regulatory Assets	4,880,974	4,714,970
Prepaid Pension and PBOP	1,336,633	1,028,207
Other Long-Term Assets	642,869	592,080
Total Deferred Debits and Other Assets	13,531,878	11,865,644
Total Assets	59,594,529	55,612,245
Current Liabilities:
Long-Term Debt – Current Portion	1,003,150	824,847
Accounts Payable	1,736,880	1,869,187
Regulatory Liabilities	632,282	591,750
Other Current Liabilities	868,491	821,404
Total Current Liabilities	6,720,957	6,341,397
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,411,206	5,303,730
Regulatory Liabilities	4,032,564	4,022,923
Other Long-Term Liabilities	1,123,999	1,029,238
Total Deferred Credits and Other Liabilities	11,652,918	10,985,489
Capitalization:
Long-Term Debt	25,701,627	23,588,616
Preferred Stock Not Subject to Mandatory Redemption	155,568	155,569
Common Shareholders' Equity:
Capital Surplus, Paid In	9,428,905	8,460,876
Retained Earnings	3,929,141	4,142,515
Accumulated Other Comprehensive Income/(Loss)	(26,472)	(33,737)
Common Shareholders' Equity	15,039,387	14,173,892
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	59,594,529	55,612,245
NSTAR Electric Company
Current Assets:
Cash	911	6,740
Unbilled Revenues	59,079	49,897
Materials, Supplies, Natural Gas and REC Inventory	220,621	173,770
Regulatory Assets	902,770	676,083
Prepayments and Other Current Assets	72,986	41,464
Total Current Assets	1,953,851	1,510,295
Property, Plant and Equipment, Net	14,037,828	12,753,787
Deferred Debits and Other Assets:
Regulatory Assets	1,204,337	1,281,836
Prepaid Pension and PBOP	724,661	608,617
Other Long-Term Assets	154,571	116,978
Total Deferred Debits and Other Assets	2,083,569	2,007,431
Total Assets	18,075,248	16,271,513
Current Liabilities:
Notes Payable to Eversource Parent	504,782	365,847
Long-Term Debt – Current Portion	250,000	0
Obligations to Third Party Suppliers	163,711	139,823
Renewable Portfolio Standards Compliance Obligations	106,399	116,010
Regulatory Liabilities	436,312	368,070
Other Current Liabilities	95,798	84,688
Total Current Liabilities	2,245,542	1,818,756
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	2,005,439	1,849,613
Regulatory Liabilities	1,643,079	1,585,311
Other Long-Term Liabilities	377,462	327,388
Total Deferred Credits and Other Liabilities	4,025,980	3,762,312
Capitalization:
Long-Term Debt	4,844,920	4,496,947
Preferred Stock Not Subject to Mandatory Redemption	43,000	43,000
Common Shareholders' Equity:
Common Shares	0	0
Capital Surplus, Paid In	3,788,842	3,013,842
Retained Earnings	3,127,105	3,136,612
Accumulated Other Comprehensive Income/(Loss)	(141)	44
Common Shareholders' Equity	6,915,806	6,150,498
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	18,075,248	16,271,513
NSTAR Electric Company | Nonrelated Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	614,563	487,707
Current Liabilities:
Accounts Payable	534,868	599,696
NSTAR Electric Company | Related Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	82,921	74,634
Current Liabilities:
Accounts Payable	$ 153,672	$ 144,622

NSTAR ELECTRIC COMPANY AND SU_2

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Allowance for uncollectible accounts, current	$ 556,164	$ 554,455
NSTAR Electric
Allowance for uncollectible accounts, current	$ 114,910	$ 97,026

NSTAR ELECTRIC COMPANY AND SU_3

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Revenues	$ 11,900,809	$ 11,910,705	$ 12,289,336
Operating Expenses:
Purchased Power and Transmission	3,736,078	5,168,241	5,014,074
Operations and Maintenance	2,012,926	1,895,703	1,865,328
Depreciation	1,433,503	1,305,840	1,194,246
Energy Efficiency Programs	671,828	691,344	658,051
Taxes Other Than Income Taxes	997,901	940,359	910,591
Total Operating Expenses	9,492,100	9,511,370	10,091,182
Operating Income	2,408,709	2,399,335	2,198,154
Interest Expense	1,111,336	855,441	678,274
Other Income, Net	410,482	348,069	346,088
Income/(Loss) Before Income Tax Expense	1,243,836	(275,037)	1,865,968
Income Tax Expense	424,664	159,684	453,574
NSTAR Electric Company
Operating Revenues	3,720,877	3,515,539	3,583,070
Operating Expenses:
Purchased Power and Transmission	1,045,306	1,154,013	1,264,824
Operations and Maintenance	735,019	668,466	640,834
Depreciation	407,699	372,578	361,969
Amortization of Regulatory Assets/(Liabilities), Net	130,869	16,150	83,855
Energy Efficiency Programs	263,405	325,593	332,247
Taxes Other Than Income Taxes	280,261	256,090	246,705
Total Operating Expenses	2,862,559	2,792,890	2,930,434
Operating Income	858,318	722,649	652,636
Interest Expense	222,794	189,254	162,892
Other Income, Net	191,405	164,129	142,661
Income/(Loss) Before Income Tax Expense	826,929	697,524	632,405
Income Tax Expense	190,576	152,996	139,977
Net Income/(Loss)	$ 636,353	$ 544,528	$ 492,428

NSTAR ELECTRIC COMPANY AND SU_4

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Other Comprehensive Income/(Loss), Net of Tax:
Comprehensive Income/(Loss) Attributable to Common Shareholders	$ 818,918	$ (436,556)	$ 1,407,729
NSTAR Electric Company
Net Income/(Loss)	636,353	544,528	492,428
Other Comprehensive Income/(Loss), Net of Tax:
Changes in Funded Status of SERP Benefit Plan	(205)	(272)	(221)
Qualified Cash Flow Hedging Instruments	20	20	20
Changes in Unrealized Gains/(Losses) on Marketable Securities	0	12	(16)
Other Comprehensive Income/(Loss), Net of Tax	(185)	(240)	(217)
Comprehensive Income/(Loss) Attributable to Common Shareholders	$ 636,168	$ 544,288	$ 492,211

NSTAR ELECTRIC COMPANY AND SU_5

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus, Paid In	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	NSTAR Electric	NSTAR Electric Common Stock	NSTAR Electric Capital Surplus, Paid In	NSTAR Electric Retained Earnings	NSTAR Electric Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2021		344,403,196					200
Beginning balance at Dec. 31, 2021	$ 14,599,844	$ 1,789,092	$ 8,098,514	$ 5,005,391	$ (42,275)	$ 4,973,019	$ 0	$ 2,253,942	$ 2,718,576	$ 501
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						492,428			492,428
Dividends on Preferred Stock	(7,519)			(7,519)		(1,960)			(1,960)
Dividends on Common Stock	(883,113)			(883,113)		(287,600)			(287,600)
Capital Contributions from Eversource Parent						525,000		525,000
Other Comprehensive Loss, Net of Tax						(217)				(217)
Ending balance (in shares) at Dec. 31, 2022		348,443,855					200
Ending balance at Dec. 31, 2022	15,473,158	$ 1,799,920	8,401,731	5,527,153	(39,421)	5,700,670	$ 0	2,778,942	2,921,444	284
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						544,528			544,528
Dividends on Preferred Stock	(7,519)			(7,519)		(1,960)			(1,960)
Dividends on Common Stock	$ (942,398)			(942,398)		(327,400)			(327,400)
Capital Contributions from Eversource Parent						234,900		234,900
Other Comprehensive Loss, Net of Tax					5,700	(240)				(240)
Ending balance (in shares) at Dec. 31, 2023	349,540,266	349,540,266					200
Ending balance at Dec. 31, 2023	$ 14,173,892	$ 1,799,920	8,460,876	4,142,515	(33,737)	6,150,498	$ 0	3,013,842	3,136,612	44
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						636,353			636,353
Dividends on Preferred Stock	(7,519)			(7,519)		(1,960)			(1,960)
Dividends on Common Stock	$ (1,025,027)			(1,025,027)		(643,900)			(643,900)
Capital Contributions from Eversource Parent						775,000		775,000
Other Comprehensive Loss, Net of Tax					7,200	(185)				(185)
Ending balance (in shares) at Dec. 31, 2024	366,608,052	366,608,052					200
Ending balance at Dec. 31, 2024	$ 15,039,387	$ 1,878,622	$ 9,428,905	$ 3,929,141	$ (26,472)	$ 6,915,806	$ 0	$ 3,788,842	$ 3,127,105	$ (141)

NSTAR ELECTRIC COMPANY AND SU_6

NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Adjustments to Reconcile Net Income/(Loss) to Net Cash Flows Provided by Operating Activities:
Depreciation	$ 1,433,503	$ 1,305,840	$ 1,194,246
Deferred Income Taxes	435,889	85,405	346,779
Uncollectible Expense	74,069	72,468	61,876
Pension, SERP and PBOP Income, Net	(73,564)	(90,706)	(160,857)
Pension Contributions	(5,915)	(6,860)	(83,148)
Regulatory Under Recoveries, Net	(919,359)	(151,548)	(205,294)
Cost of Removal Expenditures	(294,984)	(315,699)	(303,755)
Payment in 2022 of Withheld Property Taxes	0	0	(78,446)
Other	(102,450)	(53,026)	(39,192)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(432,620)	(124,393)	(470,593)
Taxes Receivable/Accrued, Net	55,502	36,357	18,358
Accounts Payable	47,082	(287,637)	377,657
Other Current Assets and Liabilities, Net	19,529	(66,202)	(45,583)
Net Cash Flows Provided by Operating Activities	2,159,737	1,646,161	2,401,293
Investing Activities:
Investments in Property, Plant and Equipment	(4,480,529)	(4,336,849)	(3,441,852)
Other Investing Activities	(13,365)	(2,897)	20,420
Net Cash Flows Used in Investing Activities	(4,535,664)	(4,870,732)	(4,130,490)
Financing Activities:
Cash Dividends on Common Shares	(1,001,488)	(918,995)	(860,033)
Cash Dividends on Preferred Stock	(7,519)	(7,519)	(7,519)
Increase (Decrease) in Notes Payable To Eversource Parent	(94,959)	695,552	(78,170)
Issuance of Long-Term Debt	4,501,623	5,198,345	4,045,000
Retirement of Long-Term Debt	(1,949,995)	(2,008,470)	(1,175,000)
Other Financing Activities	(57,082)	(46,466)	(48,185)
Net Cash Flows Provided by Financing Activities	2,336,817	2,869,237	2,029,941
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	(39,110)	(355,334)	300,744
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	166,418	521,752	221,008
Cash, Cash Equivalents and Restricted Cash - End of Year	127,308	166,418	521,752
NSTAR Electric
Operating Activities:
Net Income/(Loss)	636,353	544,528	492,428
Adjustments to Reconcile Net Income/(Loss) to Net Cash Flows Provided by Operating Activities:
Depreciation	407,699	372,578	361,969
Deferred Income Taxes	111,177	96,224	78,039
Uncollectible Expense	33,607	22,791	21,550
Pension, SERP and PBOP Income, Net	(36,104)	(41,554)	(55,830)
Pension Contributions	0	0	(15,000)
Regulatory Under Recoveries, Net	(271,689)	(141,865)	(88,220)
Amortization of Regulatory Assets/(Liabilities), Net	130,869	16,150	83,855
Cost of Removal Expenditures	(59,187)	(68,290)	(57,339)
Payment in 2022 of Withheld Property Taxes	0	0	(76,311)
Other	(25,876)	(2,123)	(14,294)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(179,783)	(82,659)	(23,757)
Taxes Receivable/Accrued, Net	(37,779)	27,394	35,143
Accounts Payable	1,412	11,357	8,815
Other Current Assets and Liabilities, Net	(23,137)	(40,974)	20,430
Net Cash Flows Provided by Operating Activities	687,562	713,557	771,478
Investing Activities:
Investments in Property, Plant and Equipment	(1,563,326)	(1,376,135)	(954,281)
Other Investing Activities	0	48	165
Net Cash Flows Used in Investing Activities	(1,563,326)	(1,376,087)	(954,116)
Financing Activities:
Cash Dividends on Common Shares	(643,900)	(327,400)	(287,600)
Cash Dividends on Preferred Stock	(1,960)	(1,960)	(1,960)
Increase/(Decrease) in Notes Payable	138,935	365,847	(162,500)
Capital Contributions from Eversource Parent	775,000	234,900	525,000
Issuance of Long-Term Debt	600,000	150,000	850,000
Retirement of Long-Term Debt	0	(80,000)	(400,000)
Other Financing Activities	(6,073)	(1,365)	(13,188)
Net Cash Flows Provided by Financing Activities	862,002	340,022	509,752
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	(13,762)	(322,508)	327,114
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	22,785	345,293	18,179
Cash, Cash Equivalents and Restricted Cash - End of Year	$ 9,023	$ 22,785	$ 345,293

PUBLIC SERVICE COMPANY OF NEW H

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current Assets:
Cash	$ 26,656	$ 53,873
Receivables, Net (net of allowance for uncollectible accounts)	1,651,325	1,431,531
Unbilled Revenues	242,169	225,325
Materials, Supplies and REC Inventory	594,568	507,307
Regulatory Assets	2,189,660	1,674,196
Prepayments and Other Current Assets	315,368	355,762
Total Current Assets	5,076,073	4,247,994
Property, Plant and Equipment, Net	40,986,578	39,498,607
Deferred Debits and Other Assets:
Regulatory Assets	4,880,974	4,714,970
Prepaid Pension and PBOP	1,336,633	1,028,207
Other Long-Term Assets	642,869	592,080
Total Deferred Debits and Other Assets	13,531,878	11,865,644
Total Assets	59,594,529	55,612,245
Current Liabilities:
Long-Term Debt – Current Portion	1,003,150	824,847
Rate Reduction Bonds – Current Portion	43,210	43,210
Accounts Payable	1,736,880	1,869,187
Regulatory Liabilities	632,282	591,750
Other Current Liabilities	868,491	821,404
Total Current Liabilities	6,720,957	6,341,397
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	5,411,206	5,303,730
Regulatory Liabilities	4,032,564	4,022,923
Other Long-Term Liabilities	1,123,999	1,029,238
Total Deferred Credits and Other Liabilities	11,652,918	10,985,489
Capitalization:
Long-Term Debt	25,701,627	23,588,616
Rate Reduction Bonds	324,072	367,282
Common Shareholders' Equity:
Capital Surplus, Paid In	9,428,905	8,460,876
Retained Earnings	3,929,141	4,142,515
Accumulated Other Comprehensive Income/(Loss)	(26,472)	(33,737)
Common Shareholders' Equity	15,039,387	14,173,892
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	59,594,529	55,612,245
PSNH
Current Assets:
Cash	1,431	240
Unbilled Revenues	57,226	55,012
Materials, Supplies and REC Inventory	75,778	77,066
Regulatory Assets	173,267	189,450
Special Deposits	32,668	31,586
Prepayments and Other Current Assets	15,916	45,635
Total Current Assets	546,634	569,479
Property, Plant and Equipment, Net	5,089,943	4,574,652
Deferred Debits and Other Assets:
Regulatory Assets	892,411	773,783
Prepaid Pension and PBOP	91,005	58,979
Other Long-Term Assets	21,948	16,558
Total Deferred Debits and Other Assets	1,005,364	849,320
Total Assets	6,641,941	5,993,451
Current Liabilities:
Notes Payable to Eversource Parent	131,100	233,000
Rate Reduction Bonds – Current Portion	43,210	43,210
Regulatory Liabilities	121,058	117,515
Other Current Liabilities	92,018	72,328
Total Current Liabilities	658,601	713,069
Deferred Credits and Other Liabilities:
Accumulated Deferred Income Taxes	781,559	691,532
Regulatory Liabilities	394,982	393,574
Other Long-Term Liabilities	43,859	42,484
Total Deferred Credits and Other Liabilities	1,220,400	1,127,590
Capitalization:
Long-Term Debt	1,732,066	1,431,591
Rate Reduction Bonds	324,072	367,282
Common Shareholders' Equity:
Common Shares	0	0
Capital Surplus, Paid In	1,898,134	1,698,134
Retained Earnings	808,668	655,785
Common Shareholders' Equity	2,706,802	2,353,919
Commitments and Contingencies (Note 13)
Total Liabilities and Capitalization	6,641,941	5,993,451
PSNH | Nonrelated Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	163,063	152,276
Current Liabilities:
Accounts Payable	226,074	205,744
PSNH | Related Party
Current Assets:
Receivables, Net (net of allowance for uncollectible accounts)	27,285	18,214
Current Liabilities:
Notes Payable to Eversource Parent	131,100	233,000
Accounts Payable	$ 45,141	$ 41,272

PUBLIC SERVICE COMPANY OF NEW_2

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Allowance for uncollectible accounts, current	$ 556,164	$ 554,455
PSNH
Allowance for uncollectible accounts, current	$ 14,090	$ 14,322

PUBLIC SERVICE COMPANY OF NEW_3

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Revenues	$ 11,900,809	$ 11,910,705	$ 12,289,336
Operating Expenses:
Purchased Power and Transmission	3,736,078	5,168,241	5,014,074
Operations and Maintenance	2,012,926	1,895,703	1,865,328
Depreciation	1,433,503	1,305,840	1,194,246
Energy Efficiency Programs	671,828	691,344	658,051
Taxes Other Than Income Taxes	997,901	940,359	910,591
Total Operating Expenses	9,492,100	9,511,370	10,091,182
Operating Income	2,408,709	2,399,335	2,198,154
Interest Expense	1,111,336	855,441	678,274
Other Income, Net	410,482	348,069	346,088
Income/(Loss) Before Income Tax Expense	1,243,836	(275,037)	1,865,968
Income Tax Expense	424,664	159,684	453,574
PSNH
Operating Revenues	1,294,493	1,447,873	1,474,799
Operating Expenses:
Purchased Power and Transmission	244,351	604,983	665,478
Operations and Maintenance	288,342	284,442	255,991
Depreciation	154,072	140,417	127,962
Amortization of Regulatory Assets/(Liabilities), Net	136,113	(16,343)	42,867
Energy Efficiency Programs	42,871	39,618	37,434
Taxes Other Than Income Taxes	96,969	93,894	95,301
Total Operating Expenses	962,718	1,147,011	1,225,033
Operating Income	331,775	300,862	249,766
Interest Expense	77,770	72,786	59,548
Other Income, Net	31,123	26,597	32,666
Income/(Loss) Before Income Tax Expense	285,128	254,673	222,884
Income Tax Expense	70,245	59,014	51,314
Net Income/(Loss)	$ 214,883	$ 195,659	$ 171,570

PUBLIC SERVICE COMPANY OF NEW_4

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Other Comprehensive Income/(Loss), Net of Tax:
Comprehensive Income/(Loss) Attributable to Common Shareholders	$ 818,918	$ (436,556)	$ 1,407,729
PSNH
Net Income/(Loss)	214,883	195,659	171,570
Other Comprehensive Income/(Loss), Net of Tax:
Changes in Unrealized Gains/(Losses) on Marketable Securities	0	73	(96)
Other Comprehensive Income/(Loss), Net of Tax	0	73	(96)
Comprehensive Income/(Loss) Attributable to Common Shareholders	$ 214,883	$ 195,732	$ 171,474

PUBLIC SERVICE COMPANY OF NEW_5

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus, Paid In	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	PSNH	PSNH Common Stock	PSNH Capital Surplus, Paid In	PSNH Retained Earnings	PSNH Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2021		344,403,196					301
Beginning balance at Dec. 31, 2021	$ 14,599,844	$ 1,789,092	$ 8,098,514	$ 5,005,391	$ (42,275)	$ 1,592,713	$ 0	$ 1,088,134	$ 504,556	$ 23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						171,570			171,570
Dividends on Common Stock	(883,113)			(883,113)		(104,000)			(104,000)
Capital Contributions from Eversource Parent						210,000		210,000
Other Comprehensive Loss, Net of Tax						(96)				(96)
Ending balance (in shares) at Dec. 31, 2022		348,443,855					301
Ending balance at Dec. 31, 2022	15,473,158	$ 1,799,920	8,401,731	5,527,153	(39,421)	1,870,187	$ 0	1,298,134	572,126	(73)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						195,659			195,659
Dividends on Common Stock	$ (942,398)			(942,398)		(112,000)			(112,000)
Capital Contributions from Eversource Parent						400,000		400,000
Other Comprehensive Loss, Net of Tax					5,700	73				73
Ending balance (in shares) at Dec. 31, 2023	349,540,266	349,540,266					301
Ending balance at Dec. 31, 2023	$ 14,173,892	$ 1,799,920	8,460,876	4,142,515	(33,737)	2,353,919	$ 0	1,698,134	655,785	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income/(Loss)						214,883			214,883
Dividends on Common Stock	$ (1,025,027)			(1,025,027)		(62,000)			(62,000)
Capital Contributions from Eversource Parent						200,000		200,000
Other Comprehensive Loss, Net of Tax					7,200	0
Ending balance (in shares) at Dec. 31, 2024	366,608,052	366,608,052					301
Ending balance at Dec. 31, 2024	$ 15,039,387	$ 1,878,622	$ 9,428,905	$ 3,929,141	$ (26,472)	$ 2,706,802	$ 0	$ 1,898,134	$ 808,668	$ 0

PUBLIC SERVICE COMPANY OF NEW_6

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Adjustments to Reconcile Net Income/(Loss) to Net Cash Flows Provided by Operating Activities:
Depreciation	$ 1,433,503	$ 1,305,840	$ 1,194,246
Deferred Income Taxes	435,889	85,405	346,779
Uncollectible Expense	74,069	72,468	61,876
Pension, SERP and PBOP Income, Net	(73,564)	(90,706)	(160,857)
Regulatory (Under)/Over Recoveries, Net	(919,359)	(151,548)	(205,294)
Cost of Removal Expenditures	(294,984)	(315,699)	(303,755)
Other	(102,450)	(53,026)	(39,192)
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(432,620)	(124,393)	(470,593)
Taxes Receivable/Accrued, Net	55,502	36,357	18,358
Accounts Payable	47,082	(287,637)	377,657
Other Current Assets and Liabilities, Net	19,529	(66,202)	(45,583)
Net Cash Flows Provided by Operating Activities	2,159,737	1,646,161	2,401,293
Investing Activities:
Investments in Property, Plant and Equipment	(4,480,529)	(4,336,849)	(3,441,852)
Other Investing Activities	(13,365)	(2,897)	20,420
Net Cash Flows Used in Investing Activities	(4,535,664)	(4,870,732)	(4,130,490)
Financing Activities:
Cash Dividends on Common Shares	(1,001,488)	(918,995)	(860,033)
Increase (Decrease) in Notes Payable To Eversource Parent	(94,959)	695,552	(78,170)
Issuance of Long-Term Debt	4,501,623	5,198,345	4,045,000
Retirement of Long-Term Debt	(1,949,995)	(2,008,470)	(1,175,000)
Repayment of Rate Reduction Bonds	(43,210)	(43,210)	(43,210)
Other Financing Activities	(57,082)	(46,466)	(48,185)
Net Cash Flows Provided by Financing Activities	2,336,817	2,869,237	2,029,941
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	(39,110)	(355,334)	300,744
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	166,418	521,752	221,008
Cash, Cash Equivalents and Restricted Cash - End of Year	127,308	166,418	521,752
PSNH
Operating Activities:
Net Income/(Loss)	214,883	195,659	171,570
Adjustments to Reconcile Net Income/(Loss) to Net Cash Flows Provided by Operating Activities:
Depreciation	154,072	140,417	127,962
Deferred Income Taxes	77,082	118,970	15,765
Uncollectible Expense	4,688	3,989	9,211
Pension, SERP and PBOP Income, Net	(8,759)	(10,484)	(16,421)
Regulatory (Under)/Over Recoveries, Net	(227,943)	(273,472)	53,181
Amortization of Regulatory Assets/(Liabilities), Net	136,113	(16,343)	42,867
Cost of Removal Expenditures	(42,507)	(39,976)	(39,895)
Other	53	10,391	8,691
Changes in Current Assets and Liabilities:
Receivables and Unbilled Revenues, Net	(29,875)	(5,434)	(62,078)
Taxes Receivable/Accrued, Net	30,443	916	(23,492)
Accounts Payable	(7,204)	(55,957)	81,046
Other Current Assets and Liabilities, Net	20,255	(36,637)	(6,908)
Net Cash Flows Provided by Operating Activities	321,301	32,039	361,499
Investing Activities:
Investments in Property, Plant and Equipment	(608,812)	(605,109)	(485,611)
Other Investing Activities	0	296	1,013
Net Cash Flows Used in Investing Activities	(608,812)	(604,813)	(484,598)
Financing Activities:
Cash Dividends on Common Shares	(62,000)	(112,000)	(104,000)
Increase (Decrease) in Notes Payable To Eversource Parent	(101,900)	59,700	62,700
Issuance of Long-Term Debt	300,000	600,000	0
Retirement of Long-Term Debt	0	(325,000)	0
Repayment of Rate Reduction Bonds	(43,210)	(43,210)	(43,210)
Capital Contributions from Eversource Parent	200,000	400,000	210,000
Other Financing Activities	(3,140)	(8,524)	(705)
Net Cash Flows Provided by Financing Activities	289,750	570,966	124,785
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	2,239	(1,808)	1,686
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	35,004	36,812	35,126
Cash, Cash Equivalents and Restricted Cash - End of Year	$ 37,243	$ 35,004	$ 36,812

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES A. About Eversource, CL&P, NSTAR Electric and PSNH Eversource Energy is a public utility holding company primarily engaged, through its wholly-owned regulated utility subsidiaries, in the energy delivery business. Eversource Energy's wholly-owned regulated utility subsidiaries consist of CL&P, NSTAR Electric and PSNH (electric utilities), Yankee Gas, NSTAR Gas and EGMA (natural gas utilities), and Aquarion (water utilities). Eversource provides energy delivery and/or water service to approximately 4.6 million electric, natural gas and water customers through twelve regulated utilities in Connecticut, Massachusetts and New Hampshire. Eversource, CL&P, NSTAR Electric and PSNH are reporting companies under the Securities Exchange Act of 1934. Eversource Energy is a public utility holding company under the Public Utility Holding Company Act of 2005. Arrangements among the regulated electric companies and other Eversource companies, outside agencies and other utilities covering interconnections, interchange of electric power and sales of utility property are subject to regulation by the FERC. Eversource's regulated companies are subject to regulation of rates, accounting and other matters by the FERC and/or applicable state regulatory commissions (the PURA for CL&P, Yankee Gas and Aquarion, the DPU for NSTAR Electric, NSTAR Gas, EGMA and Aquarion, and the NHPUC for PSNH and Aquarion). CL&P, NSTAR Electric and PSNH furnish franchised retail electric service in Connecticut, Massachusetts and New Hampshire, respectively. NSTAR Gas and EGMA are engaged in the distribution and sale of natural gas to customers within Massachusetts and Yankee Gas is engaged in the distribution and sale of natural gas to customers within Connecticut. Aquarion is engaged in the collection, treatment and distribution of water in Connecticut, Massachusetts and New Hampshire. CL&P, NSTAR Electric and PSNH's results include the operations of their respective distribution and transmission businesses. The distribution business also includes the results of NSTAR Electric's solar power facilities. Eversource Service, Eversource's service company, and several wholly-owned real estate subsidiaries of Eversource, provide support services to Eversource, including its regulated companies. B. Basis of Presentation The consolidated financial statements of Eversource, NSTAR Electric and PSNH include the accounts of each of their respective subsidiaries. Intercompany transactions have been eliminated in consolidation. The accompanying consolidated financial statements of Eversource, NSTAR Electric and PSNH and the financial statements of CL&P are herein collectively referred to as the "financial statements." The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. CYAPC and YAEC are inactive regional nuclear power companies engaged in the long-term storage of their spent nuclear fuel. Eversource consolidates the operations of CYAPC and YAEC because CL&P's, NSTAR Electric's and PSNH's combined ownership and voting interests in each of these entities is greater than 50 percent. Intercompany transactions between CL&P, NSTAR Electric, PSNH and the CYAPC and YAEC companies have been eliminated in consolidation of the Eversource financial statements. Eversource holds equity ownership interests that are not consolidated and are accounted for under the equity method. In the third quarter of 2024, Eversource sold its 50 percent equity ownership interests in three offshore wind projects that had been accounted for under the equity method. See Note 6, “Investments in Unconsolidated Affiliates,” for further information. In accordance with accounting guidance on noncontrolling interests in consolidated financial statements, the Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric, which are not owned by Eversource or its consolidated subsidiaries and are not subject to mandatory redemption, have been presented as noncontrolling interests in the financial statements of Eversource. The Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric are considered to be temporary equity and have been classified between liabilities and permanent shareholders' equity on the balance sheets of Eversource, CL&P and NSTAR Electric due to a provision in the preferred stock agreements of both CL&P and NSTAR Electric that grant preferred stockholders the right to elect a majority of the CL&P and NSTAR Electric Boards of Directors, respectively, should certain conditions exist, such as if preferred dividends are in arrears for a specified amount of time. The Net Income reported in the statements of income and cash flows represents net income prior to apportionment to noncontrolling interests, which is represented by dividends on preferred stock of CL&P and NSTAR Electric. Eversource's utility subsidiaries' electric, natural gas and water distribution and transmission businesses are subject to rate-regulation that is based on cost recovery and meets the criteria for application of accounting guidance for entities with rate-regulated operations, which considers the effect of regulation on the differences in the timing of the recognition of certain revenues and expenses from those of other businesses and industries. See Note 2, "Regulatory Accounting," for further information. As of December 31, 2024 and 2023, Eversource's carrying amount of goodwill was $3.57 billion and $4.53 billion, respectively. Eversource performs an assessment for possible impairment of its goodwill at least annually. Eversource completed its annual goodwill impairment assessment for each of its reporting units as of October 1, 2024, and performed an interim goodwill impairment test in the fourth quarter of 2024. Eversource recorded a goodwill impairment charge of $297 million in 2024 as a result of the likely sale of Aquarion at a loss. See Note 25, "Goodwill," for further information. The assets and liabilities of the Aquarion water distribution business, including remaining goodwill of $662.5 million, met the criteria to be classified as held for sale as of December 31, 2024. Unless otherwise specified, the amounts and information in the notes presented do not include assets and liabilities that have been reclassified as held for sale. See Note 24, "Assets Held for Sale," for further information. Certain reclassifications of prior year data were made in the accompanying financial statements to conform to the current year presentation. C. Accounting Standards Accounting Standards Recently Adopted: On January 1, 2025, the Company retrospectively adopted Accounting Standards Update (ASU) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which requires entities to disclose significant segment expenses, other segment items, and the title and position of the chief operating decision maker (CODM). Additionally, the ASU requires entities to disclose how the CODM assesses segment performance and allocates resources, among certain other required disclosures. Furthermore, current annual disclosures will be required in interim periods. The modified disclosures are included in Note 23, “Segment Information.” D. Cash Cash includes cash on hand. At the end of each reporting period, any overdraft amounts are reclassified from Cash to Accounts Payable on the balance sheets. E. Allowance for Uncollectible Accounts Receivables, Net on the balance sheets primarily includes trade receivables from retail customers and customers related to wholesale transmission contracts, wholesale market sales, sales of RECs, and property rentals. Receivables, Net also includes customer receivables for the purchase of electricity from a competitive third party supplier, the current portion of customer energy efficiency loans, property damage receivables and other miscellaneous receivables. There is no material concentration of receivables. Receivables are recorded at amortized cost, net of a credit loss provision (or allowance for uncollectible accounts). The current expected credit loss (CECL) model is applied to receivables for purposes of calculating the allowance for uncollectible accounts. This model is based on expected losses and results in the recognition of estimated expected credit losses, including uncollectible amounts for both billed and unbilled revenues, over the life of the receivable at the time a receivable is recorded. The allowance for uncollectible accounts is determined based upon a variety of judgments and factors, including an aging-based quantitative assessment that applies an estimated uncollectible percentage to each receivable aging category. Factors in determining credit loss include historical collection, write-off experience, analysis of delinquency statistics, and management's assessment of collectability from customers, including current economic conditions, customer payment trends, the impact on customer bills because of energy usage trends and changes in rates, flexible payment plans and financial hardship arrearage management programs offered to customers, reasonable forecasts, and expectations of future collectability and collection efforts. Management continuously assesses the collectability of receivables and adjusts estimates based on actual experience and future expectations based on economic conditions, collection efforts and other factors. Management also monitors the aging analysis of receivables to determine if there are changes in the collections of accounts receivable. Receivable balances are written off against the allowance for uncollectible accounts when the customer accounts are no longer in service and these balances are deemed to be uncollectible. Management concluded that the reserve balance as of December 31, 2024 adequately reflected the collection risk and net realizable value for its receivables. The PURA allows CL&P and Yankee Gas to accelerate the recovery of accounts receivable balances attributable to qualified customers under financial or medical duress (uncollectible hardship accounts receivable) outstanding for greater than 180 days and 90 days, respectively. The DPU allows NSTAR Electric, NSTAR Gas and EGMA to recover in rates amounts associated with certain uncollectible hardship accounts receivable. These uncollectible hardship customer account balances are included in Regulatory Assets or Other Long-Term Assets on the balance sheets. Hardship customers are protected from shut-off in certain circumstances, and historical collection experience has reflected a higher default risk as compared to the rest of the receivable population. Management uses a higher credit risk profile for this pool of trade receivables as compared to non-hardship receivables. The allowance for uncollectible hardship accounts is included in the total uncollectible allowance balance. The total allowance for uncollectible accounts is included in Receivables, Net on the balance sheets. The activity in the allowance for uncollectible accounts by portfolio segment is as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Total Allowance (3) Balance as of January 1, 2022 $ 226.1 $ 191.3 $ 417.4 $ 144.6 $ 36.7 $ 181.3 $ 43.3 $ 53.7 $ 97.0 $ 24.3 Uncollectible Expense — 61.9 61.9 — 15.6 15.6 — 21.6 21.6 9.2 Uncollectible Costs Deferred (1) 77.8 34.7 112.5 58.3 1.2 59.5 1.5 10.9 12.4 2.5 Write-Offs (21.3) (102.7) (124.0) (15.3) (23.0) (38.3) (1.1) (41.2) (42.3) (7.7) Recoveries Collected 1.8 16.7 18.5 1.3 5.9 7.2 — 6.3 6.3 0.9 Balance as of December 31, 2022 $ 284.4 $ 201.9 $ 486.3 $ 188.9 $ 36.4 $ 225.3 $ 43.7 $ 51.3 $ 95.0 $ 29.2 Uncollectible Expense — 72.5 72.5 — 11.7 11.7 — 22.8 22.8 4.0 Uncollectible Costs Deferred (1) 137.0 21.2 158.2 114.4 12.0 126.4 1.5 16.0 17.5 (8.7) Write-Offs (55.9) (122.2) (178.1) (44.7) (28.5) (73.2) (1.6) (41.7) (43.3) (10.9) Recoveries Collected 1.3 14.3 15.6 1.1 4.7 5.8 — 5.0 5.0 0.7 Balance as of December 31, 2023 $ 366.8 $ 187.7 $ 554.5 $ 259.7 $ 36.3 $ 296.0 $ 43.6 $ 53.4 $ 97.0 $ 14.3 Uncollectible Expense — 74.1 74.1 — 17.2 17.2 — 33.6 33.6 4.7 Uncollectible Costs Deferred (1) 71.4 48.3 119.7 35.5 11.3 46.8 16.2 21.5 37.7 5.1 Write-Offs (74.3) (129.5) (203.8) (55.1) (30.9) (86.0) (4.6) (52.4) (57.0) (10.9) Recoveries Collected 0.7 13.3 14.0 0.6 4.5 5.1 — 3.6 3.6 0.9 Decrease due to Assets Held for Sale (2) — (2.3) (2.3) — — — — — — — Balance as of December 31, 2024 $ 364.6 $ 191.6 $ 556.2 $ 240.7 $ 38.4 $ 279.1 $ 55.2 $ 59.7 $ 114.9 $ 14.1 (1) These expected credit losses are deferred as regulatory costs on the balance sheets, as these amounts are ultimately recovered in rates. Amounts include uncollectible costs for hardship accounts and other customer receivables, including uncollectible amounts related to uncollectible energy supply costs. (2) As of December 31, 2024, the allowance for uncollectible accounts attributable to the Aquarion water distribution business has been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, this balance was recorded within Receivables, Net on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” (3) In connection with PSNH’s pole purchase agreement on May 1, 2023, the purchase price included the forgiveness of previously reserved receivables for reimbursement of operation and maintenance and vegetation management costs. F. Transfer of Energy Efficiency Loans CL&P transferred a portion of its energy efficiency customer loan portfolio to outside lenders in order to make additional loans to customers. CL&P remains the servicer of the loans and will transmit customer payments to the lenders, with a maximum amount outstanding under this program of $70 million. The amounts of the loans are included in Receivables, Net and Other Long-Term Assets, and are offset by Other Current Liabilities and Other Long-Term Liabilities on CL&P’s balance sheet. The current and long-term portions totaled $9.4 million and $17.3 million, respectively, as of December 31, 2024, and $8.5 million and $14.5 million, respectively, as of December 31, 2023. G. Materials, Supplies, Natural Gas and REC Inventory Materials, Supplies, Natural Gas and REC Inventory include materials and supplies purchased primarily for construction or operation and maintenance purposes, natural gas purchased for delivery to customers, and RECs. Inventory is valued at the lower of cost or net realizable value. RECs are purchased from suppliers of renewable sources of generation and are used to meet state mandated Renewable Portfolio Standards requirements. The carrying amounts of materials and supplies, natural gas inventory, and RECs, which are included in Current Assets on the balance sheets, were as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Materials and Supplies $ 498.6 $ 217.3 $ 177.8 $ 72.1 $ 397.9 $ 156.2 $ 130.8 $ 76.5 Natural Gas 49.5 — — — 65.5 — — — RECs 46.5 — 42.8 3.7 43.9 0.3 43.0 0.6 Total $ 594.6 $ 217.3 $ 220.6 $ 75.8 $ 507.3 $ 156.5 $ 173.8 $ 77.1 As of December 31, 2024, the materials and supplies attributable to the Aquarion water distribution business have been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, these balances were recorded within Materials, Supplies, Natural Gas and REC Inventory on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” Fair value measurement guidance is applied to derivative contracts that are not elected or designated as "normal purchases" or "normal sales" (normal) and to marketable securities held in trusts. Fair value measurement guidance is also applied to valuations of the investments used to calculate the funded status of pension and PBOP plans, the nonrecurring fair value measurements of nonfinancial assets such as goodwill, long-lived assets, equity method investments, AROs, and in the valuation of business combinations and asset acquisitions. The fair value measurement guidance was also applied in estimating the fair value of preferred stock, long-term debt and RRBs. Fair Value Hierarchy: In measuring fair value, Eversource uses observable market data when available in order to minimize the use of unobservable inputs. Inputs used in fair value measurements are categorized into three fair value hierarchy levels for disclosure purposes. The entire fair value measurement is categorized based on the lowest level of input that is significant to the fair value measurement. Eversource evaluates the classification of assets and liabilities measured at fair value on a quarterly basis. The levels of the fair value hierarchy are described below: Level 1 - Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 - Inputs are quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all significant inputs are observable. Level 3 - Quoted market prices are not available. Fair value is derived from valuation techniques in which one or more significant inputs or assumptions are unobservable. Where possible, valuation techniques incorporate observable market inputs that can be validated to external sources such as industry exchanges, including prices of energy and energy-related products. Uncategorized - Investments that are measured at net asset value are not categorized within the fair value hierarchy. Determination of Fair Value: The valuation techniques and inputs used in Eversource's fair value measurements are described in Note 4, "Derivative Instruments," Note 5, "Marketable Securities," Note 6, "Investments in Unconsolidated Affiliates," Note 7, "Asset Retirement Obligations," Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," Note 15, "Fair Value of Financial Instruments," and Note 25, “Goodwill,” to the financial statements. I. Derivative Accounting Many of the electric and natural gas companies' contracts for the purchase and sale of energy or energy-related products are derivatives. The accounting treatment for energy contracts entered into varies and depends on the intended use of the particular contract and on whether or not the contract is a derivative. The application of derivative accounting is complex and requires management judgment in the following respects: identification of derivatives and embedded derivatives, election and designation of a contract as normal, and determination of the fair value of derivative contracts. All of these judgments can have a significant impact on the financial statements. The judgment applied in the election of a contract as normal (and resulting accrual accounting) includes the conclusion that it is probable at the inception of the contract and throughout its term that it will result in physical delivery of the underlying product and that the quantities will be used or sold by the business in the normal course of business. If facts and circumstances change and management can no longer support this conclusion, then a contract cannot be considered normal, accrual accounting is terminated, and fair value accounting is applied prospectively. The fair value of derivative contracts is based upon the contract terms and conditions and the underlying market price or fair value per unit. When quantities are not specified in the contract, the Company determines whether the contract has a determinable quantity by using amounts referenced in default provisions and other relevant sections of the contract. The fair value of derivative assets and liabilities with the same counterparty are offset and recorded as a net derivative asset or liability on the balance sheets. Regulatory assets or regulatory liabilities are recorded to offset the fair values of these derivative contracts related to energy and energy-related products, as contract settlements are recovered from, or refunded to, customers in future rates. All changes in the fair value of these derivative contracts are recorded as regulatory assets or liabilities and do not impact net income. For further information regarding derivative contracts, see Note 4, "Derivative Instruments," to the financial statements. J. Operating Expenses The cost of natural gas included in Purchased Power, Purchased Natural Gas and Transmission on the statements of income was as follows: For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Eversource - Cost of Natural Gas $ 689.6 $ 792.2 $ 1,010.2 AFUDC represents the cost of borrowed and equity funds used to finance construction and is included in the cost of the electric, natural gas and water companies' utility plant on the balance sheet. The portion of AFUDC attributable to borrowed funds is recorded as a reduction of Interest Expense, and the AFUDC related to equity funds is recorded as Other Income, Net on the statements of income. AFUDC costs are recovered from customers over the service life of the related plant in the form of increased revenue collected as a result of higher depreciation expense. The average AFUDC rate is based on a FERC-prescribed formula using the cost of a company's short-term financings and capitalization (preferred stock, long-term debt and common equity), as appropriate. The average rate is applied to average eligible CWIP amounts to calculate AFUDC. AFUDC costs and the weighted-average AFUDC rates were as follows: Eversource For the Years Ended December 31, (Millions of Dollars, except percentages) 2024 2023 2022 Borrowed Funds $ 64.4 $ 44.6 $ 21.8 Equity Funds 97.8 78.1 47.3 Total AFUDC $ 162.2 $ 122.7 $ 69.1 Average AFUDC Rate 6.5 % 5.8 % 4.7 % For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars, CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Borrowed Funds $ 8.1 $ 27.2 $ 8.9 $ 7.7 $ 17.2 $ 6.1 $ 4.8 $ 10.7 $ 1.4 Equity Funds 22.4 58.8 7.0 20.0 45.7 5.4 13.6 24.6 2.5 Total AFUDC $ 30.5 $ 86.0 $ 15.9 $ 27.7 $ 62.9 $ 11.5 $ 18.4 $ 35.3 $ 3.9 Average AFUDC Rate 6.7 % 7.0 % 5.5 % 6.7 % 5.9 % 5.1 % 6.6 % 5.4 % 2.6 % L. Other Income, Net The components of Other Income, Net on the statements of income were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 115.4 $ 132.9 $ 219.8 AFUDC Equity 97.8 78.1 47.3 Equity in Earnings of Unconsolidated Affiliates (2) 51.9 15.5 22.9 Investment Income/(Loss) 0.6 (4.9) 1.9 Interest Income 138.2 94.2 50.5 Other (2) 6.6 32.3 3.7 Total Other Income, Net $ 410.5 $ 348.1 $ 346.1 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 28.2 $ 52.8 $ 14.9 $ 34.9 $ 57.4 $ 16.2 $ 64.4 $ 85.5 $ 26.8 AFUDC Equity 22.4 58.8 7.0 20.0 45.7 5.4 13.6 24.6 2.5 Investment (Loss)/Income (1.4) 1.9 (0.5) (2.4) (0.2) (0.7) (1.3) 1.2 0.2 Interest Income 28.3 77.0 9.6 9.0 60.6 5.3 6.5 30.7 3.1 Other 0.1 0.9 0.1 0.1 0.6 0.4 0.1 0.7 0.1 Total Other Income, Net $ 77.6 $ 191.4 $ 31.1 $ 61.6 $ 164.1 $ 26.6 $ 83.3 $ 142.7 $ 32.7 (1) See Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for the components of net periodic benefit income/expense for the Pension, SERP and PBOP Plans. The non-service related components of pension, SERP and PBOP benefit income/expense, after capitalization or deferral, are presented as non-operating income and recorded in Other Income, Net on the statements of income. (2) Equity in Earnings of Unconsolidated Affiliates includes $23.4 million of pre-tax income recorded at Eversource in the second quarter of 2024 from Eversource’s wind equity method investment, North East Offshore, as a result of a vendor settlement agreement payment received by the joint venture. In the third quarter of 2024, Eversource sold its equity method investments in three offshore wind projects. In March 2023, Eversource’s equity method investment in a renewable energy fund was liquidated. Liquidation proceeds in excess of the carrying value were recorded in 2023 within Other in the table above. For the year ended December 31, 2022, pre-tax income of $12.2 million associated with the renewable energy fund investment was included in Equity in Earnings of Unconsolidated Affiliates within Other Income, Net in the table above. See Note 6, “Investments in Unconsolidated Affiliates,” for further information on the 2024 sales of the offshore wind investments and the 2023 liquidation of the renewable energy fund. M. Other Taxes Eversource's companies that serve customers in Connecticut collect gross receipts taxes levied by the state of Connecticut from their customers. These gross receipts taxes are recorded separately with collections in Operating Revenues and with payments in Taxes Other Than Income Taxes on the statements of income as follows: For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Eversource $ 209.4 $ 202.9 $ 194.7 CL&P 185.1 174.9 166.1 As agents for state and local governments, Eversource's companies that serve customers in Connecticut and Massachusetts collect certain sales taxes that are recorded on a net basis with no impact on the statements of income. N. Supplemental Cash Flow Information Eversource (Millions of Dollars) As of and For the Years Ended December 31, 2024 2023 2022 Cash Paid/(Received) During the Year for: Interest, Net of Amounts Capitalized $ 1,014.4 $ 783.2 $ 636.2 Income Taxes (69.6) 39.2 77.9 Non-Cash Investing Activities: Plant Additions Included in Accounts Payable (As of) 472.5 564.1 586.9 As of and For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Cash Paid/(Received) During the Year for: Interest, Net of Amounts Capitalized $ 216.8 $ 215.1 $ 78.4 $ 176.8 $ 182.8 $ 62.8 $ 167.2 $ 152.8 $ 58.3 Income Taxes (47.4) 118.7 (36.0) (44.1) 31.3 (59.9) 117.6 23.8 58.3 Non-Cash Investing Activities: Plant Additions Included in Accounts 95.8 155.4 77.7 139.8 178.9 65.9 131.8 184.3 76.2 The following table reconciles cash as reported on the balance sheets to the cash and restricted cash balance as reported on the statements of cash flows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Cash as reported on the Balance Sheets $ 26.7 $ 1.1 $ 0.9 $ 1.4 $ 53.9 $ 10.2 $ 6.7 $ 0.2 Restricted cash included in: Special Deposits 75.8 1.0 8.1 32.7 81.5 2.0 16.1 31.6 Assets Held for Sale, Current 5.8 — — — — — — — Marketable Securities 10.0 — — — 13.7 — — — Other Long-Term Assets 9.0 — — 3.1 17.3 — — 3.2 Cash and Restricted Cash as reported on the $ 127.3 $ 2.1 $ 9.0 $ 37.2 $ 166.4 $ 12.2 $ 22.8 $ 35.0 Special Deposits represent cash collections related to the PSNH RRB customer charges that are held in trust, required ISO-NE cash deposits, cash held in escrow accounts, and CYAPC and YAEC cash balances. Special Deposits are included in Current Assets on the balance sheets. Restricted cash included in Marketable Securities represents money market funds held in restricted trusts to fund CYAPC and YAEC's spent nuclear fuel storage obligations. Eversource’s restricted cash also includes an Energy Relief Fund for energy efficiency and clean energy measures in the Merrimack Valley established under the terms of the EGMA 2020 settlement agreement. This restricted cash held in escrow accounts included $20.0 million recorded as short-term in Special Deposits as of both December 31, 2024 and December 31, 2023, and $5.9 million and $14.1 million recorded in Other Long-Term Assets on the balance sheets as of December 31, 2024 and December 31, 2023, respectively. O. Related Parties Eversource Service, Eversource's service company, provides centralized accounting, administrative, engineering, financial, information technology, legal, operational, planning, purchasing, tax, and other services to Eversource's companies. The Rocky River Realty Company and Properties, Inc., two other Eversource subsidiaries, construct, acquire or lease some of the property and facilities used by Eversource's companies. Included in the CL&P, NSTAR Electric and PSNH balance sheets as of December 31, 2024 and 2023 were Accounts Receivable from Affiliated Companies and Accounts Payable to Affiliated Companies relating to transactions between CL&P, NSTAR Electric and PSNH and other subsidiaries that are wholly-owned by Eversource. These amounts have been eliminated in consolidation on the Eversource financial statements. Included in the CL&P and PSNH balance sheets as of December 31, 2024 and 2023 were Notes Payable to Eversource Parent. These amounts have been eliminated in consolidation on the Eversource financial statements. See Note 8, “Short-Term Debt” for intercompany borrowing amounts. The Eversource Energy Foundation is an independent not-for-profit charitable entity and is not included in the consolidated financial statements of Eversource as the Company does not have title to, and cannot receive contributions back from, the Eversource Energy Foundation's assets. Eversource made contributions to the Eversource Energy Foundation of $20.0 million in 2023, and $8.0 million in 2022. Eversource did not make any contributions in 2024.

REGULATORY ACCOUNTING

REGULATORY ACCOUNTING	12 Months Ended
	Dec. 31, 2024
Regulated Operations [Abstract]
REGULATORY ACCOUNTING	REGULATORY ACCOUNTING Eversource's utility companies are subject to rate regulation that is based on cost recovery and meets the criteria for application of accounting guidance for rate-regulated operations, which considers the effect of regulation on the timing of the recognition of certain revenues and expenses. The regulated companies' financial statements reflect the effects of the rate-making process. The rates charged to the customers of Eversource's regulated companies are designed to collect each company's costs to provide service, plus a return on investment. The application of accounting guidance for rate-regulated enterprises results in recording regulatory assets and liabilities. Regulatory assets represent the deferral of incurred costs that are probable of future recovery in customer rates. Regulatory assets are amortized as the incurred costs are recovered through customer rates. Regulatory liabilities represent either revenues received from customers to fund expected costs that have not yet been incurred or probable future refunds to customers. Management believes it is probable that each of the regulated companies will recover its respective investments in long-lived assets and the regulatory assets that have been recorded. If management were to determine that it could no longer apply the accounting guidance applicable to rate-regulated enterprises, or if management could not conclude it is probable that costs would be recovered from customers in future rates, the applicable costs would be charged to net income in the period in which the determination is made. Regulatory Assets: The components of regulatory assets were as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Storm Costs, Net $ 2,039.4 $ 971.1 $ 609.8 $ 458.5 $ 1,785.9 $ 896.6 $ 609.1 $ 280.2 Regulatory Tracking Mechanisms 1,781.6 507.7 650.0 162.8 1,319.2 354.5 482.9 182.2 Benefit Costs 967.4 168.8 293.6 65.6 1,117.3 197.4 336.7 79.3 Income Taxes, Net 968.4 521.0 145.4 20.7 912.4 512.6 128.6 16.4 Securitized Stranded Costs 349.3 — — 349.3 392.5 — — 392.5 Goodwill-related 247.2 — 212.3 — 264.1 — 226.7 — Asset Retirement Obligations 150.2 41.2 78.3 5.1 137.9 38.5 72.3 4.7 Derivative Liabilities 57.2 57.2 — — 120.9 120.9 — — Other Regulatory Assets 510.0 58.5 117.7 3.7 339.0 22.7 101.6 8.0 Total Regulatory Assets 7,070.7 2,325.5 2,107.1 1,065.7 6,389.2 2,143.2 1,957.9 963.3 Less: Current Portion 2,189.7 638.5 902.8 173.3 1,674.2 480.4 676.1 189.5 Total Long-Term Regulatory Assets $ 4,881.0 $ 1,687.0 $ 1,204.3 $ 892.4 $ 4,715.0 $ 1,662.8 $ 1,281.8 $ 773.8 As of December 31, 2024, the Regulatory Assets attributable to the Aquarion water distribution business have been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, these balances were recorded within Regulatory Assets on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” Storm Costs, Net: The storm cost deferrals relate to costs incurred for storm events at CL&P, NSTAR Electric and PSNH that each company expects to recover from customers. A storm must meet certain criteria to qualify for deferral and recovery with the criteria specific to each state jurisdiction and utility company. Once a storm qualifies for recovery, all qualifying expenses incurred during storm restoration efforts are deferred and recovered from customers. Costs for storms that do not meet the specific criteria are expensed as incurred. In addition to storm restoration costs, CL&P and PSNH are each allowed to recover pre-staging storm costs. Management believes all storm costs deferred were prudently incurred and meet the criteria for specific cost recovery in Connecticut, Massachusetts and New Hampshire, and that recovery from customers is probable through the applicable regulatory recovery processes. Each electric utility company either recovers a carrying charge on its deferred storm cost regulatory asset balance or the regulatory asset balance is included in rate base. Multiple tropical and severe storms over the past several years have caused extensive damage to Eversource’s electric distribution systems resulting in significant numbers and durations of customer outages, along with significant pre-staging costs. Storms in 2024 that qualified for future recovery resulted in deferred storm restoration costs and pre-staging costs totaling $410 million at Eversource, including $134 million at CL&P, $85 million at NSTAR Electric, and $191 million at PSNH. Management believes that all of these storm costs were prudently incurred and meet the criteria for specific cost recovery. Of Eversource’s total deferred storm costs, $2.10 billion either have yet to be filed with the applicable regulatory commission, are pending regulatory approval, or are subject to prudency review (including $1.12 billion at CL&P, $551 million at NSTAR Electric and $440 million at PSNH) as of December 31, 2024. These storm cost totals exclude storm funding amounts that are collected in rates, which are recorded as a reduction to the deferred storm cost regulatory asset balance. CL&P, NSTAR Electric and PSNH are seeking approval of their deferred storm restoration costs through the applicable regulatory recovery process. As part of CL&P’s October 1, 2021 settlement agreement, CL&P agreed to freeze its current base distribution rates (including storm costs) until no earlier than January 1, 2024. On March 28, 2024, PURA established a prudency review proceeding for the purpose of receiving and reviewing evidence of the costs reported by CL&P in response to catastrophic storms and pre-staging events totaling approximately $634 million that occurred between January 1, 2018 and December 31, 2021. On December 31, 2024, CL&P filed a supplement to its March 2024 prudency review application to request that PURA evaluate the prudence of its costs for nine additional catastrophic storms and two additional pre-staging events for the period January 1, 2022 through January 31, 2023 totaling approximately $173 million. Although we cannot predict the ultimate outcome of this matter, we continue to believe these deferred storm restoration costs were prudently incurred and are probable of recovery. CL&P’s storm events include the August 4, 2020 Tropical Storm Isaias, which resulted in deferred storm restoration costs of approximately $232 million at CL&P as of December 31, 2024. Although in 2021 PURA found that CL&P’s performance in its preparation for, and response to, Tropical Storm Isaias fell below applicable performance standards in certain instances, CL&P believes it presented in its 2023 storm filing, credible evidence demonstrating there is no reasonably close causal connection between the alleged sub-standard performance and the storm costs incurred. While it is possible that some amount of storm costs may be disallowed by PURA, any such amount cannot be estimated at this time. CL&P continues to believe that these storm restoration costs associated with Tropical Storm Isaias were prudently incurred and meet the criteria for cost recovery. Regulatory Tracking Mechanisms: The regulated companies' approved rates are designed to recover costs incurred to provide service to customers. The regulated companies recover certain of their costs on a fully-reconciling basis through regulatory commission-approved tracking mechanisms. The differences between the costs incurred (or the rate recovery allowed) and the actual revenues are recorded as regulatory assets (for undercollections) or as regulatory liabilities (for overcollections) to be included in future customer rates each year. Carrying charges are recovered in rates on all material regulatory tracking mechanisms. The electric and natural gas distribution companies recover, on a fully reconciling basis, the costs associated with the procurement of energy and natural gas supply, state mandated energy purchase agreements and other energy-related costs, electric transmission related costs from FERC-approved transmission tariffs, energy efficiency programs, low income assistance programs, certain uncollectible accounts receivable for hardship customers, restructuring and stranded costs as a result of deregulation (including securitized RRB charges), certain capital tracking mechanisms for infrastructure improvements, and additionally for the Massachusetts utilities, pension and PBOP benefits, net metering for distributed generation, and solar-related programs. CL&P, NSTAR Electric, Yankee Gas, NSTAR Gas, EGMA and the Aquarion Water Company of Connecticut each have a regulatory commission approved revenue decoupling mechanism. Distribution revenues are decoupled from customer sales volumes, where applicable, which breaks the relationship between sales volumes and revenues. Each company reconciles its annual base distribution rate recovery amount to the pre-established levels of baseline distribution delivery service revenues. Any difference between the allowed level of distribution revenue and the actual amount realized during a 12-month period is adjusted through rates in the following period. Benefit Costs: Deferred benefit costs represent unrecognized actuarial losses and gains and unrecognized prior service costs and credits attributable to Eversource's Pension, SERP and PBOP Plans. The regulated companies record actuarial losses and gains and prior service costs and credits arising at the December 31st remeasurement date of the funded status of the benefit plans as a regulatory asset or regulatory liability in lieu of a charge to Accumulated Other Comprehensive Income/(Loss), reflecting ultimate recovery from customers through rates. The regulatory asset or regulatory liability is amortized with the recognition of actuarial losses and gains and prior service costs and credits to net periodic benefit expense/income over the estimated average future employee service period using the corridor approach. Regulatory accounting is also applied to the portions of Eversource's service company costs that support the regulated companies, as these amounts are also recoverable. As these regulatory assets or regulatory liabilities do not represent a cash outlay for the regulated companies, no carrying charge is recovered from customers. See Note 11A, "Employee Benefits - Pension Benefits and Postretirement Benefits Other Than Pension," for further information on regulatory benefit plan amounts arising and amortized during the year. Eversource, CL&P, NSTAR Electric, and PSNH recover benefit costs related to their distribution and transmission operations from customers in rates as allowed by their applicable regulatory commissions. NSTAR Electric, NSTAR Gas and EGMA recover qualified pension and PBOP expenses related to their distribution operations through a rate reconciling mechanism that fully tracks the change in net pension and PBOP expenses each year. The electric transmission companies' rates provide for an annual true-up of estimated to actual costs, which include pension and PBOP expenses as allowed by FERC. Income Taxes, Net: The tax effect of temporary book-tax differences (differences between the periods in which transactions affect income in the financial statements and the periods in which they affect the determination of taxable income, including those differences relating to uncertain tax positions) is accounted for in accordance with the rate-making treatment of the applicable regulatory commissions and accounting guidance for income taxes. Differences in income taxes between the accounting guidance and the rate-making treatment of the applicable regulatory commissions are recorded as regulatory assets. As these assets are offset by deferred income tax liabilities, no carrying charge is collected. The amortization period of these assets varies depending on the nature and/or remaining life of the underlying assets and liabilities. For further information regarding income taxes, see Note 12, "Income Taxes," to the financial statements. Securitized Stranded Costs: In 2018, a subsidiary of PSNH issued $635.7 million of securitized RRBs to finance PSNH's unrecovered remaining costs associated with the divestiture of its generation assets. Securitized regulatory assets, which are not earning an equity return, are being recovered over the amortization period of the associated RRBs. The PSNH RRBs are expected to be repaid by February 1, 2033. For further information, see Note 10, "Rate Reduction Bonds and Variable Interest Entities," to the financial statements. Goodwill-related: The goodwill regulatory asset originated from a 1999 transaction, and the DPU allowed its recovery in NSTAR Electric and NSTAR Gas rates. This regulatory asset is currently being amortized and recovered from customers in rates without a carrying charge over a 40-year period, and as of December 31, 2024, there were 15 years of amortization remaining. Asset Retirement Obligations: The costs associated with the depreciation of the regulated companies' ARO assets and accretion of the ARO liabilities are recorded as regulatory assets in accordance with regulatory accounting guidance. The regulated companies' ARO assets, regulatory assets, and ARO liabilities offset and are excluded from rate base. These costs are being recovered over the life of the underlying property, plant and equipment. Derivative Liabilities: Regulatory assets are recorded as an offset to derivative liabilities and relate to the fair value of contracts used to purchase energy and energy-related products that will be recovered from customers in future rates. These assets are excluded from rate base and are being recovered as the actual settlements occur over the duration of the contracts. See Note 4, "Derivative Instruments," to the financial statements for further information on these contracts. Other Regulatory Assets: Other Regulatory Assets primarily include environmental remediation costs, certain uncollectible accounts receivable for hardship customers, contractual obligations associated with the spent nuclear fuel storage costs of the CYAPC, YAEC and MYAPC decommissioned nuclear power facilities, removal costs incurred that exceed amounts collected from customers, electric vehicle program costs, certain exogenous property taxes and merger-related costs allowed for recovery, losses associated with the reacquisition or redemption of long-term debt, and various other items. Regulatory Costs in Other Long-Term Assets: Eversource's regulated companies had $221.0 million (including $116.3 million for CL&P, $41.1 million for NSTAR Electric and $4.5 million for PSNH) and $241.7 million (including $166.7 million for CL&P, $21.9 million for NSTAR Electric and $1.2 million for PSNH) of additional regulatory costs not yet specifically approved as of December 31, 2024 and 2023, respectively, that were included in Other Long-Term Assets on the balance sheets. These amounts will be reclassified to Regulatory Assets upon approval by the applicable regulatory agency. Based on regulatory policies or past precedent on similar costs, management believes it is probable that these costs will ultimately be approved and recovered from customers in rates. As of December 31, 2024 and 2023, these regulatory costs included $92.5 million (including $47.2 million for CL&P and $24.4 million for NSTAR Electric) and $82.1 million (including $64.0 million for CL&P and $7.3 million for NSTAR Electric), respectively, of deferred uncollectible hardship costs. Equity Return on Regulatory Assets: For rate-making purposes, the regulated companies recover the carrying costs related to their regulatory assets. For certain regulatory assets, the carrying cost recovered includes an equity return component. This equity return is not recorded on the balance sheets. The equity return for PSNH was $22.5 million and $10.2 million as of December 31, 2024 and 2023, respectively. These carrying costs will be recovered from customers in future rates. Regulatory Liabilities: The components of regulatory liabilities were as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH EDIT due to Tax Cuts and Jobs Act of 2017 $ 2,442.7 $ 956.6 $ 877.6 $ 330.6 $ 2,548.6 $ 969.2 $ 905.1 $ 339.3 Regulatory Tracking Mechanisms 702.4 180.3 413.6 114.4 668.3 154.0 347.2 114.4 Cost of Removal 684.1 212.8 451.3 20.1 666.6 157.9 420.9 16.2 Deferred Portion of Non-Service Income 427.1 61.6 211.6 42.6 354.0 49.9 175.9 36.6 AFUDC - Transmission 154.8 65.1 89.7 — 124.3 56.1 68.2 — Benefit Costs 69.3 4.5 21.4 3.9 51.0 0.6 22.2 — Other Regulatory Liabilities 184.5 39.1 14.2 4.5 201.9 30.4 13.9 4.6 Total Regulatory Liabilities 4,664.9 1,520.0 2,079.4 516.1 4,614.7 1,418.1 1,953.4 511.1 Less: Current Portion 632.3 124.1 436.3 121.1 591.8 102.2 368.1 117.5 Total Long-Term Regulatory Liabilities $ 4,032.6 $ 1,395.9 $ 1,643.1 $ 395.0 $ 4,022.9 $ 1,315.9 $ 1,585.3 $ 393.6 As of December 31, 2024, the Regulatory Liabilities attributable to the Aquarion water distribution business have been reclassified to Liabilities Held for Sale on the Eversource balance sheet. As of December 31, 2023, these balances were recorded within Regulatory Liabilities on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” EDIT due to Tax Cuts and Jobs Act of 2017: Pursuant to the Tax Cuts and Jobs Act of 2017, Eversource had remeasured its existing deferred federal income tax balances to reflect the decrease in the U.S. federal corporate income tax rate from 35 percent to 21 percent. The remeasurement resulted in provisional regulated excess accumulated deferred income tax (excess ADIT or EDIT) liabilities that will benefit customers in future periods and were recognized as regulatory liabilities on the balance sheet. EDIT liabilities related to property, plant, and equipment are subject to IRS normalization rules and will be returned to customers using the same timing as the remaining useful lives of the underlying assets that gave rise to the ADIT liabilities. Eversource's regulated companies are in the process of refunding the EDIT liabilities to customers based on orders issued by applicable state and federal regulatory commissions. Cost of Removal: Eversource's regulated companies currently recover amounts in rates for future costs of removal of plant assets over the lives of the assets. The estimated cost to remove utility assets from service is recognized as a component of depreciation expense, and the cumulative amount collected from customers but not yet expended is recognized as a regulatory liability. Expended removal costs that exceed amounts collected from customers are recognized as regulatory assets, as they are probable of recovery in future rates. Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP: Regulatory liabilities were recorded for the deferred portion of the non-service related components of net periodic benefit expense/(income) for the Pension, SERP and PBOP Plans. These regulatory liabilities will be amortized over the remaining useful lives of the various classes of utility property, plant and equipment. AFUDC - Transmission: Regulatory liabilities were recorded by CL&P and NSTAR Electric for AFUDC accrued on certain reliability-related transmission projects to reflect local rate base recovery. These regulatory liabilities will be amortized over the depreciable life of the related transmission assets. Other Regulatory Liabilities: Other Regulatory Liabilities primarily include EGMA’s acquired regulatory liability as a result of the 2020 DPU-approved rate settlement agreement and the CMA asset acquisition on October 9, 2020, and various other items. FERC ROE Complaints: As of December 31, 2024 and 2023, Eversource has a reserve established for the second ROE complaint period in the pending FERC ROE complaint proceedings, which was recorded as a regulatory liability and is reflected within Regulatory Tracking Mechanisms in the table above. The cumulative pre-tax reserve (excluding interest) as of December 31, 2024 and 2023 totaled $39.1 million for Eversource (including $21.4 million for CL&P, $14.6 million for NSTAR Electric and $3.1 million for PSNH). See Note 13E, "Commitments and Contingencies – FERC ROE Complaints," for further information on developments in the pending ROE complaint proceedings. Regulatory Developments: CL&P RAM Filing: On April 17, 2024, PURA issued an interim decision in CL&P’s RAM filing and approved rates for six RAM components, with rates effective July 1, 2024 through April 30, 2025. The rate approvals include the recovery of NBFMCC and SBC net underrecoveries as of December 31, 2023 of $264.9 million and $86.2 million, respectively, and the recovery of expected net costs of $388.5 million for the NBFMCC and $254.4 million for the SBC for the period July 1, 2024 through April 30, 2025. The NBFMCC rate adjustment is primarily driven by long-term nuclear power purchase agreements required by state policy (Millstone and Seabrook) and the SBC rate adjustment is primarily driven by costs associated with accounts receivable hardship customer protection and the new low-income discount rate effective December 2023. On August 14, 2024, PURA issued a final decision that approved a further adjustment to the NBFMCC rate to include the recovery of incurred and deferred electric vehicle program costs from 2021 through May 31, 2024 of $44.4 million and expected electric vehicle program costs from June 1, 2024 through December 31, 2024 of $24.3 million. The $44.4 million, plus $5.4 million in carrying costs, will be recovered over a 20-month period of September 1, 2024 through April 30, 2026, and the $24.3 million will be recovered over an eight-month period of September 1, 2024 through April 30, 2025. In addition, PURA approved an incremental $3.5 million of 2024 Innovative Energy Solutions program costs and $1.5 million of Connecticut Green Bank program costs over an eight-month period of September 1, 2024 through April 30, 2025. These amounts are included in the “Public Benefits” portion of the customer bills in Connecticut. Yankee Gas Distribution Rate Case: On November 12, 2024, Yankee Gas filed an application with PURA to amend its existing distribution rates for effect on November 1, 2025. Yankee Gas’s rate application requested approval of a distribution rate increase of $209 million, which included a base distribution rate increase of $274 million partially offset by a reduction of $65 million in the combined Gas System Improvements and System Expansion Reconciliation rates. In addition, Yankee Gas requested approval to implement a rate credit of $37.4 million to offset the PGA rate for non-firm margin credits over one year beginning November 1, 2025. As part of the rate case, Yankee Gas proposed to implement a multi-year performance-based rate making plan with a four-year initial term from November 1, 2025 to October 31, 2029 that would adjust rates annually and includes performance metrics. A final decision by PURA is expected in October 2025. NSTAR Electric Distribution Rates : NSTAR Electric’s performance based regulation (PBR) mechanism allows for an annual adjustment to base distribution rates for inflation, exogenous events and future capital additions based on a historical five-year average of total capital additions. On September 16, 2024, NSTAR Electric submitted its annual PBR Adjustment filing for a $55.8 million increase to base distribution rates, for effect on January 1, 2025. The requested base distribution rate increase is comprised of a $35.3 million inflation-based adjustment and a $20.5 million adjustment for capital additions based on the difference between the historical five-year average of total capital additions and the base capital revenue requirement. On December 23, 2024, the DPU approved this filing. NSTAR Electric submitted its first annual PBR Adjustment filing on September 15, 2023 and on December 26, 2023, the DPU approved a $104.9 million increase to base distribution rates effective January 1, 2024. The base distribution rate increase was comprised of a $50.6 million inflation-based adjustment and a $54.3 million adjustment for capital additions based on the difference between the historical five-year average of total capital additions and the base capital revenue requirement. NSTAR Gas Distribution Rates: NSTAR Gas’ PBR mechanism allows for an annual adjustment to base distribution rates for inflation and exogenous events. On September 16, 2024, NSTAR Gas submitted its annual PBR Adjustment filing for a $12.7 million increase to base distribution rates for effect on November 1, 2024. On October 30, 2024, the DPU approved this filing. NSTAR Gas submitted its third annual PBR Adjustment filing on September 15, 2023 and on October 30, 2023, the DPU approved a $25.4 million increase to base distribution rates, of which, $15.5 million was associated with a base rate adjustment and the remainder for a prior period exogenous cost adjustment, for effect on November 1, 2023. EGMA Distribution Rates: On November 4, 2024, EGMA submitted a revised filing for its first rate base reset for rates to be effective November 1, 2024, in accordance with an October 7, 2020 EGMA Rate Settlement Agreement approved by the DPU. The compliance filing was ordered by the DPU on October 31, 2024. The rate base reset occurring on November 1, 2024 adjusted distribution rates to account for capital additions (including the roll-in of GSEP capital additions), depreciation expense, property taxes, and return on rate base for capital additions placed into service through December 31, 2023. The total revenue requirement calculated for the first rate base reset is an increase to base distribution rates of $147.8 million, of which $34.0 million is associated with GSEP investments through December 31, 2023. Under the terms of the Rate Settlement Agreement, EGMA applied a cap on the revenue change effective November 1, 2024, and the amount in excess of the cap will be deferred for recovery through the Local Distribution Adjustment Clause (LDAC) on May 1, 2025, including carrying charges. After adjusting for the cap, the increase to base distribution rates is $85.6 million effective November 1, 2024 (of which $8.8 million is offset by a reduction in the GSEP revenue requirement and GSEP rate also taking effect on November 1, 2024 for a net distribution rate change on November 1, 2024 of $76.8 million). Base distribution rates will be increased effective November 1, 2025 to incorporate the $62.2 million remaining revenue requirement. On November 7, 2024, the DPU approved this filing. PSNH Distribution Rate Case : On June 11, 2024, PSNH filed an application with the NHPUC for approval of a temporary annual base distribution rate increase. On July 31, 2024, the NHPUC approved a settlement agreement that was reached by PSNH, New Hampshire Department of Energy, and the Office of the Consumer Advocate to implement a temporary annual base distribution rate increase of $61.2 million effective August 1, 2024. Also on June 11, 2024, PSNH filed an application with the NHPUC to request an increase in permanent base distribution rates of $181.9 million, which is inclusive of the temporary rate increase, and proposed to take effect August 1, 2025. The temporary rates are subject to reconciliation based on the outcome of the permanent rate case back to the date when temporary rates took effect. The permanent rate increase request includes $247 million in unrecovered storm costs to be recovered over a five-year period. As part of the rate case, PSNH proposed to implement a performance-based rate making plan that would adjust rates annually over a four-year term, with a commitment to not file another rate case for at least four years. The plan includes a revenue-cap formula adjusted for inflation, a supplemental capital adjustment formula to support PSNH’s planned capital infrastructure improvements, an exogenous events recovery mechanism, performance metrics and an earnings sharing mechanism, among others. If the NHPUC approves the performance-based rate making plan as proposed, the previously established RRA and PPAM rate reconciling mechanisms and lost base revenues will be eliminated. The NHPUC is permitted up to twelve months to investigate the proposed rates and issue a final order. A decision by the NHPUC on permanent rates is expected by August 1, 2025. 2023 PSNH Pole Acquisition Approval: On November 18, 2022, the NHPUC issued a decision that approved a proposed purchase agreement between PSNH and Consolidated Communications, in which, PSNH would acquire both jointly-owned and solely-owned poles and pole assets. The NHPUC also authorized PSNH to recover certain expenses associated with the operation and maintenance of the transferred poles, pole inspections, and vegetation management expenses through a new cost recovery mechanism, the Pole Plant Adjustment Mechanism (PPAM), subject to consummation of the purchase agreement. The purchase agreement was finalized on May 1, 2023 for a purchase price of $23.3 million. Upon consummation of the purchase agreement, PSNH established a regulatory asset of $16.9 million for operation and maintenance expenses and vegetation management expenses associated with the purchased poles incurred from February 10, 2021 through April 30, 2023 that PSNH is authorized to collect through the PPAM regulatory tracking mechanism. The establishment of the PPAM regulatory asset resulted in a pre-tax benefit recorded in Amortization expense on the PSNH statement of income in 2023.

PROPERTY, PLANT AND EQUIPMENT A

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION	12 Months Ended
	Dec. 31, 2024
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION	PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION Utility property, plant and equipment is recorded at original cost. Original cost includes materials, labor, construction overheads and AFUDC for regulated property. The cost of repairs and maintenance is charged to Operations and Maintenance expense as incurred. The following tables summarize property, plant and equipment by asset category: Eversource As of December 31, (Millions of Dollars) 2024 2023 Distribution - Electric $ 21,144.1 $ 19,656.5 Distribution - Natural Gas 8,922.2 8,155.3 Transmission - Electric 16,130.9 14,666.8 Distribution - Water (1) — 2,280.1 Solar 201.0 201.1 Utility 46,398.2 44,959.8 Other (2) 2,254.1 2,006.8 Property, Plant and Equipment, Gross 48,652.3 46,966.6 Less: Accumulated Depreciation Utility (9,636.5) (9,670.1) Other (1,044.1) (869.6) Total Accumulated Depreciation (10,680.6) (10,539.7) Property, Plant and Equipment, Net 37,971.7 36,426.9 Construction Work in Progress 3,014.9 3,071.7 Total Property, Plant and Equipment, Net $ 40,986.6 $ 39,498.6 As of December 31, 2024 2023 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH Distribution - Electric $ 8,437.9 $ 9,782.3 $ 2,964.2 $ 7,897.1 $ 9,000.5 $ 2,799.2 Transmission - Electric 6,937.7 6,375.2 2,819.6 6,548.2 5,630.8 2,489.5 Solar — 201.0 — — 201.1 — Property, Plant and Equipment, Gross 15,375.6 16,358.5 5,783.8 14,445.3 14,832.4 5,288.7 Less: Accumulated Depreciation (2,928.0) (3,782.0) (1,032.3) (2,670.5) (3,585.9) (984.0) Property, Plant and Equipment, Net 12,447.6 12,576.5 4,751.5 11,774.8 11,246.5 4,304.7 Construction Work in Progress 554.6 1,461.3 338.4 565.4 1,507.3 270.0 Total Property, Plant and Equipment, Net $ 13,002.2 $ 14,037.8 $ 5,089.9 $ 12,340.2 $ 12,753.8 $ 4,574.7 (1) As of December 31, 2024, the property, plant and equipment balance, net of accumulated depreciation, attributable to the Aquarion water distribution business has been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, this balance was recorded within Property, Plant and Equipment, Net on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” (2) These assets are primarily comprised of computer software, hardware and equipment at Eversource Service and buildings at The Rocky River Realty Company. Depreciation: Depreciation of utility assets is calculated on a straight-line basis using composite rates based on the estimated remaining useful lives of the various classes of property (estimated useful life for PSNH distribution and the water utilities). The composite rates, which are subject to approval by the appropriate state regulatory agency, include a cost of removal component, which is collected from customers over the lives of the plant assets and is recognized as a regulatory liability. Depreciation rates are applied to property from the time it is placed in service. Upon retirement from service, the cost of the utility asset is charged to the accumulated provision for depreciation. The actual incurred removal costs are applied against the related regulatory liability. The depreciation rates for the various classes of utility property, plant and equipment aggregate to composite rates as follows: (Percent) 2024 2023 2022 Eversource 3.2 % 3.1 % 3.0 % CL&P 2.9 % 2.8 % 2.8 % NSTAR Electric 2.8 % 2.7 % 2.7 % PSNH 3.0 % 3.0 % 3.0 % The following table summarizes average remaining useful lives of depreciable assets: As of December 31, 2024 (Years) Eversource CL&P NSTAR Electric PSNH Distribution - Electric 33.4 34.7 33.4 29.9 Distribution - Natural Gas 34.7 — — — Transmission - Electric 39.7 35.8 45.1 39.8 Distribution - Water 45.2 — — — Solar 22.8 — 22.8 — Other (1) 9.9 — — — (1) The estimated useful life of computer software, hardware and equipment primarily ranges from 5 to 15 years and of buildings is 40 years.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS The electric and natural gas companies purchase and procure energy and energy-related products, which are subject to price volatility, for their customers. The costs associated with supplying energy to customers are recoverable from customers in future rates. These regulated companies manage the risks associated with the price volatility of energy and energy-related products through the use of derivative and non-derivative contracts. Many of the derivative contracts meet the definition of, and are designated as, normal and qualify for accrual accounting under the applicable accounting guidance. The costs and benefits of derivative contracts that meet the definition of normal are recognized in Operating Expenses on the statements of income as electricity or natural gas is delivered. Derivative contracts that are not designated as normal are recorded at fair value as derivative assets or liabilities on the balance sheets. For the electric and natural gas companies, regulatory assets or regulatory liabilities are recorded to offset the fair values of derivatives, as contract settlement amounts are recovered from, or refunded to, customers in their respective energy supply rates. The gross fair values of derivative assets and liabilities with the same counterparty are offset and reported as net Derivative Assets or Derivative Liabilities, with current and long-term portions, on the balance sheets. The following table presents the gross fair values of contracts, categorized by risk type, and the net amounts recorded as current or long-term derivative assets or liabilities: As of December 31, 2024 2023 CL&P (Millions of Dollars) Fair Value Hierarchy Commodity Supply Netting (1) Net Amount Commodity Supply Netting (1) Net Amount Current Derivative Assets Level 2 $ 14.2 $ (0.3) $ 13.9 $ 16.4 $ (0.5) $ 15.9 Long-Term Derivative Assets Level 2 — — — 13.6 (0.5) 13.1 Current Derivative Liabilities Level 2 (71.1) — (71.1) (81.9) — (81.9) Long-Term Derivative Liabilities Level 2 — — — (68.0) — (68.0) (1) Amounts represent derivative assets and liabilities that Eversource elected to record net on the balance sheets. These amounts are subject to master netting agreements or similar agreements for which the right of offset exists. The business activities that result in the recognition of derivative assets also create exposure to various counterparties. As of December 31, 2024, CL&P's derivative assets were exposed to counterparty credit risk and contracted with investment grade entities. Derivative Contracts at Fair Value with Offsetting Regulatory Amounts Commodity Supply and Price Risk Management : As required by regulation, CL&P, along with UI, has capacity-related contracts with generation facilities. CL&P has a sharing agreement with UI, with 80 percent of the costs or benefits of each contract borne by or allocated to CL&P and 20 percent borne by or allocated to UI. The combined capacities of these contracts as of December 31, 2024 and 2023 were 610 MW and 682 MW, respectively. The capacity contracts extend through 2026 and obligate both CL&P and UI to make or receive payments on a monthly basis to or from the generation facilities based on the difference between a set capacity price and the capacity market price received in the ISO-NE capacity markets. For the years ended December 31, 2024, 2023 and 2022, there were losses of $3.8 million, losses of $3.9 million and gains of $10.1 million, respectively. These changes in fair value associated with CL&P’s derivative contracts are deferred in Regulatory Assets on the balance sheet. Fair Value Measurements of Derivative Instruments The fair value of derivative contracts utilizes both observable and unobservable inputs. The fair value is modeled using income techniques, such as discounted cash flow valuations adjusted for assumptions related to exit price. Valuations of derivative contracts using a discounted cash flow methodology include assumptions regarding the timing and likelihood of scheduled capacity payments and also reflect non-performance risk, including credit, using the default probability approach based on the counterparty’s credit rating for assets and the Company’s credit rating for liabilities. Significant observable inputs for valuations of these contracts include energy-related product prices in future years for which quoted prices in an active market exist. Valuations incorporate estimates of premiums or discounts that would be required by a market participant to arrive at an exit price, using historical market transactions adjusted for the terms of the contract. Fair value measurements were prepared by individuals with expertise in valuation techniques, pricing of energy-related products, and accounting requirements. All derivative contracts were classified as Level 2 in the fair value hierarchy as of both December 31, 2024 and 2023. The following table presents changes in the Level 3 category of derivative assets and derivative liabilities measured at fair value on a recurring basis. The derivative assets and liabilities are presented on a net basis. CL&P (Millions of Dollars) For the Year Ended December 31, 2023 Derivatives, Net: Fair Value as of Beginning of Period $ (181.8) Net Realized/Unrealized Losses Included in Regulatory Assets (3.9) Settlements 64.8 Transfers out of Level 3 (1) 120.9 Fair Value as of End of Period $ — (1) Transfers out of Level 3 pertain to certain significant valuation inputs becoming observable as well as certain unobservable inputs no longer being significant to the fair value of the derivative contracts. Eversource's policy is to recognize transfers between levels of the fair value hierarchy as of the end of the reporting period.

MARKETABLE SECURITIES

MARKETABLE SECURITIES	12 Months Ended
	Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]
MARKETABLE SECURITIES	MARKETABLE SECURITIES Eversource’s marketable securities include the CYAPC and YAEC legally restricted trusts that each hold equity and available-for-sale debt securities to fund the spent nuclear fuel removal obligations of their nuclear fuel storage facilities. Eversource also holds trusts that are not subject to regulatory oversight by state or federal agencies that are primarily used to fund certain non-qualified executive benefits. The marketable securities within the non-qualified executive benefit trusts were sold in 2023. Equity and available-for-sale debt marketable securities are recorded at fair value, with the current portion recorded in Prepayments and Other Current Assets and the long-term portion recorded in Marketable Securities on the balance sheets. CYAPC and YAEC’s spent nuclear fuel trusts are restricted and are classified in long-term Marketable Securities on the balance sheets. Equity Securities: Eversource's equity securities include CYAPC's and YAEC's marketable securities held in spent nuclear fuel trusts, which had fair values of $163.1 million and $173.6 million as of December 31, 2024 and 2023, respectively. Unrealized gains and losses for these spent nuclear fuel trusts are subject to regulatory accounting treatment and are recorded in Marketable Securities with the corresponding offset to long-term liabilities on the balance sheets, with no impact on the statements of income. Unrealized gains and losses on equity securities held in other trusts are recorded in Other Income, Net on the statements of income. The equity securities within Eversource’s non-qualified executive benefits trusts were sold during 2023 and resulted in a $1.1 million gain recorded in Other Income, Net for the year ended December 31, 2023. The remaining equity securities held in Eversource’s trusts as of December 31, 2024 of $4.1 million were reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, these equity securities totaled $3.3 million and there were unrealized gains of $0.6 million recorded in Other Income, Net in 2023. For further information, see Note 24, “Assets Held for Sale.” Available-for-Sale Debt Securities: The following is a summary of available-for-sale debt securities, which are held in CYAPC’s and YAEC’s spent nuclear fuel trusts: As of December 31, 2024 2023 Eversource (Millions of Dollars) Amortized Pre-Tax Pre-Tax Fair Value Amortized Pre-Tax Pre-Tax Fair Value Debt Securities $ 163.2 $ 0.1 $ (6.1) $ 157.2 $ 169.5 $ 1.4 $ (6.6) $ 164.3 Unrealized gains and losses for available-for-sale debt securities included in the CYAPC and YAEC spent nuclear fuel trusts are subject to regulatory accounting treatment and are recorded in Marketable Securities with the corresponding offset to long-term liabilities on the balance sheets, with no impact on the statements of income. Any unrealized gains and losses on available-for-sale debt securities held in other trusts are recorded in Accumulated Other Comprehensive Income, excluding amounts related to credit losses or losses on securities intended to be sold, which are recorded in Other Income, Net. The debt securities within Eversource’s non-qualified executive benefits trusts were sold during 2023. There were $1.2 million of realized losses recorded on securities sold for the year ended December 31, 2023 that were reclassified out of Accumulated Other Comprehensive Income and recorded in Other Income, Net. There were no credit losses for the years ended December 31, 2024 and 2023, and no allowance for credit losses as of December 31, 2024. Factors considered in determining whether a credit loss exists include adverse conditions specifically affecting the issuer, the payment history, ratings and rating changes of the security, and the severity of the impairment. For asset-backed debt securities, underlying collateral and expected future cash flows are also evaluated. As of December 31, 2024, the contractual maturities of available-for-sale debt securities were as follows: Eversource (Millions of Dollars) Amortized Fair Less than one year $ 11.3 $ 11.7 One to five years 35.6 35.6 Six to ten years 43.5 42.6 Greater than ten years 72.8 67.3 Total Debt Securities $ 163.2 $ 157.2 Realized Gains and Losses: Realized gains and losses are offset in long-term liabilities for CYAPC and YAEC and are recorded in Other Income, Net for Eversource's benefit trusts. Eversource utilizes the average cost basis method for the CYAPC and YAEC spent nuclear fuel trusts and the specific identification basis method for the Eversource non-qualified benefit trusts to compute the realized gains and losses on the sale of marketable securities. Fair Value Measurements: The following table presents the marketable securities recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Eversource (Millions of Dollars) As of December 31, 2024 2023 Level 1: Mutual Funds and Equities $ 163.1 $ 176.9 Money Market Funds 10.0 13.7 Total Level 1 $ 173.1 $ 190.6 Level 2: U.S. Government Issued Debt Securities (Agency and Treasury) $ 92.0 $ 90.1 Corporate Debt Securities 32.5 34.0 Asset-Backed Debt Securities 7.8 5.6 Municipal Bonds 6.8 9.8 Other Fixed Income Securities 8.1 11.1 Total Level 2 $ 147.2 $ 150.6 Total Marketable Securities $ 320.3 $ 341.2 U.S. government issued debt securities are valued using market approaches that incorporate transactions for the same or similar bonds and adjustments for yields and maturity dates. Corporate debt securities are valued using a market approach, utilizing recent trades of the same or similar instruments and also incorporating yield curves, credit spreads and specific bond terms and conditions. Asset-backed debt securities include collateralized mortgage obligations, commercial mortgage backed securities, and securities collateralized by auto loans, credit card loans or receivables. Asset-backed debt securities are valued using recent trades of similar instruments, prepayment assumptions, yield curves, issuance and maturity dates, and tranche information. Municipal bonds are valued using a market approach that incorporates reported trades and benchmark yields. Other fixed income securities are valued using pricing models, quoted prices of securities with similar characteristics, and discounted cash flows.

INVESTMENTS IN UNCONSOLIDATED A

INVESTMENTS IN UNCONSOLIDATED AFFILIATES	12 Months Ended
	Dec. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENTS IN UNCONSOLIDATED AFFILIATES	INVESTMENTS IN UNCONSOLIDATED AFFILIATES Investments in entities that are not consolidated are included in long-term assets on the balance sheets. Investments in affiliates where Eversource has the ability to exercise significant influence, but not control, over an investee are initially recognized as an equity method investment at cost. Earnings impacts from these equity investments are included in Other Income, Net on the statements of income. Eversource's investments accounted for under the equity method include the following: Investment Balance as of December 31, (Millions of Dollars) Ownership Interest 2024 2023 Offshore Wind Business 50% - 100% $ 22.2 $ 515.5 Natural Gas Pipeline - Algonquin Gas Transmission, LLC 15% 112.6 116.0 Other various 33.9 29.0 Total Investments in Unconsolidated Affiliates $ 168.7 $ 660.5 For the years ended December 31, 2024, 2023 and 2022, Eversource had equity in earnings of unconsolidated affiliates of $51.9 million, $15.5 million, and $22.9 million, respectively. Eversource received dividends from its equity method investees (excluding proceeds received from sale or liquidation of investments) of $20.5 million, $20.1 million, and $26.2 million, respectively, for the years ended December 31, 2024, 2023 and 2022. Offshore Wind Business: Eversource’s previous offshore wind business included 50 percent ownership interests in each of North East Offshore and South Fork Class B Member, LLC. During 2024, Eversource sold its interest in these entities, and in doing so, sold its interests in the Revolution Wind project, the South Fork Wind project, and the Sunrise Wind project. Eversource’s current offshore wind business is now comprised only of a noncontrolling tax equity investment in South Fork Wind through a 100 percent ownership in South Fork Wind Holdings, LLC Class A interests. On May 25, 2023, Eversource announced that it had completed a strategic review of its offshore wind investments and determined that it would pursue the sale of its offshore wind investments. On September 7, 2023, Eversource completed the sale of its 50 percent interest in an uncommitted lease area consisting of approximately 175,000 developable acres located 25 miles off the south coast of Massachusetts to Ørsted for $625 million in an all-cash transaction. In September of 2023, Eversource made a $528 million investment in a tax equity interest for South Fork Wind. South Fork Wind was restructured as a tax equity investment, with Eversource purchasing 100 percent ownership of a new Class A tax equity membership interest. This investment will result in Eversource receiving cash flow benefits from investment tax credits (ITC) and other future cash flow benefits as well. As of December 31, 2024, $459 million of expected investment tax credits and other expected tax benefits were reclassified from the South Fork Wind tax equity investment balance reported in Investments in Unconsolidated Affiliates as a decrease in Accumulated Deferred Income Taxes on the Eversource balance sheet, which represented a non-cash reclassification. As a result of these investment tax credits, Eversource expects lower federal income tax payments from 2025 to 2027. As of December 31, 2024, the tax equity interest in South Fork Wind totaled $22.2 million. On January 24, 2024, Eversource entered into an agreement with Ørsted to sell Eversource’s 50 percent share of Sunrise Wind, subject to certain conditions and regulatory approvals. On April 18, 2024, Eversource and Ørsted executed an equity and asset purchase agreement and on July 9, 2024, Eversource completed the sale of its 50 percent ownership share of Sunrise Wind to Ørsted. In accordance with the equity and asset purchase agreement and after adjustment for a reduction in capital spending compared to forecasted amounts, adjusted proceeds totaled $152 million. Ørsted paid Eversource $118 million at the closing of the sale transaction, which was used to repay parent company debt. Remaining proceeds of $34 million will be paid after onshore construction is completed and certain other construction milestones are achieved. The remaining expected proceeds have been recorded in Other Long-Term Assets on Eversource’s balance sheet as of December 31, 2024. Eversource recorded a pre-tax gain on the sale of Sunrise Wind of $377 million in 2024. With completion of the sale, Eversource does not have any ongoing financial obligations associated with Sunrise Wind. On February 13, 2024, Eversource executed an agreement to sell its 50 percent interests in the South Fork Wind and Revolution Wind projects to Global Infrastructure Partners (GIP) for an initial gross purchase price of approximately $1.1 billion. The initial purchase price was subject to adjustment based on, among other things, the progress, timing and the construction cost of Revolution Wind, including changes in actual versus forecasted capital spending between signing the agreement and closing of the transaction. On September 30, 2024, Eversource completed the sale of its 50 percent ownership share in the South Fork Wind and Revolution Wind projects to GIP for adjusted gross proceeds of $745 million, which were received at closing. Adjusted gross proceeds from the sale were approximately $375 million lower than the previously estimated purchase price. This reduction reflects approximately $150 million resulting from lower capital spending between signing the agreement and closing, and approximately $225 million related to the final terms of the sale transaction, primarily due to the delay of the commercial operations date of Revolution Wind. Proceeds from the transaction were used to repay parent company debt. As part of the Revolution Wind and South Fork Wind sale, Eversource and GIP agreed to make certain post-closing purchase price adjustment payments, which could further impact the final purchase price. The post-closing purchase price adjustment payments include cost sharing obligations that require Eversource to share equally with GIP in GIP’s funding obligations up to an effective cap of approximately $240 million of incremental capital expenditure overruns incurred during the construction phase for Revolution Wind, after which Eversource will have responsibility for GIP’s obligations for any additional capital expenditure overruns in excess of this amount. The purchase price is also subject to post-closing adjustments as a result of final project economics, which includes Eversource’s obligation to maintain GIP’s internal rate of return through the construction period for each project as specified in the agreement. Post-closing purchase price adjustment payments will be made following the commercial operation date of Revolution Wind. South Fork Wind has achieved commercial operation, and Eversource is in the process of finalizing the construction cost post-close purchase price adjustment payment related to this project, which is not expected to be material. Upon the completion of both sale transactions in 2024, the total proceeds were compared to the carrying value of the investments, including an estimate of liability for post-closing adjustment payments to GIP, and Eversource recognized an aggregate, net after-tax loss on the sales of its offshore wind investments of $524 million. The aggregate, net after-tax loss is comprised of (1) the lower proceeds related to final terms of the sale transaction to GIP of approximately $225 million related to non-construction costs for the Revolution Wind and South Fork Wind projects, primarily due to a purchase price reduction of $150 million resulting from the delay of the commercial operations date of Revolution Wind, (2) recently identified forecasted construction costs as a result of a delay in the anticipated commercial operation date related to Revolution Wind of approximately $350 million, which includes an estimate for the anticipated post-closing adjustment to GIP related to Eversource’s expected cost overrun sharing obligation, and (3) approximately $326 million, which includes an estimate for the anticipated post-closing adjustment related to Eversource’s expected obligations to GIP as a result of final economics of the Revolution Wind and South Fork Wind projects and other future costs, as well as a net $60 million increase in income tax expense including an increase in the valuation allowance for unused capital losses. These losses were partially offset by the $377 million gain on the sale of Sunrise Wind. Upon sale, Eversource recorded a contingent liability of $365 million, reflecting its estimate of the future obligations under the GIP sale terms, which include the expected cost overrun sharing obligation, expected obligation to maintain GIP’s internal rate of return, and obligation for other future costs. The majority of this liability is expected to be settled upon the completion of the Revolution Wind project. The long-term portion of the liability of $350 million is recorded in Other Long-Term Liabilities, and $15 million is recorded in Other Current Liabilities on Eversource’s balance sheet as of December 31, 2024. Contingencies are evaluated using the best information available at the time the financial statements are prepared, and this assessment involves judgments and assumptions about future events. Factors that could increase the post-closing adjustment payments owed to GIP include the ultimate cost of construction and extent of cost overruns for Revolution Wind, delays in construction, which would impact the economics associated with the purchase price adjustment, and Revolution Wind’s eligibility for federal investment tax credits at a lower value than assumed and included in the purchase price. The purchase price included the sales value related to a 40 percent level of federal investment tax credits, 10 percent of which is the energy community investment tax credit (ITC) adder included in the Inflation Reduction Act of approximately $170 million related to Revolution Wind. Although management believes the ITC adder value is realizable, there is some uncertainty at this time as to whether those ITC adders can be achieved, and management continues to evaluate the project’s qualifications and to monitor guidance issued by the United States Treasury Department. A change in the expected value or qualification of ITC adders could result in a significant loss in a future period. New information or future developments that arise as construction progresses and as cost estimates are reviewed and revised will require a reassessment of the estimated liability for the post-closing adjustment payments. The Company is currently aware that construction of the offshore foundations, offshore substation and turbine tower installations could result in increased cost overruns in the future. Only preliminary construction cost projections are available for these cost overruns, and there is insufficient updated information at this point in order for Eversource to change its estimate with reasonably estimable information. Eversource will continue to assess the potential exposure and adjust the liability as needed. It is expected that updated costs estimates will become available in the first half of 2025, and adverse changes in facts and circumstances could result in additional losses that could be material. The Company believes it is reasonably possible that there is an additional loss in excess of the liability recorded, but management cannot reasonably estimate a range of loss beyond the $365 million recorded at this time. Total net proceeds could also be adjusted for a benefit due to Eversource if there are lower operation costs or higher availability of the projects through the period that is four years following the commercial operation of Revolution Wind. Under the agreement with GIP, Eversource’s existing and certain additional credit support obligations for Revolution Wind are expected to roll off as the project completes construction. Under the agreement with Ørsted, Eversource’s existing credit support obligations for Sunrise Wind were either terminated or indemnified by Ørsted as a result of the sale. Eversource has entered into separate construction management agreements to manage Sunrise Wind’s and Revolution Wind’s onshore electric substation construction through completion. In this role, Eversource will be solely a service provider to Sunrise Wind and Revolution Wind. 2023 Impairments: Equity method investments are assessed for impairment when conditions exist as of the balance sheet date that indicate that the fair value of the investment may be less than book value. Eversource continually monitors and evaluates its equity method investments to determine if there are indicators of an other-than-temporary impairment. If the decline in value is considered to be other-than-temporary, the investment is written down to its estimated fair value, which establishes a new cost basis in the investment. Impairment evaluations are based on best information available at the impairment assessment date. Subsequent declines or recoveries after the reporting date are not considered in the impairment recognized. Investments that are other-than-temporarily impaired and written down to their estimated fair value cannot subsequently be written back up for increases in estimated fair value. Impairment evaluations involve a significant degree of judgment and estimation, including identifying circumstances that indicate an impairment may exist at the equity method investment level, selecting discount rates used to determine fair values, and developing an estimate of discounted future cash flows expected from investment operations or the sale of the investment. During 2023, in connection with the process to divest its offshore wind business, Eversource identified indicators for impairment in both the second and fourth quarters of 2023. In each impairment assessment, Eversource evaluated its investments and determined that the carrying value of the equity method offshore wind investments exceeded the fair value of the investments and that the decline in fair value was other-than-temporary. The completion of the strategic review in the second quarter of 2023 resulted in Eversource recording a pre-tax other-than-temporary impairment charge of $401 million ($331 million after-tax) to reflect the investment at estimated fair value based on the expected sales price at that time. This established a new cost basis in the investments. Negative developments in the fourth quarter of 2023, including a lower expected sales price, additional projected construction cost increases, and the October 2023 OREC pricing denial for Sunrise Wind, resulted in Eversource conducting an impairment evaluation and recognizing an additional pre-tax other-than-temporary impairment charge of $1.77 billion ($1.62 billion after-tax) and establishing a new cost basis in the investments as of December 31, 2023. The Eversource statement of income for the year ended 2023 reflects a total pre-tax other-than-temporary impairment charge of $2.17 billion ($1.95 billion after-tax) in its offshore wind investments. The impairment charges were non-cash charges and did not impact Eversource’s cash position at the time of the impairment. Eversource’s offshore wind investments did not meet the criteria to qualify for presentation as a discontinued operation. The 2023 impairment evaluations involved judgments in developing the estimates and timing of the future cash flows arising from the expected sales price of Eversource’s 50 percent interest in the wind projects, including expected sales value from investment tax credit adder amounts, less estimated costs to sell, and uncertainties related to the Sunrise Wind re-bid process in New York’s offshore wind solicitation in 2024. Additional assumptions in the fourth quarter 2023 assessment included revised projected construction costs and estimated project cost overruns, management’s assumption that the Sunrise Wind project would ultimately be abandoned, estimated termination costs, salvage values of Sunrise Wind assets, and the value of the tax equity ownership interest. The assumptions used in the discounted cash flow analyses were subject to inherent uncertainties and subjectivity. All significant inputs into the impairment evaluations were Level 3 fair value measurements. A summary of the significant estimates and assumptions included in the 2023 impairment charges is as follows: Second Quarter 2023 Fourth Quarter 2023 Total (Millions of Dollars) Lower expected sales proceeds across all three wind projects $ 401 $ 525 $ 926 Expected cost overruns not recovered in the sales price — 441 441 Loss of sales value from the sale price offered by GIP, including loss of ITC adders value, cancellation costs and other impacts assuming Sunrise Wind project is abandoned — 800 800 Impairment Charges, pre-tax 401 1,766 2,167 Tax Benefit (70) (144) (214) Impairment Charges, after-tax $ 331 $ 1,622 1,953 A summary of the carrying value by investee and by project as of December 31, 2023 is as follows: Investments Expected to be Disposed of Investment to be Held North East Offshore South Fork Class B Member, LLC South Fork Wind Holdings, LLC Class A Total Offshore Wind Investments (Millions of Dollars) Sunrise Wind Revolution Wind Carrying Value as of December 31, 2023, before $ 699 $ 799 $ 299 $ 485 $ 2,282 Fourth Quarter 2023 Impairment Charge (1,218) (544) — (4) (1,766) Carrying Value as of December 31, 2023 $ (519) $ 255 $ 299 $ 481 $ 516 During 2024, Eversource sold its interest in the North East Offshore and South Fork Class B, Member LLC equity method investments and recognized an aggregate, net after-tax loss on the sale of its offshore wind investments of $524 million. Capital contributions in the offshore wind investments, including the 2023 contribution for the tax equity investment in South Fork Wind, were included in Investments in Unconsolidated Affiliates on the statements of cash flows. Proceeds received from the sale of the investments in 2024, and proceeds received from the 2023 sale of the unused lease area and from an October 2023 distribution of $318 million received primarily as a result of being a 50 percent joint owner in the Class B shares of South Fork Wind which was restructured as a tax equity investment, were included in Proceeds from Unconsolidated Affiliates on the statements of cash flows. Liquidation of Renewable Energy Investment Fund: On March 21, 2023, Eversource’s equity method investment in a renewable energy investment fund was liquidated by the fund’s general partner in accordance with the partnership agreement. Proceeds received from the liquidation totaled $147.6 million and were included in Proceeds from Unconsolidated Affiliates on the statement of cash flows for the year ended December 31, 2023. A portion of the proceeds was used to make a charitable contribution to the Eversource Energy Foundation (a related party) of $20.0 million in 2023. The liquidation benefit received in excess of the investment’s carrying value and the charitable contribution were included in Other Income, Net on the statement of income. NSTAR Electric: As of December 31, 2024 and 2023, NSTAR Electric's investments included a 14.5 percent ownership interest in two companies that transmit hydro-electricity imported from the Hydro-Quebec system in Canada of $11.5 million and $9.6 million, respectively.

ASSET RETIREMENT OBLIGATIONS

ASSET RETIREMENT OBLIGATIONS	12 Months Ended
	Dec. 31, 2024
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATIONS	ASSET RETIREMENT OBLIGATIONS Eversource, including CL&P, NSTAR Electric and PSNH, recognizes a liability for the fair value of an ARO on the obligation date if the liability's fair value can be reasonably estimated, even if it is conditional on a future event. Settlement dates and future costs are reasonably estimated when sufficient information becomes available. Management has identified various categories of AROs, primarily CYAPC's and YAEC's obligation to dispose of spent nuclear fuel and high level waste, and also certain assets containing asbestos and hazardous contamination. Management has performed fair value calculations reflecting expected probabilities for settlement scenarios. The fair value of an ARO is recorded as a long-term liability with a corresponding amount included in Property, Plant and Equipment, Net on the balance sheets. The ARO assets are depreciated, and the ARO liabilities are accreted over the estimated life of the obligation and the corresponding credits are recorded as accumulated depreciation and ARO liabilities, respectively. As the electric and natural gas companies are rate-regulated on a cost-of-service basis, these companies apply regulatory accounting guidance and both the depreciation and accretion costs associated with these companies' AROs are recorded as increases to Regulatory Assets on the balance sheets. A reconciliation of the beginning and ending carrying amounts of ARO liabilities is as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Balance as of Beginning of Year $ 505.8 $ 39.9 $ 104.8 $ 5.2 $ 502.7 $ 37.4 $ 101.3 $ 4.9 Liabilities Settled During the Year (24.6) — — — (24.9) — — — Accretion 29.5 2.6 4.5 0.4 29.2 2.5 4.3 0.3 Revisions in Estimated Cash Flows 80.2 — — — (1.2) — (0.8) — Balance as of End of Year $ 590.9 $ 42.5 $ 109.3 $ 5.6 $ 505.8 $ 39.9 $ 104.8 $ 5.2 Eversource's amounts include CYAPC and YAEC's AROs of $391.7 million and $315.8 million as of December 31, 2024 and 2023, respectively. The fair value of the ARO for CYAPC and YAEC includes uncertainties of the fuel off-load dates related to the DOE's timing of performance regarding its obligation to dispose of the spent nuclear fuel and high level waste and other assumptions, including discount rates. The incremental asset recorded as an offset to the ARO liability was fully depreciated since the plants have no remaining useful life. Any changes in the ARO liability are recorded with a corresponding offset to the related regulatory asset. The assets held in the CYAPC and YAEC spent nuclear fuel trusts are restricted for settling the ARO and all other nuclear fuel storage obligations. For further information on the assets held in the spent nuclear fuel trusts, see Note 5, "Marketable Securities," to the financial statements.

SHORT-TERM DEBT

SHORT-TERM DEBT	12 Months Ended
	Dec. 31, 2024
Debt Disclosure [Abstract]
SHORT-TERM DEBT	SHORT-TERM DEBT Short-Term Debt - Borrowing Limits: The amount of short-term borrowings that may be incurred by CL&P and NSTAR Electric is subject to periodic approval by the FERC. Because the NHPUC has jurisdiction over PSNH's short-term debt, PSNH is not currently required to obtain FERC approval for its short-term borrowings. On November 30, 2023, the FERC granted authorization that allows CL&P to issue total short-term borrowings in an aggregate principal amount not to exceed $600 million outstanding at any one time, through December 31, 2025. On December 18, 2023, the FERC granted authorization that allows NSTAR Electric to issue total short-term borrowings in an aggregate principal amount not to exceed $655 million outstanding at any one time, through December 31, 2025. PSNH is authorized by regulation of the NHPUC to incur short-term borrowings up to 10 percent of net fixed plant plus an additional $60 million until further ordered by the NHPUC. As of December 31, 2024, PSNH's short-term debt authorization under the 10 percent of net fixed plant test plus $60 million totaled $526.7 million. CL&P's certificate of incorporation contains preferred stock provisions restricting the amount of unsecured debt that CL&P may incur, including limiting unsecured indebtedness with a maturity of less than 10 years to 10 percent of total capitalization. As of December 31, 2024, CL&P had $901.0 million of unsecured debt capacity available under this authorization. Yankee Gas, NSTAR Gas and EGMA are not required to obtain approval from any state or federal authority to incur short-term debt. Short-Term Debt - Commercial Paper Programs and Credit Agreements : Eversource parent has a $2.00 billion commercial paper program allowing Eversource parent to issue commercial paper as a form of short-term debt. Eversource parent, CL&P, PSNH, NSTAR Gas, Yankee Gas, EGMA and Aquarion Water Company of Connecticut are parties to a five-year $2.00 billion revolving credit facility, which terminates on October 11, 2029. This re volving credit facility serves to backstop Eversource parent's $2.00 billion commercial paper program. NSTAR Electric has a $650 million commercial paper program allowing NSTAR Electric to issue commercial paper as a form of short-term debt. NSTAR Electric is also a party to a five-year $650 million revolving credit facility, which terminates on October 11, 2029, that serves to backstop NSTAR Electric's $650 million commercial paper program. The amount of borrowings outstanding and available under the commercial paper programs were as follows: Borrowings Outstanding Available Borrowing Capacity as of December 31, Weighted-Average Interest Rate as of December 31, (Millions of Dollars) 2024 2023 2024 2023 2024 2023 Eversource Parent Commercial Paper Program $ 1,538.0 $ 1,771.9 $ 462.0 $ 228.1 4.76 % 5.60 % NSTAR Electric Commercial Paper Program 504.8 365.8 145.2 284.2 4.55 % 5.40 % There were no borrowings outstanding on the revolving credit facilities as of December 31, 2024 or 2023. CL&P and PSNH have uncommitted line of credit agreements totaling $375 million and $250 million, respectively, all of which will expire in either May 2025, September 2025 or October 2025. There are no borrowings outstanding on either the CL&P or PSNH uncommitted line of credit agreements as of December 31, 2024. Amounts outstanding under the commercial paper programs are included in Notes Payable and classified in current liabilities on the Eversource and NSTAR Electric balance sheets, as all borrowings are outstanding for no more than 364 days at one time. As a result of the CL&P long-term debt issuance in January 2024, $207.3 million of commercial paper borrowings under the Eversource parent commercial paper program were reclassified to Long-Term Debt on Eversource parent’s balance sheet as of December 31, 2023. Under the credit facilities described above, Eversource and its subsidiaries, including CL&P, NSTAR Electric, PSNH, NSTAR Gas, EGMA, Yankee Gas, and Aquarion Water Company of Connecticut, must comply with certain financial and non-financial covenants, including a consolidated debt to total capitalization ratio. As of December 31, 2024 and 2023, Eversource and its subsidiaries were in compliance with these covenants. If Eversource or its subsidiaries were not in compliance with these covenants, an event of default would occur requiring all outstanding borrowings by such borrower to be repaid, and additional borrowings by such borrower would not be permitted under its respective credit facility. Intercompany Borrowings: Eversource parent uses its available capital resources to provide loans to its subsidiaries to assist in meeting their short-term borrowing needs. Eversource parent records intercompany interest income from its loans to subsidiaries, which is eliminated in consolidation. Intercompany loans from Eversource parent to its subsidiaries are eliminated in consolidation on Eversource's balance sheets. As of December 31, 2024, there were intercompany loans from Eversource parent to CL&P of $280.0 million and to PSNH of $131.1 million. As of December 31, 2023, there were intercompany loans from Eversource parent to CL&P of $457.0 million and to PSNH of $233.0 million. Eversource parent charges interest on these intercompany loans at the same weighted-average interest rate as its commercial paper program. Intercompany loans from Eversource parent are included in Notes Payable to Eversource Parent and classified in current liabilities on the respective subsidiary's balance sheets, as these intercompany borrowings are outstanding for no more than 364 days at one time. As a result of the CL&P long-term debt issuance in January 2024, $207.3 million of CL&P’s intercompany borrowings were reclassified to Long-Term Debt on CL&P’s balance sheet as of December 31, 2023. Sources and Uses of Cash

LONG-TERM DEBT

LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2024
Debt Disclosure [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT Details of long-term debt outstanding are as follows: CL&P (Millions of Dollars) As of December 31, Interest Rate 2024 2023 First Mortgage Bonds: 1994 Series D due 2024 7.875 % $ — $ 139.8 2004 Series B due 2034 5.750 % 130.0 130.0 2005 Series B due 2035 5.625 % 100.0 100.0 2006 Series A due 2036 6.350 % 250.0 250.0 2007 Series B due 2037 5.750 % 150.0 150.0 2007 Series D due 2037 6.375 % 100.0 100.0 2014 Series A due 2044 4.300 % 475.0 475.0 2015 Series A due 2045 4.150 % 350.0 350.0 2017 Series A due 2027 3.200 % 500.0 500.0 2018 Series A due 2048 4.000 % 800.0 800.0 2020 Series A due 2025 0.750 % 400.0 400.0 2021 Series A due 2031 2.050 % 425.0 425.0 2023 Series A due 2053 5.250 % 500.0 500.0 2023 Series B due 2033 4.900 % 300.0 300.0 2024 Series A due 2029 4.650 % 350.0 — 2024 Series B due 2034 4.950 % 300.0 — Total First Mortgage Bonds 5,130.0 4,619.8 Less Amounts due Within One Year (400.0) (139.8) Current Portion Classified as Long-Term Debt (1) 397.1 139.8 Commercial Paper Classified as Long-Term Debt (See Note 8, Short-Term Debt) — 207.3 Unamortized Premiums and Discounts, Net 14.3 18.0 Unamortized Debt Issuance Costs (33.2) (30.7) CL&P Long-Term Debt $ 5,108.2 $ 4,814.4 NSTAR Electric (Millions of Dollars) As of December 31, Interest Rate 2024 2023 Debentures: 2006 Debentures due 2036 5.750 % $ 200.0 $ 200.0 2010 Debentures due 2040 5.500 % 300.0 300.0 2014 Debentures due 2044 4.400 % 300.0 300.0 2015 Debentures due 2025 3.250 % 250.0 250.0 2016 Debentures due 2026 2.700 % 250.0 250.0 2017 Debentures due 2027 3.200 % 700.0 700.0 2019 Debentures due 2029 3.250 % 400.0 400.0 2020 Debentures due 2030 3.950 % 400.0 400.0 2021 Debentures due 2051 3.100 % 300.0 300.0 2021 Debentures due 2031 1.950 % 300.0 300.0 2022 Debentures due 2052 4.550 % 450.0 450.0 2022 Debentures due 2052 4.950 % 400.0 400.0 2023 Debentures due 2028 5.600 % 150.0 150.0 2024 Debentures due 2034 5.400 % 600.0 — Total Debentures 5,000.0 4,400.0 Notes: 2004 Senior Notes Series B due 2034 5.900 % 50.0 50.0 2007 Senior Notes Series D due 2037 6.700 % 40.0 40.0 2016 Senior Notes Series H due 2026 2.750 % 50.0 50.0 Total Notes 140.0 140.0 Less Amounts due Within One Year (250.0) — Unamortized Premiums and Discounts, Net (14.0) (14.0) Unamortized Debt Issuance Costs (31.1) (29.1) NSTAR Electric Long-Term Debt $ 4,844.9 $ 4,496.9 PSNH (Millions of Dollars) As of December 31, Interest Rate 2024 2023 First Mortgage Bonds: 2005 Series M due 2035 5.600 % $ 50.0 $ 50.0 2019 Series T due 2049 3.600 % 300.0 300.0 2020 Series U due 2050 2.400 % 150.0 150.0 2021 Series V due 2031 2.200 % 350.0 350.0 2023 Series W due 2053 5.150 % 300.0 300.0 2023 Series X due 2033 5.350 % 600.0 300.0 Total First Mortgage Bonds 1,750.0 1,450.0 Unamortized Premiums and Discounts, Net (2.6) (4.9) Unamortized Debt Issuance Costs (15.3) (13.5) PSNH Long-Term Debt $ 1,732.1 $ 1,431.6 OTHER (Millions of Dollars) As of December 31, Interest Rate 2024 2023 Eversource Parent - Senior Notes due 2025 - 2050 0.800 % - 5.950% $ 11,350.0 $ 10,300.0 Yankee Gas - First Mortgage Bonds due 2025 - 2051 1.380 % - 5.740% 1,095.0 1,015.0 NSTAR Gas - First Mortgage Bonds due 2025 - 2051 2.250 % - 7.110% 905.0 705.0 EGMA - First Mortgage Bonds due 2028 - 2052 2.110 % - 5.730% 808.0 708.0 Aquarion - Senior Notes due 2024 4.000% — 360.0 Aquarion - Unsecured Notes due 2028 - 2052 (2) 3.000 % - 6.430% 596.8 527.0 Aquarion - Secured Debt due 2027 - 2045 (2) 1.296 % - 9.290% 40.7 39.0 Pre-1983 Spent Nuclear Fuel Obligation (CYAPC) 5.6 12.5 Fair Value Adjustment (3) — 19.3 Less Fair Value Adjustment - Current Portion (3) — (5.5) Less Amounts due in One Year (750.3) (1,810.2) Current Portion Classified as Long-Term Debt (1) — 990.9 Unamortized Premiums and Discounts, Net 41.7 49.7 Unamortized Debt Issuance Costs (76.1) (65.0) Total Other Long-Term Debt $ 14,016.4 $ 12,845.7 Total Eversource Long-Term Debt $ 25,701.6 $ 23,588.6 (1) As a result of the CL&P long-term debt issuance in January 2025, $397.1 million of current portion of long-term debt was reclassified to Long-Term Debt on Eversource’s and CL&P’s balance sheets as of December 31, 2024. As a result of the CL&P and Eversource parent long-term debt issuances in January 2024, $139.8 million and $990.9 million, respectively, of current portion of long-term debt were reclassified to Long-Term Debt on CL&P’s and Eversource parent’s balance sheets as of December 31, 2023. (2) In January 2025, Eversource entered into an agreement to sell Aquarion. Upon close of the sale, Aquarion’s long-term debt will be repaid by Eversource and has therefore not been classified as held for sale. The sale is expected to close in late 2025. (3) The fair value adjustment amount is the purchase price adjustments, net of amortization, required to record long-term debt at fair value on the dates of the 2012 merger with NSTAR and the 2017 acquisition of Aquarion. As of December 31, 2024, the fair value adjustments were only related to the Aquarion acquisition and were reclassified to Liabilities Held for Sale. Availability under Long-Term Debt Issuance Authorizations: On May 1, 2024, the DPU approved NSTAR Electric’s request for authorization to issue up to $2.40 billion in long-term debt through December 31, 2026. On July 24, 2024, PURA approved CL&P’s request for authorization to issue up to $1.00 billion in long-term debt through December 31, 2025. On August 12, 2024, the DPU approved EGMA’s request for authorization to issue up to $325 million in long-term debt through December 31, 2026. On December 18, 2024, the DPU approved NSTAR Gas’ request for authorization to issue up to $475 million in long-term debt through December 31, 2027. On January 28, 2025, Yankee Gas submitted an application to PURA requesting authorization to issue up to $360 million in long-term debt through December 31, 2026. PSNH has utilized its long-term debt authorizations in place with NHPUC. Long-Term Debt Issuances and Repayments: The following table summarizes long-term debt issuances and repayments: (Millions of Dollars) Interest Rate Issuance/ Issue Date or Repayment Date Maturity Date Use of Proceeds for Issuance/ CL&P 2024 Series A First Mortgage Bonds 4.65 % $ 350.0 January 2024 January 2029 Repaid short-term debt, paid capital expenditures and working capital CL&P Series B First Mortgage Bonds 4.95 % 300.0 August 2024 August 2034 Repaid Series D Bonds, repaid short-term debt, and working capital CL&P Series D First Mortgage Bonds 7.875 % (139.8) October 2024 October 2024 Paid at maturity CL&P 2025 Series A First Mortgage Bonds 4.95 % 400.0 January 2025 January 2030 Repaid short-term debt, paid capital expenditures and working capital NSTAR Electric Debentures 5.40 % 600.0 May 2024 June 2034 Repaid short-term debt, paid capital expenditures and working capital PSNH Series X First Mortgage Bonds 5.35 % 300.0 April 2024 October 2033 Repaid short-term debt, paid capital expenditures and working capital Eversource Parent Series DD Senior Notes 5.00 % 350.0 January 2024 January 2027 Repaid short-term debt Eversource Parent Series EE Senior Notes 5.50 % 650.0 January 2024 January 2034 Repaid short-term debt Eversource Parent Series FF Senior Notes 5.85 % 700.0 April 2024 April 2031 Repaid Series X Senior Notes and Aquarion’s 2014 Senior Notes at maturity and short-term debt Eversource Parent Series GG Senior Notes 5.95 % 700.0 April 2024 July 2034 Repaid Series X Senior Notes and Aquarion’s 2014 Senior Notes at maturity and short-term debt Eversource Parent Series X Senior Notes 4.20 % (900.0) June 2024 June 2024 Paid at maturity Eversource Parent Series L Senior Notes 2.90 % (450.0) October 2024 October 2024 Paid at maturity Eversource Parent Series H Senior Notes 3.15 % (300.0) January 2025 January 2025 Paid at maturity NSTAR Gas Series W First Mortgage Bonds 5.29 % 160.0 June 2024 June 2029 Repaid short-term debt, paid capital expenditures and general corporate purposes NSTAR Gas Series X First Mortgage Bonds 5.48 % 40.0 June 2024 June 2034 Repaid short-term debt, paid capital expenditures and general corporate purposes Yankee Gas Series W First Mortgage Bonds 5.50 % 90.0 July 2024 July 2029 Repaid short-term debt, paid capital expenditures, working capital and repaid Series P bonds at maturity Yankee Gas Series X First Mortgage Bonds 5.74 % 90.0 July 2024 July 2034 Repaid short-term debt, paid capital expenditures, working capital and repaid Series P bonds at maturity Yankee Gas Series P First Mortgage Bonds 2.23 % (100.0) October 2024 October 2024 Paid at maturity EGMA Series E First Mortgage Bonds 5.17 % 100.0 October 2024 November 2034 Refinanced existing indebtedness, paid capital expenditures and general corporate purposes Aquarion Senior Notes 4.00 % (360.0) August 2024 August 2024 Paid at maturity Aquarion Water Company of Connecticut Senior Notes 5.57 % 70.0 August 2024 September 2034 Repaid short-term debt, paid capital expenditures and general corporate purposes Long-Term Debt Provisions: The utility plant of CL&P, PSNH, Yankee Gas, NSTAR Gas, EGMA and a portion of Aquarion is subject to the lien of each company's respective first mortgage bond indenture. The Eversource parent, NSTAR Electric and a portion of Aquarion debt is unsecured. Additionally, the long-term debt agreements provide that Eversource and certain of its subsidiaries must comply with certain covenants as are customarily included in such agreements, including equity requirements for NSTAR Electric, NSTAR Gas and Aquarion. Under the equity requirements, NSTAR Electric's and Aquarion's senior notes must maintain a certain consolidated indebtedness to capitalization ratio as of the end of any fiscal quarter and NSTAR Gas' outstanding long-term debt must not exceed equity. Certain secured and unsecured long-term debt securities are callable at redemption price or are subject to make-whole provisions. No long-term debt defaults have occurred as of December 31, 2024. CYAPC's Pre-1983 Spent Nuclear Fuel Obligation: Under the Nuclear Waste Policy Act of 1982, the DOE is responsible for the selection and development of repositories for, and the disposal of, spent nuclear fuel and high-level radioactive waste. CYAPC is obligated to pay the DOE for the costs to dispose of spent nuclear fuel and high-level radioactive waste generated prior to April 7, 1983 (pre-1983 Spent Nuclear Fuel). CYAPC has partially paid this obligation and recorded an accrual for its remaining liability to the DOE. This liability accrues interest costs at the 3-month Treasury bill yield rate. For nuclear fuel used to generate electricity prior to April 7, 1983, payment may be made any time prior to the first delivery of spent fuel to the DOE. As of December 31, 2024 and 2023, as a result of consolidating CYAPC, Eversource has consolidated $5.6 million and $12.5 million, respectively, in pre-1983 spent nuclear fuel obligations to the DOE. The obligation includes accumulated interest costs of $4.3 million and $9.5 million as of December 31, 2024 and 2023, respectively. CYAPC maintains a trust to fund amounts due to the DOE for the disposal of pre-1983 spent nuclear fuel. For further information, see Note 5, "Marketable Securities," to the financial statements. Fees for disposal of nuclear fuel burned on or after April 7, 1983 were billed to member companies and paid to the DOE. Long-Term Debt Maturities: Long-term debt maturities on debt outstanding for the years 2025 through 2029 and thereafter are shown below. These amounts exclude PSNH rate reduction bonds, CYAPC pre-1983 spent nuclear fuel obligation, and unamortized premiums, discounts, and debt issuance costs as of December 31, 2024: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2025 $ 1,400.3 $ 400.0 $ 250.0 $ — 2026 1,390.2 — 300.0 — 2027 2,889.2 500.0 700.0 — 2028 1,978.5 — 150.0 — 2029 2,300.3 350.0 400.0 — Thereafter 16,857.0 3,880.0 3,340.0 1,750.0 Total $ 26,815.5 $ 5,130.0 $ 5,140.0 $ 1,750.0

RATE REDUCTION BONDS AND VARIAB

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES	12 Months Ended
	Dec. 31, 2024
Rate Reduction Bonds and Variable Interest Entity [Abstract]
RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES	RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES Rate Reduction Bonds: In May 2018, PSNH Funding, a wholly-owned subsidiary of PSNH, issued $635.7 million of securitized RRBs in multiple tranches with a weighted average interest rate of 3.66 percent, and final maturity dates ranging from 2026 to 2035. The RRBs are expected to be repaid by February 1, 2033. RRB payments consist of principal and interest and are paid semi-annually, beginning on February 1, 2019. The RRBs were issued pursuant to a finance order issued by the NHPUC in January 2018 to recover remaining costs resulting from the divestiture of PSNH’s generation assets. The proceeds were used by PSNH Funding to purchase PSNH’s stranded cost asset-recovery property, including its vested property right to bill, collect and adjust a non-bypassable stranded cost recovery charge from PSNH’s retail customers. The collections are used to pay principal, interest and other costs in connection with the RRBs. The RRBs are secured by the stranded cost asset-recovery property. Cash collections from the stranded cost recovery charges and funds on deposit in trust accounts are the sole source of funds to satisfy the debt obligation. PSNH is not the owner of the RRBs, and PSNH Funding’s assets and revenues are not available to pay PSNH’s creditors. The RRBs are non-recourse senior secured obligations of PSNH Funding and are not insured or guaranteed by PSNH or Eversource Energy. PSNH Funding was formed solely to issue RRBs to finance PSNH's unrecovered remaining costs associated with the divestiture of its generation assets. PSNH Funding is considered a VIE primarily because the equity capitalization is insufficient to support its operations. PSNH has the power to direct the significant activities of the VIE and is most closely associated with the VIE as compared to other interest holders. Therefore, PSNH is considered the primary beneficiary and consolidates PSNH Funding in its consolidated financial statements. The following tables summarize the impact of PSNH Funding on PSNH's balance sheets and income statements: (Millions of Dollars) As of December 31, PSNH Balance Sheets: 2024 2023 Restricted Cash - Current Portion (included in Special Deposits) $ 31.0 $ 30.0 Restricted Cash - Long-Term Portion (included in Other Long-Term Assets) 3.1 3.2 Securitized Stranded Cost (included in Regulatory Assets) 349.3 392.5 Other Regulatory Liabilities (included in Regulatory Liabilities) 6.9 5.3 Accrued Interest (included in Other Current Liabilities) 5.7 6.3 Rate Reduction Bonds - Current Portion 43.2 43.2 Rate Reduction Bonds - Long-Term Portion 324.1 367.3 (Millions of Dollars) PSNH Income Statements: For the Years Ended December 31, 2024 2023 2022 Amortization of RRB Principal (included in Amortization of Regulatory Assets/(Liabilities), Net) $ 43.2 $ 43.2 $ 43.2 Interest Expense on RRB Principal (included in Interest Expense) 14.3 15.7 17.0 Estimated principal payments on RRBs as of December 31, 2024, is summarized annually through 2029 and thereafter as follows: (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total PSNH $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 151.3 $ 367.3 Variable Interest Entities - Other: The Company's variable interests outside of the consolidated group include contracts that are required by regulation and provide for regulatory recovery of contract costs and benefits through customer rates. Eversource, CL&P and NSTAR Electric hold variable interests in VIEs through agreements with certain entities that own single renewable energy or peaking generation power plants, with other independent power producers and with transmission businesses. Eversource, CL&P and NSTAR Electric do not control the activities that are economically significant to these VIEs or provide financial or other support to these VIEs. Therefore, Eversource, CL&P and NSTAR Electric do not consolidate these VIEs.

EMPLOYEE BENEFITS

EMPLOYEE BENEFITS	12 Months Ended
	Dec. 31, 2024
Postemployment Benefits [Abstract]
EMPLOYEE BENEFITS	EMPLOYEE BENEFITS A. Pension Benefits and Postretirement Benefits Other Than Pension Eversource provides defined benefit retirement plans (Pension Plans) that cover eligible employees and are subject to the provisions of ERISA, as amended by the Pension Protection Act of 2006. Eversource's policy is to annually fund the Pension Plans in an amount at least equal to an amount that will satisfy all federal funding requirements. In addition to the Pension Plans, Eversource maintains non-qualified defined benefit retirement plans (SERP Plans), which provide benefits in excess of Internal Revenue Code limitations to eligible participants consisting of current and retired employees. Eversource also provides defined benefit postretirement plans (PBOP Plans) that provide life insurance and a health reimbursement arrangement created for the purpose of reimbursing retirees and dependents for health insurance premiums and certain medical expenses to eligible employees that meet certain age and service eligibility requirements. The benefits provided under the PBOP Plans are not vested, and the Company has the right to modify any benefit provision subject to applicable laws at that time. Eversource annually funds postretirement costs through tax deductible contributions to external trusts. In August 2024, Eversource communicated to its employees participating in the Eversource 401k Plan enhanced defined contribution feature (referred to as K-Vantage) that effective January 1, 2025, a Cash Balance Pension Plan is established, which replaces employer K-Vantage contributions. Eversource transferred into the Cash Balance Pension Plan employees who are participants in the K-Vantage plan, with the exception of one union group with ongoing negotiations, and will credit employees a set percentage of an employee’s eligible pay based on age and years of service on the employee’s behalf. This benefit is a new, additional obligation of the existing Pension Plan and will be funded through the existing assets of the Eversource Pension Plan. This plan amendment did not require a remeasurement in 2024 and the liability will begin to accrue benefits upon the effective date of January 1, 2025. Funded Status: The Pension, SERP and PBOP Plans are accounted for under the multiple-employer approach, with each operating company's balance sheet reflecting its share of the funded status of the plans. The SERP Plans do not contain any assets. The following tables provide information on the plan benefit obligations, fair values of plan assets, and funded status: Pension and SERP As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (5,238.4) $ (1,048.5) $ (1,107.0) $ (562.3) $ (5,220.1) $ (1,030.0) $ (1,110.4) $ (556.2) Service Cost (44.3) (12.7) (7.7) (4.3) (43.1) (12.3) (7.8) (4.3) Interest Cost (250.0) (50.3) (51.6) (26.8) (254.0) (50.5) (53.9) (27.3) Actuarial Gain/(Loss) 280.2 56.2 74.1 30.7 (110.4) (19.7) (17.6) (11.6) Benefits Paid - Pension 320.9 68.1 67.1 38.0 317.3 66.1 76.7 35.7 Benefits Paid - Lump Sum 24.0 — 7.6 0.1 28.9 — 5.3 1.0 Benefits Paid - SERP 19.4 0.3 0.2 0.4 43.0 0.3 0.2 0.4 Employee Transfers — 4.0 13.8 2.7 — (2.4) 0.5 — Reclassified to Assets Held for Sale 142.5 — — — — — — — Benefit Obligation as of End of Year $ (4,745.7) $ (982.9) $ (1,003.5) $ (521.5) $ (5,238.4) $ (1,048.5) $ (1,107.0) $ (562.3) Change in Pension Plan Assets: Fair Value of Pension Plan Assets as of $ 5,775.0 $ 1,170.0 $ 1,411.6 $ 614.0 $ 5,806.4 $ 1,172.0 $ 1,418.8 $ 618.0 Employer Contributions 5.0 — — — 5.0 — — — Actual Return on Pension Plan Assets 227.0 46.5 55.1 24.3 309.8 61.7 75.3 32.7 Benefits Paid - Pension (320.9) (68.1) (67.1) (38.0) (317.3) (66.1) (76.7) (35.7) Benefits Paid - Lump Sum (24.0) — (7.6) (0.1) (28.9) — (5.3) (1.0) Employee Transfers — (4.0) (13.8) (2.7) — 2.4 (0.5) — Reclassified to Assets Held for Sale (148.1) — — — — — — — Fair Value of Pension Plan Assets as of End of Year $ 5,514.0 $ 1,144.4 $ 1,378.2 $ 597.5 $ 5,775.0 $ 1,170.0 $ 1,411.6 $ 614.0 Funded Status as of December 31st $ 768.3 $ 161.5 $ 374.7 $ 76.0 $ 536.6 $ 121.5 $ 304.6 $ 51.7 Actuarial Gain/(Loss): For the year ended December 31, 2024, the actuarial gain was primarily attributable to an increase in the discount rate, which resulted in a decrease to Eversource's Pension and SERP Plans’ projected benefit obligation of $332.9 million, partially offset by an actuarial loss of $42.1 million related to updated census data. For the year ended December 31, 2023, the actuarial loss was primarily attributable to a decrease in the discount rate, which resulted in an increase to Eversource's Pension and SERP Plans’ projected benefit obligation of $98.9 million. As of December 31, 2024 and 2023, the accumulated benefit obligation for the Pension and SERP Plans is as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2024 $ 4,617.1 $ 953.9 $ 969.5 $ 507.4 2023 4,936.8 977.8 1,051.9 522.1 PBOP As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (676.0) $ (120.6) $ (188.3) $ (72.0) $ (693.7) $ (127.9) $ (189.5) $ (74.6) Service Cost (7.0) (1.2) (1.2) (0.6) (7.6) (1.3) (1.2) (0.7) Interest Cost (31.9) (5.6) (8.8) (3.4) (33.8) (6.2) (9.2) (3.7) Actuarial Gain/(Loss) 41.3 8.9 10.7 3.9 5.0 4.4 (5.8) 0.8 Benefits Paid 51.7 9.4 15.9 6.2 52.7 10.0 16.7 6.1 Employee Transfers — — 0.3 — — — 0.5 (0.1) Plan Amendment — — — — 1.4 0.4 0.2 0.2 Reclassified to Assets Held for Sale 34.5 — — — — — — — Benefit Obligation as of End of Year $ (587.4) $ (109.1) $ (171.4) $ (65.9) $ (676.0) $ (120.6) $ (188.3) $ (72.0) Change in Plan Assets: Fair Value of Plan Assets as of Beginning of Year $ 1,024.4 $ 123.0 $ 490.4 $ 74.7 $ 970.1 $ 120.6 $ 456.1 $ 72.3 Actual Return on Plan Assets 92.3 11.2 45.8 7.6 104.7 12.6 52.3 8.3 Employer Contributions 0.9 — — — 1.9 — — — Benefits Paid (51.8) (9.4) (15.9) (6.1) (52.3) (10.0) (16.7) (6.1) Employee Transfers — (0.4) (1.1) 0.2 — (0.2) (1.3) 0.2 Reclassified to Assets Held for Sale (29.5) — — — — — — — Fair Value of Plan Assets as of End of Year $ 1,036.3 $ 124.4 $ 519.2 $ 76.4 $ 1,024.4 $ 123.0 $ 490.4 $ 74.7 Funded Status as of December 31st $ 448.9 $ 15.3 $ 347.8 $ 10.5 $ 348.4 $ 2.4 $ 302.1 $ 2.7 Actuarial Gain/(Loss): For the year ended December 31, 2024, the actuarial gain was primarily attributable to an increase in the discount rate, which resulted in a decrease to the Eversource PBOP projected benefit obligation of $39.8 million. For the year ended December 31, 2023, the actuarial gain was primarily attributable to changes to termination, retirement, and dependency rates that were updated as a result of an experience study performed in 2023, updated census data, changes to plan provisions, and other assumption changes, which resulted in a decrease to the Eversource PBOP projected benefit obligation of $17 million. The actuarial gain was partially offset by a decrease in the discount rate, which resulted in an increase to the Eversource PBOP projected benefit obligation of $12 million. A reconciliation of the prepaid assets and liabilities within the Eversource Pension, SERP and PBOP Plans’ funded status to the balance sheets is as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Prepaid Pension (1) $ 887.7 $ 167.2 $ 376.9 $ 80.5 $ 672.2 $ 127.4 $ 306.5 $ 56.3 Prepaid PBOP 448.9 15.3 347.8 10.5 356.0 2.4 302.1 2.7 Prepaid Pension and PBOP $ 1,336.6 $ 182.5 $ 724.7 $ 91.0 $ 1,028.2 $ 129.8 $ 608.6 $ 59.0 Accrued SERP (1) $ 119.4 $ 5.7 $ 2.2 $ 4.5 $ 135.6 $ 5.9 $ 1.9 $ 4.6 Accrued PBOP (1) — — — — 7.6 — — — Less: Accrued SERP - current portion (24.0) (0.4) (0.2) (0.4) (19.4) (0.3) (0.2) (0.4) Accrued SERP and PBOP $ 95.4 $ 5.3 $ 2.0 $ 4.1 $ 123.8 $ 5.6 $ 1.7 $ 4.2 (1) As of December 31, 2024, the Aquarion water distribution business’s prepaid pension has been reclassified to Assets Held for Sale and the accrued SERP and PBOP liabilities have been reclassified to Liabilities Held for Sale on the Eversource balance sheet. As of December 31, 2023, these balances were recorded within Prepaid Pension and PBOP and Accrued SERP and PBOP on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” The following actuarial assumptions were used in calculating the Pension, SERP and PBOP Plans' year end funded status: Pension and SERP PBOP As of December 31, As of December 31, 2024 2023 2024 2023 Discount Rate 5.6% — 5.7% 4.9% — 5.0% 5.7% 5.0% — 5.2% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% N/A For the Eversource Service PBOP Plan, the health care cost trend rate is not applicable. For the Aquarion PBOP Plan, the health care cost trend rate for pre-65 retirees is 7.5 percent, with an ultimate rate of 5 percent in 2035, and for post-65 retirees, the health care trend rate and ultimate rate is 3.5 percent. Expense: Eversource charges net periodic benefit plan expense/(income) for the Pension, SERP and PBOP Plans to its subsidiaries based on the actual participant demographic data for each subsidiary's participants. The actual investment return in the trust is allocated to each of the subsidiaries annually in proportion to the investment return expected to be earned during the year. The Company utilizes the spot rate methodology to estimate the discount rate for the service and interest cost components of benefit plan expense, which provides a relatively precise measurement by matching projected cash flows to the corresponding spot rates on the yield curve. The components of net periodic benefit plan expense/(income) for the Pension, SERP and PBOP Plans, prior to amounts capitalized as Property, Plant and Equipment or deferred as regulatory assets/(liabilities) for future recovery or refund, are shown below. The service cost component of net periodic benefit plan expense/(income), less the capitalized portion, is included in Operations and Maintenance expense on the statements of income. The remaining components of net periodic benefit plan expense/(income), less the deferred portion, are included in Other Income, Net on the statements of income. Pension, SERP and PBOP plan expense/(income) reflected in the statements of cash flows for CL&P, NSTAR Electric and PSNH does not include intercompany allocations of net periodic benefit plan expense/(income), as these amounts are cash settled on a short-term basis. Pension and SERP PBOP For the Year Ended December 31, 2024 For the Year Ended December 31, 2024 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 44.3 $ 12.7 $ 7.7 $ 4.3 $ 7.0 $ 1.2 $ 1.2 $ 0.6 Interest Cost 250.0 50.3 51.6 26.8 31.9 5.6 8.8 3.4 Expected Return on Plan Assets (462.6) (93.5) (112.4) (48.9) (81.2) (9.5) (39.5) (5.6) Actuarial Loss/(Gain) 85.9 12.1 25.6 5.0 (0.4) — — — Prior Service Cost/(Credit) 1.3 — 0.3 — (21.6) 1.1 (17.0) 0.4 Settlement Loss 4.3 — — — — — — — Total Net Periodic Benefit Plan Income $ (76.8) $ (18.4) $ (27.2) $ (12.8) $ (64.3) $ (1.6) $ (46.5) $ (1.2) Intercompany Income Allocations N/A $ (1.6) $ (1.3) $ (0.4) N/A $ (2.2) $ (2.6) $ (0.9) Pension and SERP PBOP For the Year Ended December 31, 2023 For the Year Ended December 31, 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 43.1 $ 12.3 $ 7.8 $ 4.3 $ 7.6 $ 1.3 $ 1.2 $ 0.7 Interest Cost 254.0 50.5 53.9 27.3 33.8 6.2 9.2 3.7 Expected Return on Plan Assets (465.0) (94.2) (113.8) (49.5) (77.1) (9.4) (36.9) (5.5) Actuarial Loss 45.8 2.5 17.1 1.5 — — — — Prior Service Cost/(Credit) 1.3 — 0.3 — (21.6) 1.1 (17.0) 0.4 Settlement Loss 12.4 — — — — — — — Total Net Periodic Benefit Plan Income $ (108.4) $ (28.9) $ (34.7) $ (16.4) $ (57.3) $ (0.8) $ (43.5) $ (0.7) Intercompany Income Allocations N/A $ (4.0) $ (3.0) $ (0.8) N/A $ (1.9) $ (2.1) $ (0.7) Pension and SERP PBOP For the Year Ended December 31, 2022 For the Year Ended December 31, 2022 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 70.1 $ 18.7 $ 13.8 $ 6.9 $ 11.6 $ 2.0 $ 2.0 $ 1.1 Interest Cost 154.5 31.3 32.8 16.9 20.2 3.7 5.3 2.2 Expected Return on Plan Assets (523.6) (106.3) (128.4) (56.1) (89.9) (11.4) (42.4) (6.7) Actuarial Loss 116.0 16.2 32.8 7.9 — — — — Prior Service Cost/(Credit) 1.4 — 0.3 — (21.7) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Income $ (181.6) $ (40.1) $ (48.7) $ (24.4) $ (79.8) $ (4.6) $ (52.1) $ (3.0) Intercompany Income Allocations N/A $ (16.0) $ (12.4) $ (3.6) N/A $ (3.7) $ (3.6) $ (1.2) The following actuarial assumptions were used to calculate Pension, SERP and PBOP expense amounts: Pension and SERP PBOP For the Years Ended December 31, For the Years Ended December 31, 2024 2023 2022 2024 2023 2022 Discount Rate 4.7% — 5.1% 4.9% — 5.3% 2.2% — 3.2% 4.9% — 5.2% 5.1% — 5.4% 2.3% — 3.3% Expected Long-Term Rate of Return 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% 3.5% — 4.0% N/A N/A N/A For the Aquarion Pension Plan, the expected long-term rate of return was 8.25 percent and 7.94 percent for the years ended December 31, 2024 and 2023, respectively. For the Aquarion PBOP Plan, the expected long-term rate of return was 7 percent for the years ended December 31, 2024 and 2023 and the health care cost trend rate was a range of 3.5 percent to 6.75 percent for the year ended December 31, 2024 and 3.5 percent to 7 percent for the year ended December 31, 2023. Regulatory Assets and Accumulated Other Comprehensive Income/(Loss) Amounts: The Pension, SERP and PBOP Plans cover eligible employees, including, among others, employees of the regulated companies. The regulated companies record actuarial losses and gains and prior service costs and credits arising at the December 31st remeasurement date of the funded status of the benefit plans as a regulatory asset or regulatory liability in lieu of a charge to Accumulated Other Comprehensive Income/(Loss), reflecting ultimate recovery from customers through rates. Regulatory accounting is also applied to the portions of the Eversource Service retiree benefit costs that support the regulated companies, as these costs are also recovered from customers. Adjustments to the Pension, SERP and PBOP Plans' funded status for the unregulated companies are recorded on an after-tax basis to Accumulated Other Comprehensive Income/(Loss). For further information, see Note 2, "Regulatory Accounting," and Note 16, "Accumulated Other Comprehensive Income/(Loss)," to the financial statements. The difference between the actual return and calculated expected return on plan assets for the Pension and PBOP Plans, as well as changes in actuarial assumptions impacting the projected benefit obligation, are recorded as unamortized actuarial gains or losses arising during the year in Regulatory Assets or Accumulated Other Comprehensive Income/(Loss). Unamortized actuarial gains or losses are amortized as a component of pension and PBOP expense over the estimated average future employee service period using the corridor approach. The following is a summary of the changes in plan assets and benefit obligations recognized in Regulatory Assets and Other Comprehensive Income (OCI) as well as amounts in Regulatory Assets and OCI that were reclassified as net periodic benefit expense during the years presented: Pension and SERP PBOP Regulatory Assets OCI Regulatory Assets OCI For the Years Ended December 31, For the Years Ended December 31, (Millions of Dollars) 2024 2023 2024 2023 2024 2023 2024 2023 Actuarial (Gain)/Loss Arising During the Year $ (49.2) $ 251.1 $ 2.3 $ 14.0 $ (50.9) $ (32.0) $ (0.6) $ (0.3) Actuarial (Loss)/Gain Reclassified as Net Periodic Benefit (Expense)/Income (79.1) (38.8) (6.8) (7.0) 0.4 — — — Actuarial (Loss)/Gain Reclassified as Held for Sale (16.6) — — — 7.1 — — — Settlement Loss — — (4.3) (12.4) — — — — Prior Service Cost/(Credit) Arising During the Year 1.3 — — — — (0.9) — — Prior Service (Cost)/Credit Reclassified as Net Periodic (1.2) (1.2) (0.1) (0.1) 21.8 21.8 (0.2) (0.2) Prior Service Cost Reclassified as Held for Sale (1.2) — — — (0.6) — — — The following is a summary of the remaining Regulatory Assets and Accumulated Other Comprehensive Income amounts that have not been recognized as components of net periodic benefit expense as of December 31, 2024 and 2023: Regulatory Assets as of December 31, AOCI as of December 31, (Millions of Dollars) 2024 2023 2024 2023 Pension and SERP Actuarial Loss $ 956.1 $ 1,101.0 $ 47.7 $ 56.5 Prior Service Cost 1.8 2.9 0.2 0.3 PBOP Actuarial Loss $ 6.4 $ 49.8 $ 1.8 $ 2.4 Prior Service (Credit)/Cost (66.2) (87.4) 0.5 0.7 Estimated Future Benefit Payments: The following benefit payments, which reflect expected future service, are expected to be paid by the Pension, SERP and PBOP Plans: (Millions of Dollars) 2025 2026 2027 2028 2029 2030 - 2034 Pension and SERP $ 367.3 $ 363.3 $ 369.5 $ 372.9 $ 375.4 $ 1,879.4 PBOP 51.3 50.6 49.8 48.9 48.0 223.3 Eversource Contributions: Based on the current status of the Pension Plans and federal pension funding requirements, for our Eversource Service Pension Plan there is no minimum funding requirement in 2025 and we do not expect to make pension contributions in 2025. We do not expect to make any contributions to the Eversource Service PBOP Plan in 2025. Eversource contributed $5.0 million and $0.9 million to the Aquarion Pension and PBOP Plans, respectively, in 2024. Fair Value of Pension and PBOP Plan Assets: Pension and PBOP funds are held in external trusts. Trust assets, including accumulated earnings, must be used exclusively for Pension and PBOP payments. Eversource's investment strategy for its Pension and PBOP Plans is to maximize the long-term rates of return on these plans' assets within an acceptable level of risk. The investment guidelines for each asset category includes a diversification of asset types, fund strategies and fund managers and it establishes target asset allocations that are routinely reviewed and periodically rebalanced. PBOP assets are comprised of assets held in the PBOP Plan trust, as well as specific assets within the Pension Plan trust (401(h) assets). The investment policy and strategy of the 401(h) assets is consistent with that of the defined benefit pension plan. Eversource's expected long-term rates of return on Pension and PBOP Plan assets are based on target asset allocation assumptions and related expected long- term rates of return. In developing its expected long-term rate of return assumptions for the Pension and PBOP Plans, Eversource evaluated input from consultants, as well as long-term inflation assumptions and historical returns. Management has assumed long-term rates of return of 8.25 percent for the Eversource Service Pension Plan assets, the Eversource Service PBOP Plan assets and the Aquarion Pension Plan assets, and a 7 percent long-term rate of return for the Aquarion PBOP Plan, to estimate its 2025 Pension and PBOP costs. These long-term rates of return are based on the assumed rates of return for the target asset allocations as follows: As of December 31, 2024 2023 Target Asset Allocation Assumed Rate of Return Target Asset Allocation Assumed Rate of Return Eversource Pension Plan Eversource PBOP Plan Eversource Pension Plan and PBOP Plan Eversource Pension Plan Eversource PBOP Plan Eversource Pension Plan and PBOP Plan Equity Securities: United States — % 20.0 % 8.5 % — % 20.0 % 8.5 % Global 20.0 % — % 8.8 % 20.0 % — % 8.75 % Non-United States — % 11.0 % 8.5 % — % 11.0 % 8.5 % Emerging Markets — % 6.0 % 10.0 % — % 6.0 % 10.0 % Debt Securities: Fixed Income 16.0 % 17.0 % 5.5 % 16.0 % 17.0 % 5.5 % Public High Yield Fixed Income 5.0 % — % 7.5 % 5.0 % — % 7.5 % United States Treasuries 11.0 % — % 4.5 % 11.0 % — % 4.5 % Private Debt 10.0 % 13.0 % 10.0 % 10.0 % 13.0 % 10.0 % Private Equity 23.0 % 18.0 % 12.0 % 23.0 % 18.0 % 12.0 % Real Assets 15.0 % 15.0 % 7.5 % 15.0 % 15.0 % 7.5 % The following tables present, by asset category, the Pension and PBOP Plan assets recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Pension Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2024 (1) 2023 (2) Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 323.6 $ — $ 826.0 $ 1,149.6 $ 374.0 $ — $ 853.0 $ 1,227.0 Fixed Income 314.3 344.7 1,329.6 1,988.6 354.6 340.9 1,516.4 2,211.9 Private Equity — — 1,710.9 1,710.9 — — 1,685.3 1,685.3 Real Assets 243.8 — 652.2 896.0 173.6 — 722.1 895.7 Total $ 881.7 $ 344.7 $ 4,518.7 $ 5,745.1 $ 902.2 $ 340.9 $ 4,776.8 $ 6,019.9 Less: 401(h) PBOP Assets (3) (231.1) (244.9) Total Pension Assets $ 5,514.0 $ 5,775.0 PBOP Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2024 (1) 2023 Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 184.8 $ — $ 166.3 $ 351.1 $ 139.1 $ — $ 212.1 $ 351.2 Fixed Income 61.8 44.6 127.5 233.9 33.4 43.0 159.8 236.2 Private Equity — — 99.0 99.0 — — 87.7 87.7 Real Assets 83.7 — 37.5 121.2 70.5 — 33.9 104.4 Total $ 330.3 $ 44.6 $ 430.3 $ 805.2 $ 243.0 $ 43.0 $ 493.5 $ 779.5 Add: 401(h) PBOP Assets (3) 231.1 244.9 Total PBOP Assets $ 1,036.3 $ 1,024.4 (1) As of December 31, 2024, the funded status of the Aquarion water distribution business’s Pension and PBOP benefit plans have been reclassified in held for sale presentation on the Eversource balance sheet. Therefore, these Pension and PBOP asset balances have been excluded from the table above as of December 31, 2024. (2) Fixed Income investments classified as Level 1 as of December 31, 2023 include pending purchases and pending redemption settlements of $31 million. (3) The assets of the Pension Plan include a 401(h) account that has been allocated to provide health and welfare postretirement benefits under the PBOP Plan. The Company values assets based on observable inputs when available. Equity securities, fixed income exchange traded funds and real asset futures contracts classified as Level 1 in the fair value hierarchy are priced based on the closing price on the primary exchange as of the balance sheet date. Fixed income securities, such as government issued securities and corporate bonds, are included in Level 2 and are valued using pricing models, quoted prices of securities with similar characteristics or discounted cash flows. The pricing models utilize observable inputs such as recent trades for the same or similar instruments, yield curves, discount margins and bond structures. Swaps are valued using pricing models that incorporate interest rates and equity and fixed income index closing prices to determine a net present value of the cash flows. Certain investments, such as commingled funds, private equity investments, fixed income funds, real asset funds and hedge funds are valued using the net asset value (NAV) as a practical expedient. Assets valued at NAV are uncategorized in the fair value hierarchy. These investments are structured as investment companies offering shares or units to multiple investors for the purpose of providing a return. Commingled funds are recorded at NAV provided by the asset manager, which is based on the market prices of the underlying equity securities. Private Equity investments, Fixed Income partnership funds and Real Assets are valued using the NAV provided by the partnerships, which are based on discounted cash flows of the underlying investments, real estate appraisals or public market comparables of the underlying investments, or the NAV of underlying assets held in hedge funds. Equity Securities investments in United States, Global, Non-United States and Emerging Markets that are uncategorized include investments in commingled funds and hedge funds that are overlaid with equity index swaps and futures contracts. Fixed Income investments that are uncategorized include investments in commingled funds, fixed income funds that invest in a variety of opportunistic credit and private debt strategies, and hedge funds that are overlaid with fixed income futures. Eversource maintains defined contribution plans on behalf of eligible participants. The Eversource 401k Plan provides for employee and employer contributions up to statutory limits. For the years ended December 31, 2024, 2023 and 2022, for eligible employees, the Eversource 401k Plan provided employer matching contributions of either 100 percent up to a maximum of three percent of eligible compensation or 50 percent up to a maximum of eight percent of eligible compensation. The Eversource 401k Plan also contained a K-Vantage feature for the benefit of eligible participants, which provided an additional annual employer contribution based on age and years of service. K-Vantage participants were not eligible to actively participate in the Eversource Pension Plan. The total Eversource 401k Plan employer matching contributions, including the K-Vantage contributions, were as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2024 $ 76.2 $ 10.6 $ 15.4 $ 6.0 2023 67.3 9.0 13.7 5.4 2022 59.9 7.7 12.8 4.8 Effective January 1, 2025 for eligible Plan participants, the Eversource 401k Plan began providing employer matching contributions of 100 percent up to a maximum of six percent of eligible compensation. Also effective January 1, 2025, Eversource replaced employer K-Vantage contributions with the Cash Balance Pension Plan. See Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for further information. Share-based compensation awards are recorded using a fair-value based method at the date of grant. Eversource, CL&P, NSTAR Electric and PSNH record compensation expense related to these awards, as applicable, for shares issued to their respective employees and officers, as well as for the allocation of costs associated with shares issued to Eversource's service company employees and officers that support CL&P, NSTAR Electric and PSNH. Eversource Incentive Plans: Eversource maintains long-term equity-based incentive plans in which Eversource, CL&P, NSTAR Electric and PSNH employees, officers and board members are eligible to participate. The incentive plans authorize Eversource to grant up to 7,400,000 new shares for various types of awards, including RSUs and performance shares, to eligible employees, officers, and board members. As of December 31, 2024 and 2023, Eversource had 3,790,353 and 4,587,376 common shares, respectively, available for issuance under these plans. Eversource accounts for its various share-based plans as follows: • RSUs - Eversource records compensation expense, net of estimated forfeitures, on a straight-line basis over the requisite service period based upon the fair value of Eversource's common shares at the date of grant. The par value of RSUs is reclassified to Common Stock from Capital Surplus, Paid In as RSUs become issued as common shares. • Performance Shares - Eversource records compensation expense, net of estimated forfeitures, over the requisite service period. Performance shares vest based upon the extent to which Company goals are achieved. Vesting of outstanding performance shares is based upon the Company's EPS growth over the requisite service period and level of payout is determined based on the total shareholder return as compared to the Edison Electric Institute (EEI) Index during the requisite service period. The fair value of performance shares is determined at the date of grant using a lattice model. Compensation expense is subject to volatility until payout is established. RSUs: Eversource granted RSUs under the annual long-term incentive programs that are subject to three-year graded vesting schedules for employees, and one-year graded vesting schedules, or immediate vesting, for board members. RSUs are paid in shares, reduced by amounts sufficient to satisfy withholdings for income taxes, subsequent to vesting. A summary of RSU transactions is as follows: RSUs Weighted Average Outstanding as of December 31, 2023 672,242 $ 65.89 Granted 372,400 $ 57.93 Shares Issued (289,372) $ 65.25 Forfeited (39,828) $ 66.91 Outstanding as of December 31, 2024 715,442 $ 61.95 The weighted average grant-date fair value of RSUs granted for the years ended December 31, 2024, 2023 and 2022 was $57.93, $76.42 and $85.96, respectively. As of December 31, 2024 and 2023, the number and weighted average grant-date fair value of unvested RSUs was 455,620 and $65.29 per share, and 326,581 and $80.76 per share, respectively. During 2024, there were 280,938 RSUs at a weighted average grant-date fair value of $65.20 per share that vested during the year and were either paid or deferred. As of December 31, 2024, 259,822 RSUs were fully vested and deferred and an additional 432,839 are expected to vest. Performance Shares: Eversource granted performance shares under the annual long-term incentive programs that vest based upon the extent to which Company goals are achieved at the end of three-year performance measurement periods. Performance shares are paid in shares, after the performance measurement period. A summary of performance share transactions is as follows: Performance Shares Weighted Average Outstanding as of December 31, 2023 664,424 $ 85.33 Granted 431,789 $ 55.87 Shares Issued (126,054) $ 85.54 Forfeited (105,967) $ 77.98 Outstanding as of December 31, 2024 864,192 $ 71.48 The weighted average grant-date fair value of performance shares granted for the years ended December 31, 2024, 2023 and 2022 was $55.87, $83.39 and $83.34, respectively. As of December 31, 2024 and 2023, the number and weighted average grant-date fair value of unvested performance shares was 737,738 and $69.12 per share, and 485,480 and $85.20 per share, respectively. During 2024, there were 72,723 performance shares at a weighted average grant-date fair value of $84.87 per share that vested during the year and were either paid or deferred. As of December 31, 2024, 126,454 performance shares were fully vested and deferred. Compensation Expense: The total compensation expense and associated future income tax benefits recognized by Eversource, CL&P, NSTAR Electric and PSNH for share-based compensation awards were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Compensation Expense $ 30.0 $ 27.8 $ 33.4 Future Income Tax Benefit 7.8 7.3 8.7 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Compensation Expense $ 9.3 $ 9.6 $ 3.6 $ 8.7 $ 8.7 $ 3.0 $ 10.0 $ 10.7 $ 3.6 Future Income Tax Benefit 2.4 2.5 0.9 2.3 2.3 0.8 2.6 2.8 0.9 As of December 31, 2024, there was $31.2 million of total unrecognized compensation expense related to nonvested share-based awards for Eversource, including $5.5 million for CL&P, $8.8 million for NSTAR Electric, and $2.0 million for PSNH. This cost is expected to be recognized ratably over a weighted-average period of 1.76 years for Eversource, CL&P, and PSNH and 1.77 years for NSTAR Electric. An income tax rate of 26 percent was used to estimate the tax effect on total share-based payments determined under the fair-value based method for all awards. The Company issues treasury shares to settle fully vested RSUs and performance shares under the Company's incentive plans. For the years ended December 31, 2024 and 2023, a tax deficiency associated with the distribution of stock compensation awards increased income tax expense by $2.3 million and $0.5 million, respectively, which decreased cash flows from operating activities on the statements of cash flows. For the year ended December 31, 2022, excess tax benefits associated with the distribution of stock compensation awards reduced income tax expense by $2.1 million, which increased cash flows from operating activities on the statements of cash flows. Eversource provides retirement and other benefits for certain current and past company officers. These benefits are accounted for on an accrual basis and expensed over a period equal to the service lives of the employees. The actuarially-determined liability for these benefits is included in Other Current and Long-Term Liabilities on the balance sheets. The related expense, which includes the allocation of expense associated with Eversource's service company officers that support CL&P, NSTAR E

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2024
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The components of income tax expense are as follows: Eversource (Millions of Dollars) For the Years Ended December 31, 2024 2023 2022 Current Income Taxes: Federal $ (23.4) $ 75.8 $ 95.8 State 14.3 0.6 13.6 Total Current (9.1) 76.4 109.4 Deferred Income Taxes, Net: Federal 266.3 (0.9) 198.8 State 169.6 86.3 148.0 Total Deferred 435.9 85.4 346.8 Investment Tax Credits, Net (2.1) (2.1) (2.6) Income Tax Expense $ 424.7 $ 159.7 $ 453.6 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Current Income Taxes: Federal $ 25.9 $ 65.9 $ (1.7) $ (10.8) $ 50.7 $ (40.0) $ 106.2 $ 55.0 $ 29.6 State (6.8) 15.2 (5.2) (2.3) 7.8 (20.0) 20.1 8.7 5.9 Total Current 19.1 81.1 (6.9) (13.1) 58.5 (60.0) 126.3 63.7 35.5 Deferred Income Taxes, Net: Federal 107.9 63.9 50.8 130.3 50.1 81.2 17.2 35.6 5.9 State 67.5 47.3 26.3 53.7 46.1 37.8 28.2 42.4 9.9 Total Deferred 175.4 111.2 77.1 184.0 96.2 119.0 45.4 78.0 15.8 Investment Tax Credits, Net — (1.7) — — (1.7) — (0.5) (1.7) — Income Tax Expense $ 194.5 $ 190.6 $ 70.2 $ 170.9 $ 153.0 $ 59.0 $ 171.2 $ 140.0 $ 51.3 A reconciliation between income tax expense and the expected tax expense at the statutory rate is as follows: Eversource (Millions of Dollars, except percentages) For the Years Ended December 31, 2024 2023 2022 Income/(Loss) Before Income Tax Expense $ 1,243.8 $ (275.0) $ 1,866.0 Statutory Federal Income Tax Expense at 21% 261.2 (57.7) 391.9 Tax Effect of Differences: Depreciation (22.6) (25.8) (17.1) Investment Tax Credit Amortization (2.1) (2.1) (2.6) Other Federal Tax Credits (67.0) (42.5) — State Income Taxes, Net of Federal Impact 43.2 (11.4) 75.9 Dividends on ESOP (5.5) (5.3) (5.1) Tax Asset Valuation Allowance/Reserve Adjustments 278.6 295.8 51.6 Tax Deficiency/(Excess Stock Benefit) 2.3 0.5 (2.1) EDIT Amortization (37.0) (51.5) (49.1) Other, Net (26.4) 59.7 10.2 Income Tax Expense $ 424.7 $ 159.7 $ 453.6 Effective Tax Rate 34.1 % (58.1) % 24.3 % For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars, except percentages) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Income Before Income Tax Expense $ 707.1 $ 826.9 $ 285.1 $ 689.6 $ 697.5 $ 254.7 $ 704.1 $ 632.4 $ 222.9 Statutory Federal Income Tax Expense at 21% 148.5 173.7 59.9 144.9 146.5 53.5 147.9 132.8 46.8 Tax Effect of Differences: Depreciation 0.4 (10.9) (1.0) (5.6) (8.8) (1.0) (3.7) (4.2) 0.9 Investment Tax Credit Amortization — (1.7) — — (1.7) — (0.5) (1.7) — State Income Taxes, Net of Federal Impact (2.8) 49.4 16.7 (10.7) 42.5 14.1 (6.6) 40.3 12.5 Tax Asset Valuation 50.8 — — 51.3 — — 44.7 — — Tax Deficiency/(Excess Stock Benefit) 0.8 0.8 0.3 0.2 0.2 0.1 (0.7) (0.8) (0.3) EDIT Amortization (9.2) (20.0) (6.5) (10.5) (28.4) (6.8) (9.2) (29.2) (7.7) Other, Net 6.0 (0.7) 0.8 1.3 2.7 (0.9) (0.7) 2.8 (0.9) Income Tax Expense $ 194.5 $ 190.6 $ 70.2 $ 170.9 $ 153.0 $ 59.0 $ 171.2 $ 140.0 $ 51.3 Effective Tax Rate 27.5 % 23.0 % 24.6 % 24.8 % 21.9 % 23.2 % 24.3 % 22.1 % 23.0 % Eversource, CL&P, NSTAR Electric and PSNH file a consolidated federal income tax return and unitary, combined and separate state income tax returns. These entities are also parties to a tax allocation agreement under which taxable subsidiaries do not pay any more taxes than they would have otherwise paid had they filed a separate company tax return, and subsidiaries generating tax losses, if any, are paid for their losses when utilized. Deferred tax assets and liabilities are recognized for the future tax effects of temporary differences between the carrying amounts and the tax basis of assets and liabilities. The tax effect of temporary differences is accounted for in accordance with the rate-making treatment of the applicable regulatory commissions and relevant accounting authoritative literature. The tax effects of temporary differences that give rise to the net accumulated deferred income tax obligations are as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Deferred Tax Assets: Employee Benefits $ 266.9 $ 33.7 $ 83.5 $ 14.5 $ 244.5 $ 29.9 $ 66.8 $ 13.0 Derivative Liabilities 19.6 19.6 — — 33.0 33.0 — — Regulatory Deferrals - Liabilities 508.7 128.0 316.7 19.6 452.0 94.4 291.5 23.8 Allowance for Uncollectible Accounts 145.3 75.4 26.5 3.8 143.8 79.6 21.5 3.9 Tax Effect - Tax Regulatory Liabilities 720.8 317.6 214.3 93.2 739.0 320.7 227.1 95.5 Net Operating Loss Carryforwards 198.2 — — 1.5 13.8 — — — Purchase Accounting Adjustment 52.1 — — — 56.7 — — — Equity Method Wind Investments 1,098.6 — — — 584.9 — — — Other 267.1 134.7 31.5 24.1 200.1 125.3 25.0 23.4 Total Deferred Tax Assets 3,277.3 709.0 672.5 156.7 2,467.8 682.9 631.9 159.6 Less: Valuation Allowance (1) 558.2 104.1 — — 328.1 80.6 — — Net Deferred Tax Assets $ 2,719.1 $ 604.9 $ 672.5 $ 156.7 $ 2,139.7 $ 602.3 $ 631.9 $ 159.6 Deferred Tax Liabilities: Accelerated Depreciation and Other $ 5,493.3 $ 1,820.3 $ 1,845.2 $ 618.4 $ 5,103.3 $ 1,703.4 $ 1,728.6 $ 566.5 Property Tax Accruals 107.4 49.8 44.5 6.5 95.0 42.0 39.8 6.3 Regulatory Amounts: Regulatory Deferrals - Assets 1,709.1 522.9 519.9 277.8 1,512.3 470.0 474.5 250.3 Tax Effect - Tax Regulatory Assets 294.5 194.7 10.0 9.4 284.0 191.9 10.5 8.3 Goodwill-related Regulatory Asset - 1999 Merger 67.5 — 58.0 — 72.2 — 61.9 — Employee Benefits 353.0 51.0 175.4 23.5 282.0 38.8 146.7 16.8 Derivative Assets 3.8 3.8 — — 6.4 6.4 — — Other 101.7 15.2 24.9 2.7 88.2 9.9 19.5 2.9 Total Deferred Tax Liabilities $ 8,130.3 $ 2,657.7 $ 2,677.9 $ 938.3 $ 7,443.4 $ 2,462.4 $ 2,481.5 $ 851.1 (1) As of December 31, 2024 and 2023, the Eversource Valuation Allowance of $558.2 million and $328.1 million, includes $427.0 million and $224.0 million, respectively, related to Eversource’s share of offshore wind investments. Carryforwards: The following table provides the amounts and expiration dates of state tax credit and loss carryforwards and federal tax credit and net operating loss carryforwards: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Expiration Range Eversource CL&P NSTAR PSNH Expiration Range Federal Net Operating Loss $ 877.7 $ — $ — $ 7.1 — $ — $ — $ — $ — — Federal Tax Credit 404.1 — — — 2044 — — — — — Federal Capital Loss 2,700.0 — — — 2024 - 2029 — — — — — State Net Operating Loss 214.1 — — — 2024 - 2044 243.4 — — — 2023 - 2041 State Tax Credit 238.3 157.7 — — 2024 - 2029 228.5 157.5 — — 2023 - 2028 State Capital Loss 2,700.0 — — — 2024 - 2029 — — — — — State Charitable Contribution 15.2 — — — 2024 - 2028 7.9 — — — 2023 - 2027 In 2024 and 2023, the Company increased its valuation allowance reserve for state credits by $27.3 million ($23.5 million for CL&P), net of tax, and $21.3 million ($17.3 million for CL&P), net of tax, respectively, to reflect an update for expiring tax credits. For 2024, state credit and federal and state loss carryforwards have been partially reserved by a valuation allowance of $558.2 million (net of tax) and for 2023, state credit and state loss carryforwards were partially reserved by a valuation allowance of $104.1 million (net of tax). Unrecognized Tax Benefits: A reconciliation of the activity in unrecognized tax benefits, all of which would impact the effective tax rate if recognized, is as follows: (Millions of Dollars) Eversource CL&P Balance as of January 1, 2022 $ 65.8 $ 26.2 Gross Increases - Current Year 11.5 3.5 Gross Decreases - Prior Year (2.4) (0.9) Lapse of Statute of Limitations (7.8) (3.3) Balance as of December 31, 2022 67.1 25.5 Gross Increases - Current Year 23.4 4.0 Gross Increases - Prior Year 0.1 0.1 Gross Decreases - Prior Year (0.1) — Lapse of Statute of Limitations (9.2) (3.8) Balance as of December 31, 2023 81.3 25.8 Gross Increases - Current Year 14.2 2.9 Gross Increases - Prior Year 11.0 — Gross Decreases - Prior Year (0.2) (0.2) Lapse of Statute of Limitations (12.6) (6.6) Balance as of December 31, 2024 $ 93.7 $ 21.9 Interest and Penalties: Interest on uncertain tax positions is recorded and generally classified as a component of Other Interest Expense on the statements of income. However, when resolution of uncertainties results in the Company receiving interest income, any related interest benefit is recorded in Other Income, Net on the statements of income. No penalties have been recorded. The amount of interest expense recognized on uncertain tax positions was $1.3 million and $0.3 million for the years ended December 31, 2024 and 2023, respectively. There was no interest expense/(income) recognized on uncertain tax positions for the year ended December 31, 2022. Accrued interest payable was $1.7 million and $0.4 million as of December 31, 2024 and 2023, respectively. Tax Positions: During 2024 and 2023, Eversource did not resolve any of its uncertain tax positions. Open Tax Years: The following table summarizes Eversource, CL&P, NSTAR Electric, and PSNH's tax years that remain subject to examination by major tax jurisdictions as of December 31, 2024: Description Tax Years Federal 2022 - 2024 (1) Connecticut 2021 - 2024 Massachusetts 2022 - 2024 New Hampshire 2021 - 2024 (1) The Company’s Corporate Income Tax Returns for 2022 and 2023 were reviewed and closed as part of the annual IRS CAP program, with the exception for partnership investments of the Company. The Company was recently informed of an IRS audit of one of the partnership returns for the tax year 2022 and the IRS reserves the right to audit 2023. The Company recorded in the above Unrecognized Tax Benefits a reserve associated with this Partnership audit. These years remain open in relation to those audits. Eversource does not estimate to have an earnings impact related to unrecognized tax benefits during the next twelve months.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES A. Environmental Matters Eversource, CL&P, NSTAR Electric and PSNH are subject to environmental laws and regulations intended to mitigate or remove the effect of past operations and improve or maintain the quality of the environment. These laws and regulations require the removal or the remedy of the effect on the environment of the disposal or release of certain specified hazardous substances at current and former operating sites. Eversource, CL&P, NSTAR Electric and PSNH have an active environmental auditing and training program and each believes it is substantially in compliance with all enacted laws and regulations. Environmental reserves are accrued when assessments indicate it is probable that a liability has been incurred and an amount can be reasonably estimated. The approach used estimates the liability based on the most likely action plan from a variety of available remediation options, including no action required or several different remedies ranging from establishing institutional controls to full site remediation and monitoring. These liabilities are estimated on an undiscounted basis and do not assume that the amounts are recoverable from insurance companies or other third parties. The environmental reserves include sites at different stages of discovery and remediation and do not include any unasserted claims. These reserve estimates are subjective in nature as they take into consideration several different remediation options at each specific site. The reliability and precision of these estimates can be affected by several factors, including new information concerning either the level of contamination at the site, the extent of Eversource's, CL&P's, NSTAR Electric's and PSNH's responsibility for remediation or the extent of remediation required, recently enacted laws and regulations or changes in cost estimates due to certain economic factors. It is possible that new information or future developments could require a reassessment of the potential exposure to required environmental remediation. As this information becomes available, management will continue to assess the potential exposure and adjust the reserves accordingly. The amounts recorded as environmental reserves are included in Other Current Liabilities and Other Long-Term Liabilities on the balance sheets and represent management's best estimate of the liability for environmental costs, and take into consideration site assessment, remediation and long-term monitoring costs. The environmental reserves also take into account recurring costs of managing hazardous substances and pollutants, mandated expenditures to remediate contaminated sites and any other infrequent and non-recurring clean-up costs. A reconciliation of the activity in the environmental reserves (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Balance as of January 1, 2023 $ 122.6 $ 13.9 $ 3.4 $ 6.1 Additions 16.8 2.6 2.5 1.7 Payments/Reductions (11.2) (2.7) (0.5) (0.2) Balance as of December 31, 2023 128.2 13.8 5.4 7.6 Additions 11.0 0.8 1.9 0.2 Payments/Reductions (11.2) (1.2) (0.7) (1.5) Balance as of December 31, 2024 $ 128.0 $ 13.4 $ 6.6 $ 6.3 The number of environmental sites for which remediation or long-term monitoring, preliminary site work or site assessment is being performed are as follows: Eversource CL&P NSTAR Electric PSNH 2024 65 15 14 8 2023 65 16 12 8 Included in the number of sites and reserve amounts above are former MGP sites that were operated several decades ago and manufactured natural gas from coal and other processes, which resulted in certain by-products remaining in the environment that may pose a potential risk to human health and the environment, for which Eversource may have potential liability. The reserve balances related to these former MGP sites were $115.9 million and $117.1 million as of December 31, 2024 and 2023, respectively, and related primarily to the natural gas business segment. As of December 31, 2024, for 17 environmental sites (9 for CL&P and 2 for NSTAR Electric) that are included in the Company's reserve for environmental costs, management cannot reasonably estimate the exposure to loss in excess of the reserve, or range of loss, as these sites are under investigation and/or there is significant uncertainty as to what remedial actions, if any, the Company may be required to undertake. As of December 31, 2024, $30.7 million (including $5.7 million for CL&P and $1.4 million for NSTAR Electric) had been accrued as a liability for these sites. As of December 31, 2024, for 8 environmental sites (1 for NSTAR Electric) that are included in the Company's reserve for environmental costs, the information known and the nature of the remediation options allow for the Company to estimate the range of losses for environmental costs. As of December 31, 2024, $29.5 million has been accrued as a liability for these sites, which represents the low end of the range of the liabilities for environmental costs. Management believes that additional losses of up to approximately $17.5 million may be incurred in executing current remediation plans for these sites. As of December 31, 2024, for the remaining 40 environmental sites (including 6 for CL&P, 11 for NSTAR Electric and 8 for PSNH) that are included in the Company's reserve for environmental costs, the $67.8 million accrual (including $7.7 million for CL&P, $5.2 million for NSTAR Electric and $6.3 million for PSNH) represents management's best estimate of the probable liability and no additional loss is estimable at this time. Estimated Future Annual Costs: The estimated future annual costs of significant executed, non-cancelable, long-term contractual arrangements in effect as of December 31, 2024 are as follows: Eversource (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Renewable Energy Purchase Contracts $ 771.8 $ 865.2 $ 919.9 $ 918.0 $ 785.5 $ 6,289.9 $ 10,550.3 Natural Gas Procurement 532.6 486.1 364.6 308.1 294.9 1,004.4 2,990.7 Capacity and Purchased Power 75.2 2.9 2.7 2.7 2.3 2.3 88.1 Peaker CfDs 28.3 27.7 23.1 23.3 24.1 84.6 211.1 Transmission Support Commitments 17.1 18.8 20.0 20.9 21.8 22.6 121.2 Total $ 1,425.0 $ 1,400.7 $ 1,330.3 $ 1,273.0 $ 1,128.6 $ 7,403.8 $ 13,961.4 CL&P (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Renewable Energy Purchase Contracts $ 651.0 $ 671.9 $ 723.7 $ 724.5 $ 588.4 $ 3,473.6 $ 6,833.1 Capacity 72.4 0.1 — — — — 72.5 Peaker CfDs 28.3 27.7 23.1 23.3 24.1 84.6 211.1 Transmission Support Commitments 6.8 7.4 7.9 8.3 8.6 8.9 47.9 Total $ 758.5 $ 707.1 $ 754.7 $ 756.1 $ 621.1 $ 3,567.1 $ 7,164.6 NSTAR Electric (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Renewable Energy Purchase Contracts $ 120.8 $ 193.3 $ 196.2 $ 193.5 $ 197.1 $ 2,816.3 $ 3,717.2 Purchased Power 2.8 2.8 2.7 2.7 2.3 2.3 15.6 Transmission Support Commitments 6.7 7.4 7.9 8.2 8.6 8.9 47.7 Total $ 130.3 $ 203.5 $ 206.8 $ 204.4 $ 208.0 $ 2,827.5 $ 3,780.5 PSNH (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Transmission Support Commitments $ 3.6 $ 4.0 $ 4.2 $ 4.4 $ 4.6 $ 4.8 $ 25.6 The contractual obligations table above does not include CL&P's, NSTAR Electric's or PSNH's standard/basic service contracts for the purchase of energy supply, the amounts of which vary with customers' energy needs. Renewable Energy Purchase Contracts: Renewable energy purchase contracts include non-cancellable commitments under contracts of CL&P and NSTAR Electric for the purchase of energy and capacity from renewable energy facilities. Such contracts extend through 2046 for CL&P and 2045 for NSTAR Electric. In 2024, the NHPUC approved the termination of a PPA for the purchase of capacity, renewable energy and RECs from a New Hampshire generation plant and there are no remaining long-term renewable energy purchase contracts at PSNH. Renewable energy purchase contracts include long-term commitments of NSTAR Electric pertaining to the Vineyard Wind LLC contract awarded under the Massachusetts Clean Energy 83C procurement solicitation. NSTAR Electric, along with other Massachusetts distribution companies, entered into 20-year contracts to purchase electricity generated by this 800 megawatt offshore wind project. Construction on the Vineyard Wind project commenced in 2022. Estimated energy costs under this contract are expected to begin when the facilities are in service in 2025 and range between $100 million and $200 million per year und er NSTAR Electric’s 20-year contract, totaling approximately $2.6 billion. As required by 2018 regulation, CL&P and UI each entered into PURA-approved ten-year contracts in 2019 to purchase a combined total of approximately 9 million MWh annually from the Millstone Nuclear Power Station generation facility, which represents a combined amount of approximately 50 percent of the facility's output (approximately 40 percent by CL&P). Also as required by 2018 regulation, CL&P and UI each entered into PURA-approved eight-year contracts in 2019 to purchase a combined amount of approximately 18 percent of the Seabrook Nuclear Power Plant’s output (approximately 15 percent by CL&P) beginning January 1, 2022. The total estimated remaining future cost of the Millstone Nuclear Power Station and Seabrook Nuclear Power Plant energy purchase contracts are $2.6 billion and are reflected in the table above. As required by law, CL&P cannot use this power to satisfy its customers’ supply obligations. CL&P sells the energy purchased under these contracts into the market and uses the proceeds from these energy sales to offset the contract costs. As the net costs under these contracts are recovered from customers in future rates, the contracts do not have an impact on the net income of CL&P. These contracts do not meet the definition of a derivative, and accordingly, the costs of these contracts are being accounted for as incurred. The contractual obligations table above does not include long-term commitments signed by CL&P and NSTAR Electric, as required by the PURA and the DPU, respectively, for the purchase of renewable energy and related products that are contingent on the future construction of energy facilities, such as the long-term commitments of NSTAR Electric pertaining to the Massachusetts Clean Energy 83D contract entered into in 2018. Natural Gas Procurement: Eversource's natural gas distribution businesses have long-term contracts for the purchase, transportation and storage of natural gas as part of its portfolio of supplies, which extend through 2045. Capacity and Purchased Power: These contracts include capacity CfDs with generation facilities at CL&P through 2026, and a purchase obligation for electricity which extends through 2031 for NSTAR Electric. CL&P's portion of the costs and benefits under these capacity contracts are recovered from, or refunded to, CL&P's customers. Peaker CfDs: CL&P, along with UI, has three peaker CfDs for a total of approximately 500 MW of peaking capacity through 2042. CL&P has a sharing agreement with UI, whereby CL&P is responsible for 80 percent and UI for 20 percent of the net costs or benefits of these CfDs. The Peaker CfDs pay the generation facility owner the difference between capacity, forward reserve and energy market revenues and a cost-of-service payment stream for 30 years. The ultimate cost or benefit to CL&P under these contracts will depend on the costs of plant operation and the prices that the projects receive for capacity and other products in the ISO-NE markets. CL&P's portion of the amounts paid or received under the Peaker CfDs are recovered from, or refunded to, CL&P's customers. Transmission Support Commitments: Along with other New England utilities, CL&P, NSTAR Electric and PSNH have entered into agreements to support the costs of, and receive rights to use, transmission and terminal facilities that import electricity from the Hydro-Québec system in Canada. CL&P, NSTAR Electric and PSNH are obligated to pay, over a 20-year period ending in 2040, their proportionate shares of the annual operation and maintenance expenses and capital costs of those facilities. The total costs incurred under these agreements were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Renewable Energy Purchase Contracts $ 591.4 $ 581.4 $ 678.1 Natural Gas Procurement 695.0 695.8 1,042.8 Capacity and Purchased Power 70.5 69.0 61.6 Peaker CfDs 23.1 20.1 13.4 Transmission Support Commitments 16.7 14.2 12.7 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Renewable Energy Purchase Contracts $ 529.0 $ 62.4 $ — $ 474.1 $ 60.0 $ 47.3 $ 513.2 $ 90.8 $ 74.1 Capacity and Purchased Power 67.6 2.9 — 65.5 2.9 0.6 57.7 3.0 0.9 Peaker CfDs 23.1 — — 20.1 — — 13.4 — — Transmission Support Commitments 6.6 6.6 3.5 5.6 5.6 3.0 5.0 5.0 2.7 CL&P, NSTAR Electric and PSNH have plant closure and fuel storage cost obligations to the Yankee Companies, which have each completed the physical decommissioning of their respective nuclear power facilities and are now engaged in the long-term storage of their spent fuel. The Yankee Companies fund these costs through litigation proceeds received from the DOE and, to the extent necessary, through wholesale, FERC-approved rates charged under power purchase agreements with several New England utilities, including CL&P, NSTAR Electric and PSNH. CL&P, NSTAR Electric and PSNH, in turn recover these costs from their customers through state regulatory commission-approved retail rates. The Yankee Companies collect amounts that management believes are adequate to recover the remaining plant closure and fuel storage cost estimates for the respective plants. Management believes CL&P and NSTAR Electric will recover their shares of these obligations from their customers. PSNH has recovered its total share of these costs from its customers. Spent Nuclear Fuel Litigation: The Yankee Companies have filed complaints against the DOE in the Court of Federal Claims seeking monetary damages resulting from the DOE's failure to accept delivery of, and provide for a permanent facility to store, spent nuclear fuel pursuant to the terms of the 1983 spent fuel and high-level waste disposal contracts between the Yankee Companies and the DOE. The court previously awarded the Yankee Companies damages for Phases I, II, III and IV of litigation resulting from the DOE's failure to meet its contractual obligations. These Phases covered damages incurred in the years 1998 through 2016, and the awarded damages have been received by the Yankee Companies with certain amounts of the damages refunded to their customers. DOE Phase V Damages - On March 25, 2021, each of the Yankee Companies filed a fifth set of lawsuits against the DOE in the Court of Federal Claims resulting from the DOE's failure to begin accepting spent nuclear fuel for disposal covering the years from 2017 to 2020. The Yankee Companies filed claims seeking monetary damages totaling $120.4 million for CYAPC, YAEC and MYAPC. Pursuant to a June 2, 2022 court order, the Yankee Companies were subsequently permitted to include monetary damages relating to the year 2021 in the DOE Phase V complaint. The Yankee Companies submitted a supplemental filing to include these costs of $33.1 million on June 8, 2022. In September 2024, the parties reached an agreement in principle to settle the Phase V complaint totaling $145 million for CYAPC, YAEC, and MYAPC. The settlement was approved on November 19, 2024 and the Department of Justice filed a Notice of Appeal on January 17, 2025 on an issue outside the scope of the settlement. Oral arguments are expected to be scheduled in the second half of 2025. D. Guarantees and Indemnifications In the normal course of business, Eversource parent provides credit assurances on behalf of its subsidiaries, including CL&P, NSTAR Electric and PSNH, in the form of guarantees. Management does not anticipate a material impact to net income or cash flows as a result of these various guarantees and indemnifications. Guarantees issued on behalf of unconsolidated entities, including equity method ownership interests, for which Eversource parent is the guarantor, are recorded at fair value as a liability on the balance sheet at the inception of the guarantee. The fair value of guarantees issued on behalf of unconsolidated entities are recorded within Other Long-Term Liabilities on the balance sheet, and were $1.2 million and $4.4 million as of December 31, 2024 and 2023, respectively. Eversource regularly reviews performance risk under these guarantee arrangements, and believes the likelihood of payments being required under the guarantees is remote. In the event it becomes probable that Eversource parent will be required to perform under the guarantee, the amount of probable payment will be recorded. On September 30, 2024, Eversource completed the sale of its 50 percent ownership share in the South Fork Wind and Revolution Wind projects to GIP. Under the agreement with GIP, Eversource’s existing and certain additional credit support obligations for Revolution Wind are expected to roll off as the project completes construction. On July 9, 2024, Eversource completed the sale of its 50 percent ownership share of Sunrise Wind to Ørsted. Under the agreement with Ørsted, Eversource’s existing credit support obligations for Sunrise Wind were either terminated or indemnified by Ørsted as a result of the sale. The following table summarizes Eversource parent's exposure to guarantees and indemnifications of its subsidiaries and affiliates to external parties, and primarily relates to its previously-owned offshore wind investments: As of December 31, 2024 Company (Obligor) Description Maximum Exposure Revolution Wind, LLC and TurbineCo, LLC Offshore wind construction-related purchase agreements with third-party contractors (1) $ 357.0 Eversource Investment LLC, Eversource Investment Service Company LLC and South Fork Class B Member, LLC Offshore wind funding and indemnification obligations (2) 277.5 Eversource Investment LLC Letters of Credit (3) 5.3 Eversource TEI LLC South Fork Wind Tax Equity (4) 50.0 South Fork Wind, LLC Power Purchase Agreement Security (5) 7.1 Various Eversource subsidiaries Surety bonds (6) 30.7 (1) Eversource parent issued guarantees on behalf of its previously 50 percent-owned affiliate, Revolution Wind, LLC, and on behalf of TurbineCo, LLC (successor in interest to North East Offshore, LLC (NEO)), under which Eversource parent agreed to guarantee each entity’s performance of obligations under certain construction-related purchase agreements with third-party contractors, in an aggregate amount not to exceed $935.6 million. Eversource parent’s obligations under the guarantees expire upon the earlier of (i) dates ranging between December 2024 and November 2027 and (ii) full performance of the guaranteed obligations. (2) Eversource parent issued guarantees on behalf of its wholly-owned subsidiary Eversource Investment LLC (EI), which held Eversource's previous investments in offshore wind-related equity method investments until sale, and on behalf of its previously 50 percent-owned affiliate, South Fork Class B Member, LLC, whereby Eversource parent will guarantee each entity’s performance of certain funding obligations of the South Fork and Revolution Wind projects. Eversource parent also guaranteed certain indemnification obligations of EI associated with third party credit support for EI’s investment in NEO. On September 30, 2024, Eversource parent issued a guaranty on behalf of its wholly-owned subsidiary, Eversource Investment Service Company LLC, whereby Eversource parent will guarantee Eversource Investment Service Company LLC’s performance of certain indemnification obligations during the onshore construction phase of the Revolution Wind project, in an amount not to exceed $100.0 million. These guarantees will not exceed $1.62 billion and expire upon the full performance of the guaranteed obligations. (3) Eversource parent entered into a guarantee on behalf of EI, under which Eversource parent would guarantee EI's obligations under a letter of credit facility with a financial institution that EI may request in an aggregate amount of up to approximately $25 million. As of December 31, 2024, EI has issued two letters of credit on behalf of South Fork Wind, LLC and one letter of credit on behalf of Revolution Wind, LLC totaling $5.3 million. The guarantee will remain in effect until full performance of the guaranteed obligations. On January 24, 2025, the $1.0 million letter of credit issued on behalf of Revolution Wind, LLC was terminated. (4) Eversource parent issued a guarantee on behalf of its wholly-owned subsidiary, Eversource TEI LLC, whereby Eversource parent will guarantee Eversource TEI LLC’s performance of certain obligations, in an amount not to exceed $50.0 million, in connection with any remaining obligations under the LLC agreement. Eversource parent’s obligations expire upon the full performance of the guaranteed obligations. (5) Eversource parent issued a guarantee on behalf of its previously 50 percent-owned affiliate, South Fork Wind, LLC, whereby Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations, in an amount not to exceed $7.1 million, under a Power Purchase Agreement between the Long Island Power Authority and South Fork Wind, LLC (the Agreement). The guarantee expires upon the later of (i) the end of the Agreement term, January 2044, with the option to extend to January 2049 and (ii) full performance of the guaranteed obligations. (6) Surety bonds expire in 2025. Expiration dates reflect termination dates, the majority of which will be renewed or extended. Certain surety bonds contain credit ratings triggers that would require Eversource parent to post collateral in the event that the unsecured debt credit ratings of Eversource parent are downgraded. On September 30, 2024, Eversource entered into an agreement with GIP and Ørsted to contingently provide future credit support up to a maximum of $850 million in guarantees, if required, to support third party tax equity financing for Revolution Wind. Four separate complaints were filed at the FERC by combinations of New England state attorneys general, state regulatory commissions, consumer advocates, consumer groups, municipal parties and other parties (collectively, the Complainants). In each of the first three complaints, filed on October 1, 2011, December 27, 2012, and July 31, 2014, respectively, the Complainants challenged the NETOs' base ROE of 11.14 percent that had been utilized since 2005 and sought an order to reduce it prospectively from the date of the final FERC order and for the separate 15-month complaint periods. In the fourth complaint, filed April 29, 2016, the Complainants challenged the NETOs' base ROE billed of 10.57 percent and the maximum ROE for transmission incentive (incentive cap) of 11.74 percent, asserting that these ROEs were unjust and unreasonable. The ROE originally billed during the period October 1, 2011 (beginning of the first complaint period) through October 15, 2014 consisted of a base ROE of 11.14 percent and incentives up to 13.1 percent. On October 16, 2014, FERC issued Opinion No. 531-A and set the base ROE at 10.57 percent and the incentive cap at 11.74 percent for the first complaint period. This was also effective for all prospective billings to customers beginning October 16, 2014. This FERC order was vacated on April 14, 2017 by the U.S. Court of Appeals for the D.C. Circuit (the Court). All amounts associated with the first complaint period have been refunded, which totaled $38.9 million (pre-tax and excluding interest) at Eversource and reflected both the base ROE and incentive cap prescribed by the FERC order. The refund consisted of $22.4 million for CL&P, $13.7 million for NSTAR Electric and $2.8 million for PSNH. Eversource has recorded a reserve of $39.1 million (pre-tax and excluding interest) for the second complaint period as of both December 31, 2024 and 2023. This reserve represents the difference between the billed rates during the second complaint period and a 10.57 percent base ROE and 11.74 percent incentive cap. The reserve consisted of $21.4 million for CL&P, $14.6 million for NSTAR Electric and $3.1 million for PSNH as of both December 31, 2024 and 2023. On October 16, 2018, FERC issued an order on all four complaints describing how it intends to address the issues that were remanded by the Court. FERC proposed a new framework to determine (1) whether an existing ROE is unjust and unreasonable and, if so, (2) how to calculate a replacement ROE. Initial briefs were filed by the NETOs, Complainants and FERC Trial Staff on January 11, 2019 and reply briefs were filed on March 8, 2019. The NETOs' brief was supportive of the overall ROE methodology determined in the October 16, 2018 order provided the FERC does not change the proposed methodology or alter its implementation in a manner that has a material impact on the results. The FERC order included illustrative calculations for the first complaint using FERC's proposed frameworks with financial data from that complaint. Those illustrative calculations indicated that for the first complaint period, for the NETOs, which FERC concludes are of average financial risk, the preliminary just and reasonable base ROE is 10.41 percent and the preliminary incentive cap on total ROE is 13.08 percent. If the results of the illustrative calculations were included in a final FERC order for each of the complaint periods, then a 10.41 percent base ROE and a 13.08 percent incentive cap would not have a significant impact on our financial statements for all of the complaint periods. These preliminary calculations are not binding and do not represent what we believe to be the most likely outcome of a final FERC order. On November 21, 2019, FERC issued Opinion No. 569 affecting the two pending transmission ROE complaints against the Midcontinent ISO (MISO) transmission owners, in which FERC adopted a new methodology for determining base ROEs. Various parties sought rehearing. On December 23, 2019, the NETOs filed supplementary materials in the NETOs' four pending cases to respond to this new methodology because of the uncertainty of the applicability to the NETOs' cases. On May 21, 2020, the FERC issued its order in Opinion No. 569-A on the rehearing of the MISO transmission owners' cases, in which FERC again changed its methodology for determining the MISO transmission owners' base ROEs. On November 19, 2020, the FERC issued Opinion No. 569-B denying rehearing of Opinion No. 569-A and reaffirmed the methodology previously adopted in Opinion No. 569-A. The new methodology differs significantly from the methodology proposed by FERC in its October 16, 2018 order to determine the NETOs' base ROEs in their four pending cases. FERC Opinion Nos. 569-A and 569-B were appealed to the Court. On August 9, 2022, the Court issued its decision vacating MISO ROE FERC Opinion Nos. 569, 569-A and 569-B and remanded to FERC to reopen the proceedings. The Court found that FERC’s development of the new return methodology was arbitrary and capricious due to FERC’s failure to offer a reasonable explanation for its decision to reintroduce the risk-premium financial model in its new methodology for calculating a just and reasonable return. On October 17, 2024, FERC issued an order on the remand of the MISO ROE proceedings. The order addressed the Court’s decision that the reintroduction of the risk-premium financial model in the ROE methodology was arbitrary and capricious by removing the risk-premium financial model from the ROE methodology. The removal of the risk-premium financial model was the only revision to FERC’s ROE methodology and resulted in a two-model approach utilizing the two-step discounted cash flow model and the capital asset pricing model. MISO was directed to provide refunds for the period November 12, 2013 to February 11, 2015 (the first MISO ROE complaint refund period) and for the period from September 28, 2016 (the date of FERC’s order on the first MISO ROE complaint) to October 17, 2024 by December 1, 2025. The order also stated that FERC does not preclude the use of the risk-premium financial model in future proceedings if the parties can demonstrate that FERC’s stated concerns around the inclusion of the model have been addressed. On November 13, 2024, the NETOs filed a supplemental brief in their four pending ROE proceedings to explain to FERC that it cannot apply the reasoning and methodologies of the MISO ROE case to the NETOs’ cases due to the entirely different set of facts in the MISO and NETOs ROE proceedings. Doing so would violate the substance of the Court’s April 14, 2017 order and would violate the legal standard required by the Federal Power Act. On February 4, 2025, the MISO transmission owners submitted a petition for review with the Court requesting review of the October 17, 2024 MISO ROE order on remand and a December 19, 2024 notice of denial of rehearing. The petition requests review of FERC’s decision to retroactively backdate the MISO transmission owners’ base ROE to the date of an earlier order that FERC abandoned when it issued Order No. 569, treat an underlying unlawful complaint as if it were legitimate, and order eight years of interest as part of the directed refunds. Given the significant uncertainty regarding the applicability of the FERC order in the MISO transmission owners’ two complaint cases to the NETOs’ pending four complaint cases due to the complex differences between the cases, Eversource concluded that there is no reasonable basis for a change to the reserve or recognized ROEs for any of the complaints or subsequent periods at this time and Eversource cannot reasonably estimate any potential range of loss for any of the four complaint proceedings at this time. The resolution of these proceedings could have a material impact on the financial condition, results of operations, and cash flows. Eversource, CL&P, NSTAR Electric and PSNH currently record revenues at the 10.57 percent base ROE and incentive cap at 11.74 percent established in the October 16, 2014 FERC order. A change of 10 basis points to the base ROE used to establish the reserves would impact Eversource’s after-tax earnings by an average of approximately $3 million for each of the four 15-month complaint periods. F. Litigation and Legal Proceedings Eversource, including CL&P, NSTAR Electric and PSNH, are involved in legal, tax and regulatory proceedings regarding matters arising in the ordinary course of business, which involve management's assessment to determine the probability of whether a loss will occur and, if probable, its best estimate of probable loss. The Company records and discloses losses when these losses are probable and reasonably estimable, and discloses matters when losses are probable but not estimable or when losses are reasonably possible. Legal costs related to the defense of loss contingencies are expensed as incurred.

LEASES

LEASES	12 Months Ended
	Dec. 31, 2024
Leases [Abstract]
LEASES	LEASES Eversource, including CL&P, NSTAR Electric and PSNH, has entered into lease agreements as a lessee for the use of land, office space, service centers, vehicles, information technology, and equipment. These lease agreements are classified as either finance or operating leases and the liability and right-of-use asset are recognized on the balance sheet at lease commencement. Leases with an initial term of 12 months or less are not recorded on the balance sheet and are recognized as lease expense on a straight-line basis over the lease term. Eversource determines whether or not a contract contains a lease based on whether or not it provides Eversource with the use of a specifically identified asset for a period of time, as well as both the right to direct the use of that asset and receive the significant economic benefits of the asset. Eversource has elected the practical expedient to not separate non-lease components from lease components and instead to account for both as a single lease component, with the exception of the information technology asset class where the lease and non-lease components are separated. The provisions of Eversource, CL&P, NSTAR Electric and PSNH lease agreements contain renewal options. The renewal options range from one year to twenty years. The renewal period is included in the measurement of the lease liability if it is reasonably certain that Eversource will exercise these renewal options. For leases entered into or modified after the January 1, 2019 implementation date of the leases standard under Topic 842, the discount rate utilized for classification and measurement purposes as of the inception date of the lease is based on each company's collateralized incremental interest rate to borrow over a comparable term for an individual lease because the rate implicit in the lease is not determinable. CL&P and PSNH entered into certain contracts for the purchase of energy that qualify as leases. These contracts do not have minimum lease payments and therefore are not recognized as a lease liability on the balance sheet and are not reflected in the future minimum lease payments table below. Expense related to these contracts is included as variable lease cost in the table below. The expense and long-term obligation for these contracts are also included in Note 13B, "Commitments and Contingencies - Long-Term Contractual Arrangements," to the financial statements. In 2024, these contracts at PSNH were terminated. The components of lease cost, prior to amounts capitalized, are as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Finance Lease Cost: Amortization of Right-of-use-Assets $ 6.4 $ 4.8 $ 8.3 Interest on Lease Liabilities 2.7 2.0 2.0 Total Finance Lease Cost 9.1 6.8 10.3 Operating Lease Cost 15.2 11.4 11.6 Variable Lease Cost 18.3 69.2 78.1 Total Lease Cost $ 42.6 $ 87.4 100.0 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Finance Lease Cost: Amortization of Right-of-use-Assets $ 1.7 $ 0.2 $ — $ — $ 0.2 $ — $ — $ 0.2 $ 0.1 Interest on Lease Liabilities 0.8 0.6 — — 0.6 — — 0.6 — Total Finance Lease Cost 2.5 0.8 — — 0.8 — — 0.8 0.1 Operating Lease Cost 2.6 5.3 1.8 0.7 3.0 0.4 0.3 2.3 0.1 Variable Lease Cost 18.9 — (0.6) 21.9 — 47.3 25.6 — 52.5 Total Lease Cost $ 24.0 $ 6.1 $ 1.2 $ 22.6 $ 3.8 $ 47.7 $ 25.9 $ 3.1 $ 52.7 Operating lease cost, net of the capitalized portion, is included in Operations and Maintenance (or Purchased Power, Purchased Natural Gas and Transmission expense for transmission leases) on the statements of income. Amortization of finance lease assets is included in Depreciation on the statements of income. Interest expense on finance leases is included in Interest Expense on the statements of income. Supplemental balance sheet information related to leases is as follows: As of December 31, 2024 As of December 31, 2023 (Millions of Dollars) Balance Sheet Classification Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Operating Leases: Right-of-use-Assets, Net Other Long-Term Assets $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 53.5 $ 2.2 $ 27.7 $ 4.7 Operating Lease Liabilities Current Portion Other Current Liabilities $ 10.4 $ 2.2 $ 3.7 $ 1.7 $ 9.5 $ 0.8 $ 2.2 $ 1.5 Long-Term Other Long-Term Liabilities 45.7 5.5 25.7 1.6 44.0 1.4 25.5 3.2 Total Operating Lease Liabilities $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 53.5 $ 2.2 $ 27.7 $ 4.7 Finance Leases: Right-of-use-Assets, Net Property, Plant and Equipment, Net $ 61.9 $ 16.6 $ 2.8 $ — $ 68.6 $ 18.3 $ 3.0 $ — Finance Lease Liabilities Current Portion Other Current Liabilities $ 5.6 $ 1.5 $ — $ — $ 5.4 $ 1.4 $ — $ — Long-Term Other Long-Term Liabilities 62.1 15.6 4.9 — 67.3 16.9 4.9 — Total Finance Lease Liabilities $ 67.7 $ 17.1 $ 4.9 $ — $ 72.7 $ 18.3 $ 4.9 $ — The finance lease payments that NSTAR Electric will make over the next twelve months are entirely interest-related, due to escalating payments. As such, none of the finance lease payments over the next twelve months will reduce the finance lease liability. As of December 31, 2024, the operating lease balances attributable to the Aquarion water distribution business have been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, these balances were recorded within Other Long-Term Assets on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” Other information related to leases is as follows: As of December 31, 2024 2023 Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Weighted-Average Remaining Lease Term (Years): Operating Leases 9 4 12 2 9 4 13 3 Finance Leases 12 8 17 — 13 9 18 — Weighted-Average Discount Rate (Percentage): Operating Leases 4.1 % 5.2 % 4.2 % 5.2 % 4.0 % 5.2 % 4.2 % 5.2 % Finance Leases 3.3 % 5.3 % 2.9 % — % 3.3 % 5.3 % 2.9 % — % (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2024 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 14.5 $ 2.5 $ 4.9 $ 1.8 Operating Cash Flows from Finance Leases 2.6 0.7 0.7 — Financing Cash Flows from Finance Leases 5.2 1.2 — — Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 15.3 7.8 5.7 0.3 Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 0.3 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2023 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 10.5 $ 0.7 $ 2.5 $ 0.4 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — — Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 12.8 0.6 7.0 5.0 Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 18.5 18.3 — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2022 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 11.3 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 18.9 2.4 — — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 3.5 — — — As of December 31, 2024, there are no lease agreements for Eversource, CL&P, NSTAR Electric or PSNH which have been executed but have yet to commence and have not been recorded as right-of-use assets. Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2024 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric Year Ending December 31, 2025 $ 12.5 $ 2.6 $ 4.9 $ 1.9 $ 8.3 $ 2.3 $ 0.7 2026 11.0 2.3 4.9 1.5 7.9 2.4 0.7 2027 7.0 1.8 2.9 0.1 7.9 2.5 0.7 2028 6.6 1.8 2.6 — 7.3 2.6 0.7 2029 4.5 — 2.5 — 7.3 2.6 0.7 Thereafter 26.2 — 22.2 — 50.5 8.9 10.2 Future lease payments 67.8 8.5 40.0 3.5 89.2 21.3 13.7 Less amount representing interest 11.7 0.8 10.6 0.2 21.5 4.2 8.8 Present value of future minimum lease payments $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 67.7 $ 17.1 $ 4.9
LEASES	LEASES Eversource, including CL&P, NSTAR Electric and PSNH, has entered into lease agreements as a lessee for the use of land, office space, service centers, vehicles, information technology, and equipment. These lease agreements are classified as either finance or operating leases and the liability and right-of-use asset are recognized on the balance sheet at lease commencement. Leases with an initial term of 12 months or less are not recorded on the balance sheet and are recognized as lease expense on a straight-line basis over the lease term. Eversource determines whether or not a contract contains a lease based on whether or not it provides Eversource with the use of a specifically identified asset for a period of time, as well as both the right to direct the use of that asset and receive the significant economic benefits of the asset. Eversource has elected the practical expedient to not separate non-lease components from lease components and instead to account for both as a single lease component, with the exception of the information technology asset class where the lease and non-lease components are separated. The provisions of Eversource, CL&P, NSTAR Electric and PSNH lease agreements contain renewal options. The renewal options range from one year to twenty years. The renewal period is included in the measurement of the lease liability if it is reasonably certain that Eversource will exercise these renewal options. For leases entered into or modified after the January 1, 2019 implementation date of the leases standard under Topic 842, the discount rate utilized for classification and measurement purposes as of the inception date of the lease is based on each company's collateralized incremental interest rate to borrow over a comparable term for an individual lease because the rate implicit in the lease is not determinable. CL&P and PSNH entered into certain contracts for the purchase of energy that qualify as leases. These contracts do not have minimum lease payments and therefore are not recognized as a lease liability on the balance sheet and are not reflected in the future minimum lease payments table below. Expense related to these contracts is included as variable lease cost in the table below. The expense and long-term obligation for these contracts are also included in Note 13B, "Commitments and Contingencies - Long-Term Contractual Arrangements," to the financial statements. In 2024, these contracts at PSNH were terminated. The components of lease cost, prior to amounts capitalized, are as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Finance Lease Cost: Amortization of Right-of-use-Assets $ 6.4 $ 4.8 $ 8.3 Interest on Lease Liabilities 2.7 2.0 2.0 Total Finance Lease Cost 9.1 6.8 10.3 Operating Lease Cost 15.2 11.4 11.6 Variable Lease Cost 18.3 69.2 78.1 Total Lease Cost $ 42.6 $ 87.4 100.0 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Finance Lease Cost: Amortization of Right-of-use-Assets $ 1.7 $ 0.2 $ — $ — $ 0.2 $ — $ — $ 0.2 $ 0.1 Interest on Lease Liabilities 0.8 0.6 — — 0.6 — — 0.6 — Total Finance Lease Cost 2.5 0.8 — — 0.8 — — 0.8 0.1 Operating Lease Cost 2.6 5.3 1.8 0.7 3.0 0.4 0.3 2.3 0.1 Variable Lease Cost 18.9 — (0.6) 21.9 — 47.3 25.6 — 52.5 Total Lease Cost $ 24.0 $ 6.1 $ 1.2 $ 22.6 $ 3.8 $ 47.7 $ 25.9 $ 3.1 $ 52.7 Operating lease cost, net of the capitalized portion, is included in Operations and Maintenance (or Purchased Power, Purchased Natural Gas and Transmission expense for transmission leases) on the statements of income. Amortization of finance lease assets is included in Depreciation on the statements of income. Interest expense on finance leases is included in Interest Expense on the statements of income. Supplemental balance sheet information related to leases is as follows: As of December 31, 2024 As of December 31, 2023 (Millions of Dollars) Balance Sheet Classification Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Operating Leases: Right-of-use-Assets, Net Other Long-Term Assets $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 53.5 $ 2.2 $ 27.7 $ 4.7 Operating Lease Liabilities Current Portion Other Current Liabilities $ 10.4 $ 2.2 $ 3.7 $ 1.7 $ 9.5 $ 0.8 $ 2.2 $ 1.5 Long-Term Other Long-Term Liabilities 45.7 5.5 25.7 1.6 44.0 1.4 25.5 3.2 Total Operating Lease Liabilities $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 53.5 $ 2.2 $ 27.7 $ 4.7 Finance Leases: Right-of-use-Assets, Net Property, Plant and Equipment, Net $ 61.9 $ 16.6 $ 2.8 $ — $ 68.6 $ 18.3 $ 3.0 $ — Finance Lease Liabilities Current Portion Other Current Liabilities $ 5.6 $ 1.5 $ — $ — $ 5.4 $ 1.4 $ — $ — Long-Term Other Long-Term Liabilities 62.1 15.6 4.9 — 67.3 16.9 4.9 — Total Finance Lease Liabilities $ 67.7 $ 17.1 $ 4.9 $ — $ 72.7 $ 18.3 $ 4.9 $ — The finance lease payments that NSTAR Electric will make over the next twelve months are entirely interest-related, due to escalating payments. As such, none of the finance lease payments over the next twelve months will reduce the finance lease liability. As of December 31, 2024, the operating lease balances attributable to the Aquarion water distribution business have been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, these balances were recorded within Other Long-Term Assets on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” Other information related to leases is as follows: As of December 31, 2024 2023 Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Weighted-Average Remaining Lease Term (Years): Operating Leases 9 4 12 2 9 4 13 3 Finance Leases 12 8 17 — 13 9 18 — Weighted-Average Discount Rate (Percentage): Operating Leases 4.1 % 5.2 % 4.2 % 5.2 % 4.0 % 5.2 % 4.2 % 5.2 % Finance Leases 3.3 % 5.3 % 2.9 % — % 3.3 % 5.3 % 2.9 % — % (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2024 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 14.5 $ 2.5 $ 4.9 $ 1.8 Operating Cash Flows from Finance Leases 2.6 0.7 0.7 — Financing Cash Flows from Finance Leases 5.2 1.2 — — Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 15.3 7.8 5.7 0.3 Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 0.3 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2023 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 10.5 $ 0.7 $ 2.5 $ 0.4 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — — Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 12.8 0.6 7.0 5.0 Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 18.5 18.3 — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2022 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 11.3 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 18.9 2.4 — — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 3.5 — — — As of December 31, 2024, there are no lease agreements for Eversource, CL&P, NSTAR Electric or PSNH which have been executed but have yet to commence and have not been recorded as right-of-use assets. Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2024 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric Year Ending December 31, 2025 $ 12.5 $ 2.6 $ 4.9 $ 1.9 $ 8.3 $ 2.3 $ 0.7 2026 11.0 2.3 4.9 1.5 7.9 2.4 0.7 2027 7.0 1.8 2.9 0.1 7.9 2.5 0.7 2028 6.6 1.8 2.6 — 7.3 2.6 0.7 2029 4.5 — 2.5 — 7.3 2.6 0.7 Thereafter 26.2 — 22.2 — 50.5 8.9 10.2 Future lease payments 67.8 8.5 40.0 3.5 89.2 21.3 13.7 Less amount representing interest 11.7 0.8 10.6 0.2 21.5 4.2 8.8 Present value of future minimum lease payments $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 67.7 $ 17.1 $ 4.9

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2024
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE OF FINANCIAL INSTRUMENTS The following methods and assumptions were used to estimate the fair value of each of the following financial instruments: Preferred Stock, Long-Term Debt and Rate Reduction Bonds: The fair value of CL&P's and NSTAR Electric's preferred stock is based upon pricing models that incorporate interest rates and other market factors, valuations or trades of similar securities and cash flow projections. The fair value of long-term debt and RRB debt securities is based upon pricing models that incorporate quoted market prices for those issues or similar issues adjusted for market conditions, credit ratings of the respective companies and treasury benchmark yields. The fair values provided in the table below are classified as Level 2 within the fair value hierarchy. Carrying amounts and estimated fair values are as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Carrying Amount Fair Value Carrying Fair Carrying Fair Carrying Fair As of December 31, 2024: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 123.8 $ 116.2 $ 90.3 $ 43.0 $ 33.5 $ — $ — Long-Term Debt 26,704.8 24,791.4 5,111.1 4,705.8 5,094.9 4,759.4 1,732.1 1,529.7 Rate Reduction Bonds 367.3 352.1 — — — — 367.3 352.1 As of December 31, 2023: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 122.2 $ 116.2 $ 90.4 $ 43.0 $ 31.8 $ — $ — Long-Term Debt 24,413.5 22,855.2 4,814.4 4,572.0 4,496.9 4,273.7 1,431.6 1,292.6 Rate Reduction Bonds 410.5 395.0 — — — — 410.5 395.0 Derivative Instruments and Marketable Securities: Derivative instruments and investments in marketable securities are carried at fair value. For further information, see Note 4, "Derivative Instruments," and Note 5, "Marketable Securities," to the financial statements. See Note 1H, "Summary of Significant Accounting Policies – Fair Value Measurements," for the fair value measurement policy and the fair value hierarchy.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)	ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) The changes in accumulated other comprehensive income/(loss) by component, net of tax, are as follows: For the Year Ended December 31, 2024 For the Year Ended December 31, 2023 Eversource (Millions of Dollars) Qualified Defined Total Qualified Unrealized Defined Total Balance as of January 1st $ (0.4) $ (33.3) $ (33.7) $ (0.4) $ (1.2) $ (37.8) $ (39.4) OCI Before Reclassifications — (2.5) (2.5) — — (8.8) (8.8) Amounts Reclassified from AOCI — 9.7 9.7 — 1.2 13.3 14.5 Net OCI — 7.2 7.2 — 1.2 4.5 5.7 Balance as of December 31st $ (0.4) $ (26.1) $ (26.5) $ (0.4) $ — $ (33.3) $ (33.7) Defined benefit plan OCI amounts before reclassifications relate to actuarial gains and losses that arose during the year and were recognized in AOCI. The unamortized actuarial gains and losses and prior service costs on the defined benefit plans are amortized from AOCI into Other Income, Net over the average future employee service period, and are reflected in amounts reclassified from AOCI. The related tax effects of the defined benefit plan OCI amounts before reclassifications recognized in AOCI were net deferred tax assets of $0.4 million, $4.9 million and $1.3 million in 2024, 2023 and 2022, respectively. The following table sets forth the amounts reclassified from AOCI by component and the impacted line item on the statements of income: Amounts Reclassified from AOCI Eversource (Millions of Dollars) For the Years Ended December 31, Statements of Income 2024 2023 2022 Unrealized Loss on Marketable Securities — (1.6) — Other Income, Net Tax Effect — 0.4 — Income Tax Expense Unrealized Loss on Marketable Securities, Net of Tax — (1.2) — Defined Benefit Plan Costs: Amortization of Actuarial Losses (6.8) (7.0) (9.0) Other Income, Net (1) Amortization of Prior Service Cost (0.3) (0.3) (0.3) Other Income, Net (1) Settlement Losses (4.3) (12.4) — Other Income, Net (1) Total Defined Benefit Plan Costs (11.4) (19.7) (9.3) Tax Effect 1.7 6.4 2.3 Income Tax Expense Defined Benefit Plan Costs, Net of Tax (9.7) (13.3) (7.0) Total Amounts Reclassified from AOCI, Net of Tax $ (9.7) $ (14.5) $ (7.0) (1) These amounts are included in the computation of net periodic Pension, SERP and PBOP costs. See Note 1L, "Summary of Significant Accounting Policies – Other Income, Net" and Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for further information.

DIVIDEND RESTRICTIONS

DIVIDEND RESTRICTIONS	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
DIVIDEND RESTRICTIONS	DIVIDEND RESTRICTIONS Eversource parent's ability to pay dividends may be affected by certain state statutes, the ability of its subsidiaries to pay common dividends and the leverage restriction tied to its consolidated total indebtedness to total capitalization ratio requirement in its revolving credit agreements. Pursuant to the joint revolving credit agreement of Eversource, CL&P, PSNH, NSTAR Gas, Yankee Gas, EGMA and Aquarion Water Company of Connecticut, and to the NSTAR Electric revolving credit agreement, Eversource is required to maintain consolidated total indebtedness to total capitalization ratio of no greater than 70 percent at the end of each fiscal quarter and each other company is required to maintain consolidated total indebtedness to total capitalization ratio of no greater than 65 percent at the end of each fiscal quarter. As of December 31, 2024, all companies were in compliance with suc h covenant and in compliance with all such provisions of the revolving credit agreements that may restrict the payment of dividends as of December 31, 2024. The Retained Earnings balances subject to dividend restrictions were $3.93 billion for Eversource, $2.82 billion for CL&P, $3.13 billion for NSTAR Electric and $808.7 million for PSNH as of December 31, 2024.

COMMON SHARES

COMMON SHARES	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
COMMON SHARES	COMMON SHARES The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2024 and 2023 Issued as of December 31, 2024 2023 Eversource $ 5 410,000,000 375,724,367 359,984,073 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Common Share Issuances: Eversource had an equity distribution agreement pursuant to which it could offer and sell up to $1.2 billion of its common shares from time to time through an “at-the-market” (ATM) equity offering program. Eversource issued and sold its common shares through its sales agents during the term of this agreement. Shares were offered in transactions on the New York Stock Exchange, in the over-the-counter market, through negotiated transactions or otherwise. Sales were made at either market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices. In 2024, Eversource issued 15,740,294 common shares, which resulted in proceeds of $989.4 million, net of issuance costs. Eversource used the net proceeds received for general corporate purposes. In 2023, no shares were issued under this agreement. Eversource completed the program in October 2024. Treasury Shares: As of December 31, 2024 and 2023, there were 9,116,315 and 10,443,807 Eversource common shares held as treasury shares, respectively. As of December 31, 2024 and 2023, there were 366,608,052 and 349,540,266 Eversource common shares outstanding, respectively. Acquisition of The Torrington Water Company: On October 3, 2022, Aquarion acquired The Torrington Water Company (TWC) following the receipt of all required approvals. The acquisition was structured as a stock-for-stock merger and Eversource issued 925,264 treasury shares at closing for a purchase price of $72.1 million. Eversource issues treasury shares to satisfy awards under the Company's incentive plans, shares issued under the dividend reinvestment and share purchase plan, and matching contributions under the Eversource 401k Plan. Eversource also issued treasury shares for its October 2022 water business acquisitions. The issuance of treasury shares represents a non-cash transaction, as the treasury shares were used to fulfill Eversource's obligations that require the issuance of common shares. On May 3, 2023, shareholders voted to increase the authorized common shares from 380,000,000 shares to 410,000,000 shares. Dividends on the preferred stock of CL&P and NSTAR Electric totaled $7.5 million for each of the years ended December 31, 2024, 2023 and 2022. These dividends were presented as Net Income Attributable to Noncontrolling Interests on the Eversource statements of income. Noncontrolling Interest – Preferred Stock of Subsidiaries on the Eversource balance sheets totaled $155.6 million as of December 31, 2024 and 2023. On the Eversource balance sheets, Common Shareholders' Equity was fully attributable to Eversource parent and Noncontrolling Interest – Preferred Stock of Subsidiaries was fully attributable to the noncontrolling interest.

PREFERRED STOCK NOT SUBJECT TO

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION	PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION The CL&P and NSTAR Electric preferred stock is not subject to mandatory redemption and is presented as a noncontrolling interest of a subsidiary in Eversource's financial statements. Details of preferred stock not subject to mandatory redemption are as follows (in millions, except in redemption price and shares): Redemption Price Shares Outstanding as of December 31, As of December 31, Series 2024 2023 2024 2023 CL&P $1.90 Series of 1947 $ 52.50 163,912 163,912 $ 8.2 $ 8.2 $2.00 Series of 1947 $ 54.00 336,088 336,088 16.8 16.8 $2.04 Series of 1949 $ 52.00 100,000 100,000 5.0 5.0 $2.20 Series of 1949 $ 52.50 200,000 200,000 10.0 10.0 3.90% Series of 1949 $ 50.50 160,000 160,000 8.0 8.0 $2.06 Series E of 1954 $ 51.00 200,000 200,000 10.0 10.0 $2.09 Series F of 1955 $ 51.00 100,000 100,000 5.0 5.0 4.50% Series of 1956 $ 50.75 104,000 104,000 5.2 5.2 4.96% Series of 1958 $ 50.50 100,000 100,000 5.0 5.0 4.50% Series of 1963 $ 50.50 160,000 160,000 8.0 8.0 5.28% Series of 1967 $ 51.43 200,000 200,000 10.0 10.0 $3.24 Series G of 1968 $ 51.84 300,000 300,000 15.0 15.0 6.56% Series of 1968 $ 51.44 200,000 200,000 10.0 10.0 Total CL&P 2,324,000 2,324,000 $ 116.2 $ 116.2 NSTAR Electric 4.25% Series of 1956 $ 103.625 180,000 180,000 $ 18.0 $ 18.0 4.78% Series of 1958 $ 102.80 250,000 250,000 25.0 25.0 Total NSTAR Electric 430,000 430,000 $ 43.0 $ 43.0 Fair Value Adjustment due to Merger with NSTAR (3.6) (3.6) Total Eversource - Noncontrolling Interest - Preferred Stock of Subsidiaries $ 155.6 $ 155.6

COMMON SHAREHOLDERS' EQUITY AND

COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS	COMMON SHARES The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2024 and 2023 Issued as of December 31, 2024 2023 Eversource $ 5 410,000,000 375,724,367 359,984,073 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Common Share Issuances: Eversource had an equity distribution agreement pursuant to which it could offer and sell up to $1.2 billion of its common shares from time to time through an “at-the-market” (ATM) equity offering program. Eversource issued and sold its common shares through its sales agents during the term of this agreement. Shares were offered in transactions on the New York Stock Exchange, in the over-the-counter market, through negotiated transactions or otherwise. Sales were made at either market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices. In 2024, Eversource issued 15,740,294 common shares, which resulted in proceeds of $989.4 million, net of issuance costs. Eversource used the net proceeds received for general corporate purposes. In 2023, no shares were issued under this agreement. Eversource completed the program in October 2024. Treasury Shares: As of December 31, 2024 and 2023, there were 9,116,315 and 10,443,807 Eversource common shares held as treasury shares, respectively. As of December 31, 2024 and 2023, there were 366,608,052 and 349,540,266 Eversource common shares outstanding, respectively. Acquisition of The Torrington Water Company: On October 3, 2022, Aquarion acquired The Torrington Water Company (TWC) following the receipt of all required approvals. The acquisition was structured as a stock-for-stock merger and Eversource issued 925,264 treasury shares at closing for a purchase price of $72.1 million. Eversource issues treasury shares to satisfy awards under the Company's incentive plans, shares issued under the dividend reinvestment and share purchase plan, and matching contributions under the Eversource 401k Plan. Eversource also issued treasury shares for its October 2022 water business acquisitions. The issuance of treasury shares represents a non-cash transaction, as the treasury shares were used to fulfill Eversource's obligations that require the issuance of common shares. On May 3, 2023, shareholders voted to increase the authorized common shares from 380,000,000 shares to 410,000,000 shares. Dividends on the preferred stock of CL&P and NSTAR Electric totaled $7.5 million for each of the years ended December 31, 2024, 2023 and 2022. These dividends were presented as Net Income Attributable to Noncontrolling Interests on the Eversource statements of income. Noncontrolling Interest – Preferred Stock of Subsidiaries on the Eversource balance sheets totaled $155.6 million as of December 31, 2024 and 2023. On the Eversource balance sheets, Common Shareholders' Equity was fully attributable to Eversource parent and Noncontrolling Interest – Preferred Stock of Subsidiaries was fully attributable to the noncontrolling interest.

EARNINGS_(LOSS) PER SHARE

EARNINGS/(LOSS) PER SHARE	12 Months Ended
	Dec. 31, 2024
Earnings Per Share [Abstract]
EARNINGS/(LOSS) PER SHARE	EARNINGS/(LOSS) PER SHARE Basic earnings/(loss) per share is computed based upon the weighted average number of common shares outstanding during each period. Diluted earnings/(loss) per share is computed on the basis of the weighted average number of common shares outstanding plus the potential dilutive effect of certain share-based compensation awards as if they were converted into outstanding common shares. The dilutive effect of unvested RSU and performance share awards is calculated using the treasury stock method. RSU and performance share awards are included in basic weighted average common shares outstanding as of the date that all necessary vesting conditions have been satisfied. For the years ended December 31, 2024, 2023 and 2022, there were no antidilutive share awards excluded from the computation. The following table sets forth the components of basic and diluted earnings/(loss) per share: Eversource (Millions of Dollars, except share information) For the Years Ended December 31, 2024 2023 2022 Net Income/(Loss) Attributable to Common Shareholders $ 811.7 $ (442.2) $ 1,404.9 Weighted Average Common Shares Outstanding: Basic 357,482,965 349,580,638 346,783,444 Dilutive Effect 296,443 259,843 463,324 Diluted 357,779,408 349,840,481 347,246,768 Basic Earnings/(Loss) Per Common Share $ 2.27 $ (1.27) $ 4.05 Diluted Earnings/(Loss) Per Common Share $ 2.27 $ (1.26) $ 4.05

REVENUES

REVENUES	12 Months Ended
	Dec. 31, 2024
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenue is recognized when promised goods or services (referred to as performance obligations) are transferred to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. A five-step model is used for recognizing and measuring revenue from contracts with customers, which includes identifying the contract with the customer, identifying the performance obligations promised within the contract, determining the transaction price (the amount of consideration to which the company expects to be entitled), allocating the transaction price to the performance obligations and recognizing revenue when (or as) the performance obligation is satisfied. The following tables present operating revenues disaggregated by revenue source: For the Year Ended December 31, 2024 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 4,904.8 $ 1,129.1 $ — $ 150.4 $ — $ — $ 6,184.3 Commercial 2,973.3 588.0 — 70.3 — (7.7) 3,623.9 Industrial 389.0 172.5 — 4.7 — (22.4) 543.8 Total Retail Tariff Sales Revenues 8,267.1 1,889.6 — 225.4 — (30.1) 10,352.0 Wholesale Transmission Revenues — — 2,032.4 — — (1,529.3) 503.1 Wholesale Market Sales Revenues 658.9 161.9 — 4.2 — — 825.0 Other Revenues from Contracts with Customers 92.2 5.1 13.9 5.7 1,701.3 (1,694.6) 123.6 Reserve for Revenues Subject to Refund — — — (1.9) — — (1.9) Total Revenues from Contracts with Customers 9,018.2 2,056.6 2,046.3 233.4 1,701.3 (3,254.0) 11,801.8 Alternative Revenue Programs 28.7 44.5 74.2 (5.3) — (67.2) 74.9 Other Revenues 19.6 2.8 0.5 1.2 — — 24.1 Total Operating Revenues $ 9,066.5 $ 2,103.9 $ 2,121.0 $ 229.3 $ 1,701.3 $ (3,321.2) $ 11,900.8 For the Year Ended December 31, 2023 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 5,054.2 $ 1,145.4 $ — $ 144.7 $ — $ — $ 6,344.3 Commercial 2,893.2 637.7 — 69.8 — (4.8) 3,595.9 Industrial 352.4 186.8 — 4.5 — (19.7) 524.0 Total Retail Tariff Sales Revenues 8,299.8 1,969.9 — 219.0 — (24.5) 10,464.2 Wholesale Transmission Revenues — — 1,777.5 — — (1,310.5) 467.0 Wholesale Market Sales Revenues 625.0 206.7 — 3.9 — — 835.6 Other Revenues from Contracts with Customers 82.6 5.6 14.6 8.1 1,636.6 (1,628.0) 119.5 Amortization of Revenues Subject to Refund — — 4.3 — — — 4.3 Total Revenues from Contracts with Customers 9,007.4 2,182.2 1,796.4 231.0 1,636.6 (2,963.0) 11,890.6 Alternative Revenue Programs (54.3) 35.5 118.9 0.4 — (106.5) (6.0) Other Revenues 20.4 4.0 0.6 1.1 — — 26.1 Total Operating Revenues $ 8,973.5 $ 2,221.7 $ 1,915.9 $ 232.5 $ 1,636.6 $ (3,069.5) $ 11,910.7 For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 4,796.1 $ 1,204.9 $ — $ 141.7 $ — $ — $ 6,142.7 Commercial 2,903.3 648.5 — 66.5 — (4.1) 3,614.2 Industrial 374.9 199.7 — 4.7 — (20.1) 559.2 Total Retail Tariff Sales Revenues 8,074.3 2,053.1 — 212.9 — (24.2) 10,316.1 Wholesale Transmission Revenues — — 1,700.5 — — (1,264.5) 436.0 Wholesale Market Sales Revenues 1,190.9 140.8 — 3.8 — — 1,335.5 Other Revenues from Contracts with Customers 72.3 5.6 14.1 8.4 1,435.5 (1,425.3) 110.6 Amortization of/(Reserve for) Revenues 72.0 — 0.7 (0.7) — — 72.0 Total Revenues from Contracts with Customers 9,409.5 2,199.5 1,715.3 224.4 1,435.5 (2,714.0) 12,270.2 Alternative Revenue Programs (15.4) 14.8 92.7 (2.5) — (84.3) 5.3 Other Revenues 11.2 1.3 0.7 0.6 — — 13.8 Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Revenues from Contracts with Customers Retail Tariff Sales Residential $ 2,493.7 $ 1,771.8 $ 639.3 $ 2,597.8 $ 1,691.0 $ 765.4 $ 2,397.2 $ 1,601.8 $ 797.1 Commercial 1,164.8 1,466.7 343.6 1,082.1 1,442.3 369.6 1,067.9 1,457.4 380.8 Industrial 164.2 118.1 106.7 137.2 123.2 92.0 146.4 135.8 92.7 Total Retail Tariff Sales Revenues 3,822.7 3,356.6 1,089.6 3,817.1 3,256.5 1,227.0 3,611.5 3,195.0 1,270.6 Wholesale Transmission Revenues 870.8 794.1 367.5 794.7 692.0 290.8 755.1 670.4 275.0 Wholesale Market Sales Revenues 491.9 131.1 35.9 429.1 131.8 64.1 873.7 215.0 102.2 Other Revenues from Contracts 36.7 50.2 21.2 32.4 49.1 18.1 30.2 46.9 11.8 Amortization of Revenues Subject — — — 4.3 — — 72.7 — — Total Revenues from Contracts 5,222.1 4,332.0 1,514.2 5,077.6 4,129.4 1,600.0 5,343.2 4,127.3 1,659.6 Alternative Revenue Programs 45.4 36.7 20.8 66.8 (52.0) 49.8 56.5 0.7 20.1 Other Revenues 9.0 8.5 2.6 9.6 8.4 3.0 1.8 7.2 2.9 Eliminations (661.5) (656.3) (243.1) (575.2) (570.3) (204.9) (583.8) (552.1) (207.8) Total Operating Revenues $ 4,615.0 $ 3,720.9 $ 1,294.5 $ 4,578.8 $ 3,515.5 $ 1,447.9 $ 4,817.7 $ 3,583.1 $ 1,474.8 Retail Tariff Sales: Regulated utilities provide products and services to their regulated customers under rates, pricing, payment terms and conditions of service, regulated by each state regulatory agency. The arrangement whereby a utility provides commodity service to a customer for a price approved by the respective state regulatory commission is referred to as a tariff sale contract, and the tariff governs all aspects of the provision of regulated services by utilities. The majority of revenue for Eversource, CL&P, NSTAR Electric and PSNH is derived from regulated retail tariff sales for the sale and distribution of electricity, natural gas and water to residential, commercial and industrial retail customers. The utility's performance obligation for the regulated tariff sales is to provide electricity, natural gas or water to the customer as demanded. The promise to provide the commodity represents a single performance obligation, as it is a promise to transfer a series of distinct goods or services that are substantially the same and that have the same pattern of transfer to the customer. Revenue is recognized over time as the customer simultaneously receives and consumes the benefits provided by the utility, and the utility satisfies its performance obligation. Revenue is recognized based on the output method as there is a directly observable output to the customer (electricity, natural gas or water units delivered to the customer and immediately consumed). Each Eversource utility is entitled to be compensated for performance completed to date (service taken by the customer) until service is terminated. In regulated tariff sales, the transaction prices are the rates approved by the respective state regulatory commissions. In general, rates can only be changed through formal proceedings with the state regulatory commissions. These rates are designed to recover the costs to provide service to customers and include a return on investment. Regulatory commission-approved tracking mechanisms are included in these rates and are also used to recover, on a fully-reconciling basis, certain costs, such as the procurement of energy supply, state mandated energy purchase agreements, retail transmission charges, energy efficiency program costs, net metering for distributed generation, and restructuring and stranded costs, among others. These tracking mechanisms result in rates being changed periodically to ensure recovery of actual costs incurred and the refund of any overcollection of costs. Electric customers may elect to purchase electricity from each Eversource electric utility or may contract separately with a competitive third party supplier. Certain eligible natural gas customers may elect to purchase natural gas from each Eversource natural gas utility or may contract separately with a gas supply operator. Revenue is not recorded for the sale of the electricity or the natural gas commodity to customers who have contracted separately with these suppliers, only the delivery to a customer, as the utility is acting as an agent on behalf of the supplier. Wholesale Transmission Revenues: The Eversource electric transmission-owning companies (CL&P, NSTAR Electric and PSNH) each own and maintain transmission facilities that are part of an interstate power transmission grid over which electricity is transmitted throughout New England. CL&P, NSTAR Electric and PSNH, as well as most other New England utilities, are parties to a series of agreements that provide for coordinated planning and operation of the region's transmission facilities and the rules by which they acquire transmission services. The Eversource electric transmission-owning companies have a combination of FERC-approved regional and local formula rates that are designed to work in tandem to recover all their transmission costs. These rates are part of the ISO-NE Tariff. Regional rates recover the costs of higher voltage transmission facilities that benefit the region and are collected from all New England transmission customers, including the Eversource distribution businesses. Eversource's local rates generally recover the costs of transmission facilities that do not provide a benefit to the region, and are collected from Eversource's distribution businesses and other transmission customers. The distribution businesses of Eversource, in turn, recover the FERC approved charges from retail customers through annual tracking mechanisms, which are retail tariff sales. The utility's performance obligation for regulated wholesale transmission sales is to provide transmission services to the customer as demanded. The promise to provide transmission service represents a single performance obligation. The transaction prices are the transmission rate formulas as defined by the ISO-NE Tariff and are regulated and established by FERC. Wholesale transmission revenue is recognized over time as the performance obligation is completed, which occurs as transmission services are provided to customers. The revenue is recognized based on the output method. Each Eversource utility is entitled to be compensated for performance completed to date (e.g., use of the transmission system by the customer). Wholesale Market Sales Revenues: Wholesale market sales transactions include sales of energy and energy-related products into the ISO-NE wholesale electricity market, sales of natural gas to third party marketers, and also the sale of RECs to various counterparties. ISO-NE oversees the region's wholesale electricity market and administers the transactions and terms and conditions, including payment terms, which are established in the ISO-NE tariff, between the buyers and sellers in the market. Pricing is set by the wholesale market. The wholesale transactions in the ISO-NE market occur on a day-ahead basis or a real-time basis (daily) and are, therefore, short-term. Transactions are tracked and reported by ISO-NE net by the hour, which is the net hourly position of energy sales and purchases by each market participant. The performance obligation for ISO-NE energy transactions is defined to be the net by hour transaction. Revenue is recognized when the performance obligation for these energy sales transactions is satisfied, which is when the sale occurs and the energy is transferred to the customer. For sales of natural gas, transportation, and natural gas pipeline capacity to third party marketers, revenue is recognized when the performance obligation is satisfied at the point in time the sale occurs and the natural gas or related product is transferred to the marketer. RECs are sold to various counterparties, and revenue is recognized when the performance obligation is satisfied upon transfer of title to the customer through the New England Power Pool Generation Information System. Wholesale transactions also include the sale of CL&P’s, NSTAR Electric’s and PSNH’s transmission rights associated with their proportionate equity ownership share in the transmission lines of the Hydro-Québec system in Canada. Other Revenues from Contracts with Customers: Other revenues from contracts with customers primarily include property rentals that are not deemed leases. These revenues are generally recognized on a straight-line basis over time as the service is provided to the customer. Other revenues also include revenues from Eversource's service company, which is eliminated in consolidation. Amortization of/(Reserve for) Revenues Subject to Refund: A reserve is recorded as a reduction to revenues when future refunds to customers are deemed probable. The reserve is reversed as refunds are provided to customers in rates. Amortization of Revenues Subject to Refund within the Electric Distribution segment in 2022 represents the reversal of a 2021 reserve at CL&P established to provide bill credits to customers as a result of the settlement agreement on October 1, 2021 and a storm performance penalty assessed by PURA. The reserve of $93.4 million was reversed as customer credits were distributed to CL&P’s customers in retail electric rates in 2021 and 2022. Alternative Revenue Programs: In accordance with accounting guidance for rate-regulated operations, certain of Eversource's utilities' rate making mechanisms qualify as alternative revenue programs (ARPs) if they meet specified criteria, in which case revenues may be recognized prior to billing based on allowed levels of collection in rates. Eversource's utility companies recognize revenue and record a regulatory asset or liability once the condition or event allowing for the automatic adjustment of future rates occurs. ARP revenues include both the recognition of the deferral adjustment to ARP revenues, when the regulator-specified condition or event allowing for additional billing or refund has occurred, and an equal and offsetting reversal of the ARP deferral to revenues as those amounts are reflected in the price of service in subsequent periods. Eversource’s ARPs include the revenue decoupling mechanism, the annual reconciliation adjustment to transmission formula rates, and certain capital tracker mechanisms. Certain Eversource electric, natural gas and water companies, including CL&P and NSTAR Electric, have revenue decoupling mechanisms approved by a regulatory commission (decoupled companies). Decoupled companies’ distribution revenues are not directly based on sales volumes. The decoupled companies reconcile their annual base distribution rate recovery to pre-established levels of baseline distribution delivery service revenues, with any difference between the allowed level of distribution revenue and the actual amount realized adjusted through subsequent rates. The transmission formula rates provide for the annual reconciliation and recovery or refund of estimated costs to actual costs. The financial impacts of differences between actual and estimated costs are deferred for future recovery from, or refund to, transmission customers. This transmission deferral reconciles billed transmission revenues to the revenue requirement for our transmission businesses. Other Revenues: Other Revenues include certain fees charged to customers that are not considered revenue from contracts with customers. Other revenues Intercompany Eliminations: Intercompany eliminations are primarily related to the Eversource electric transmission revenues that are derived from ISO-NE regional transmission charges to the distribution businesses of CL&P, NSTAR Electric and PSNH that recover the costs of the wholesale transmission business, and revenues from Eversource's service company. Intercompany revenues and expenses between the Eversource wholesale transmission businesses and the Eversource distribution businesses and from Eversource's service company are eliminated in consolidation and included in "Eliminations" in the tables above. Receivables: Receivables, Net on the balance sheet primarily includes trade receivables from retail customers and customers related to wholesale transmission contracts, wholesale market sales, sales of RECs, and property rentals. In general, retail tariff customers and wholesale transmission customers are billed monthly and the payment terms are generally due and payable upon receipt of the bill. Unbilled Revenues: Unbilled Revenues on the balance sheet represent estimated amounts due from retail customers for electricity, natural gas or water delivered to customers but not yet billed. The utility company has satisfied its performance obligation and the customer has received and consumed the commodity as of the balance sheet date, and therefore, the utility company records revenue for those services in the period the services were provided. Only the passage of time is required before the company is entitled to payment for the satisfaction of the performance obligation. Payment from customers is due monthly as services are rendered and amounts are billed. Actual amounts billed to customers when meter readings become available may vary from the estimated amount. Unbilled revenues are recognized by allocating estimated unbilled sales volumes to the respective customer classes, and then applying an estimated rate by customer class to those sales volumes. Unbilled revenue estimates reflect seasonality, weather, customer usage patterns, customer rates in effect for customer classes, and the timing of customer billing. The companies that have a decoupling mechanism record a regulatory deferral to reflect the actual allowed amount of revenue associated with their respective decoupled distribution rate design. Practical Expedients:

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2024
Segment Reporting [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION Eversource is organized into the Electric Distribution, Electric Transmission, Natural Gas Distribution and Water Distribution reportable segments and Other based on a combination of factors, including the characteristics of each segments' services, the sources of operating revenues and expenses and the regulatory environment in which each segment operates. The Electric Distribution segment consists of the rate-regulated distribution businesses of CL&P, NSTAR Electric and PSNH, and includes the results of NSTAR Electric's solar power facilities. The Electric Transmission segment consists of the rate-regulated electric transmission businesses of CL&P, NSTAR Electric and PSNH. The Natural Gas Distribution segment consists of the rate-regulated businesses of Yankee Gas, NSTAR Gas and EGMA. The Water Distribution segment consists of the rate-regulated business of Aquarion. These reportable segments represent substantially all of Eversource's total consolidated revenues. Revenues from the sale of electricity, natural gas and water primarily are derived from residential, commercial and industrial customers and are not dependent on any single customer. Eversource's reportable segments are determined based upon the level at which Eversource's chief operating decision maker assesses performance and makes decisions about the allocation of company resources. The chief operating decision maker uses the net income of each reportable segment to evaluate return generated from assets and decide how to reinvest profits and allocate resources, to monitor budget-to-actual results, in the planning and forecasting process, in determining compensation achievement, and in benchmarking to Eversource’s peers. Eversource’s chief operating decision maker is its chief executive officer. The accounting policies of the segments are the same as those described in the summary of significant accounting policies. The remainder of Eversource's operations is presented as Other in the tables below and primarily consists of 1) the equity in earnings of Eversource parent from its subsidiaries and intercompany interest income, both of which are eliminated in consolidation, and interest expense related to the debt of Eversource parent, 2) the revenues and expenses of Eversource Service, most of which are eliminated in consolidation, 3) the operations of CYAPC and YAEC, 4) the results of other unregulated subsidiaries, which are not part of its core business, and 5) Eversource parent's equity ownership interests that are not consolidated, which primarily included the offshore wind investments until sale of the three offshore wind projects in 2024 and a natural gas pipeline owned by Enbridge, Inc. In the ordinary course of business, Yankee Gas, NSTAR Gas and EGMA purchase natural gas transmission services from the Enbridge, Inc. natural gas pipeline project described above. These affiliate transaction costs total $77.7 million annually and are classified as Purchased Power, Purchased Natural Gas and Transmission on the Eversource statements of income. Each of Eversource's subsidiaries, including CL&P, NSTAR Electric and PSNH, has one reportable segment. Cash flows used for investments in plant included in the segment information below are cash capital expenditures that do not include amounts incurred on capital projects but not yet paid, cost of removal, AFUDC related to equity funds, and the capitalized and deferred portions of pension and PBOP income/expense. Eversource's segment information is as follows: For the Year Ended December 31, 2024 Eversource (Millions of Dollars) Electric Natural Gas Electric Transmission Water Distribution Other Eliminations Total Operating Revenues $ 9,066.5 $ 2,103.9 $ 2,121.0 $ 229.3 $ 1,701.3 $ (3,321.2) $ 11,900.8 Depreciation and Amortization (934.7) (216.6) (405.1) (32.3) (198.7) 11.0 (1,776.4) Operations and Maintenance (1) Operations, Excluding Storm Costs (447.3) (180.9) (135.1) Corporate Shared Services (457.1) (106.1) (74.6) Storm Costs (76.8) — — Employee Benefits (202.5) (76.9) (52.7) Uncollectible Expense (182.8) (48.4) — Other (135.9) (29.2) (71.1) Total Operations and Maintenance (1,502.4) (441.5) (333.5) (98.7) (1,350.5) 1,713.7 (2,012.9) Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2) (5,685.3) (1,007.1) (276.0) (26.3) (7.6) 1,596.5 (5,405.8) Loss on Pending Sale of Aquarion — — — (297.0) — — (297.0) Operating Income/(Loss) 944.1 438.7 1,106.4 (225.0) 144.5 — 2,408.7 Interest Expense (359.1) (99.2) (172.4) (36.2) (662.7) 218.3 (1,111.3) Loss on Offshore Wind Investments — — — — (464.0) — (464.0) Interest Income 114.6 23.2 0.3 0.1 218.3 (218.3) 138.2 Other Income, Net 134.7 22.4 50.5 7.2 1,416.9 (1,359.4) 272.3 Income Tax (Expense)/Benefit (198.0) (94.1) (257.3) 0.2 124.5 — (424.7) Net Income/(Loss) 636.3 291.0 727.5 (253.7) 777.5 (1,359.4) 819.2 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income/(Loss) Attributable to $ 631.7 $ 291.0 $ 724.6 $ (253.7) $ 777.5 $ (1,359.4) $ 811.7 Total Assets (as of) $ 32,031.9 $ 9,786.7 $ 16,070.9 $ 2,515.8 $ 29,041.1 $ (29,851.9) $ 59,594.5 Cash Flows Used for Investments in Plant $ 1,807.4 $ 934.5 $ 1,343.3 $ 161.8 $ 233.5 $ — $ 4,480.5 For the Year Ended December 31, 2023 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 8,973.5 $ 2,221.7 $ 1,915.9 $ 232.5 $ 1,636.6 $ (3,069.5) $ 11,910.7 Depreciation and Amortization (18.2) (214.2) (371.2) (56.0) (158.8) 2.7 (815.7) Operations and Maintenance (1) Operations, Excluding Storm Costs (418.2) (172.8) (124.7) Corporate Shared Services (397.2) (103.0) (62.5) Storm Costs (71.1) — (1.3) Employee Benefits (175.6) (76.6) (46.1) Uncollectible Expense (161.9) (64.8) — Other (167.9) (27.5) (57.4) Total Operations and Maintenance (1,391.9) (444.7) (292.0) (93.2) (1,325.6) 1,651.7 (1,895.7) Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2) (6,712.7) (1,217.9) (258.5) (23.9) (4.2) 1,417.2 (6,800.0) Operating Income 850.7 344.9 994.2 59.4 148.0 2.1 2,399.3 Interest Expense (291.7) (85.7) (163.7) (38.5) (425.3) 149.5 (855.4) Loss on Offshore Wind Investments — — — — (2,167.0) — (2,167.0) Interest Income 74.5 18.2 0.4 — 150.6 (149.5) 94.2 Other Income/(Loss), Net 136.2 20.4 41.2 5.9 (261.8) 312.0 253.9 Income Tax (Expense)/Benefit (157.1) (73.0) (225.8) 6.3 289.9 — (159.7) Net Income/(Loss) 612.6 224.8 646.3 33.1 (2,265.6) 314.1 (434.7) Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income/(Loss) Attributable to $ 608.0 $ 224.8 $ 643.4 $ 33.1 $ (2,265.6) $ 314.1 $ (442.2) Total Assets (as of) $ 29,426.4 $ 8,775.3 $ 14,806.5 $ 2,944.8 $ 26,337.7 $ (26,678.5) $ 55,612.2 Cash Flows Used for Investments in Plant $ 1,668.1 $ 844.1 $ 1,406.3 $ 167.0 $ 251.3 $ — $ 4,336.8 For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 Depreciation and Amortization (970.4) (157.6) (337.4) (50.9) (132.6) 5.8 (1,643.1) Operations and Maintenance (1) Operations, Excluding Storm Costs (416.0) (182.5) (117.7) Corporate Shared Services (371.0) (109.8) (58.4) Storm Costs (74.4) — (0.1) Employee Benefits (189.6) (79.8) (39.6) Uncollectible Expense (107.3) (36.0) — Other (153.0) (30.3) (72.6) Total Operations and Maintenance (1,311.3) (438.4) (288.4) (88.4) (1,184.6) 1,445.8 (1,865.3) Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2) (6,352.4) (1,288.6) (260.0) (23.4) (4.5) 1,346.2 (6,582.7) Operating Income 771.2 331.0 922.9 59.8 113.8 (0.5) 2,198.2 Interest Expense (253.1) (71.4) (145.5) (34.7) (247.8) 74.2 (678.3) Interest Income 45.1 10.2 0.5 — 66.3 (71.6) 50.5 Other Income, Net 180.4 33.6 37.9 8.5 1,600.8 (1,565.6) 295.6 Income Tax (Expense)/Benefit (146.2) (69.2) (216.3) 3.2 (25.1) — (453.6) Net Income 597.4 234.2 599.5 36.8 1,508.0 (1,563.5) 1,412.4 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 592.8 $ 234.2 $ 596.6 $ 36.8 $ 1,508.0 $ (1,563.5) $ 1,404.9 Cash Flows Used for Investments in Plant $ 1,172.6 $ 710.3 $ 1,144.0 $ 154.4 $ 260.6 $ — $ 3,441.9 (1) The significant expense categories and amounts align with the segment-level information that is regularly provided to the chief operating decision maker. Costs of the operations organization include labor and overtime, outside services, vehicles, vegetation management, employee expenses, fees and payments, regulatory assessments, and materials, partially offset by reimbursements. Corporate shared services include corporate centralized functions. Costs within these corporate functions primarily include labor, services by vendors, fees and payments, insurance, and regulatory assessments. Other includes information technology system depreciation at Eversource Service charged to the operating businesses, as well as storm funding, capitalization and various other corporate costs. The segment-level operating expense for information technology system depreciation is eliminated and reflected in depreciation in Eversource’s consolidation. For the water distribution segment, the chief operating decision maker is provided with total operations and maintenance expense information to manage its operations. Operations and maintenance expenses primarily include employee costs, benefits, and outside services. (2)

Assets Held For Sale

Assets Held For Sale	12 Months Ended
	Dec. 31, 2024
Discontinued Operations and Disposal Groups [Abstract]
Assets Held For Sale	ASSETS HELD FOR SALE In early 2024, Eversource initiated an exploratory assessment of the potential sale of the Aquarion water distribution business. In December 2024, final bids were received, and Eversource obtained approval from its Board of Trustees to sell the Aquarion water distribution business. On January 27, 2025, Eversource entered into a definitive agreement to sell Aquarion. Subject to certain closing adjustments, the aggregate enterprise value of the sale is approximately $2.4 billion in cash, which includes approximately $1.6 billion for the equity and $800 million of net debt that will be extinguished at closing. The sale is subject to approval by PURA, DPU and the NHPUC, as well as other approvals pursuant to the Hart-Scott-Rodino Antitrust Improvements Act as well as other customary closing conditions. The sale is expected to close in late 2025. Eversource plans to use the net proceeds from the pending sale to pay down parent company debt. The assets and liabilities of the Aquarion water distribution business met the criteria to be classified as held for sale and have been classified separately as current or long-term assets and liabilities held for sale on the Eversource balance sheet as of December 31, 2024. As Eversource concluded this is the sale of a business, all goodwill held by the water distribution reporting unit was included in the carrying amount of the business and is also classified within assets held for sale. Long-term debt will be repaid by Eversource upon closing and is therefore excluded from liabilities held for sale. Assets and liabilities classified as held for sale are measured at the lower of carrying amount or fair value less costs to sell. In the fourth quarter of 2024, upon classifying the assets and liabilities as held for sale, Eversource concluded that the likely sale of Aquarion at a loss resulted in the requirement to test water distribution goodwill for impairment. Eversource performed an impairment test by comparing the fair value of the business to its carrying value and recorded a goodwill impairment of $297 million, as the estimated fair value of the business based on the anticipated sale was less than the carrying value. The fair value included future cash outflows of approximately $140 million of estimated income taxes as a result of the transaction. The goodwill impairment charge is presented separately within Operating Income on the Eversource statement of income for the year ended December 31, 2024. The water distribution business did not and will not meet the criteria to be presented as a discontinued operation. As of December 31, 2024, the major classes of Aquarion’s assets and liabilities presented in current and long-term Assets Held for Sale and Liabilities Held for Sale on the Eversource balance sheet, which are included in the Water Distribution reportable segment, were as follows: (Millions of Dollars) Restricted Cash $ 5.8 Receivables, Net 14.4 Unbilled Revenues 11.5 Prepayments and Other Current Assets 24.6 Total Current Assets Held for Sale $ 56.3 Property, Plant and Equipment, Net $ 1,885.2 Regulatory Assets 51.2 Goodwill 662.5 Other Long-Term Assets 12.2 Total Long-Term Assets Held for Sale $ 2,611.1 Accounts Payable $ 24.2 Other Current Liabilities 28.4 Total Current Liabilities Held for Sale $ 52.6 Regulatory Liabilities $ 132.2 Other Long-Term Liabilities 266.7 Total Long-Term Liabilities Held for Sale $ 398.9

GOODWILL

GOODWILL	12 Months Ended
	Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL In a business combination, the excess of the purchase price over the estimated fair values of the assets acquired and liabilities assumed is recognized as goodwill. The following table presents Eversource’s goodwill by reportable segment: (Millions of Dollars) Electric Electric Natural Gas Water Total Balance as of January 1, 2023 $ 2,543.6 $ 576.8 $ 451.0 $ 951.2 $ 4,522.6 Water Acquisitions — — — 9.5 9.5 Balance as of December 31, 2023 $ 2,543.6 $ 576.8 $ 451.0 $ 960.7 $ 4,532.1 Water Sale and Acquisition, net — — — (1.2) (1.2) Water Goodwill Impairment — — — (297.0) (297.0) Water Goodwill Reclassified as Held for Sale — — — (662.5) (662.5) Balance as of December 31, 2024 $ 2,543.6 $ 576.8 $ 451.0 $ — $ 3,571.4 In 2023, Eversource completed two water acquisitions resulting in the addition of $9.5 million of goodwill. In 2024, Eversource completed the sale of its unregulated water business resulting in a reduction to goodwill of $5.4 million and completed a water acquisition resulting in the addition of $4.2 million of goodwill. Goodwill is not amortized but is subject to an assessment for impairment at least annually and more frequently if indicators of impairment arise that would more likely than not reduce the fair value of Eversource’s reporting units below their carrying amounts. Eversource's reporting units for the purpose of testing goodwill are Electric Distribution, Electric Transmission, Natural Gas Distribution and Water Distribution. These reporting units are consistent with the operating segments underlying the reportable segments identified in Note 23, "Segment Information," to the financial statements. In assessing goodwill for impairment, an entity is permitted to first assess qualitatively whether it is more likely than not that goodwill impairment exists as of the annual impairment test date. If after performing the qualitative assessment it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value (including goodwill), then a quantitative goodwill impairment test is performed. A quantitative impairment test is required only if it is concluded that it is more likely than not that a reporting unit’s carrying value may not be recoverable. The quantitative assessment compares the estimated fair value of a reporting unit to its carrying amount, and to the extent the carrying amount exceeds the fair value, an impairment of goodwill is recognized for the excess up to the amount of goodwill allocated to the reporting unit. A resulting write-down, if any, would be charged to Operating Expenses. Eversource completed its annual goodwill impairment assessment for the Electric Distribution, Electric Transmission, Natural Gas Distribution and Water Distribution reporting units as of October 1, 2024 and determined that no impairment existed. The annual goodwill assessment included a qualitative evaluation of multiple factors that impact the fair value of the reporting units, including general, macroeconomic and market conditions, and entity-specific assumptions that affect the future cash flows of the reporting units. Key considerations include discount rates, utility sector market performance and merger transaction multiples, the Company's share price and credit ratings, analyst reports, financial performance, cost and risk factors, internal estimates and projections of future cash flows and net income, long-term strategy, the timing and outcome of rate cases, and recent regulatory and legislative proceedings. In the fourth quarter of 2024, Eversource concluded that the likely sale of Aquarion at a loss resulted in the requirement to perform an interim goodwill impairment test for Water Distribution goodwill. Eversource compared the estimated fair value of the business from the anticipated transaction to its carrying value. Assumptions used in the valuation were the future cash flows from the sale, including approximately $140 million of estimated income tax impacts as a result of the transaction. Based on the interim impairment test, Eversource recorded a goodwill impairment of $297 million to write down the carrying value of the water distribution reporting unit to its estimated fair value. The goodwill impairment charge is presented separately within Operating Income on the Eversource statement of income for the year ended December 31, 2024.

SCHEDULE I - FINANCIAL INFORMAT

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT	12 Months Ended
	Dec. 31, 2024
Condensed Financial Information Disclosure [Abstract]
SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT	SCHEDULE I EVERSOURCE ENERGY (PARENT) FINANCIAL INFORMATION OF REGISTRANT BALANCE SHEETS AS OF DECEMBER 31, 2024 AND 2023 (Thousands of Dollars) 2024 2023 ASSETS Current Assets: Cash $ 1,083 $ 542 Accounts Receivable from Subsidiaries 100,320 60,191 Notes Receivable from Subsidiaries 2,051,400 2,045,570 Prepayments and Other Current Assets, Including Assets Held for Sale 96,313 103,735 Total Current Assets 2,249,116 2,210,038 Deferred Debits and Other Assets: Investments in Subsidiary Companies, at Equity 20,080,215 17,977,812 Notes Receivable from Subsidiaries 2,296,500 2,296,500 Accumulated Deferred Income Taxes 113,718 10,131 Goodwill 3,231,811 3,852,524 Long-Term Assets Held for Sale 335,393 — Other Long-Term Assets 24,582 28,287 Total Deferred Debits and Other Assets 26,082,219 24,165,254 Total Assets $ 28,331,335 $ 26,375,292 LIABILITIES AND CAPITALIZATION Current Liabilities: Notes Payable $ 1,538,011 $ 1,564,575 Long-Term Debt - Current Portion 600,000 364,653 Accounts Payable to Subsidiaries 45,326 38,051 Accrued Interest 168,748 106,070 Other Current Liabilities 57,923 41,268 Total Current Liabilities 2,410,008 2,114,617 Deferred Credits and Other Liabilities: Long-Term Liabilities Held for Sale 15,028 — Other Long-Term Liabilities 137,656 134,432 Total Deferred Credits and Other Liabilities 152,684 134,432 Long-Term Debt 10,729,256 9,952,351 Common Shareholders' Equity: Common Shares 1,878,622 1,799,920 Capital Surplus, Paid in 9,428,905 8,460,876 Retained Earnings 3,929,141 4,142,515 Accumulated Other Comprehensive Loss (26,472) (33,737) Treasury Stock (170,809) (195,682) Common Shareholders' Equity 15,039,387 14,173,892 Total Liabilities and Capitalization $ 28,331,335 $ 26,375,292 See the Combined Notes to Financial Statements in this Annual Report on Form 10-K for a description of significant accounting matters related to Eversource parent, including the pending sale of Aquarion as described in Note 24, “Assets Held for Sale,” Eversource common shares information as described in Note 18, "Common Shares," material obligations and guarantees as described in Note 13, "Commitments and Contingencies," and debt agreements as described in Note 8, "Short-Term Debt," and Note 9, "Long-Term Debt." SCHEDULE I EVERSOURCE ENERGY (PARENT) FINANCIAL INFORMATION OF REGISTRANT STATEMENTS OF INCOME/(LOSS) FOR THE YEARS ENDED DECEMBER 31, 2024, 2023 AND 2022 (Thousands of Dollars, Except Share Information) 2024 2023 2022 Operating Revenues $ 4,442 $ 840 $ — Operating Expenses: Other 20 12,769 26,708 Loss on Pending Sale of Aquarion 297,000 — — Total Operating Expenses 297,020 12,769 26,708 Operating Loss (292,578) (11,929) (26,708) Interest Expense 549,511 397,281 237,773 Other Income, Net: Equity in Earnings/(Losses) of Subsidiaries 1,359,297 (312,040) 1,565,474 Other, Net 214,444 188,003 79,383 Other Income/(Loss), Net 1,573,741 (124,037) 1,644,857 Income/(Loss) Before Income Tax Benefit 731,652 (533,247) 1,380,376 Income Tax Benefit (80,001) (91,007) (24,499) Net Income/(Loss) $ 811,653 $ (442,240) $ 1,404,875 Basic Earnings/(Loss) per Common Share $ 2.27 $ (1.27) $ 4.05 Diluted Earnings/(Loss) per Common Share $ 2.27 $ (1.26) $ 4.05 Weighted Average Common Shares Outstanding: Basic 357,482,965 349,580,638 346,783,444 Diluted 357,779,408 349,840,481 347,246,768 STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) (Thousands of Dollars) 2024 2023 2022 Net Income/(Loss) $ 811,653 $ (442,240) $ 1,404,875 Other Comprehensive Income, Net of Tax: Qualified Cash Flow Hedging Instruments 20 20 20 Changes in Unrealized Gains/(Losses) on Marketable Securities — 1,252 (1,636) Changes in Funded Status of Pension, SERP and PBOP Benefit Plans 7,245 4,412 4,470 Other Comprehensive Income, Net of Tax 7,265 5,684 2,854 Comprehensive Income/(Loss) $ 818,918 $ (436,556) $ 1,407,729 See the Combined Notes to Financial Statements in this Annual Report on Form 10-K for a description of significant accounting matters related to Eversource parent, including the pending sale of Aquarion as described in Note 24, “Assets Held for Sale,” Eversource common shares information as described in Note 18, "Common Shares," material obligations and guarantees as described in Note 13, "Commitments and Contingencies," and debt agreements as described in Note 8, "Short-Term Debt," and Note 9, "Long-Term Debt." SCHEDULE I EVERSOURCE ENERGY (PARENT) FINANCIAL INFORMATION OF REGISTRANT STATEMENTS OF CASH FLOWS FOR THE YEARS ENDED DECEMBER 31, 2024, 2023 and 2022 (Thousands of Dollars) 2024 2023 2022 Operating Activities: Net Income/(Loss) $ 811,653 $ (442,240) $ 1,404,875 Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities: Equity in (Earnings)/Losses of Subsidiaries (1,359,297) 312,040 (1,565,474) Cash Dividends Received from Subsidiaries 1,273,700 1,027,400 855,600 Deferred Income Taxes (99,692) (22,256) 25,823 Loss on Pending Sale of Aquarion 297,000 — — Other 57,469 (12,834) 26,455 Changes in Current Assets and Liabilities: Accounts Receivables from Subsidiaries (40,129) (6,853) (9,935) Taxes Receivable/Accrued, Net 22,464 (80,968) (21,627) Accounts Payable to Subsidiaries 7,275 4,521 (4,079) Other Current Assets and Liabilities, Net 58,572 35,357 35,090 Net Cash Flows Provided by Operating Activities 1,029,015 814,167 746,728 Investing Activities: Capital Contributions to Subsidiaries (2,026,500) (1,369,700) (1,499,300) Return of Capital from Subsidiaries 17,000 438,000 12,000 Increase/(Decrease) in Notes Receivable from Subsidiaries 201,500 (1,578,100) (724,400) Other Investing Activities — 147,567 (1,289) Net Cash Flows Used in Investing Activities (1,808,000) (2,362,233) (2,212,989) Financing Activities: Issuance of Common Shares, Net of Issuance Costs 989,447 — 197,058 Cash Dividends on Common Shares (1,001,488) (918,995) (860,033) Issuance of Long-Term Debt 2,400,000 3,350,000 2,800,000 Retirement of Long-Term Debt (1,350,000) (1,200,000) (750,000) (Decrease)/Increase in Notes Payable (233,894) 329,705 99,250 Other Financing Activities (24,539) (13,076) (19,193) Net Cash Flows Provided by Financing Activities 779,526 1,547,634 1,467,082 Net Increase/(Decrease) in Cash and Restricted Cash 541 (432) 821 Cash and Restricted Cash - Beginning of Year 615 1,047 226 Cash and Restricted Cash - End of Year $ 1,156 $ 615 $ 1,047 Supplemental Cash Flow Information: Cash Paid/(Received) During the Year for: Interest $ 483,101 $ 366,645 $ 215,053 Income Taxes $ 443 $ 23,984 $ (20,992) See the Combined Notes to Financial Statements in this Annual Report on Form 10-K for a description of significant accounting matters related to Eversource parent, including the pending sale of Aquarion as described in Note 24, “Assets Held for Sale,” Eversource common shares information as described in Note 18, "Common Shares," material obligations and guarantees as described in Note 13, "Commitments and Contingencies," and debt agreements as described in Note 8, "Short-Term Debt," and Note 9, "Long-Term Debt."

SCHEDULE II - VALUATION AND QUA

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	12 Months Ended
	Dec. 31, 2024
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	SCHEDULE II EVERSOURCE ENERGY AND SUBSIDIARIES VALUATION AND QUALIFYING ACCOUNTS AND RESERVES FOR THE YEARS ENDED DECEMBER 31, 2024, 2023 AND 2022 (Thousands of Dollars) Column A Column B Column C Column D Column E Additions (1) (2) Description: Balance as of Beginning of Year Charged to Costs and Expenses Charged to Other Deductions -Describe (b) Balance as of End of Year Eversource : Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2024 $ 554,455 $ 74,069 $ 119,659 $ 192,019 $ 556,164 2023 486,297 72,468 158,205 162,515 554,455 2022 417,406 61,876 112,533 105,518 486,297 CL&P: Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2024 $ 296,030 $ 17,190 $ 46,840 $ 80,952 $ 279,108 2023 225,320 11,675 126,360 67,325 296,030 2022 181,319 15,578 59,485 31,062 225,320 NSTAR Electric: Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2024 $ 97,026 $ 33,607 $ 37,653 $ 53,376 $ 114,910 2023 94,958 22,791 17,488 38,211 97,026 2022 97,005 21,550 12,412 36,009 94,958 PSNH : Reserves Deducted from Assets - Reserves for Uncollectible Accounts: 2024 $ 14,322 $ 4,688 $ 5,131 $ 10,051 $ 14,090 2023 29,236 3,989 (8,735) 10,168 14,322 2022 24,331 9,211 2,539 6,845 29,236 (a) Amounts relate to uncollectible accounts receivables reserved for that are not charged to bad debt expense. CL&P, NSTAR Electric, NSTAR Gas, EGMA and Yankee Gas are allowed to recover in rates, amounts associated with certain uncollectible hardship accounts receivable. CL&P, NSTAR Electric, PSNH, NSTAR Gas and EGMA are also allowed to recover uncollectible energy supply costs through regulatory tracking mechanisms.

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Insider Trading Policies and Pr

Insider Trading Policies and Procedures	12 Months Ended
	Dec. 31, 2024
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Cybersecurity Risk Management a

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
	Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	The Company’s policies, practices and technologies allow it to protect its information systems and operational assets from threats. The Board of Trustees and its Finance and Audit Committees continue to provide substantial and focused attention to cyber and system security. The Finance Committee of the Board of Trustees is responsible for oversight of the Company’s enterprise-wide risks, including risks associated with cyber and physical security, and the Company’s programs and practices to monitor and mitigate these risks. Management prepares comprehensive cyber security reports that are discussed at each meeting of the Finance Committee. The reports focus on the changing threat landscape and the risks to the Company, describe Eversource’s cyber security drills and exercises, attempted and actual breaches on our systems, cyber incidents within the utility industry and around the world, and mitigation strategies. In addition, third-party experts of cyber security risks provide periodic assessments to the utility industry and the Company in particular to the Finance Committee. The Company regularly reviews and updates its cyber and system security programs, and the Finance Committee continues to enhance its robust oversight activities, including meetings with financial, information technology, legal and accounting management, other members of the Board, representatives of the Company’s independent registered public accounting firm, and outside advisors and experts in cyber security risks, at which cyber and system security programs and issues that might affect the Company’s financial statements and operational systems are discussed. The Company has a robust Enterprise Risk Management Program that has identified cyber security as a top enterprise risk. The managing and monitoring of risks are the responsibility of the Company’s Risk Committee, which meets quarterly and is chaired by the Chief Financial Officer. Members include key leaders of the Company, including the Chief Information Officer. The Company is committed to continuous monitoring and assessment of cyber security controls. The Chief Information Security Officer is responsible for developing, implementing, and enforcing our cyber security program and information security policies to protect the Company’s information systems and operational assets. The Chief Information Security Officer position requires at least 15 years of relevant information security experience and relevant security certifications. The Chief Information Security Officer reports directly to the Chief Information Officer and provides regular updates to the executive management team. Our Chief Information Security Officer has over 20 years of relevant experience. The Company created a Cyber Governance Committee, which includes the Chief Information Security Officer, Chief Information Technology Officer, Chief Accounting Officer, members of the executive management team, and other assurance functions such as Corporate Compliance, Enterprise Risk Management, and Internal Audit. To assess, identify and manage material risks from cybersecurity threats and to prevent, detect, mitigate and remediate a cyber security incident, the following key processes and programs have been implemented and are performed by the Company’s Cyber Security Group, which is overseen by the Chief Information Security Officer: • Implementation of security solutions and standards based on industry best practices to prevent unauthorized access. The Company’s cyber program has been modeled after the Department of Energy’s Cyber Capability Maturity Model and the National Institute of Standards and Technology framework; both widely accepted frameworks utilized by utilities and other critical infrastructure industries. • Periodic external assessments, including outside system access testing, are performed. Rigorous auditing of all safeguards is performed on a regular basis. Risk assessments are held to identify and address new and changing risks to protect systems and sensitive data. Identified areas are monitored and improvements are implemented. • Eversource participates in information sharing programs both within and outside the utility industry, including with the U.S. government and industry organizations, to be able to identify and respond to emerging threats. • Established an Artificial Intelligence Executive Working Committee to ensure a “Secure by Design” approach to implementations of artificial intelligence. • The Company maintains current incident response and business continuity plans, which are periodically updated and tested. • Network activity is monitored on an ongoing basis. • Anti-phishing and malware tools are utilized and assessed. • Employees are trained to recognize phishing attempts and are periodically tested. Results of phishing testing are benchmarked against other companies both within and outside the utility industry. Specific to third parties, Eversource has implemented formal screening processes for any applicable vendors by the Company’s Cyber Security Group as part of the Procurement process. The vendors are risk ranked based on the type of work being performed. Periodic rescreening is performed on critical vendors. Vendors are required to attest to their business continuity programs and provide evidence of appropriate insurance and indemnification agreements. The Company bars sourcing from countries included on the Department of Homeland Security’s list of Prohibited Nations to further protect the Company’s supply chain. The Company maintains cyber insurance which covers breaches of networks and operational technology. Our existing insurance limits may be inadequate to cover a material cyber incident. This could expose us to potentially significant claims and damages.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	The Company’s policies, practices and technologies allow it to protect its information systems and operational assets from threats. The Board of Trustees and its Finance and Audit Committees continue to provide substantial and focused attention to cyber and system security. The Finance Committee of the Board of Trustees is responsible for oversight of the Company’s enterprise-wide risks, including risks associated with cyber and physical security, and the Company’s programs and practices to monitor and mitigate these risks.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	The Company is committed to continuous monitoring and assessment of cyber security controls. The Chief Information Security Officer is responsible for developing, implementing, and enforcing our cyber security program and information security policies to protect the Company’s information systems and operational assets. The Chief Information Security Officer position requires at least 15 years of relevant information security experience and relevant security certifications. The Chief Information Security Officer reports directly to the Chief Information Officer and provides regular updates to the executive management team. Our Chief Information Security Officer has over 20 years of relevant experience.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	The Company created a Cyber Governance Committee, which includes the Chief Information Security Officer, Chief Information Technology Officer, Chief Accounting Officer, members of the executive management team, and other assurance functions such as Corporate Compliance, Enterprise Risk Management, and Internal Audit. To assess, identify and manage material risks from cybersecurity threats and to prevent, detect, mitigate and remediate a cyber security incident, the following key processes and programs have been implemented and are performed by the Company’s Cyber Security Group, which is overseen by the Chief Information Security Officer:
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	To assess, identify and manage material risks from cybersecurity threats and to prevent, detect, mitigate and remediate a cyber security incident, the following key processes and programs have been implemented and are performed by the Company’s Cyber Security Group, which is overseen by the Chief Information Security Officer: • Implementation of security solutions and standards based on industry best practices to prevent unauthorized access. The Company’s cyber program has been modeled after the Department of Energy’s Cyber Capability Maturity Model and the National Institute of Standards and Technology framework; both widely accepted frameworks utilized by utilities and other critical infrastructure industries. • Periodic external assessments, including outside system access testing, are performed. Rigorous auditing of all safeguards is performed on a regular basis. Risk assessments are held to identify and address new and changing risks to protect systems and sensitive data. Identified areas are monitored and improvements are implemented. • Eversource participates in information sharing programs both within and outside the utility industry, including with the U.S. government and industry organizations, to be able to identify and respond to emerging threats. • Established an Artificial Intelligence Executive Working Committee to ensure a “Secure by Design” approach to implementations of artificial intelligence. • The Company maintains current incident response and business continuity plans, which are periodically updated and tested. • Network activity is monitored on an ongoing basis. • Anti-phishing and malware tools are utilized and assessed. • Employees are trained to recognize phishing attempts and are periodically tested. Results of phishing testing are benchmarked against other companies both within and outside the utility industry.
Cybersecurity Risk Role of Management [Text Block]	The Company created a Cyber Governance Committee, which includes the Chief Information Security Officer, Chief Information Technology Officer, Chief Accounting Officer, members of the executive management team, and other assurance functions such as Corporate Compliance, Enterprise Risk Management, and Internal Audit. To assess, identify and manage material risks from cybersecurity threats and to prevent, detect, mitigate and remediate a cyber security incident, the following key processes and programs have been implemented and are performed by the Company’s Cyber Security Group, which is overseen by the Chief Information Security Officer: • Implementation of security solutions and standards based on industry best practices to prevent unauthorized access. The Company’s cyber program has been modeled after the Department of Energy’s Cyber Capability Maturity Model and the National Institute of Standards and Technology framework; both widely accepted frameworks utilized by utilities and other critical infrastructure industries. • Periodic external assessments, including outside system access testing, are performed. Rigorous auditing of all safeguards is performed on a regular basis. Risk assessments are held to identify and address new and changing risks to protect systems and sensitive data. Identified areas are monitored and improvements are implemented. • Eversource participates in information sharing programs both within and outside the utility industry, including with the U.S. government and industry organizations, to be able to identify and respond to emerging threats. • Established an Artificial Intelligence Executive Working Committee to ensure a “Secure by Design” approach to implementations of artificial intelligence. • The Company maintains current incident response and business continuity plans, which are periodically updated and tested. • Network activity is monitored on an ongoing basis. • Anti-phishing and malware tools are utilized and assessed. •
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	The Company created a Cyber Governance Committee, which includes the Chief Information Security Officer, Chief Information Technology Officer, Chief Accounting Officer, members of the executive management team, and other assurance functions such as Corporate Compliance, Enterprise Risk Management, and Internal Audit.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Specific to third parties, Eversource has implemented formal screening processes for any applicable vendors by the Company’s Cyber Security Group as part of the Procurement process. The vendors are risk ranked based on the type of work being performed. Periodic rescreening is performed on critical vendors. Vendors are required to attest to their business continuity programs and provide evidence of appropriate insurance and indemnification agreements. The Company bars sourcing from countries included on the Department of Homeland Security’s list of Prohibited Nations to further protect the Company’s supply chain. The Company maintains cyber insurance which covers breaches of networks and operational technology. Our existing insurance limits may be inadequate to cover a material cyber incident. This could expose us to potentially significant claims and damages.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	The Company created a Cyber Governance Committee, which includes the Chief Information Security Officer, Chief Information Technology Officer, Chief Accounting Officer, members of the executive management team, and other assurance functions such as Corporate Compliance, Enterprise Risk Management, and Internal Audit.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements of Eversource, NSTAR Electric and PSNH include the accounts of each of their respective subsidiaries. Intercompany transactions have been eliminated in consolidation. The accompanying consolidated financial statements of Eversource, NSTAR Electric and PSNH and the financial statements of CL&P are herein collectively referred to as the "financial statements." The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. CYAPC and YAEC are inactive regional nuclear power companies engaged in the long-term storage of their spent nuclear fuel. Eversource consolidates the operations of CYAPC and YAEC because CL&P's, NSTAR Electric's and PSNH's combined ownership and voting interests in each of these entities is greater than 50 percent. Intercompany transactions between CL&P, NSTAR Electric, PSNH and the CYAPC and YAEC companies have been eliminated in consolidation of the Eversource financial statements. Eversource holds equity ownership interests that are not consolidated and are accounted for under the equity method. In the third quarter of 2024, Eversource sold its 50 percent equity ownership interests in three offshore wind projects that had been accounted for under the equity method. See Note 6, “Investments in Unconsolidated Affiliates,” for further information. In accordance with accounting guidance on noncontrolling interests in consolidated financial statements, the Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric, which are not owned by Eversource or its consolidated subsidiaries and are not subject to mandatory redemption, have been presented as noncontrolling interests in the financial statements of Eversource. The Preferred Stock of CL&P and the Preferred Stock of NSTAR Electric are considered to be temporary equity and have been classified between liabilities and permanent shareholders' equity on the balance sheets of Eversource, CL&P and NSTAR Electric due to a provision in the preferred stock agreements of both CL&P and NSTAR Electric that grant preferred stockholders the right to elect a majority of the CL&P and NSTAR Electric Boards of Directors, respectively, should certain conditions exist, such as if preferred dividends are in arrears for a specified amount of time. The Net Income reported in the statements of income and cash flows represents net income prior to apportionment to noncontrolling interests, which is represented by dividends on preferred stock of CL&P and NSTAR Electric.
Accounting Standards	Accounting Standards Accounting Standards Recently Adopted: On January 1, 2025, the Company retrospectively adopted Accounting Standards Update (ASU) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which requires entities to disclose significant segment expenses, other segment items, and the title and position of the chief operating decision maker (CODM). Additionally, the ASU requires entities to disclose how the CODM assesses segment performance and allocates resources, among certain other required disclosures. Furthermore, current annual disclosures will be required in interim periods. The modified disclosures are included in Note 23, “Segment Information.”
Cash	Cash Cash includes cash on hand. At the end of each reporting period, any overdraft amounts are reclassified from Cash to Accounts Payable on the balance sheets.
Allowance for Uncollectible Accounts	Allowance for Uncollectible Accounts Receivables, Net on the balance sheets primarily includes trade receivables from retail customers and customers related to wholesale transmission contracts, wholesale market sales, sales of RECs, and property rentals. Receivables, Net also includes customer receivables for the purchase of electricity from a competitive third party supplier, the current portion of customer energy efficiency loans, property damage receivables and other miscellaneous receivables. There is no material concentration of receivables. Receivables are recorded at amortized cost, net of a credit loss provision (or allowance for uncollectible accounts). The current expected credit loss (CECL) model is applied to receivables for purposes of calculating the allowance for uncollectible accounts. This model is based on expected losses and results in the recognition of estimated expected credit losses, including uncollectible amounts for both billed and unbilled revenues, over the life of the receivable at the time a receivable is recorded. The allowance for uncollectible accounts is determined based upon a variety of judgments and factors, including an aging-based quantitative assessment that applies an estimated uncollectible percentage to each receivable aging category. Factors in determining credit loss include historical collection, write-off experience, analysis of delinquency statistics, and management's assessment of collectability from customers, including current economic conditions, customer payment trends, the impact on customer bills because of energy usage trends and changes in rates, flexible payment plans and financial hardship arrearage management programs offered to customers, reasonable forecasts, and expectations of future collectability and collection efforts. Management continuously assesses the collectability of receivables and adjusts estimates based on actual experience and future expectations based on economic conditions, collection efforts and other factors. Management also monitors the aging analysis of receivables to determine if there are changes in the collections of accounts receivable. Receivable balances are written off against the allowance for uncollectible accounts when the customer accounts are no longer in service and these balances are deemed to be uncollectible. Management concluded that the reserve balance as of December 31, 2024 adequately reflected the collection risk and net realizable value for its receivables.
Transfer of Energy Efficiency Loans	Transfer of Energy Efficiency LoansCL&P transferred a portion of its energy efficiency customer loan portfolio to outside lenders in order to make additional loans to customers.  CL&P remains the servicer of the loans and will transmit customer payments to the lenders, with a maximum amount outstanding under this program of $70 million.  The amounts of the loans are included in Receivables, Net and Other Long-Term Assets, and are offset by Other Current Liabilities and Other Long-Term Liabilities on CL&P’s balance sheet.
Materials, Supplies, Natural Gas and REC Inventory	Materials, Supplies, Natural Gas and REC InventoryMaterials, Supplies, Natural Gas and REC Inventory include materials and supplies purchased primarily for construction or operation and maintenance purposes, natural gas purchased for delivery to customers, and RECs.  Inventory is valued at the lower of cost or net realizable value. RECs are purchased from suppliers of renewable sources of generation and are used to meet state mandated Renewable Portfolio Standards requirements.
Fair Value Measurements	Fair Value Measurements Fair value measurement guidance is applied to derivative contracts that are not elected or designated as "normal purchases" or "normal sales" (normal) and to marketable securities held in trusts. Fair value measurement guidance is also applied to valuations of the investments used to calculate the funded status of pension and PBOP plans, the nonrecurring fair value measurements of nonfinancial assets such as goodwill, long-lived assets, equity method investments, AROs, and in the valuation of business combinations and asset acquisitions. The fair value measurement guidance was also applied in estimating the fair value of preferred stock, long-term debt and RRBs. Fair Value Hierarchy: In measuring fair value, Eversource uses observable market data when available in order to minimize the use of unobservable inputs. Inputs used in fair value measurements are categorized into three fair value hierarchy levels for disclosure purposes. The entire fair value measurement is categorized based on the lowest level of input that is significant to the fair value measurement. Eversource evaluates the classification of assets and liabilities measured at fair value on a quarterly basis. The levels of the fair value hierarchy are described below: Level 1 - Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 - Inputs are quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all significant inputs are observable. Level 3 - Quoted market prices are not available. Fair value is derived from valuation techniques in which one or more significant inputs or assumptions are unobservable. Where possible, valuation techniques incorporate observable market inputs that can be validated to external sources such as industry exchanges, including prices of energy and energy-related products. Uncategorized - Investments that are measured at net asset value are not categorized within the fair value hierarchy. Determination of Fair Value: The valuation techniques and inputs used in Eversource's fair value measurements are described in Note 4, "Derivative Instruments," Note 5, "Marketable Securities," Note 6, "Investments in Unconsolidated Affiliates," Note 7, "Asset Retirement Obligations," Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," Note 15, "Fair Value of Financial Instruments," and Note 25, “Goodwill,” to the financial statements.
Derivative Accounting	Derivative Accounting Many of the electric and natural gas companies' contracts for the purchase and sale of energy or energy-related products are derivatives. The accounting treatment for energy contracts entered into varies and depends on the intended use of the particular contract and on whether or not the contract is a derivative. The application of derivative accounting is complex and requires management judgment in the following respects: identification of derivatives and embedded derivatives, election and designation of a contract as normal, and determination of the fair value of derivative contracts. All of these judgments can have a significant impact on the financial statements. The judgment applied in the election of a contract as normal (and resulting accrual accounting) includes the conclusion that it is probable at the inception of the contract and throughout its term that it will result in physical delivery of the underlying product and that the quantities will be used or sold by the business in the normal course of business. If facts and circumstances change and management can no longer support this conclusion, then a contract cannot be considered normal, accrual accounting is terminated, and fair value accounting is applied prospectively. The fair value of derivative contracts is based upon the contract terms and conditions and the underlying market price or fair value per unit. When quantities are not specified in the contract, the Company determines whether the contract has a determinable quantity by using amounts referenced in default provisions and other relevant sections of the contract. The fair value of derivative assets and liabilities with the same counterparty are offset and recorded as a net derivative asset or liability on the balance sheets. Regulatory assets or regulatory liabilities are recorded to offset the fair values of these derivative contracts related to energy and energy-related products, as contract settlements are recovered from, or refunded to, customers in future rates. All changes in the fair value of these derivative contracts are recorded as regulatory assets or liabilities and do not impact net income.
Allowance for Funds Used During Construction	Allowance for Funds Used During Construction AFUDC represents the cost of borrowed and equity funds used to finance construction and is included in the cost of the electric, natural gas and water companies' utility plant on the balance sheet. The portion of AFUDC attributable to borrowed funds is recorded as a reduction of Interest Expense, and the AFUDC related to equity funds is recorded as Other Income, Net on the statements of income. AFUDC costs are recovered from customers over the service life of the related plant in the form of increased revenue collected as a result of higher depreciation expense.
Other Taxes	Other TaxesEversource's companies that serve customers in Connecticut collect gross receipts taxes levied by the state of Connecticut from their customers. As agents for state and local governments, Eversource's companies that serve customers in Connecticut and Massachusetts collect certain sales taxes that are recorded on a net basis with no impact on the statements of income.
Related Parties	Related Parties Eversource Service, Eversource's service company, provides centralized accounting, administrative, engineering, financial, information technology, legal, operational, planning, purchasing, tax, and other services to Eversource's companies. The Rocky River Realty Company and Properties, Inc., two other Eversource subsidiaries, construct, acquire or lease some of the property and facilities used by Eversource's companies. Included in the CL&P, NSTAR Electric and PSNH balance sheets as of December 31, 2024 and 2023 were Accounts Receivable from Affiliated Companies and Accounts Payable to Affiliated Companies relating to transactions between CL&P, NSTAR Electric and PSNH and other subsidiaries that are wholly-owned by Eversource. These amounts have been eliminated in consolidation on the Eversource financial statements. Included in the CL&P and PSNH balance sheets as of December 31, 2024 and 2023 were Notes Payable to Eversource Parent. These amounts have been eliminated in consolidation on the Eversource financial statements. See Note 8, “Short-Term Debt” for intercompany borrowing amounts. The Eversource Energy Foundation is an independent not-for-profit charitable entity and is not included in the consolidated financial statements of Eversource as the Company does not have title to, and cannot receive contributions back from, the Eversource Energy Foundation's assets. Eversource made contributions to the Eversource Energy Foundation of $20.0 million in 2023, and $8.0 million in 2022. Eversource did not make any contributions in 2024.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Provision for Uncollectible Accounts	The activity in the allowance for uncollectible accounts by portfolio segment is as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Hardship Accounts Retail (Non-Hardship), Total Allowance Total Allowance (3) Balance as of January 1, 2022 $ 226.1 $ 191.3 $ 417.4 $ 144.6 $ 36.7 $ 181.3 $ 43.3 $ 53.7 $ 97.0 $ 24.3 Uncollectible Expense — 61.9 61.9 — 15.6 15.6 — 21.6 21.6 9.2 Uncollectible Costs Deferred (1) 77.8 34.7 112.5 58.3 1.2 59.5 1.5 10.9 12.4 2.5 Write-Offs (21.3) (102.7) (124.0) (15.3) (23.0) (38.3) (1.1) (41.2) (42.3) (7.7) Recoveries Collected 1.8 16.7 18.5 1.3 5.9 7.2 — 6.3 6.3 0.9 Balance as of December 31, 2022 $ 284.4 $ 201.9 $ 486.3 $ 188.9 $ 36.4 $ 225.3 $ 43.7 $ 51.3 $ 95.0 $ 29.2 Uncollectible Expense — 72.5 72.5 — 11.7 11.7 — 22.8 22.8 4.0 Uncollectible Costs Deferred (1) 137.0 21.2 158.2 114.4 12.0 126.4 1.5 16.0 17.5 (8.7) Write-Offs (55.9) (122.2) (178.1) (44.7) (28.5) (73.2) (1.6) (41.7) (43.3) (10.9) Recoveries Collected 1.3 14.3 15.6 1.1 4.7 5.8 — 5.0 5.0 0.7 Balance as of December 31, 2023 $ 366.8 $ 187.7 $ 554.5 $ 259.7 $ 36.3 $ 296.0 $ 43.6 $ 53.4 $ 97.0 $ 14.3 Uncollectible Expense — 74.1 74.1 — 17.2 17.2 — 33.6 33.6 4.7 Uncollectible Costs Deferred (1) 71.4 48.3 119.7 35.5 11.3 46.8 16.2 21.5 37.7 5.1 Write-Offs (74.3) (129.5) (203.8) (55.1) (30.9) (86.0) (4.6) (52.4) (57.0) (10.9) Recoveries Collected 0.7 13.3 14.0 0.6 4.5 5.1 — 3.6 3.6 0.9 Decrease due to Assets Held for Sale (2) — (2.3) (2.3) — — — — — — — Balance as of December 31, 2024 $ 364.6 $ 191.6 $ 556.2 $ 240.7 $ 38.4 $ 279.1 $ 55.2 $ 59.7 $ 114.9 $ 14.1 (1) These expected credit losses are deferred as regulatory costs on the balance sheets, as these amounts are ultimately recovered in rates. Amounts include uncollectible costs for hardship accounts and other customer receivables, including uncollectible amounts related to uncollectible energy supply costs. (2) As of December 31, 2024, the allowance for uncollectible accounts attributable to the Aquarion water distribution business has been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, this balance was recorded within Receivables, Net on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” (3) In connection with PSNH’s pole purchase agreement on May 1, 2023, the purchase price included the forgiveness of previously reserved receivables for reimbursement of operation and maintenance and vegetation management costs.
Schedule of Utility Inventory	The carrying amounts of materials and supplies, natural gas inventory, and RECs, which are included in Current Assets on the balance sheets, were as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Materials and Supplies $ 498.6 $ 217.3 $ 177.8 $ 72.1 $ 397.9 $ 156.2 $ 130.8 $ 76.5 Natural Gas 49.5 — — — 65.5 — — — RECs 46.5 — 42.8 3.7 43.9 0.3 43.0 0.6 Total $ 594.6 $ 217.3 $ 220.6 $ 75.8 $ 507.3 $ 156.5 $ 173.8 $ 77.1
Costs Related to Fuel and Natural Gas	The cost of natural gas included in Purchased Power, Purchased Natural Gas and Transmission on the statements of income was as follows: For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Eversource - Cost of Natural Gas $ 689.6 $ 792.2 $ 1,010.2
Weighted-Average AFUDC Rates	AFUDC costs and the weighted-average AFUDC rates were as follows: Eversource For the Years Ended December 31, (Millions of Dollars, except percentages) 2024 2023 2022 Borrowed Funds $ 64.4 $ 44.6 $ 21.8 Equity Funds 97.8 78.1 47.3 Total AFUDC $ 162.2 $ 122.7 $ 69.1 Average AFUDC Rate 6.5 % 5.8 % 4.7 % For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars, CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Borrowed Funds $ 8.1 $ 27.2 $ 8.9 $ 7.7 $ 17.2 $ 6.1 $ 4.8 $ 10.7 $ 1.4 Equity Funds 22.4 58.8 7.0 20.0 45.7 5.4 13.6 24.6 2.5 Total AFUDC $ 30.5 $ 86.0 $ 15.9 $ 27.7 $ 62.9 $ 11.5 $ 18.4 $ 35.3 $ 3.9 Average AFUDC Rate 6.7 % 7.0 % 5.5 % 6.7 % 5.9 % 5.1 % 6.6 % 5.4 % 2.6 %
Components of Other Income, Net	The components of Other Income, Net on the statements of income were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 115.4 $ 132.9 $ 219.8 AFUDC Equity 97.8 78.1 47.3 Equity in Earnings of Unconsolidated Affiliates (2) 51.9 15.5 22.9 Investment Income/(Loss) 0.6 (4.9) 1.9 Interest Income 138.2 94.2 50.5 Other (2) 6.6 32.3 3.7 Total Other Income, Net $ 410.5 $ 348.1 $ 346.1 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion (1) $ 28.2 $ 52.8 $ 14.9 $ 34.9 $ 57.4 $ 16.2 $ 64.4 $ 85.5 $ 26.8 AFUDC Equity 22.4 58.8 7.0 20.0 45.7 5.4 13.6 24.6 2.5 Investment (Loss)/Income (1.4) 1.9 (0.5) (2.4) (0.2) (0.7) (1.3) 1.2 0.2 Interest Income 28.3 77.0 9.6 9.0 60.6 5.3 6.5 30.7 3.1 Other 0.1 0.9 0.1 0.1 0.6 0.4 0.1 0.7 0.1 Total Other Income, Net $ 77.6 $ 191.4 $ 31.1 $ 61.6 $ 164.1 $ 26.6 $ 83.3 $ 142.7 $ 32.7 (1) See Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for the components of net periodic benefit income/expense for the Pension, SERP and PBOP Plans. The non-service related components of pension, SERP and PBOP benefit income/expense, after capitalization or deferral, are presented as non-operating income and recorded in Other Income, Net on the statements of income. (2) Equity in Earnings of Unconsolidated Affiliates includes $23.4 million of pre-tax income recorded at Eversource in the second quarter of 2024 from Eversource’s wind equity method investment, North East Offshore, as a result of a vendor settlement agreement payment received by the joint venture. In the third quarter of 2024, Eversource sold its equity method investments in three offshore wind projects. In March 2023, Eversource’s equity method investment in a renewable energy fund was liquidated. Liquidation proceeds in excess of the carrying value were recorded in 2023 within Other in the table above. For the year ended December 31, 2022, pre-tax income of $12.2 million associated with the renewable energy fund investment was included in Equity in Earnings of Unconsolidated Affiliates within Other Income, Net in the table above. See Note 6, “Investments in Unconsolidated Affiliates,” for further information on the 2024 sales of the offshore wind investments and the 2023 liquidation of the renewable energy fund.
Other Taxes	These gross receipts taxes are recorded separately with collections in Operating Revenues and with payments in Taxes Other Than Income Taxes on the statements of income as follows: For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Eversource $ 209.4 $ 202.9 $ 194.7 CL&P 185.1 174.9 166.1
Supplemental Cash Flow Information	Eversource (Millions of Dollars) As of and For the Years Ended December 31, 2024 2023 2022 Cash Paid/(Received) During the Year for: Interest, Net of Amounts Capitalized $ 1,014.4 $ 783.2 $ 636.2 Income Taxes (69.6) 39.2 77.9 Non-Cash Investing Activities: Plant Additions Included in Accounts Payable (As of) 472.5 564.1 586.9 As of and For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Cash Paid/(Received) During the Year for: Interest, Net of Amounts Capitalized $ 216.8 $ 215.1 $ 78.4 $ 176.8 $ 182.8 $ 62.8 $ 167.2 $ 152.8 $ 58.3 Income Taxes (47.4) 118.7 (36.0) (44.1) 31.3 (59.9) 117.6 23.8 58.3 Non-Cash Investing Activities: Plant Additions Included in Accounts 95.8 155.4 77.7 139.8 178.9 65.9 131.8 184.3 76.2
Cash and Cash Equivalents as Reported on the Balance Sheet	As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Cash as reported on the Balance Sheets $ 26.7 $ 1.1 $ 0.9 $ 1.4 $ 53.9 $ 10.2 $ 6.7 $ 0.2 Restricted cash included in: Special Deposits 75.8 1.0 8.1 32.7 81.5 2.0 16.1 31.6 Assets Held for Sale, Current 5.8 — — — — — — — Marketable Securities 10.0 — — — 13.7 — — — Other Long-Term Assets 9.0 — — 3.1 17.3 — — 3.2 Cash and Restricted Cash as reported on the $ 127.3 $ 2.1 $ 9.0 $ 37.2 $ 166.4 $ 12.2 $ 22.8 $ 35.0

REGULATORY ACCOUNTING (Tables)

REGULATORY ACCOUNTING (Tables)	12 Months Ended
	Dec. 31, 2024
Regulated Operations [Abstract]
Components of Regulatory Assets	The components of regulatory assets were as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Storm Costs, Net $ 2,039.4 $ 971.1 $ 609.8 $ 458.5 $ 1,785.9 $ 896.6 $ 609.1 $ 280.2 Regulatory Tracking Mechanisms 1,781.6 507.7 650.0 162.8 1,319.2 354.5 482.9 182.2 Benefit Costs 967.4 168.8 293.6 65.6 1,117.3 197.4 336.7 79.3 Income Taxes, Net 968.4 521.0 145.4 20.7 912.4 512.6 128.6 16.4 Securitized Stranded Costs 349.3 — — 349.3 392.5 — — 392.5 Goodwill-related 247.2 — 212.3 — 264.1 — 226.7 — Asset Retirement Obligations 150.2 41.2 78.3 5.1 137.9 38.5 72.3 4.7 Derivative Liabilities 57.2 57.2 — — 120.9 120.9 — — Other Regulatory Assets 510.0 58.5 117.7 3.7 339.0 22.7 101.6 8.0 Total Regulatory Assets 7,070.7 2,325.5 2,107.1 1,065.7 6,389.2 2,143.2 1,957.9 963.3 Less: Current Portion 2,189.7 638.5 902.8 173.3 1,674.2 480.4 676.1 189.5 Total Long-Term Regulatory Assets $ 4,881.0 $ 1,687.0 $ 1,204.3 $ 892.4 $ 4,715.0 $ 1,662.8 $ 1,281.8 $ 773.8
Components of Regulatory Liabilities	The components of regulatory liabilities were as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH EDIT due to Tax Cuts and Jobs Act of 2017 $ 2,442.7 $ 956.6 $ 877.6 $ 330.6 $ 2,548.6 $ 969.2 $ 905.1 $ 339.3 Regulatory Tracking Mechanisms 702.4 180.3 413.6 114.4 668.3 154.0 347.2 114.4 Cost of Removal 684.1 212.8 451.3 20.1 666.6 157.9 420.9 16.2 Deferred Portion of Non-Service Income 427.1 61.6 211.6 42.6 354.0 49.9 175.9 36.6 AFUDC - Transmission 154.8 65.1 89.7 — 124.3 56.1 68.2 — Benefit Costs 69.3 4.5 21.4 3.9 51.0 0.6 22.2 — Other Regulatory Liabilities 184.5 39.1 14.2 4.5 201.9 30.4 13.9 4.6 Total Regulatory Liabilities 4,664.9 1,520.0 2,079.4 516.1 4,614.7 1,418.1 1,953.4 511.1 Less: Current Portion 632.3 124.1 436.3 121.1 591.8 102.2 368.1 117.5 Total Long-Term Regulatory Liabilities $ 4,032.6 $ 1,395.9 $ 1,643.1 $ 395.0 $ 4,022.9 $ 1,315.9 $ 1,585.3 $ 393.6

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION (Tables)	12 Months Ended
	Dec. 31, 2024
Property, Plant and Equipment [Abstract]
Schedule of Utility Property, Plant and Equipment	The following tables summarize property, plant and equipment by asset category: Eversource As of December 31, (Millions of Dollars) 2024 2023 Distribution - Electric $ 21,144.1 $ 19,656.5 Distribution - Natural Gas 8,922.2 8,155.3 Transmission - Electric 16,130.9 14,666.8 Distribution - Water (1) — 2,280.1 Solar 201.0 201.1 Utility 46,398.2 44,959.8 Other (2) 2,254.1 2,006.8 Property, Plant and Equipment, Gross 48,652.3 46,966.6 Less: Accumulated Depreciation Utility (9,636.5) (9,670.1) Other (1,044.1) (869.6) Total Accumulated Depreciation (10,680.6) (10,539.7) Property, Plant and Equipment, Net 37,971.7 36,426.9 Construction Work in Progress 3,014.9 3,071.7 Total Property, Plant and Equipment, Net $ 40,986.6 $ 39,498.6 As of December 31, 2024 2023 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH Distribution - Electric $ 8,437.9 $ 9,782.3 $ 2,964.2 $ 7,897.1 $ 9,000.5 $ 2,799.2 Transmission - Electric 6,937.7 6,375.2 2,819.6 6,548.2 5,630.8 2,489.5 Solar — 201.0 — — 201.1 — Property, Plant and Equipment, Gross 15,375.6 16,358.5 5,783.8 14,445.3 14,832.4 5,288.7 Less: Accumulated Depreciation (2,928.0) (3,782.0) (1,032.3) (2,670.5) (3,585.9) (984.0) Property, Plant and Equipment, Net 12,447.6 12,576.5 4,751.5 11,774.8 11,246.5 4,304.7 Construction Work in Progress 554.6 1,461.3 338.4 565.4 1,507.3 270.0 Total Property, Plant and Equipment, Net $ 13,002.2 $ 14,037.8 $ 5,089.9 $ 12,340.2 $ 12,753.8 $ 4,574.7 (1) As of December 31, 2024, the property, plant and equipment balance, net of accumulated depreciation, attributable to the Aquarion water distribution business has been reclassified to Assets Held for Sale on the Eversource balance sheet. As of December 31, 2023, this balance was recorded within Property, Plant and Equipment, Net on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.” (2) These assets are primarily comprised of computer software, hardware and equipment at Eversource Service and buildings at The Rocky River Realty Company. The depreciation rates for the various classes of utility property, plant and equipment aggregate to composite rates as follows: (Percent) 2024 2023 2022 Eversource 3.2 % 3.1 % 3.0 % CL&P 2.9 % 2.8 % 2.8 % NSTAR Electric 2.8 % 2.7 % 2.7 % PSNH 3.0 % 3.0 % 3.0 % The following table summarizes average remaining useful lives of depreciable assets: As of December 31, 2024 (Years) Eversource CL&P NSTAR Electric PSNH Distribution - Electric 33.4 34.7 33.4 29.9 Distribution - Natural Gas 34.7 — — — Transmission - Electric 39.7 35.8 45.1 39.8 Distribution - Water 45.2 — — — Solar 22.8 — 22.8 — Other (1) 9.9 — — — (1) The estimated useful life of computer software, hardware and equipment primarily ranges from 5 to 15 years and of buildings is 40 years.

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table presents the gross fair values of contracts, categorized by risk type, and the net amounts recorded as current or long-term derivative assets or liabilities: As of December 31, 2024 2023 CL&P (Millions of Dollars) Fair Value Hierarchy Commodity Supply Netting (1) Net Amount Commodity Supply Netting (1) Net Amount Current Derivative Assets Level 2 $ 14.2 $ (0.3) $ 13.9 $ 16.4 $ (0.5) $ 15.9 Long-Term Derivative Assets Level 2 — — — 13.6 (0.5) 13.1 Current Derivative Liabilities Level 2 (71.1) — (71.1) (81.9) — (81.9) Long-Term Derivative Liabilities Level 2 — — — (68.0) — (68.0) (1) Amounts represent derivative assets and liabilities that Eversource elected to record net on the balance sheets. These amounts are subject to master netting agreements or similar agreements for which the right of offset exists.
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents changes in the Level 3 category of derivative assets and derivative liabilities measured at fair value on a recurring basis. The derivative assets and liabilities are presented on a net basis. CL&P (Millions of Dollars) For the Year Ended December 31, 2023 Derivatives, Net: Fair Value as of Beginning of Period $ (181.8) Net Realized/Unrealized Losses Included in Regulatory Assets (3.9) Settlements 64.8 Transfers out of Level 3 (1) 120.9 Fair Value as of End of Period $ — (1) Transfers out of Level 3 pertain to certain significant valuation inputs becoming observable as well as certain unobservable inputs no longer being significant to the fair value of the derivative contracts. Eversource's policy is to recognize transfers between levels of the fair value hierarchy as of the end of the reporting period.

MARKETABLE SECURITIES (Tables)

MARKETABLE SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The following is a summary of available-for-sale debt securities, which are held in CYAPC’s and YAEC’s spent nuclear fuel trusts: As of December 31, 2024 2023 Eversource (Millions of Dollars) Amortized Pre-Tax Pre-Tax Fair Value Amortized Pre-Tax Pre-Tax Fair Value Debt Securities $ 163.2 $ 0.1 $ (6.1) $ 157.2 $ 169.5 $ 1.4 $ (6.6) $ 164.3
Investments Classified by Contractual Maturity Date	As of December 31, 2024, the contractual maturities of available-for-sale debt securities were as follows: Eversource (Millions of Dollars) Amortized Fair Less than one year $ 11.3 $ 11.7 One to five years 35.6 35.6 Six to ten years 43.5 42.6 Greater than ten years 72.8 67.3 Total Debt Securities $ 163.2 $ 157.2 Realized Gains and Losses: Realized gains and losses are offset in long-term liabilities for CYAPC and YAEC and are recorded in Other Income, Net for Eversource's benefit trusts. Eversource utilizes the average cost basis method for the CYAPC and YAEC spent nuclear fuel trusts and the specific identification basis method for the Eversource non-qualified benefit trusts to compute the realized gains and losses on the sale of marketable securities.
Marketable Securities Recorded at Fair Value	The following table presents the marketable securities recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Eversource (Millions of Dollars) As of December 31, 2024 2023 Level 1: Mutual Funds and Equities $ 163.1 $ 176.9 Money Market Funds 10.0 13.7 Total Level 1 $ 173.1 $ 190.6 Level 2: U.S. Government Issued Debt Securities (Agency and Treasury) $ 92.0 $ 90.1 Corporate Debt Securities 32.5 34.0 Asset-Backed Debt Securities 7.8 5.6 Municipal Bonds 6.8 9.8 Other Fixed Income Securities 8.1 11.1 Total Level 2 $ 147.2 $ 150.6 Total Marketable Securities $ 320.3 $ 341.2

INVESTMENTS IN UNCONSOLIDATED_2

INVESTMENTS IN UNCONSOLIDATED AFFILIATES (Tables)	12 Months Ended
	Dec. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Summary of Investments	Eversource's investments accounted for under the equity method include the following: Investment Balance as of December 31, (Millions of Dollars) Ownership Interest 2024 2023 Offshore Wind Business 50% - 100% $ 22.2 $ 515.5 Natural Gas Pipeline - Algonquin Gas Transmission, LLC 15% 112.6 116.0 Other various 33.9 29.0 Total Investments in Unconsolidated Affiliates $ 168.7 $ 660.5 A summary of the significant estimates and assumptions included in the 2023 impairment charges is as follows: Second Quarter 2023 Fourth Quarter 2023 Total (Millions of Dollars) Lower expected sales proceeds across all three wind projects $ 401 $ 525 $ 926 Expected cost overruns not recovered in the sales price — 441 441 Loss of sales value from the sale price offered by GIP, including loss of ITC adders value, cancellation costs and other impacts assuming Sunrise Wind project is abandoned — 800 800 Impairment Charges, pre-tax 401 1,766 2,167 Tax Benefit (70) (144) (214) Impairment Charges, after-tax $ 331 $ 1,622 1,953 A summary of the carrying value by investee and by project as of December 31, 2023 is as follows: Investments Expected to be Disposed of Investment to be Held North East Offshore South Fork Class B Member, LLC South Fork Wind Holdings, LLC Class A Total Offshore Wind Investments (Millions of Dollars) Sunrise Wind Revolution Wind Carrying Value as of December 31, 2023, before $ 699 $ 799 $ 299 $ 485 $ 2,282 Fourth Quarter 2023 Impairment Charge (1,218) (544) — (4) (1,766) Carrying Value as of December 31, 2023 $ (519) $ 255 $ 299 $ 481 $ 516

ASSET RETIREMENT OBLIGATIONS (T

ASSET RETIREMENT OBLIGATIONS (Tables)	12 Months Ended
	Dec. 31, 2024
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Change in Asset Retirement Obligation	A reconciliation of the beginning and ending carrying amounts of ARO liabilities is as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Balance as of Beginning of Year $ 505.8 $ 39.9 $ 104.8 $ 5.2 $ 502.7 $ 37.4 $ 101.3 $ 4.9 Liabilities Settled During the Year (24.6) — — — (24.9) — — — Accretion 29.5 2.6 4.5 0.4 29.2 2.5 4.3 0.3 Revisions in Estimated Cash Flows 80.2 — — — (1.2) — (0.8) — Balance as of End of Year $ 590.9 $ 42.5 $ 109.3 $ 5.6 $ 505.8 $ 39.9 $ 104.8 $ 5.2

SHORT-TERM DEBT (Tables)

SHORT-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2024
Debt Disclosure [Abstract]
Schedule of Borrowings Outstanding	The amount of borrowings outstanding and available under the commercial paper programs were as follows: Borrowings Outstanding Available Borrowing Capacity as of December 31, Weighted-Average Interest Rate as of December 31, (Millions of Dollars) 2024 2023 2024 2023 2024 2023 Eversource Parent Commercial Paper Program $ 1,538.0 $ 1,771.9 $ 462.0 $ 228.1 4.76 % 5.60 % NSTAR Electric Commercial Paper Program 504.8 365.8 145.2 284.2 4.55 % 5.40 % Details of long-term debt outstanding are as follows: CL&P (Millions of Dollars) As of December 31, Interest Rate 2024 2023 First Mortgage Bonds: 1994 Series D due 2024 7.875 % $ — $ 139.8 2004 Series B due 2034 5.750 % 130.0 130.0 2005 Series B due 2035 5.625 % 100.0 100.0 2006 Series A due 2036 6.350 % 250.0 250.0 2007 Series B due 2037 5.750 % 150.0 150.0 2007 Series D due 2037 6.375 % 100.0 100.0 2014 Series A due 2044 4.300 % 475.0 475.0 2015 Series A due 2045 4.150 % 350.0 350.0 2017 Series A due 2027 3.200 % 500.0 500.0 2018 Series A due 2048 4.000 % 800.0 800.0 2020 Series A due 2025 0.750 % 400.0 400.0 2021 Series A due 2031 2.050 % 425.0 425.0 2023 Series A due 2053 5.250 % 500.0 500.0 2023 Series B due 2033 4.900 % 300.0 300.0 2024 Series A due 2029 4.650 % 350.0 — 2024 Series B due 2034 4.950 % 300.0 — Total First Mortgage Bonds 5,130.0 4,619.8 Less Amounts due Within One Year (400.0) (139.8) Current Portion Classified as Long-Term Debt (1) 397.1 139.8 Commercial Paper Classified as Long-Term Debt (See Note 8, Short-Term Debt) — 207.3 Unamortized Premiums and Discounts, Net 14.3 18.0 Unamortized Debt Issuance Costs (33.2) (30.7) CL&P Long-Term Debt $ 5,108.2 $ 4,814.4 NSTAR Electric (Millions of Dollars) As of December 31, Interest Rate 2024 2023 Debentures: 2006 Debentures due 2036 5.750 % $ 200.0 $ 200.0 2010 Debentures due 2040 5.500 % 300.0 300.0 2014 Debentures due 2044 4.400 % 300.0 300.0 2015 Debentures due 2025 3.250 % 250.0 250.0 2016 Debentures due 2026 2.700 % 250.0 250.0 2017 Debentures due 2027 3.200 % 700.0 700.0 2019 Debentures due 2029 3.250 % 400.0 400.0 2020 Debentures due 2030 3.950 % 400.0 400.0 2021 Debentures due 2051 3.100 % 300.0 300.0 2021 Debentures due 2031 1.950 % 300.0 300.0 2022 Debentures due 2052 4.550 % 450.0 450.0 2022 Debentures due 2052 4.950 % 400.0 400.0 2023 Debentures due 2028 5.600 % 150.0 150.0 2024 Debentures due 2034 5.400 % 600.0 — Total Debentures 5,000.0 4,400.0 Notes: 2004 Senior Notes Series B due 2034 5.900 % 50.0 50.0 2007 Senior Notes Series D due 2037 6.700 % 40.0 40.0 2016 Senior Notes Series H due 2026 2.750 % 50.0 50.0 Total Notes 140.0 140.0 Less Amounts due Within One Year (250.0) — Unamortized Premiums and Discounts, Net (14.0) (14.0) Unamortized Debt Issuance Costs (31.1) (29.1) NSTAR Electric Long-Term Debt $ 4,844.9 $ 4,496.9 PSNH (Millions of Dollars) As of December 31, Interest Rate 2024 2023 First Mortgage Bonds: 2005 Series M due 2035 5.600 % $ 50.0 $ 50.0 2019 Series T due 2049 3.600 % 300.0 300.0 2020 Series U due 2050 2.400 % 150.0 150.0 2021 Series V due 2031 2.200 % 350.0 350.0 2023 Series W due 2053 5.150 % 300.0 300.0 2023 Series X due 2033 5.350 % 600.0 300.0 Total First Mortgage Bonds 1,750.0 1,450.0 Unamortized Premiums and Discounts, Net (2.6) (4.9) Unamortized Debt Issuance Costs (15.3) (13.5) PSNH Long-Term Debt $ 1,732.1 $ 1,431.6 OTHER (Millions of Dollars) As of December 31, Interest Rate 2024 2023 Eversource Parent - Senior Notes due 2025 - 2050 0.800 % - 5.950% $ 11,350.0 $ 10,300.0 Yankee Gas - First Mortgage Bonds due 2025 - 2051 1.380 % - 5.740% 1,095.0 1,015.0 NSTAR Gas - First Mortgage Bonds due 2025 - 2051 2.250 % - 7.110% 905.0 705.0 EGMA - First Mortgage Bonds due 2028 - 2052 2.110 % - 5.730% 808.0 708.0 Aquarion - Senior Notes due 2024 4.000% — 360.0 Aquarion - Unsecured Notes due 2028 - 2052 (2) 3.000 % - 6.430% 596.8 527.0 Aquarion - Secured Debt due 2027 - 2045 (2) 1.296 % - 9.290% 40.7 39.0 Pre-1983 Spent Nuclear Fuel Obligation (CYAPC) 5.6 12.5 Fair Value Adjustment (3) — 19.3 Less Fair Value Adjustment - Current Portion (3) — (5.5) Less Amounts due in One Year (750.3) (1,810.2) Current Portion Classified as Long-Term Debt (1) — 990.9 Unamortized Premiums and Discounts, Net 41.7 49.7 Unamortized Debt Issuance Costs (76.1) (65.0) Total Other Long-Term Debt $ 14,016.4 $ 12,845.7 Total Eversource Long-Term Debt $ 25,701.6 $ 23,588.6 (1) As a result of the CL&P long-term debt issuance in January 2025, $397.1 million of current portion of long-term debt was reclassified to Long-Term Debt on Eversource’s and CL&P’s balance sheets as of December 31, 2024. As a result of the CL&P and Eversource parent long-term debt issuances in January 2024, $139.8 million and $990.9 million, respectively, of current portion of long-term debt were reclassified to Long-Term Debt on CL&P’s and Eversource parent’s balance sheets as of December 31, 2023. (2) In January 2025, Eversource entered into an agreement to sell Aquarion. Upon close of the sale, Aquarion’s long-term debt will be repaid by Eversource and has therefore not been classified as held for sale. The sale is expected to close in late 2025. (3)

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2024
Debt Disclosure [Abstract]
Schedule of Outstanding Long-Term Debt	The amount of borrowings outstanding and available under the commercial paper programs were as follows: Borrowings Outstanding Available Borrowing Capacity as of December 31, Weighted-Average Interest Rate as of December 31, (Millions of Dollars) 2024 2023 2024 2023 2024 2023 Eversource Parent Commercial Paper Program $ 1,538.0 $ 1,771.9 $ 462.0 $ 228.1 4.76 % 5.60 % NSTAR Electric Commercial Paper Program 504.8 365.8 145.2 284.2 4.55 % 5.40 % Details of long-term debt outstanding are as follows: CL&P (Millions of Dollars) As of December 31, Interest Rate 2024 2023 First Mortgage Bonds: 1994 Series D due 2024 7.875 % $ — $ 139.8 2004 Series B due 2034 5.750 % 130.0 130.0 2005 Series B due 2035 5.625 % 100.0 100.0 2006 Series A due 2036 6.350 % 250.0 250.0 2007 Series B due 2037 5.750 % 150.0 150.0 2007 Series D due 2037 6.375 % 100.0 100.0 2014 Series A due 2044 4.300 % 475.0 475.0 2015 Series A due 2045 4.150 % 350.0 350.0 2017 Series A due 2027 3.200 % 500.0 500.0 2018 Series A due 2048 4.000 % 800.0 800.0 2020 Series A due 2025 0.750 % 400.0 400.0 2021 Series A due 2031 2.050 % 425.0 425.0 2023 Series A due 2053 5.250 % 500.0 500.0 2023 Series B due 2033 4.900 % 300.0 300.0 2024 Series A due 2029 4.650 % 350.0 — 2024 Series B due 2034 4.950 % 300.0 — Total First Mortgage Bonds 5,130.0 4,619.8 Less Amounts due Within One Year (400.0) (139.8) Current Portion Classified as Long-Term Debt (1) 397.1 139.8 Commercial Paper Classified as Long-Term Debt (See Note 8, Short-Term Debt) — 207.3 Unamortized Premiums and Discounts, Net 14.3 18.0 Unamortized Debt Issuance Costs (33.2) (30.7) CL&P Long-Term Debt $ 5,108.2 $ 4,814.4 NSTAR Electric (Millions of Dollars) As of December 31, Interest Rate 2024 2023 Debentures: 2006 Debentures due 2036 5.750 % $ 200.0 $ 200.0 2010 Debentures due 2040 5.500 % 300.0 300.0 2014 Debentures due 2044 4.400 % 300.0 300.0 2015 Debentures due 2025 3.250 % 250.0 250.0 2016 Debentures due 2026 2.700 % 250.0 250.0 2017 Debentures due 2027 3.200 % 700.0 700.0 2019 Debentures due 2029 3.250 % 400.0 400.0 2020 Debentures due 2030 3.950 % 400.0 400.0 2021 Debentures due 2051 3.100 % 300.0 300.0 2021 Debentures due 2031 1.950 % 300.0 300.0 2022 Debentures due 2052 4.550 % 450.0 450.0 2022 Debentures due 2052 4.950 % 400.0 400.0 2023 Debentures due 2028 5.600 % 150.0 150.0 2024 Debentures due 2034 5.400 % 600.0 — Total Debentures 5,000.0 4,400.0 Notes: 2004 Senior Notes Series B due 2034 5.900 % 50.0 50.0 2007 Senior Notes Series D due 2037 6.700 % 40.0 40.0 2016 Senior Notes Series H due 2026 2.750 % 50.0 50.0 Total Notes 140.0 140.0 Less Amounts due Within One Year (250.0) — Unamortized Premiums and Discounts, Net (14.0) (14.0) Unamortized Debt Issuance Costs (31.1) (29.1) NSTAR Electric Long-Term Debt $ 4,844.9 $ 4,496.9 PSNH (Millions of Dollars) As of December 31, Interest Rate 2024 2023 First Mortgage Bonds: 2005 Series M due 2035 5.600 % $ 50.0 $ 50.0 2019 Series T due 2049 3.600 % 300.0 300.0 2020 Series U due 2050 2.400 % 150.0 150.0 2021 Series V due 2031 2.200 % 350.0 350.0 2023 Series W due 2053 5.150 % 300.0 300.0 2023 Series X due 2033 5.350 % 600.0 300.0 Total First Mortgage Bonds 1,750.0 1,450.0 Unamortized Premiums and Discounts, Net (2.6) (4.9) Unamortized Debt Issuance Costs (15.3) (13.5) PSNH Long-Term Debt $ 1,732.1 $ 1,431.6 OTHER (Millions of Dollars) As of December 31, Interest Rate 2024 2023 Eversource Parent - Senior Notes due 2025 - 2050 0.800 % - 5.950% $ 11,350.0 $ 10,300.0 Yankee Gas - First Mortgage Bonds due 2025 - 2051 1.380 % - 5.740% 1,095.0 1,015.0 NSTAR Gas - First Mortgage Bonds due 2025 - 2051 2.250 % - 7.110% 905.0 705.0 EGMA - First Mortgage Bonds due 2028 - 2052 2.110 % - 5.730% 808.0 708.0 Aquarion - Senior Notes due 2024 4.000% — 360.0 Aquarion - Unsecured Notes due 2028 - 2052 (2) 3.000 % - 6.430% 596.8 527.0 Aquarion - Secured Debt due 2027 - 2045 (2) 1.296 % - 9.290% 40.7 39.0 Pre-1983 Spent Nuclear Fuel Obligation (CYAPC) 5.6 12.5 Fair Value Adjustment (3) — 19.3 Less Fair Value Adjustment - Current Portion (3) — (5.5) Less Amounts due in One Year (750.3) (1,810.2) Current Portion Classified as Long-Term Debt (1) — 990.9 Unamortized Premiums and Discounts, Net 41.7 49.7 Unamortized Debt Issuance Costs (76.1) (65.0) Total Other Long-Term Debt $ 14,016.4 $ 12,845.7 Total Eversource Long-Term Debt $ 25,701.6 $ 23,588.6 (1) As a result of the CL&P long-term debt issuance in January 2025, $397.1 million of current portion of long-term debt was reclassified to Long-Term Debt on Eversource’s and CL&P’s balance sheets as of December 31, 2024. As a result of the CL&P and Eversource parent long-term debt issuances in January 2024, $139.8 million and $990.9 million, respectively, of current portion of long-term debt were reclassified to Long-Term Debt on CL&P’s and Eversource parent’s balance sheets as of December 31, 2023. (2) In January 2025, Eversource entered into an agreement to sell Aquarion. Upon close of the sale, Aquarion’s long-term debt will be repaid by Eversource and has therefore not been classified as held for sale. The sale is expected to close in late 2025. (3)
Schedule of Issuance and Repayments of Long-Term Debt	The following table summarizes long-term debt issuances and repayments: (Millions of Dollars) Interest Rate Issuance/ Issue Date or Repayment Date Maturity Date Use of Proceeds for Issuance/ CL&P 2024 Series A First Mortgage Bonds 4.65 % $ 350.0 January 2024 January 2029 Repaid short-term debt, paid capital expenditures and working capital CL&P Series B First Mortgage Bonds 4.95 % 300.0 August 2024 August 2034 Repaid Series D Bonds, repaid short-term debt, and working capital CL&P Series D First Mortgage Bonds 7.875 % (139.8) October 2024 October 2024 Paid at maturity CL&P 2025 Series A First Mortgage Bonds 4.95 % 400.0 January 2025 January 2030 Repaid short-term debt, paid capital expenditures and working capital NSTAR Electric Debentures 5.40 % 600.0 May 2024 June 2034 Repaid short-term debt, paid capital expenditures and working capital PSNH Series X First Mortgage Bonds 5.35 % 300.0 April 2024 October 2033 Repaid short-term debt, paid capital expenditures and working capital Eversource Parent Series DD Senior Notes 5.00 % 350.0 January 2024 January 2027 Repaid short-term debt Eversource Parent Series EE Senior Notes 5.50 % 650.0 January 2024 January 2034 Repaid short-term debt Eversource Parent Series FF Senior Notes 5.85 % 700.0 April 2024 April 2031 Repaid Series X Senior Notes and Aquarion’s 2014 Senior Notes at maturity and short-term debt Eversource Parent Series GG Senior Notes 5.95 % 700.0 April 2024 July 2034 Repaid Series X Senior Notes and Aquarion’s 2014 Senior Notes at maturity and short-term debt Eversource Parent Series X Senior Notes 4.20 % (900.0) June 2024 June 2024 Paid at maturity Eversource Parent Series L Senior Notes 2.90 % (450.0) October 2024 October 2024 Paid at maturity Eversource Parent Series H Senior Notes 3.15 % (300.0) January 2025 January 2025 Paid at maturity NSTAR Gas Series W First Mortgage Bonds 5.29 % 160.0 June 2024 June 2029 Repaid short-term debt, paid capital expenditures and general corporate purposes NSTAR Gas Series X First Mortgage Bonds 5.48 % 40.0 June 2024 June 2034 Repaid short-term debt, paid capital expenditures and general corporate purposes Yankee Gas Series W First Mortgage Bonds 5.50 % 90.0 July 2024 July 2029 Repaid short-term debt, paid capital expenditures, working capital and repaid Series P bonds at maturity Yankee Gas Series X First Mortgage Bonds 5.74 % 90.0 July 2024 July 2034 Repaid short-term debt, paid capital expenditures, working capital and repaid Series P bonds at maturity Yankee Gas Series P First Mortgage Bonds 2.23 % (100.0) October 2024 October 2024 Paid at maturity EGMA Series E First Mortgage Bonds 5.17 % 100.0 October 2024 November 2034 Refinanced existing indebtedness, paid capital expenditures and general corporate purposes Aquarion Senior Notes 4.00 % (360.0) August 2024 August 2024 Paid at maturity Aquarion Water Company of Connecticut Senior Notes 5.57 % 70.0 August 2024 September 2034 Repaid short-term debt, paid capital expenditures and general corporate purposes
Schedule of Maturities of Long-Term Debt Outstanding	Long-term debt maturities on debt outstanding for the years 2025 through 2029 and thereafter are shown below. These amounts exclude PSNH rate reduction bonds, CYAPC pre-1983 spent nuclear fuel obligation, and unamortized premiums, discounts, and debt issuance costs as of December 31, 2024: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2025 $ 1,400.3 $ 400.0 $ 250.0 $ — 2026 1,390.2 — 300.0 — 2027 2,889.2 500.0 700.0 — 2028 1,978.5 — 150.0 — 2029 2,300.3 350.0 400.0 — Thereafter 16,857.0 3,880.0 3,340.0 1,750.0 Total $ 26,815.5 $ 5,130.0 $ 5,140.0 $ 1,750.0

RATE REDUCTION BONDS AND VARI_2

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES (Tables)	12 Months Ended
	Dec. 31, 2024
Rate Reduction Bonds and Variable Interest Entity [Abstract]
Summary of the Impact of Funding on the Balance Sheets and Income Statements	The following tables summarize the impact of PSNH Funding on PSNH's balance sheets and income statements: (Millions of Dollars) As of December 31, PSNH Balance Sheets: 2024 2023 Restricted Cash - Current Portion (included in Special Deposits) $ 31.0 $ 30.0 Restricted Cash - Long-Term Portion (included in Other Long-Term Assets) 3.1 3.2 Securitized Stranded Cost (included in Regulatory Assets) 349.3 392.5 Other Regulatory Liabilities (included in Regulatory Liabilities) 6.9 5.3 Accrued Interest (included in Other Current Liabilities) 5.7 6.3 Rate Reduction Bonds - Current Portion 43.2 43.2 Rate Reduction Bonds - Long-Term Portion 324.1 367.3 (Millions of Dollars) PSNH Income Statements: For the Years Ended December 31, 2024 2023 2022 Amortization of RRB Principal (included in Amortization of Regulatory Assets/(Liabilities), Net) $ 43.2 $ 43.2 $ 43.2 Interest Expense on RRB Principal (included in Interest Expense) 14.3 15.7 17.0
Schedule Of Rate Reduction Bonds, Principal And Interest Payments	Estimated principal payments on RRBs as of December 31, 2024, is summarized annually through 2029 and thereafter as follows: (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total PSNH $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 43.2 $ 151.3 $ 367.3

EMPLOYEE BENEFITS (Tables)

EMPLOYEE BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2024
Postemployment Benefits [Abstract]
Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets	The following tables provide information on the plan benefit obligations, fair values of plan assets, and funded status: Pension and SERP As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (5,238.4) $ (1,048.5) $ (1,107.0) $ (562.3) $ (5,220.1) $ (1,030.0) $ (1,110.4) $ (556.2) Service Cost (44.3) (12.7) (7.7) (4.3) (43.1) (12.3) (7.8) (4.3) Interest Cost (250.0) (50.3) (51.6) (26.8) (254.0) (50.5) (53.9) (27.3) Actuarial Gain/(Loss) 280.2 56.2 74.1 30.7 (110.4) (19.7) (17.6) (11.6) Benefits Paid - Pension 320.9 68.1 67.1 38.0 317.3 66.1 76.7 35.7 Benefits Paid - Lump Sum 24.0 — 7.6 0.1 28.9 — 5.3 1.0 Benefits Paid - SERP 19.4 0.3 0.2 0.4 43.0 0.3 0.2 0.4 Employee Transfers — 4.0 13.8 2.7 — (2.4) 0.5 — Reclassified to Assets Held for Sale 142.5 — — — — — — — Benefit Obligation as of End of Year $ (4,745.7) $ (982.9) $ (1,003.5) $ (521.5) $ (5,238.4) $ (1,048.5) $ (1,107.0) $ (562.3) Change in Pension Plan Assets: Fair Value of Pension Plan Assets as of $ 5,775.0 $ 1,170.0 $ 1,411.6 $ 614.0 $ 5,806.4 $ 1,172.0 $ 1,418.8 $ 618.0 Employer Contributions 5.0 — — — 5.0 — — — Actual Return on Pension Plan Assets 227.0 46.5 55.1 24.3 309.8 61.7 75.3 32.7 Benefits Paid - Pension (320.9) (68.1) (67.1) (38.0) (317.3) (66.1) (76.7) (35.7) Benefits Paid - Lump Sum (24.0) — (7.6) (0.1) (28.9) — (5.3) (1.0) Employee Transfers — (4.0) (13.8) (2.7) — 2.4 (0.5) — Reclassified to Assets Held for Sale (148.1) — — — — — — — Fair Value of Pension Plan Assets as of End of Year $ 5,514.0 $ 1,144.4 $ 1,378.2 $ 597.5 $ 5,775.0 $ 1,170.0 $ 1,411.6 $ 614.0 Funded Status as of December 31st $ 768.3 $ 161.5 $ 374.7 $ 76.0 $ 536.6 $ 121.5 $ 304.6 $ 51.7 PBOP As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Change in Benefit Obligation: Benefit Obligation as of Beginning of Year $ (676.0) $ (120.6) $ (188.3) $ (72.0) $ (693.7) $ (127.9) $ (189.5) $ (74.6) Service Cost (7.0) (1.2) (1.2) (0.6) (7.6) (1.3) (1.2) (0.7) Interest Cost (31.9) (5.6) (8.8) (3.4) (33.8) (6.2) (9.2) (3.7) Actuarial Gain/(Loss) 41.3 8.9 10.7 3.9 5.0 4.4 (5.8) 0.8 Benefits Paid 51.7 9.4 15.9 6.2 52.7 10.0 16.7 6.1 Employee Transfers — — 0.3 — — — 0.5 (0.1) Plan Amendment — — — — 1.4 0.4 0.2 0.2 Reclassified to Assets Held for Sale 34.5 — — — — — — — Benefit Obligation as of End of Year $ (587.4) $ (109.1) $ (171.4) $ (65.9) $ (676.0) $ (120.6) $ (188.3) $ (72.0) Change in Plan Assets: Fair Value of Plan Assets as of Beginning of Year $ 1,024.4 $ 123.0 $ 490.4 $ 74.7 $ 970.1 $ 120.6 $ 456.1 $ 72.3 Actual Return on Plan Assets 92.3 11.2 45.8 7.6 104.7 12.6 52.3 8.3 Employer Contributions 0.9 — — — 1.9 — — — Benefits Paid (51.8) (9.4) (15.9) (6.1) (52.3) (10.0) (16.7) (6.1) Employee Transfers — (0.4) (1.1) 0.2 — (0.2) (1.3) 0.2 Reclassified to Assets Held for Sale (29.5) — — — — — — — Fair Value of Plan Assets as of End of Year $ 1,036.3 $ 124.4 $ 519.2 $ 76.4 $ 1,024.4 $ 123.0 $ 490.4 $ 74.7 Funded Status as of December 31st $ 448.9 $ 15.3 $ 347.8 $ 10.5 $ 348.4 $ 2.4 $ 302.1 $ 2.7
Schedule of Defined Benefit Plans	As of December 31, 2024 and 2023, the accumulated benefit obligation for the Pension and SERP Plans is as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2024 $ 4,617.1 $ 953.9 $ 969.5 $ 507.4 2023 4,936.8 977.8 1,051.9 522.1 A reconciliation of the prepaid assets and liabilities within the Eversource Pension, SERP and PBOP Plans’ funded status to the balance sheets is as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Prepaid Pension (1) $ 887.7 $ 167.2 $ 376.9 $ 80.5 $ 672.2 $ 127.4 $ 306.5 $ 56.3 Prepaid PBOP 448.9 15.3 347.8 10.5 356.0 2.4 302.1 2.7 Prepaid Pension and PBOP $ 1,336.6 $ 182.5 $ 724.7 $ 91.0 $ 1,028.2 $ 129.8 $ 608.6 $ 59.0 Accrued SERP (1) $ 119.4 $ 5.7 $ 2.2 $ 4.5 $ 135.6 $ 5.9 $ 1.9 $ 4.6 Accrued PBOP (1) — — — — 7.6 — — — Less: Accrued SERP - current portion (24.0) (0.4) (0.2) (0.4) (19.4) (0.3) (0.2) (0.4) Accrued SERP and PBOP $ 95.4 $ 5.3 $ 2.0 $ 4.1 $ 123.8 $ 5.6 $ 1.7 $ 4.2 (1) As of December 31, 2024, the Aquarion water distribution business’s prepaid pension has been reclassified to Assets Held for Sale and the accrued SERP and PBOP liabilities have been reclassified to Liabilities Held for Sale on the Eversource balance sheet. As of December 31, 2023, these balances were recorded within Prepaid Pension and PBOP and Accrued SERP and PBOP on the Eversource balance sheet. For further information, see Note 24, “Assets Held for Sale.”
Schedule of Assumptions Used	The following actuarial assumptions were used in calculating the Pension, SERP and PBOP Plans' year end funded status: Pension and SERP PBOP As of December 31, As of December 31, 2024 2023 2024 2023 Discount Rate 5.6% — 5.7% 4.9% — 5.0% 5.7% 5.0% — 5.2% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% N/A The following actuarial assumptions were used to calculate Pension, SERP and PBOP expense amounts: Pension and SERP PBOP For the Years Ended December 31, For the Years Ended December 31, 2024 2023 2022 2024 2023 2022 Discount Rate 4.7% — 5.1% 4.9% — 5.3% 2.2% — 3.2% 4.9% — 5.2% 5.1% — 5.4% 2.3% — 3.3% Expected Long-Term Rate of Return 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% Compensation/Progression Rate 3.5% — 4.0% 3.5% — 4.0% 3.5% — 4.0% N/A N/A N/A
Schedule of Net Benefit Costs	The components of net periodic benefit plan expense/(income) for the Pension, SERP and PBOP Plans, prior to amounts capitalized as Property, Plant and Equipment or deferred as regulatory assets/(liabilities) for future recovery or refund, are shown below. The service cost component of net periodic benefit plan expense/(income), less the capitalized portion, is included in Operations and Maintenance expense on the statements of income. The remaining components of net periodic benefit plan expense/(income), less the deferred portion, are included in Other Income, Net on the statements of income. Pension, SERP and PBOP plan expense/(income) reflected in the statements of cash flows for CL&P, NSTAR Electric and PSNH does not include intercompany allocations of net periodic benefit plan expense/(income), as these amounts are cash settled on a short-term basis. Pension and SERP PBOP For the Year Ended December 31, 2024 For the Year Ended December 31, 2024 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 44.3 $ 12.7 $ 7.7 $ 4.3 $ 7.0 $ 1.2 $ 1.2 $ 0.6 Interest Cost 250.0 50.3 51.6 26.8 31.9 5.6 8.8 3.4 Expected Return on Plan Assets (462.6) (93.5) (112.4) (48.9) (81.2) (9.5) (39.5) (5.6) Actuarial Loss/(Gain) 85.9 12.1 25.6 5.0 (0.4) — — — Prior Service Cost/(Credit) 1.3 — 0.3 — (21.6) 1.1 (17.0) 0.4 Settlement Loss 4.3 — — — — — — — Total Net Periodic Benefit Plan Income $ (76.8) $ (18.4) $ (27.2) $ (12.8) $ (64.3) $ (1.6) $ (46.5) $ (1.2) Intercompany Income Allocations N/A $ (1.6) $ (1.3) $ (0.4) N/A $ (2.2) $ (2.6) $ (0.9) Pension and SERP PBOP For the Year Ended December 31, 2023 For the Year Ended December 31, 2023 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 43.1 $ 12.3 $ 7.8 $ 4.3 $ 7.6 $ 1.3 $ 1.2 $ 0.7 Interest Cost 254.0 50.5 53.9 27.3 33.8 6.2 9.2 3.7 Expected Return on Plan Assets (465.0) (94.2) (113.8) (49.5) (77.1) (9.4) (36.9) (5.5) Actuarial Loss 45.8 2.5 17.1 1.5 — — — — Prior Service Cost/(Credit) 1.3 — 0.3 — (21.6) 1.1 (17.0) 0.4 Settlement Loss 12.4 — — — — — — — Total Net Periodic Benefit Plan Income $ (108.4) $ (28.9) $ (34.7) $ (16.4) $ (57.3) $ (0.8) $ (43.5) $ (0.7) Intercompany Income Allocations N/A $ (4.0) $ (3.0) $ (0.8) N/A $ (1.9) $ (2.1) $ (0.7) Pension and SERP PBOP For the Year Ended December 31, 2022 For the Year Ended December 31, 2022 (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Service Cost $ 70.1 $ 18.7 $ 13.8 $ 6.9 $ 11.6 $ 2.0 $ 2.0 $ 1.1 Interest Cost 154.5 31.3 32.8 16.9 20.2 3.7 5.3 2.2 Expected Return on Plan Assets (523.6) (106.3) (128.4) (56.1) (89.9) (11.4) (42.4) (6.7) Actuarial Loss 116.0 16.2 32.8 7.9 — — — — Prior Service Cost/(Credit) 1.4 — 0.3 — (21.7) 1.1 (17.0) 0.4 Total Net Periodic Benefit Plan Income $ (181.6) $ (40.1) $ (48.7) $ (24.4) $ (79.8) $ (4.6) $ (52.1) $ (3.0) Intercompany Income Allocations N/A $ (16.0) $ (12.4) $ (3.6) N/A $ (3.7) $ (3.6) $ (1.2)
Schedule of Amounts Recognized in Regulatory Assets and OCI	The following is a summary of the changes in plan assets and benefit obligations recognized in Regulatory Assets and Other Comprehensive Income (OCI) as well as amounts in Regulatory Assets and OCI that were reclassified as net periodic benefit expense during the years presented: Pension and SERP PBOP Regulatory Assets OCI Regulatory Assets OCI For the Years Ended December 31, For the Years Ended December 31, (Millions of Dollars) 2024 2023 2024 2023 2024 2023 2024 2023 Actuarial (Gain)/Loss Arising During the Year $ (49.2) $ 251.1 $ 2.3 $ 14.0 $ (50.9) $ (32.0) $ (0.6) $ (0.3) Actuarial (Loss)/Gain Reclassified as Net Periodic Benefit (Expense)/Income (79.1) (38.8) (6.8) (7.0) 0.4 — — — Actuarial (Loss)/Gain Reclassified as Held for Sale (16.6) — — — 7.1 — — — Settlement Loss — — (4.3) (12.4) — — — — Prior Service Cost/(Credit) Arising During the Year 1.3 — — — — (0.9) — — Prior Service (Cost)/Credit Reclassified as Net Periodic (1.2) (1.2) (0.1) (0.1) 21.8 21.8 (0.2) (0.2) Prior Service Cost Reclassified as Held for Sale (1.2) — — — (0.6) — — — The following is a summary of the remaining Regulatory Assets and Accumulated Other Comprehensive Income amounts that have not been recognized as components of net periodic benefit expense as of December 31, 2024 and 2023: Regulatory Assets as of December 31, AOCI as of December 31, (Millions of Dollars) 2024 2023 2024 2023 Pension and SERP Actuarial Loss $ 956.1 $ 1,101.0 $ 47.7 $ 56.5 Prior Service Cost 1.8 2.9 0.2 0.3 PBOP Actuarial Loss $ 6.4 $ 49.8 $ 1.8 $ 2.4 Prior Service (Credit)/Cost (66.2) (87.4) 0.5 0.7
Schedule of Expected Benefit Payments	The following benefit payments, which reflect expected future service, are expected to be paid by the Pension, SERP and PBOP Plans: (Millions of Dollars) 2025 2026 2027 2028 2029 2030 - 2034 Pension and SERP $ 367.3 $ 363.3 $ 369.5 $ 372.9 $ 375.4 $ 1,879.4 PBOP 51.3 50.6 49.8 48.9 48.0 223.3
Schedule of Allocation of Plan Assets	These long-term rates of return are based on the assumed rates of return for the target asset allocations as follows: As of December 31, 2024 2023 Target Asset Allocation Assumed Rate of Return Target Asset Allocation Assumed Rate of Return Eversource Pension Plan Eversource PBOP Plan Eversource Pension Plan and PBOP Plan Eversource Pension Plan Eversource PBOP Plan Eversource Pension Plan and PBOP Plan Equity Securities: United States — % 20.0 % 8.5 % — % 20.0 % 8.5 % Global 20.0 % — % 8.8 % 20.0 % — % 8.75 % Non-United States — % 11.0 % 8.5 % — % 11.0 % 8.5 % Emerging Markets — % 6.0 % 10.0 % — % 6.0 % 10.0 % Debt Securities: Fixed Income 16.0 % 17.0 % 5.5 % 16.0 % 17.0 % 5.5 % Public High Yield Fixed Income 5.0 % — % 7.5 % 5.0 % — % 7.5 % United States Treasuries 11.0 % — % 4.5 % 11.0 % — % 4.5 % Private Debt 10.0 % 13.0 % 10.0 % 10.0 % 13.0 % 10.0 % Private Equity 23.0 % 18.0 % 12.0 % 23.0 % 18.0 % 12.0 % Real Assets 15.0 % 15.0 % 7.5 % 15.0 % 15.0 % 7.5 % The following tables present, by asset category, the Pension and PBOP Plan assets recorded at fair value on a recurring basis by the level in which they are classified within the fair value hierarchy: Pension Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2024 (1) 2023 (2) Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 323.6 $ — $ 826.0 $ 1,149.6 $ 374.0 $ — $ 853.0 $ 1,227.0 Fixed Income 314.3 344.7 1,329.6 1,988.6 354.6 340.9 1,516.4 2,211.9 Private Equity — — 1,710.9 1,710.9 — — 1,685.3 1,685.3 Real Assets 243.8 — 652.2 896.0 173.6 — 722.1 895.7 Total $ 881.7 $ 344.7 $ 4,518.7 $ 5,745.1 $ 902.2 $ 340.9 $ 4,776.8 $ 6,019.9 Less: 401(h) PBOP Assets (3) (231.1) (244.9) Total Pension Assets $ 5,514.0 $ 5,775.0 PBOP Plan Fair Value Measurements as of December 31, (Millions of Dollars) 2024 (1) 2023 Asset Category: Level 1 Level 2 Uncategorized Total Level 1 Level 2 Uncategorized Total Equity Securities $ 184.8 $ — $ 166.3 $ 351.1 $ 139.1 $ — $ 212.1 $ 351.2 Fixed Income 61.8 44.6 127.5 233.9 33.4 43.0 159.8 236.2 Private Equity — — 99.0 99.0 — — 87.7 87.7 Real Assets 83.7 — 37.5 121.2 70.5 — 33.9 104.4 Total $ 330.3 $ 44.6 $ 430.3 $ 805.2 $ 243.0 $ 43.0 $ 493.5 $ 779.5 Add: 401(h) PBOP Assets (3) 231.1 244.9 Total PBOP Assets $ 1,036.3 $ 1,024.4 (1) As of December 31, 2024, the funded status of the Aquarion water distribution business’s Pension and PBOP benefit plans have been reclassified in held for sale presentation on the Eversource balance sheet. Therefore, these Pension and PBOP asset balances have been excluded from the table above as of December 31, 2024. (2) Fixed Income investments classified as Level 1 as of December 31, 2023 include pending purchases and pending redemption settlements of $31 million. (3) The assets of the Pension Plan include a 401(h) account that has been allocated to provide health and welfare postretirement benefits under the PBOP Plan.
Schedule of Defined Contribution Plans	The total Eversource 401k Plan employer matching contributions, including the K-Vantage contributions, were as follows: (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH 2024 $ 76.2 $ 10.6 $ 15.4 $ 6.0 2023 67.3 9.0 13.7 5.4 2022 59.9 7.7 12.8 4.8
Summary of Share Transactions	A summary of RSU transactions is as follows: RSUs Weighted Average Outstanding as of December 31, 2023 672,242 $ 65.89 Granted 372,400 $ 57.93 Shares Issued (289,372) $ 65.25 Forfeited (39,828) $ 66.91 Outstanding as of December 31, 2024 715,442 $ 61.95 Performance Shares Weighted Average Outstanding as of December 31, 2023 664,424 $ 85.33 Granted 431,789 $ 55.87 Shares Issued (126,054) $ 85.54 Forfeited (105,967) $ 77.98 Outstanding as of December 31, 2024 864,192 $ 71.48
Schedule of Compensation Expense and Income Tax Benefit	The total compensation expense and associated future income tax benefits recognized by Eversource, CL&P, NSTAR Electric and PSNH for share-based compensation awards were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Compensation Expense $ 30.0 $ 27.8 $ 33.4 Future Income Tax Benefit 7.8 7.3 8.7 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Compensation Expense $ 9.3 $ 9.6 $ 3.6 $ 8.7 $ 8.7 $ 3.0 $ 10.0 $ 10.7 $ 3.6 Future Income Tax Benefit 2.4 2.5 0.9 2.3 2.3 0.8 2.6 2.8 0.9
Schedule of Other Retirement Benefits	The liability and expense amounts are as follows: Eversource (Millions of Dollars) As of and For the Years Ended December 31, 2024 2023 2022 Actuarially-Determined Liability $ 30.2 $ 32.6 $ 43.4 Other Retirement Benefits Expense (1) 2.4 2.6 10.9 As of and For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Actuarially-Determined Liability 0.1 $ — $ 1.0 $ 0.2 $ — $ 1.1 $ 0.2 $ 0.1 $ 1.3 Other Retirement Benefits Expense (1) 0.8 0.8 0.3 0.8 0.8 0.4 4.0 3.7 1.3 (1) Other Retirement Benefits Expense in 2022 includes a one-time special retirement benefit payable of $9.2 million, which was paid in 2023.

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2024
Income Tax Disclosure [Abstract]
Components of Income Tax Expense	The components of income tax expense are as follows: Eversource (Millions of Dollars) For the Years Ended December 31, 2024 2023 2022 Current Income Taxes: Federal $ (23.4) $ 75.8 $ 95.8 State 14.3 0.6 13.6 Total Current (9.1) 76.4 109.4 Deferred Income Taxes, Net: Federal 266.3 (0.9) 198.8 State 169.6 86.3 148.0 Total Deferred 435.9 85.4 346.8 Investment Tax Credits, Net (2.1) (2.1) (2.6) Income Tax Expense $ 424.7 $ 159.7 $ 453.6 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Current Income Taxes: Federal $ 25.9 $ 65.9 $ (1.7) $ (10.8) $ 50.7 $ (40.0) $ 106.2 $ 55.0 $ 29.6 State (6.8) 15.2 (5.2) (2.3) 7.8 (20.0) 20.1 8.7 5.9 Total Current 19.1 81.1 (6.9) (13.1) 58.5 (60.0) 126.3 63.7 35.5 Deferred Income Taxes, Net: Federal 107.9 63.9 50.8 130.3 50.1 81.2 17.2 35.6 5.9 State 67.5 47.3 26.3 53.7 46.1 37.8 28.2 42.4 9.9 Total Deferred 175.4 111.2 77.1 184.0 96.2 119.0 45.4 78.0 15.8 Investment Tax Credits, Net — (1.7) — — (1.7) — (0.5) (1.7) — Income Tax Expense $ 194.5 $ 190.6 $ 70.2 $ 170.9 $ 153.0 $ 59.0 $ 171.2 $ 140.0 $ 51.3
Summary of Reconciliation Between Income Tax Expense and Expected Tax	A reconciliation between income tax expense and the expected tax expense at the statutory rate is as follows: Eversource (Millions of Dollars, except percentages) For the Years Ended December 31, 2024 2023 2022 Income/(Loss) Before Income Tax Expense $ 1,243.8 $ (275.0) $ 1,866.0 Statutory Federal Income Tax Expense at 21% 261.2 (57.7) 391.9 Tax Effect of Differences: Depreciation (22.6) (25.8) (17.1) Investment Tax Credit Amortization (2.1) (2.1) (2.6) Other Federal Tax Credits (67.0) (42.5) — State Income Taxes, Net of Federal Impact 43.2 (11.4) 75.9 Dividends on ESOP (5.5) (5.3) (5.1) Tax Asset Valuation Allowance/Reserve Adjustments 278.6 295.8 51.6 Tax Deficiency/(Excess Stock Benefit) 2.3 0.5 (2.1) EDIT Amortization (37.0) (51.5) (49.1) Other, Net (26.4) 59.7 10.2 Income Tax Expense $ 424.7 $ 159.7 $ 453.6 Effective Tax Rate 34.1 % (58.1) % 24.3 % For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars, except percentages) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Income Before Income Tax Expense $ 707.1 $ 826.9 $ 285.1 $ 689.6 $ 697.5 $ 254.7 $ 704.1 $ 632.4 $ 222.9 Statutory Federal Income Tax Expense at 21% 148.5 173.7 59.9 144.9 146.5 53.5 147.9 132.8 46.8 Tax Effect of Differences: Depreciation 0.4 (10.9) (1.0) (5.6) (8.8) (1.0) (3.7) (4.2) 0.9 Investment Tax Credit Amortization — (1.7) — — (1.7) — (0.5) (1.7) — State Income Taxes, Net of Federal Impact (2.8) 49.4 16.7 (10.7) 42.5 14.1 (6.6) 40.3 12.5 Tax Asset Valuation 50.8 — — 51.3 — — 44.7 — — Tax Deficiency/(Excess Stock Benefit) 0.8 0.8 0.3 0.2 0.2 0.1 (0.7) (0.8) (0.3) EDIT Amortization (9.2) (20.0) (6.5) (10.5) (28.4) (6.8) (9.2) (29.2) (7.7) Other, Net 6.0 (0.7) 0.8 1.3 2.7 (0.9) (0.7) 2.8 (0.9) Income Tax Expense $ 194.5 $ 190.6 $ 70.2 $ 170.9 $ 153.0 $ 59.0 $ 171.2 $ 140.0 $ 51.3 Effective Tax Rate 27.5 % 23.0 % 24.6 % 24.8 % 21.9 % 23.2 % 24.3 % 22.1 % 23.0 %
Schedule of Accumulated Deferred Income Tax Obligations	The tax effects of temporary differences that give rise to the net accumulated deferred income tax obligations are as follows: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Eversource CL&P NSTAR PSNH Deferred Tax Assets: Employee Benefits $ 266.9 $ 33.7 $ 83.5 $ 14.5 $ 244.5 $ 29.9 $ 66.8 $ 13.0 Derivative Liabilities 19.6 19.6 — — 33.0 33.0 — — Regulatory Deferrals - Liabilities 508.7 128.0 316.7 19.6 452.0 94.4 291.5 23.8 Allowance for Uncollectible Accounts 145.3 75.4 26.5 3.8 143.8 79.6 21.5 3.9 Tax Effect - Tax Regulatory Liabilities 720.8 317.6 214.3 93.2 739.0 320.7 227.1 95.5 Net Operating Loss Carryforwards 198.2 — — 1.5 13.8 — — — Purchase Accounting Adjustment 52.1 — — — 56.7 — — — Equity Method Wind Investments 1,098.6 — — — 584.9 — — — Other 267.1 134.7 31.5 24.1 200.1 125.3 25.0 23.4 Total Deferred Tax Assets 3,277.3 709.0 672.5 156.7 2,467.8 682.9 631.9 159.6 Less: Valuation Allowance (1) 558.2 104.1 — — 328.1 80.6 — — Net Deferred Tax Assets $ 2,719.1 $ 604.9 $ 672.5 $ 156.7 $ 2,139.7 $ 602.3 $ 631.9 $ 159.6 Deferred Tax Liabilities: Accelerated Depreciation and Other $ 5,493.3 $ 1,820.3 $ 1,845.2 $ 618.4 $ 5,103.3 $ 1,703.4 $ 1,728.6 $ 566.5 Property Tax Accruals 107.4 49.8 44.5 6.5 95.0 42.0 39.8 6.3 Regulatory Amounts: Regulatory Deferrals - Assets 1,709.1 522.9 519.9 277.8 1,512.3 470.0 474.5 250.3 Tax Effect - Tax Regulatory Assets 294.5 194.7 10.0 9.4 284.0 191.9 10.5 8.3 Goodwill-related Regulatory Asset - 1999 Merger 67.5 — 58.0 — 72.2 — 61.9 — Employee Benefits 353.0 51.0 175.4 23.5 282.0 38.8 146.7 16.8 Derivative Assets 3.8 3.8 — — 6.4 6.4 — — Other 101.7 15.2 24.9 2.7 88.2 9.9 19.5 2.9 Total Deferred Tax Liabilities $ 8,130.3 $ 2,657.7 $ 2,677.9 $ 938.3 $ 7,443.4 $ 2,462.4 $ 2,481.5 $ 851.1 (1) As of December 31, 2024 and 2023, the Eversource Valuation Allowance of $558.2 million and $328.1 million, includes $427.0 million and $224.0 million, respectively, related to Eversource’s share of offshore wind investments.
Summary of Tax Credits and Loss Carryforwards	The following table provides the amounts and expiration dates of state tax credit and loss carryforwards and federal tax credit and net operating loss carryforwards: As of December 31, 2024 2023 (Millions of Dollars) Eversource CL&P NSTAR PSNH Expiration Range Eversource CL&P NSTAR PSNH Expiration Range Federal Net Operating Loss $ 877.7 $ — $ — $ 7.1 — $ — $ — $ — $ — — Federal Tax Credit 404.1 — — — 2044 — — — — — Federal Capital Loss 2,700.0 — — — 2024 - 2029 — — — — — State Net Operating Loss 214.1 — — — 2024 - 2044 243.4 — — — 2023 - 2041 State Tax Credit 238.3 157.7 — — 2024 - 2029 228.5 157.5 — — 2023 - 2028 State Capital Loss 2,700.0 — — — 2024 - 2029 — — — — — State Charitable Contribution 15.2 — — — 2024 - 2028 7.9 — — — 2023 - 2027
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the activity in unrecognized tax benefits, all of which would impact the effective tax rate if recognized, is as follows: (Millions of Dollars) Eversource CL&P Balance as of January 1, 2022 $ 65.8 $ 26.2 Gross Increases - Current Year 11.5 3.5 Gross Decreases - Prior Year (2.4) (0.9) Lapse of Statute of Limitations (7.8) (3.3) Balance as of December 31, 2022 67.1 25.5 Gross Increases - Current Year 23.4 4.0 Gross Increases - Prior Year 0.1 0.1 Gross Decreases - Prior Year (0.1) — Lapse of Statute of Limitations (9.2) (3.8) Balance as of December 31, 2023 81.3 25.8 Gross Increases - Current Year 14.2 2.9 Gross Increases - Prior Year 11.0 — Gross Decreases - Prior Year (0.2) (0.2) Lapse of Statute of Limitations (12.6) (6.6) Balance as of December 31, 2024 $ 93.7 $ 21.9
Summary of Income Tax Examinations	The following table summarizes Eversource, CL&P, NSTAR Electric, and PSNH's tax years that remain subject to examination by major tax jurisdictions as of December 31, 2024: Description Tax Years Federal 2022 - 2024 (1) Connecticut 2021 - 2024 Massachusetts 2022 - 2024 New Hampshire 2021 - 2024 (1) The Company’s Corporate Income Tax Returns for 2022 and 2023 were reviewed and closed as part of the annual IRS CAP program, with the exception for partnership investments of the Company. The Company was recently informed of an IRS audit of one of the partnership returns for the tax year 2022 and the IRS reserves the right to audit 2023. The Company recorded in the above Unrecognized Tax Benefits a reserve associated with this Partnership audit. These years remain open in relation to those audits.

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule of Environmental Loss Contingencies by Site	A reconciliation of the activity in the environmental reserves (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Balance as of January 1, 2023 $ 122.6 $ 13.9 $ 3.4 $ 6.1 Additions 16.8 2.6 2.5 1.7 Payments/Reductions (11.2) (2.7) (0.5) (0.2) Balance as of December 31, 2023 128.2 13.8 5.4 7.6 Additions 11.0 0.8 1.9 0.2 Payments/Reductions (11.2) (1.2) (0.7) (1.5) Balance as of December 31, 2024 $ 128.0 $ 13.4 $ 6.6 $ 6.3 The number of environmental sites for which remediation or long-term monitoring, preliminary site work or site assessment is being performed are as follows: Eversource CL&P NSTAR Electric PSNH 2024 65 15 14 8 2023 65 16 12 8
Schedule of Estimated Future Annual Costs of Long term Contractual Agreement	The estimated future annual costs of significant executed, non-cancelable, long-term contractual arrangements in effect as of December 31, 2024 are as follows: Eversource (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Renewable Energy Purchase Contracts $ 771.8 $ 865.2 $ 919.9 $ 918.0 $ 785.5 $ 6,289.9 $ 10,550.3 Natural Gas Procurement 532.6 486.1 364.6 308.1 294.9 1,004.4 2,990.7 Capacity and Purchased Power 75.2 2.9 2.7 2.7 2.3 2.3 88.1 Peaker CfDs 28.3 27.7 23.1 23.3 24.1 84.6 211.1 Transmission Support Commitments 17.1 18.8 20.0 20.9 21.8 22.6 121.2 Total $ 1,425.0 $ 1,400.7 $ 1,330.3 $ 1,273.0 $ 1,128.6 $ 7,403.8 $ 13,961.4 CL&P (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Renewable Energy Purchase Contracts $ 651.0 $ 671.9 $ 723.7 $ 724.5 $ 588.4 $ 3,473.6 $ 6,833.1 Capacity 72.4 0.1 — — — — 72.5 Peaker CfDs 28.3 27.7 23.1 23.3 24.1 84.6 211.1 Transmission Support Commitments 6.8 7.4 7.9 8.3 8.6 8.9 47.9 Total $ 758.5 $ 707.1 $ 754.7 $ 756.1 $ 621.1 $ 3,567.1 $ 7,164.6 NSTAR Electric (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Renewable Energy Purchase Contracts $ 120.8 $ 193.3 $ 196.2 $ 193.5 $ 197.1 $ 2,816.3 $ 3,717.2 Purchased Power 2.8 2.8 2.7 2.7 2.3 2.3 15.6 Transmission Support Commitments 6.7 7.4 7.9 8.2 8.6 8.9 47.7 Total $ 130.3 $ 203.5 $ 206.8 $ 204.4 $ 208.0 $ 2,827.5 $ 3,780.5 PSNH (Millions of Dollars) 2025 2026 2027 2028 2029 Thereafter Total Transmission Support Commitments $ 3.6 $ 4.0 $ 4.2 $ 4.4 $ 4.6 $ 4.8 $ 25.6 The total costs incurred under these agreements were as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Renewable Energy Purchase Contracts $ 591.4 $ 581.4 $ 678.1 Natural Gas Procurement 695.0 695.8 1,042.8 Capacity and Purchased Power 70.5 69.0 61.6 Peaker CfDs 23.1 20.1 13.4 Transmission Support Commitments 16.7 14.2 12.7 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Renewable Energy Purchase Contracts $ 529.0 $ 62.4 $ — $ 474.1 $ 60.0 $ 47.3 $ 513.2 $ 90.8 $ 74.1 Capacity and Purchased Power 67.6 2.9 — 65.5 2.9 0.6 57.7 3.0 0.9 Peaker CfDs 23.1 — — 20.1 — — 13.4 — — Transmission Support Commitments 6.6 6.6 3.5 5.6 5.6 3.0 5.0 5.0 2.7
Schedule of Guarantor Obligations	The following table summarizes Eversource parent's exposure to guarantees and indemnifications of its subsidiaries and affiliates to external parties, and primarily relates to its previously-owned offshore wind investments: As of December 31, 2024 Company (Obligor) Description Maximum Exposure Revolution Wind, LLC and TurbineCo, LLC Offshore wind construction-related purchase agreements with third-party contractors (1) $ 357.0 Eversource Investment LLC, Eversource Investment Service Company LLC and South Fork Class B Member, LLC Offshore wind funding and indemnification obligations (2) 277.5 Eversource Investment LLC Letters of Credit (3) 5.3 Eversource TEI LLC South Fork Wind Tax Equity (4) 50.0 South Fork Wind, LLC Power Purchase Agreement Security (5) 7.1 Various Eversource subsidiaries Surety bonds (6) 30.7 (1) Eversource parent issued guarantees on behalf of its previously 50 percent-owned affiliate, Revolution Wind, LLC, and on behalf of TurbineCo, LLC (successor in interest to North East Offshore, LLC (NEO)), under which Eversource parent agreed to guarantee each entity’s performance of obligations under certain construction-related purchase agreements with third-party contractors, in an aggregate amount not to exceed $935.6 million. Eversource parent’s obligations under the guarantees expire upon the earlier of (i) dates ranging between December 2024 and November 2027 and (ii) full performance of the guaranteed obligations. (2) Eversource parent issued guarantees on behalf of its wholly-owned subsidiary Eversource Investment LLC (EI), which held Eversource's previous investments in offshore wind-related equity method investments until sale, and on behalf of its previously 50 percent-owned affiliate, South Fork Class B Member, LLC, whereby Eversource parent will guarantee each entity’s performance of certain funding obligations of the South Fork and Revolution Wind projects. Eversource parent also guaranteed certain indemnification obligations of EI associated with third party credit support for EI’s investment in NEO. On September 30, 2024, Eversource parent issued a guaranty on behalf of its wholly-owned subsidiary, Eversource Investment Service Company LLC, whereby Eversource parent will guarantee Eversource Investment Service Company LLC’s performance of certain indemnification obligations during the onshore construction phase of the Revolution Wind project, in an amount not to exceed $100.0 million. These guarantees will not exceed $1.62 billion and expire upon the full performance of the guaranteed obligations. (3) Eversource parent entered into a guarantee on behalf of EI, under which Eversource parent would guarantee EI's obligations under a letter of credit facility with a financial institution that EI may request in an aggregate amount of up to approximately $25 million. As of December 31, 2024, EI has issued two letters of credit on behalf of South Fork Wind, LLC and one letter of credit on behalf of Revolution Wind, LLC totaling $5.3 million. The guarantee will remain in effect until full performance of the guaranteed obligations. On January 24, 2025, the $1.0 million letter of credit issued on behalf of Revolution Wind, LLC was terminated. (4) Eversource parent issued a guarantee on behalf of its wholly-owned subsidiary, Eversource TEI LLC, whereby Eversource parent will guarantee Eversource TEI LLC’s performance of certain obligations, in an amount not to exceed $50.0 million, in connection with any remaining obligations under the LLC agreement. Eversource parent’s obligations expire upon the full performance of the guaranteed obligations. (5) Eversource parent issued a guarantee on behalf of its previously 50 percent-owned affiliate, South Fork Wind, LLC, whereby Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations, in an amount not to exceed $7.1 million, under a Power Purchase Agreement between the Long Island Power Authority and South Fork Wind, LLC (the Agreement). The guarantee expires upon the later of (i) the end of the Agreement term, January 2044, with the option to extend to January 2049 and (ii) full performance of the guaranteed obligations. (6) Surety bonds expire in 2025. Expiration dates reflect termination dates, the majority of which will be renewed or extended. Certain surety bonds contain credit ratings triggers that would require Eversource parent to post collateral in the event that the unsecured debt credit ratings of Eversource parent are downgraded.

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2024
Leases [Abstract]
Components of Lease Cost	The components of lease cost, prior to amounts capitalized, are as follows: Eversource For the Years Ended December 31, (Millions of Dollars) 2024 2023 2022 Finance Lease Cost: Amortization of Right-of-use-Assets $ 6.4 $ 4.8 $ 8.3 Interest on Lease Liabilities 2.7 2.0 2.0 Total Finance Lease Cost 9.1 6.8 10.3 Operating Lease Cost 15.2 11.4 11.6 Variable Lease Cost 18.3 69.2 78.1 Total Lease Cost $ 42.6 $ 87.4 100.0 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR PSNH CL&P NSTAR PSNH CL&P NSTAR PSNH Finance Lease Cost: Amortization of Right-of-use-Assets $ 1.7 $ 0.2 $ — $ — $ 0.2 $ — $ — $ 0.2 $ 0.1 Interest on Lease Liabilities 0.8 0.6 — — 0.6 — — 0.6 — Total Finance Lease Cost 2.5 0.8 — — 0.8 — — 0.8 0.1 Operating Lease Cost 2.6 5.3 1.8 0.7 3.0 0.4 0.3 2.3 0.1 Variable Lease Cost 18.9 — (0.6) 21.9 — 47.3 25.6 — 52.5 Total Lease Cost $ 24.0 $ 6.1 $ 1.2 $ 22.6 $ 3.8 $ 47.7 $ 25.9 $ 3.1 $ 52.7
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases is as follows: As of December 31, 2024 As of December 31, 2023 (Millions of Dollars) Balance Sheet Classification Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Operating Leases: Right-of-use-Assets, Net Other Long-Term Assets $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 53.5 $ 2.2 $ 27.7 $ 4.7 Operating Lease Liabilities Current Portion Other Current Liabilities $ 10.4 $ 2.2 $ 3.7 $ 1.7 $ 9.5 $ 0.8 $ 2.2 $ 1.5 Long-Term Other Long-Term Liabilities 45.7 5.5 25.7 1.6 44.0 1.4 25.5 3.2 Total Operating Lease Liabilities $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 53.5 $ 2.2 $ 27.7 $ 4.7 Finance Leases: Right-of-use-Assets, Net Property, Plant and Equipment, Net $ 61.9 $ 16.6 $ 2.8 $ — $ 68.6 $ 18.3 $ 3.0 $ — Finance Lease Liabilities Current Portion Other Current Liabilities $ 5.6 $ 1.5 $ — $ — $ 5.4 $ 1.4 $ — $ — Long-Term Other Long-Term Liabilities 62.1 15.6 4.9 — 67.3 16.9 4.9 — Total Finance Lease Liabilities $ 67.7 $ 17.1 $ 4.9 $ — $ 72.7 $ 18.3 $ 4.9 $ —
Other Information Related to Leases	Other information related to leases is as follows: As of December 31, 2024 2023 Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric PSNH Weighted-Average Remaining Lease Term (Years): Operating Leases 9 4 12 2 9 4 13 3 Finance Leases 12 8 17 — 13 9 18 — Weighted-Average Discount Rate (Percentage): Operating Leases 4.1 % 5.2 % 4.2 % 5.2 % 4.0 % 5.2 % 4.2 % 5.2 % Finance Leases 3.3 % 5.3 % 2.9 % — % 3.3 % 5.3 % 2.9 % — % (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2024 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 14.5 $ 2.5 $ 4.9 $ 1.8 Operating Cash Flows from Finance Leases 2.6 0.7 0.7 — Financing Cash Flows from Finance Leases 5.2 1.2 — — Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 15.3 7.8 5.7 0.3 Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 0.3 — — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2023 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 10.5 $ 0.7 $ 2.5 $ 0.4 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — — Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 12.8 0.6 7.0 5.0 Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 18.5 18.3 — — (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH For the Year Ended December 31, 2022 Cash Paid for Amounts Included in the Measurement of Lease Liabilities: Operating Cash Flows from Operating Leases $ 11.3 $ 0.3 $ 2.1 $ 0.1 Operating Cash Flows from Finance Leases 2.0 — 0.6 — Financing Cash Flows from Finance Leases 3.9 — — 0.1 Supplemental Non-Cash Information on Lease Liabilities: Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities 18.9 2.4 — — Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities 3.5 — — —
Future Minimum Lease Payments under Long-Term Finance Leases	Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2024 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric Year Ending December 31, 2025 $ 12.5 $ 2.6 $ 4.9 $ 1.9 $ 8.3 $ 2.3 $ 0.7 2026 11.0 2.3 4.9 1.5 7.9 2.4 0.7 2027 7.0 1.8 2.9 0.1 7.9 2.5 0.7 2028 6.6 1.8 2.6 — 7.3 2.6 0.7 2029 4.5 — 2.5 — 7.3 2.6 0.7 Thereafter 26.2 — 22.2 — 50.5 8.9 10.2 Future lease payments 67.8 8.5 40.0 3.5 89.2 21.3 13.7 Less amount representing interest 11.7 0.8 10.6 0.2 21.5 4.2 8.8 Present value of future minimum lease payments $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 67.7 $ 17.1 $ 4.9
Future Minimum Lease Payments under Long-Term Operating Leases	Future minimum lease payments, excluding variable costs, under long-term leases, as of December 31, 2024 are as follows: Operating Leases Finance Leases (Millions of Dollars) Eversource CL&P NSTAR Electric PSNH Eversource CL&P NSTAR Electric Year Ending December 31, 2025 $ 12.5 $ 2.6 $ 4.9 $ 1.9 $ 8.3 $ 2.3 $ 0.7 2026 11.0 2.3 4.9 1.5 7.9 2.4 0.7 2027 7.0 1.8 2.9 0.1 7.9 2.5 0.7 2028 6.6 1.8 2.6 — 7.3 2.6 0.7 2029 4.5 — 2.5 — 7.3 2.6 0.7 Thereafter 26.2 — 22.2 — 50.5 8.9 10.2 Future lease payments 67.8 8.5 40.0 3.5 89.2 21.3 13.7 Less amount representing interest 11.7 0.8 10.6 0.2 21.5 4.2 8.8 Present value of future minimum lease payments $ 56.1 $ 7.7 $ 29.4 $ 3.3 $ 67.7 $ 17.1 $ 4.9

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2024
Fair Value Disclosures [Abstract]
Carrying Amounts and Estimated Fair Values of Financial Instruments	The fair values provided in the table below are classified as Level 2 within the fair value hierarchy. Carrying amounts and estimated fair values are as follows: Eversource CL&P NSTAR Electric PSNH (Millions of Dollars) Carrying Amount Fair Value Carrying Fair Carrying Fair Carrying Fair As of December 31, 2024: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 123.8 $ 116.2 $ 90.3 $ 43.0 $ 33.5 $ — $ — Long-Term Debt 26,704.8 24,791.4 5,111.1 4,705.8 5,094.9 4,759.4 1,732.1 1,529.7 Rate Reduction Bonds 367.3 352.1 — — — — 367.3 352.1 As of December 31, 2023: Preferred Stock Not Subject to Mandatory Redemption $ 155.6 $ 122.2 $ 116.2 $ 90.4 $ 43.0 $ 31.8 $ — $ — Long-Term Debt 24,413.5 22,855.2 4,814.4 4,572.0 4,496.9 4,273.7 1,431.6 1,292.6 Rate Reduction Bonds 410.5 395.0 — — — — 410.5 395.0

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Tables)	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income/(Loss) by Component, Net of Tax	The changes in accumulated other comprehensive income/(loss) by component, net of tax, are as follows: For the Year Ended December 31, 2024 For the Year Ended December 31, 2023 Eversource (Millions of Dollars) Qualified Defined Total Qualified Unrealized Defined Total Balance as of January 1st $ (0.4) $ (33.3) $ (33.7) $ (0.4) $ (1.2) $ (37.8) $ (39.4) OCI Before Reclassifications — (2.5) (2.5) — — (8.8) (8.8) Amounts Reclassified from AOCI — 9.7 9.7 — 1.2 13.3 14.5 Net OCI — 7.2 7.2 — 1.2 4.5 5.7 Balance as of December 31st $ (0.4) $ (26.1) $ (26.5) $ (0.4) $ — $ (33.3) $ (33.7)
Schedule of Amounts Reclassified from AOCI by Component	The following table sets forth the amounts reclassified from AOCI by component and the impacted line item on the statements of income: Amounts Reclassified from AOCI Eversource (Millions of Dollars) For the Years Ended December 31, Statements of Income 2024 2023 2022 Unrealized Loss on Marketable Securities — (1.6) — Other Income, Net Tax Effect — 0.4 — Income Tax Expense Unrealized Loss on Marketable Securities, Net of Tax — (1.2) — Defined Benefit Plan Costs: Amortization of Actuarial Losses (6.8) (7.0) (9.0) Other Income, Net (1) Amortization of Prior Service Cost (0.3) (0.3) (0.3) Other Income, Net (1) Settlement Losses (4.3) (12.4) — Other Income, Net (1) Total Defined Benefit Plan Costs (11.4) (19.7) (9.3) Tax Effect 1.7 6.4 2.3 Income Tax Expense Defined Benefit Plan Costs, Net of Tax (9.7) (13.3) (7.0) Total Amounts Reclassified from AOCI, Net of Tax $ (9.7) $ (14.5) $ (7.0) (1) These amounts are included in the computation of net periodic Pension, SERP and PBOP costs. See Note 1L, "Summary of Significant Accounting Policies – Other Income, Net" and Note 11A, "Employee Benefits – Pension Benefits and Postretirement Benefits Other Than Pension," for further information.

COMMON SHARES (Tables)

COMMON SHARES (Tables)	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
Common Shares Authorized and Issued	The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2024 and 2023 Issued as of December 31, 2024 2023 Eversource $ 5 410,000,000 375,724,367 359,984,073 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Details of preferred stock not subject to mandatory redemption are as follows (in millions, except in redemption price and shares): Redemption Price Shares Outstanding as of December 31, As of December 31, Series 2024 2023 2024 2023 CL&P $1.90 Series of 1947 $ 52.50 163,912 163,912 $ 8.2 $ 8.2 $2.00 Series of 1947 $ 54.00 336,088 336,088 16.8 16.8 $2.04 Series of 1949 $ 52.00 100,000 100,000 5.0 5.0 $2.20 Series of 1949 $ 52.50 200,000 200,000 10.0 10.0 3.90% Series of 1949 $ 50.50 160,000 160,000 8.0 8.0 $2.06 Series E of 1954 $ 51.00 200,000 200,000 10.0 10.0 $2.09 Series F of 1955 $ 51.00 100,000 100,000 5.0 5.0 4.50% Series of 1956 $ 50.75 104,000 104,000 5.2 5.2 4.96% Series of 1958 $ 50.50 100,000 100,000 5.0 5.0 4.50% Series of 1963 $ 50.50 160,000 160,000 8.0 8.0 5.28% Series of 1967 $ 51.43 200,000 200,000 10.0 10.0 $3.24 Series G of 1968 $ 51.84 300,000 300,000 15.0 15.0 6.56% Series of 1968 $ 51.44 200,000 200,000 10.0 10.0 Total CL&P 2,324,000 2,324,000 $ 116.2 $ 116.2 NSTAR Electric 4.25% Series of 1956 $ 103.625 180,000 180,000 $ 18.0 $ 18.0 4.78% Series of 1958 $ 102.80 250,000 250,000 25.0 25.0 Total NSTAR Electric 430,000 430,000 $ 43.0 $ 43.0 Fair Value Adjustment due to Merger with NSTAR (3.6) (3.6) Total Eversource - Noncontrolling Interest - Preferred Stock of Subsidiaries $ 155.6 $ 155.6

PREFERRED STOCK NOT SUBJECT T_2

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION (Tables)	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
Schedule of Preferred Stock Not Subject to Mandatory Redemption	The following table sets forth the Eversource parent common shares and the shares of common stock of CL&P, NSTAR Electric and PSNH that were authorized and issued, as well as the respective per share par values: Shares Par Value Authorized as of December 31, 2024 and 2023 Issued as of December 31, 2024 2023 Eversource $ 5 410,000,000 375,724,367 359,984,073 CL&P $ 10 24,500,000 6,035,205 6,035,205 NSTAR Electric $ 1 100,000,000 200 200 PSNH $ 1 100,000,000 301 301 Details of preferred stock not subject to mandatory redemption are as follows (in millions, except in redemption price and shares): Redemption Price Shares Outstanding as of December 31, As of December 31, Series 2024 2023 2024 2023 CL&P $1.90 Series of 1947 $ 52.50 163,912 163,912 $ 8.2 $ 8.2 $2.00 Series of 1947 $ 54.00 336,088 336,088 16.8 16.8 $2.04 Series of 1949 $ 52.00 100,000 100,000 5.0 5.0 $2.20 Series of 1949 $ 52.50 200,000 200,000 10.0 10.0 3.90% Series of 1949 $ 50.50 160,000 160,000 8.0 8.0 $2.06 Series E of 1954 $ 51.00 200,000 200,000 10.0 10.0 $2.09 Series F of 1955 $ 51.00 100,000 100,000 5.0 5.0 4.50% Series of 1956 $ 50.75 104,000 104,000 5.2 5.2 4.96% Series of 1958 $ 50.50 100,000 100,000 5.0 5.0 4.50% Series of 1963 $ 50.50 160,000 160,000 8.0 8.0 5.28% Series of 1967 $ 51.43 200,000 200,000 10.0 10.0 $3.24 Series G of 1968 $ 51.84 300,000 300,000 15.0 15.0 6.56% Series of 1968 $ 51.44 200,000 200,000 10.0 10.0 Total CL&P 2,324,000 2,324,000 $ 116.2 $ 116.2 NSTAR Electric 4.25% Series of 1956 $ 103.625 180,000 180,000 $ 18.0 $ 18.0 4.78% Series of 1958 $ 102.80 250,000 250,000 25.0 25.0 Total NSTAR Electric 430,000 430,000 $ 43.0 $ 43.0 Fair Value Adjustment due to Merger with NSTAR (3.6) (3.6) Total Eversource - Noncontrolling Interest - Preferred Stock of Subsidiaries $ 155.6 $ 155.6

EARNINGS_(LOSS) PER SHARE (Tabl

EARNINGS/(LOSS) PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2024
Earnings Per Share [Abstract]
Components of Basic and Diluted EPS	The following table sets forth the components of basic and diluted earnings/(loss) per share: Eversource (Millions of Dollars, except share information) For the Years Ended December 31, 2024 2023 2022 Net Income/(Loss) Attributable to Common Shareholders $ 811.7 $ (442.2) $ 1,404.9 Weighted Average Common Shares Outstanding: Basic 357,482,965 349,580,638 346,783,444 Dilutive Effect 296,443 259,843 463,324 Diluted 357,779,408 349,840,481 347,246,768 Basic Earnings/(Loss) Per Common Share $ 2.27 $ (1.27) $ 4.05 Diluted Earnings/(Loss) Per Common Share $ 2.27 $ (1.26) $ 4.05

REVENUES (Tables)

REVENUES (Tables)	12 Months Ended
	Dec. 31, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following tables present operating revenues disaggregated by revenue source: For the Year Ended December 31, 2024 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 4,904.8 $ 1,129.1 $ — $ 150.4 $ — $ — $ 6,184.3 Commercial 2,973.3 588.0 — 70.3 — (7.7) 3,623.9 Industrial 389.0 172.5 — 4.7 — (22.4) 543.8 Total Retail Tariff Sales Revenues 8,267.1 1,889.6 — 225.4 — (30.1) 10,352.0 Wholesale Transmission Revenues — — 2,032.4 — — (1,529.3) 503.1 Wholesale Market Sales Revenues 658.9 161.9 — 4.2 — — 825.0 Other Revenues from Contracts with Customers 92.2 5.1 13.9 5.7 1,701.3 (1,694.6) 123.6 Reserve for Revenues Subject to Refund — — — (1.9) — — (1.9) Total Revenues from Contracts with Customers 9,018.2 2,056.6 2,046.3 233.4 1,701.3 (3,254.0) 11,801.8 Alternative Revenue Programs 28.7 44.5 74.2 (5.3) — (67.2) 74.9 Other Revenues 19.6 2.8 0.5 1.2 — — 24.1 Total Operating Revenues $ 9,066.5 $ 2,103.9 $ 2,121.0 $ 229.3 $ 1,701.3 $ (3,321.2) $ 11,900.8 For the Year Ended December 31, 2023 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 5,054.2 $ 1,145.4 $ — $ 144.7 $ — $ — $ 6,344.3 Commercial 2,893.2 637.7 — 69.8 — (4.8) 3,595.9 Industrial 352.4 186.8 — 4.5 — (19.7) 524.0 Total Retail Tariff Sales Revenues 8,299.8 1,969.9 — 219.0 — (24.5) 10,464.2 Wholesale Transmission Revenues — — 1,777.5 — — (1,310.5) 467.0 Wholesale Market Sales Revenues 625.0 206.7 — 3.9 — — 835.6 Other Revenues from Contracts with Customers 82.6 5.6 14.6 8.1 1,636.6 (1,628.0) 119.5 Amortization of Revenues Subject to Refund — — 4.3 — — — 4.3 Total Revenues from Contracts with Customers 9,007.4 2,182.2 1,796.4 231.0 1,636.6 (2,963.0) 11,890.6 Alternative Revenue Programs (54.3) 35.5 118.9 0.4 — (106.5) (6.0) Other Revenues 20.4 4.0 0.6 1.1 — — 26.1 Total Operating Revenues $ 8,973.5 $ 2,221.7 $ 1,915.9 $ 232.5 $ 1,636.6 $ (3,069.5) $ 11,910.7 For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Revenues from Contracts with Customers Retail Tariff Sales Residential $ 4,796.1 $ 1,204.9 $ — $ 141.7 $ — $ — $ 6,142.7 Commercial 2,903.3 648.5 — 66.5 — (4.1) 3,614.2 Industrial 374.9 199.7 — 4.7 — (20.1) 559.2 Total Retail Tariff Sales Revenues 8,074.3 2,053.1 — 212.9 — (24.2) 10,316.1 Wholesale Transmission Revenues — — 1,700.5 — — (1,264.5) 436.0 Wholesale Market Sales Revenues 1,190.9 140.8 — 3.8 — — 1,335.5 Other Revenues from Contracts with Customers 72.3 5.6 14.1 8.4 1,435.5 (1,425.3) 110.6 Amortization of/(Reserve for) Revenues 72.0 — 0.7 (0.7) — — 72.0 Total Revenues from Contracts with Customers 9,409.5 2,199.5 1,715.3 224.4 1,435.5 (2,714.0) 12,270.2 Alternative Revenue Programs (15.4) 14.8 92.7 (2.5) — (84.3) 5.3 Other Revenues 11.2 1.3 0.7 0.6 — — 13.8 Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 For the Years Ended December 31, 2024 2023 2022 (Millions of Dollars) CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH CL&P NSTAR Electric PSNH Revenues from Contracts with Customers Retail Tariff Sales Residential $ 2,493.7 $ 1,771.8 $ 639.3 $ 2,597.8 $ 1,691.0 $ 765.4 $ 2,397.2 $ 1,601.8 $ 797.1 Commercial 1,164.8 1,466.7 343.6 1,082.1 1,442.3 369.6 1,067.9 1,457.4 380.8 Industrial 164.2 118.1 106.7 137.2 123.2 92.0 146.4 135.8 92.7 Total Retail Tariff Sales Revenues 3,822.7 3,356.6 1,089.6 3,817.1 3,256.5 1,227.0 3,611.5 3,195.0 1,270.6 Wholesale Transmission Revenues 870.8 794.1 367.5 794.7 692.0 290.8 755.1 670.4 275.0 Wholesale Market Sales Revenues 491.9 131.1 35.9 429.1 131.8 64.1 873.7 215.0 102.2 Other Revenues from Contracts 36.7 50.2 21.2 32.4 49.1 18.1 30.2 46.9 11.8 Amortization of Revenues Subject — — — 4.3 — — 72.7 — — Total Revenues from Contracts 5,222.1 4,332.0 1,514.2 5,077.6 4,129.4 1,600.0 5,343.2 4,127.3 1,659.6 Alternative Revenue Programs 45.4 36.7 20.8 66.8 (52.0) 49.8 56.5 0.7 20.1 Other Revenues 9.0 8.5 2.6 9.6 8.4 3.0 1.8 7.2 2.9 Eliminations (661.5) (656.3) (243.1) (575.2) (570.3) (204.9) (583.8) (552.1) (207.8) Total Operating Revenues $ 4,615.0 $ 3,720.9 $ 1,294.5 $ 4,578.8 $ 3,515.5 $ 1,447.9 $ 4,817.7 $ 3,583.1 $ 1,474.8

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2024
Segment Reporting [Abstract]
Summary of Segment Information and Segmented Total Assets	Eversource's segment information is as follows: For the Year Ended December 31, 2024 Eversource (Millions of Dollars) Electric Natural Gas Electric Transmission Water Distribution Other Eliminations Total Operating Revenues $ 9,066.5 $ 2,103.9 $ 2,121.0 $ 229.3 $ 1,701.3 $ (3,321.2) $ 11,900.8 Depreciation and Amortization (934.7) (216.6) (405.1) (32.3) (198.7) 11.0 (1,776.4) Operations and Maintenance (1) Operations, Excluding Storm Costs (447.3) (180.9) (135.1) Corporate Shared Services (457.1) (106.1) (74.6) Storm Costs (76.8) — — Employee Benefits (202.5) (76.9) (52.7) Uncollectible Expense (182.8) (48.4) — Other (135.9) (29.2) (71.1) Total Operations and Maintenance (1,502.4) (441.5) (333.5) (98.7) (1,350.5) 1,713.7 (2,012.9) Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2) (5,685.3) (1,007.1) (276.0) (26.3) (7.6) 1,596.5 (5,405.8) Loss on Pending Sale of Aquarion — — — (297.0) — — (297.0) Operating Income/(Loss) 944.1 438.7 1,106.4 (225.0) 144.5 — 2,408.7 Interest Expense (359.1) (99.2) (172.4) (36.2) (662.7) 218.3 (1,111.3) Loss on Offshore Wind Investments — — — — (464.0) — (464.0) Interest Income 114.6 23.2 0.3 0.1 218.3 (218.3) 138.2 Other Income, Net 134.7 22.4 50.5 7.2 1,416.9 (1,359.4) 272.3 Income Tax (Expense)/Benefit (198.0) (94.1) (257.3) 0.2 124.5 — (424.7) Net Income/(Loss) 636.3 291.0 727.5 (253.7) 777.5 (1,359.4) 819.2 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income/(Loss) Attributable to $ 631.7 $ 291.0 $ 724.6 $ (253.7) $ 777.5 $ (1,359.4) $ 811.7 Total Assets (as of) $ 32,031.9 $ 9,786.7 $ 16,070.9 $ 2,515.8 $ 29,041.1 $ (29,851.9) $ 59,594.5 Cash Flows Used for Investments in Plant $ 1,807.4 $ 934.5 $ 1,343.3 $ 161.8 $ 233.5 $ — $ 4,480.5 For the Year Ended December 31, 2023 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 8,973.5 $ 2,221.7 $ 1,915.9 $ 232.5 $ 1,636.6 $ (3,069.5) $ 11,910.7 Depreciation and Amortization (18.2) (214.2) (371.2) (56.0) (158.8) 2.7 (815.7) Operations and Maintenance (1) Operations, Excluding Storm Costs (418.2) (172.8) (124.7) Corporate Shared Services (397.2) (103.0) (62.5) Storm Costs (71.1) — (1.3) Employee Benefits (175.6) (76.6) (46.1) Uncollectible Expense (161.9) (64.8) — Other (167.9) (27.5) (57.4) Total Operations and Maintenance (1,391.9) (444.7) (292.0) (93.2) (1,325.6) 1,651.7 (1,895.7) Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2) (6,712.7) (1,217.9) (258.5) (23.9) (4.2) 1,417.2 (6,800.0) Operating Income 850.7 344.9 994.2 59.4 148.0 2.1 2,399.3 Interest Expense (291.7) (85.7) (163.7) (38.5) (425.3) 149.5 (855.4) Loss on Offshore Wind Investments — — — — (2,167.0) — (2,167.0) Interest Income 74.5 18.2 0.4 — 150.6 (149.5) 94.2 Other Income/(Loss), Net 136.2 20.4 41.2 5.9 (261.8) 312.0 253.9 Income Tax (Expense)/Benefit (157.1) (73.0) (225.8) 6.3 289.9 — (159.7) Net Income/(Loss) 612.6 224.8 646.3 33.1 (2,265.6) 314.1 (434.7) Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income/(Loss) Attributable to $ 608.0 $ 224.8 $ 643.4 $ 33.1 $ (2,265.6) $ 314.1 $ (442.2) Total Assets (as of) $ 29,426.4 $ 8,775.3 $ 14,806.5 $ 2,944.8 $ 26,337.7 $ (26,678.5) $ 55,612.2 Cash Flows Used for Investments in Plant $ 1,668.1 $ 844.1 $ 1,406.3 $ 167.0 $ 251.3 $ — $ 4,336.8 For the Year Ended December 31, 2022 Eversource (Millions of Dollars) Electric Natural Gas Electric Water Distribution Other Eliminations Total Operating Revenues $ 9,405.3 $ 2,215.6 $ 1,808.7 $ 222.5 $ 1,435.5 $ (2,798.3) $ 12,289.3 Depreciation and Amortization (970.4) (157.6) (337.4) (50.9) (132.6) 5.8 (1,643.1) Operations and Maintenance (1) Operations, Excluding Storm Costs (416.0) (182.5) (117.7) Corporate Shared Services (371.0) (109.8) (58.4) Storm Costs (74.4) — (0.1) Employee Benefits (189.6) (79.8) (39.6) Uncollectible Expense (107.3) (36.0) — Other (153.0) (30.3) (72.6) Total Operations and Maintenance (1,311.3) (438.4) (288.4) (88.4) (1,184.6) 1,445.8 (1,865.3) Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2) (6,352.4) (1,288.6) (260.0) (23.4) (4.5) 1,346.2 (6,582.7) Operating Income 771.2 331.0 922.9 59.8 113.8 (0.5) 2,198.2 Interest Expense (253.1) (71.4) (145.5) (34.7) (247.8) 74.2 (678.3) Interest Income 45.1 10.2 0.5 — 66.3 (71.6) 50.5 Other Income, Net 180.4 33.6 37.9 8.5 1,600.8 (1,565.6) 295.6 Income Tax (Expense)/Benefit (146.2) (69.2) (216.3) 3.2 (25.1) — (453.6) Net Income 597.4 234.2 599.5 36.8 1,508.0 (1,563.5) 1,412.4 Net Income Attributable to Noncontrolling Interests (4.6) — (2.9) — — — (7.5) Net Income Attributable to Common Shareholders $ 592.8 $ 234.2 $ 596.6 $ 36.8 $ 1,508.0 $ (1,563.5) $ 1,404.9 Cash Flows Used for Investments in Plant $ 1,172.6 $ 710.3 $ 1,144.0 $ 154.4 $ 260.6 $ — $ 3,441.9 (1) The significant expense categories and amounts align with the segment-level information that is regularly provided to the chief operating decision maker. Costs of the operations organization include labor and overtime, outside services, vehicles, vegetation management, employee expenses, fees and payments, regulatory assessments, and materials, partially offset by reimbursements. Corporate shared services include corporate centralized functions. Costs within these corporate functions primarily include labor, services by vendors, fees and payments, insurance, and regulatory assessments. Other includes information technology system depreciation at Eversource Service charged to the operating businesses, as well as storm funding, capitalization and various other corporate costs. The segment-level operating expense for information technology system depreciation is eliminated and reflected in depreciation in Eversource’s consolidation. For the water distribution segment, the chief operating decision maker is provided with total operations and maintenance expense information to manage its operations. Operations and maintenance expenses primarily include employee costs, benefits, and outside services. (2)

Assets Held For Sale (Tables)

Assets Held For Sale (Tables)	12 Months Ended
	Dec. 31, 2024
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations	As of December 31, 2024, the major classes of Aquarion’s assets and liabilities presented in current and long-term Assets Held for Sale and Liabilities Held for Sale on the Eversource balance sheet, which are included in the Water Distribution reportable segment, were as follows: (Millions of Dollars) Restricted Cash $ 5.8 Receivables, Net 14.4 Unbilled Revenues 11.5 Prepayments and Other Current Assets 24.6 Total Current Assets Held for Sale $ 56.3 Property, Plant and Equipment, Net $ 1,885.2 Regulatory Assets 51.2 Goodwill 662.5 Other Long-Term Assets 12.2 Total Long-Term Assets Held for Sale $ 2,611.1 Accounts Payable $ 24.2 Other Current Liabilities 28.4 Total Current Liabilities Held for Sale $ 52.6 Regulatory Liabilities $ 132.2 Other Long-Term Liabilities 266.7 Total Long-Term Liabilities Held for Sale $ 398.9

GOODWILL (Tables)

GOODWILL (Tables)	12 Months Ended
	Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill by Reportable Segment	The following table presents Eversource’s goodwill by reportable segment: (Millions of Dollars) Electric Electric Natural Gas Water Total Balance as of January 1, 2023 $ 2,543.6 $ 576.8 $ 451.0 $ 951.2 $ 4,522.6 Water Acquisitions — — — 9.5 9.5 Balance as of December 31, 2023 $ 2,543.6 $ 576.8 $ 451.0 $ 960.7 $ 4,532.1 Water Sale and Acquisition, net — — — (1.2) (1.2) Water Goodwill Impairment — — — (297.0) (297.0) Water Goodwill Reclassified as Held for Sale — — — (662.5) (662.5) Balance as of December 31, 2024 $ 2,543.6 $ 576.8 $ 451.0 $ — $ 3,571.4

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	12 Months Ended
	Dec. 31, 2024 USD ($) project regulatedUtility customer	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Summary of Accounting Policies [Line Items]
Number of electric and natural gas customers | customer	4,600,000
Number of offshore wind projects | project	3
Goodwill	$ 3,571,333,000	$ 4,532,100,000	$ 4,522,600,000
Charitable contributions	$ 0	20,000,000	$ 8,000,000
Offshore Wind Business
Summary of Accounting Policies [Line Items]
Ownership interest (in percent)	50%
Tax Equity
Summary of Accounting Policies [Line Items]
Ownership interest (in percent)	50%
Energy Relief Fund
Summary of Accounting Policies [Line Items]
Restricted cash, current	$ 20,000,000	20,000,000
Restricted cash, noncurrent	$ 5,900,000	14,100,000
CL&P
Summary of Accounting Policies [Line Items]
Period of accounts receivable recoverable under financial or medical duress	180 days
Maximum loans receivable outstanding	$ 70,000,000
Loans transferred receivable current	9,400,000	8,500,000
Loans transferred receivable non-current	$ 17,300,000	$ 14,500,000
Yankee Gas Services Company
Summary of Accounting Policies [Line Items]
Period of accounts receivable recoverable under financial or medical duress	90 days
Connecticut, Massachusetts and New Hampshire
Summary of Accounting Policies [Line Items]
Number of regulated utilities | regulatedUtility	12

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Allowance for Uncollectible Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 554,500	$ 486,300	$ 417,400
Uncollectible Expense	74,069	72,468	61,876
Uncollectible Costs Deferred	119,700	158,200	112,500
Write-Offs	(203,800)	(178,100)	(124,000)
Recoveries Collected	14,000	15,600	18,500
Decrease due to Assets Held for Sale	(2,300)
Ending Balance	556,200	554,500	486,300
Hardship Accounts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	366,800	284,400	226,100
Uncollectible Expense	0	0	0
Uncollectible Costs Deferred	71,400	137,000	77,800
Write-Offs	(74,300)	(55,900)	(21,300)
Recoveries Collected	700	1,300	1,800
Decrease due to Assets Held for Sale	0
Ending Balance	364,600	366,800	284,400
Retail (Non-Hardship), Wholesale, and Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	187,700	201,900	191,300
Uncollectible Expense	74,100	72,500	61,900
Uncollectible Costs Deferred	48,300	21,200	34,700
Write-Offs	(129,500)	(122,200)	(102,700)
Recoveries Collected	13,300	14,300	16,700
Decrease due to Assets Held for Sale	(2,300)
Ending Balance	191,600	187,700	201,900
CL&P
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	296,000	225,300	181,300
Uncollectible Expense	17,190	11,675	15,578
Uncollectible Costs Deferred	46,800	126,400	59,500
Write-Offs	(86,000)	(73,200)	(38,300)
Recoveries Collected	5,100	5,800	7,200
Decrease due to Assets Held for Sale	0
Ending Balance	279,100	296,000	225,300
CL&P | Hardship Accounts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	259,700	188,900	144,600
Uncollectible Expense	0	0	0
Uncollectible Costs Deferred	35,500	114,400	58,300
Write-Offs	(55,100)	(44,700)	(15,300)
Recoveries Collected	600	1,100	1,300
Decrease due to Assets Held for Sale	0
Ending Balance	240,700	259,700	188,900
CL&P | Retail (Non-Hardship), Wholesale, and Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	36,300	36,400	36,700
Uncollectible Expense	17,200	11,700	15,600
Uncollectible Costs Deferred	11,300	12,000	1,200
Write-Offs	(30,900)	(28,500)	(23,000)
Recoveries Collected	4,500	4,700	5,900
Decrease due to Assets Held for Sale	0
Ending Balance	38,400	36,300	36,400
NSTAR Electric
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	97,000	95,000	97,000
Uncollectible Expense	33,607	22,791	21,550
Uncollectible Costs Deferred	37,700	17,500	12,400
Write-Offs	(57,000)	(43,300)	(42,300)
Recoveries Collected	3,600	5,000	6,300
Decrease due to Assets Held for Sale	0
Ending Balance	114,900	97,000	95,000
NSTAR Electric | Hardship Accounts
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	43,600	43,700	43,300
Uncollectible Expense	0	0	0
Uncollectible Costs Deferred	16,200	1,500	1,500
Write-Offs	(4,600)	(1,600)	(1,100)
Recoveries Collected	0	0	0
Decrease due to Assets Held for Sale	0
Ending Balance	55,200	43,600	43,700
NSTAR Electric | Retail (Non-Hardship), Wholesale, and Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	53,400	51,300	53,700
Uncollectible Expense	33,600	22,800	21,600
Uncollectible Costs Deferred	21,500	16,000	10,900
Write-Offs	(52,400)	(41,700)	(41,200)
Recoveries Collected	3,600	5,000	6,300
Decrease due to Assets Held for Sale	0
Ending Balance	59,700	53,400	51,300
PSNH
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	14,300	29,200	24,300
Uncollectible Expense	4,688	3,989	9,211
Uncollectible Costs Deferred	5,100	(8,700)	2,500
Write-Offs	(10,900)	(10,900)	(7,700)
Recoveries Collected	900	700	900
Decrease due to Assets Held for Sale	0
Ending Balance	$ 14,100	$ 14,300	$ 29,200

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Materials, Supplies, Natural Gas, and REC Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Public Utilities, Inventory [Line Items]
Total	$ 594.6	$ 507.3
Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	498.6	397.9
Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	49.5	65.5
RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	46.5	43.9
CL&P
Public Utilities, Inventory [Line Items]
Total	217.3	156.5
CL&P | Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	217.3	156.2
CL&P | Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0
CL&P | RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0.3
NSTAR Electric
Public Utilities, Inventory [Line Items]
Total	220.6	173.8
NSTAR Electric | Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	177.8	130.8
NSTAR Electric | Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0
NSTAR Electric | RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	42.8	43
PSNH
Public Utilities, Inventory [Line Items]
Total	75.8	77.1
PSNH | Materials and Supplies
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	72.1	76.5
PSNH | Natural Gas
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	0	0
PSNH | RECs
Public Utilities, Inventory [Line Items]
Other inventory, capitalized costs, gross	$ 3.7	$ 0.6

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Operating Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Eversource - Cost of Natural Gas	$ 689.6	$ 792.2	$ 1,010.2

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of AFUDC and Weighted Average AFUDC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 64.4	$ 44.6	$ 21.8
Equity Funds	97.8	78.1	47.3
Total AFUDC	$ 162.2	$ 122.7	$ 69.1
Average AFUDC Rate (in percent)	6.50%	5.80%	4.70%
CL&P
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 8.1	$ 7.7	$ 4.8
Equity Funds	22.4	20	13.6
Total AFUDC	$ 30.5	$ 27.7	$ 18.4
Average AFUDC Rate (in percent)	6.70%	6.70%	6.60%
NSTAR Electric
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 27.2	$ 17.2	$ 10.7
Equity Funds	58.8	45.7	24.6
Total AFUDC	$ 86	$ 62.9	$ 35.3
Average AFUDC Rate (in percent)	7%	5.90%	5.40%
PSNH
Components of Other Operating Costs and Expense [Line Items]
Borrowed Funds	$ 8.9	$ 6.1	$ 1.4
Equity Funds	7	5.4	2.5
Total AFUDC	$ 15.9	$ 11.5	$ 3.9
Average AFUDC Rate (in percent)	5.50%	5.10%	2.60%

SUMMARY OF SIGNIFICANT ACCOUN_9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Other Income (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Summary of Accounting Policies [Line Items]
Other Income, Net		$ 410,482	$ 348,069	$ 346,088
Unrealized gain associated with investment		51,900	15,500	22,900
Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net		115,400	132,900	219,800
AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net		97,800	78,100	47,300
Equity in Earnings of Unconsolidated Affiliates
Summary of Accounting Policies [Line Items]
Other Income, Net		51,900	15,500	22,900
Unrealized gain associated with investment				12,200
Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net		600	(4,900)	1,900
Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net		138,200	94,200	50,500
Other
Summary of Accounting Policies [Line Items]
Other Income, Net		6,600	32,300	3,700
Equity in Earnings Of Unconsolidated Affiliate
Summary of Accounting Policies [Line Items]
Unrealized gain associated with investment	$ 23,400
CL&P
Summary of Accounting Policies [Line Items]
Other Income, Net		77,591	61,560	83,252
CL&P | Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net		28,200	34,900	64,400
CL&P | AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net		22,400	20,000	13,600
CL&P | Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net		(1,400)	(2,400)	(1,300)
CL&P | Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net		28,300	9,000	6,500
CL&P | Other
Summary of Accounting Policies [Line Items]
Other Income, Net		100	100	100
NSTAR Electric
Summary of Accounting Policies [Line Items]
Other Income, Net		191,405	164,129	142,661
NSTAR Electric | Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net		52,800	57,400	85,500
NSTAR Electric | AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net		58,800	45,700	24,600
NSTAR Electric | Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net		1,900	(200)	1,200
NSTAR Electric | Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net		77,000	60,600	30,700
NSTAR Electric | Other
Summary of Accounting Policies [Line Items]
Other Income, Net		900	600	700
PSNH
Summary of Accounting Policies [Line Items]
Other Income, Net		31,123	26,597	32,666
PSNH | Pension, SERP and PBOP Non-Service Income Components, Net of Deferred Portion
Summary of Accounting Policies [Line Items]
Other Income, Net		14,900	16,200	26,800
PSNH | AFUDC Equity
Summary of Accounting Policies [Line Items]
Other Income, Net		7,000	5,400	2,500
PSNH | Investment (Loss)/Income
Summary of Accounting Policies [Line Items]
Other Income, Net		(500)	(700)	200
PSNH | Interest Income
Summary of Accounting Policies [Line Items]
Other Income, Net		9,600	5,300	3,100
PSNH | Other
Summary of Accounting Policies [Line Items]
Other Income, Net		$ 100	$ 400	$ 100

SUMMARY OF SIGNIFICANT ACCOU_10

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Other Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Summary of Accounting Policies [Line Items]
Excise and sales taxes	$ 209.4	$ 202.9	$ 194.7
CL&P
Summary of Accounting Policies [Line Items]
Excise and sales taxes	$ 185.1	$ 174.9	$ 166.1

SUMMARY OF SIGNIFICANT ACCOU_11

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash Paid/(Received) During the Year for:
Interest, Net of Amounts Capitalized	$ 1,014.4	$ 783.2	$ 636.2
Income Taxes	(69.6)	39.2	77.9
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	472.5	564.1	586.9
CL&P
Cash Paid/(Received) During the Year for:
Interest, Net of Amounts Capitalized	216.8	176.8	167.2
Income Taxes	(47.4)	(44.1)	117.6
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	95.8	139.8	131.8
NSTAR Electric
Cash Paid/(Received) During the Year for:
Interest, Net of Amounts Capitalized	215.1	182.8	152.8
Income Taxes	118.7	31.3	23.8
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	155.4	178.9	184.3
PSNH
Cash Paid/(Received) During the Year for:
Interest, Net of Amounts Capitalized	78.4	62.8	58.3
Income Taxes	(36)	(59.9)	58.3
Non-Cash Investing Activities:
Plant Additions Included in Accounts Payable (As of)	$ 77.7	$ 65.9	$ 76.2

SUMMARY OF SIGNIFICANT ACCOU_12

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restricted Cash and Cash Equivalents Items [Line Items]
Cash as reported on the Balance Sheets	$ 26,700	$ 53,900
Cash and Restricted Cash as reported on the Statements of Cash Flows	127,308	166,418	$ 521,752	$ 221,008
CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Cash as reported on the Balance Sheets	1,100	10,200
Cash and Restricted Cash as reported on the Statements of Cash Flows	2,109	12,243	20,327	74,788
NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Cash as reported on the Balance Sheets	900	6,700
Cash and Restricted Cash as reported on the Statements of Cash Flows	9,023	22,785	345,293	18,179
PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Cash as reported on the Balance Sheets	1,400	200
Cash and Restricted Cash as reported on the Statements of Cash Flows	37,243	35,004	$ 36,812	$ 35,126
Special Deposits
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	75,800	81,500
Special Deposits | CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	1,000	2,000
Special Deposits | NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	8,100	16,100
Special Deposits | PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	32,700	31,600
Assets Held for Sale, Current
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	5,800	0
Assets Held for Sale, Current | CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Assets Held for Sale, Current | NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Assets Held for Sale, Current | PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Marketable Securities
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	10,000	13,700
Marketable Securities | CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Marketable Securities | NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Marketable Securities | PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Other Long-Term Assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	9,000	17,300
Other Long-Term Assets | CL&P
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Other Long-Term Assets | NSTAR Electric
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	0	0
Other Long-Term Assets | PSNH
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	$ 3,100	$ 3,200

REGULATORY ACCOUNTING - Compone

REGULATORY ACCOUNTING - Components of Regulatory Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 7,070,700	$ 6,389,200
Less:  Current Portion	2,189,660	1,674,196
Total Long-Term Regulatory Assets	4,880,974	4,714,970
Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	2,039,400	1,785,900
Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	1,781,600	1,319,200
Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	967,400	1,117,300
Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	968,400	912,400
Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	349,300	392,500
Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	247,200	264,100
Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	150,200	137,900
Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	57,200	120,900
Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	510,000	339,000
CL&P
Regulatory Assets [Line Items]
Total Regulatory Assets	2,325,500	2,143,200
Less:  Current Portion	638,529	480,369
Total Long-Term Regulatory Assets	1,687,029	1,662,778
CL&P | Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	971,100	896,600
CL&P | Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	507,700	354,500
CL&P | Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	168,800	197,400
CL&P | Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	521,000	512,600
CL&P | Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
CL&P | Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
CL&P | Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	41,200	38,500
CL&P | Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	57,200	120,900
CL&P | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	58,500	22,700
NSTAR Electric
Regulatory Assets [Line Items]
Total Regulatory Assets	2,107,100	1,957,900
Less:  Current Portion	902,770	676,083
Total Long-Term Regulatory Assets	1,204,337	1,281,836
NSTAR Electric | Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	609,800	609,100
NSTAR Electric | Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	650,000	482,900
NSTAR Electric | Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	293,600	336,700
NSTAR Electric | Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	145,400	128,600
NSTAR Electric | Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
NSTAR Electric | Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	212,300	226,700
NSTAR Electric | Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	78,300	72,300
NSTAR Electric | Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
NSTAR Electric | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	117,700	101,600
PSNH
Regulatory Assets [Line Items]
Total Regulatory Assets	1,065,700	963,300
Less:  Current Portion	173,267	189,450
Total Long-Term Regulatory Assets	892,411	773,783
PSNH | Storm Costs, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	458,500	280,200
PSNH | Regulatory Tracking Mechanisms
Regulatory Assets [Line Items]
Total Regulatory Assets	162,800	182,200
PSNH | Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	65,600	79,300
PSNH | Income Taxes, Net
Regulatory Assets [Line Items]
Total Regulatory Assets	20,700	16,400
PSNH | Securitized Stranded Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	349,300	392,500
PSNH | Goodwill-related
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
PSNH | Asset Retirement Obligations
Regulatory Assets [Line Items]
Total Regulatory Assets	5,100	4,700
PSNH | Derivative Liabilities
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
PSNH | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 3,700	$ 8,000

REGULATORY ACCOUNTING - Narrati

REGULATORY ACCOUNTING - Narrative (Details) $ in Millions

12 Months Ended

Nov. 01, 2025 USD ($)

Dec. 23, 2024 USD ($)

Nov. 07, 2024 USD ($)

Oct. 30, 2024 USD ($)

Aug. 01, 2024 USD ($)

Jun. 11, 2024 USD ($)

Dec. 31, 2023 USD ($)

Dec. 26, 2023 USD ($)

Oct. 30, 2023 USD ($)

May 01, 2023 USD ($)

Dec. 31, 2024 USD ($) storm

Dec. 31, 2023 USD ($)

Aug. 14, 2024 USD ($)

Mar. 28, 2024 USD ($)

May 31, 2018 USD ($)

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

$ 241.7

$ 221

$ 241.7

Deferred costs

82.1

92.5

82.1

Regulatory assets

6,389.2

7,070.7

6,389.2

FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

39.1

39.1

Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

410

Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

$ 2,100

Goodwill-related

Regulatory Assets [Line Items]

Recovery period (in years)

40 years

Remaining amortization (in years)

15 years

Regulatory assets

264.1

$ 247.2

264.1

PSNH

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

1.2

4.5

1.2

Equity return not recorded on the balance sheet

10.2

$ 22.5

10.2

Public utilities, request rate, unrecovered costs

$ 247

Public utilities, requested rate, unrecovered costs, recovery period

5 years

Public utilities, annual rate adjustment term

4 years

Public utilities, commitment agreement term

4 years

Regulatory assets

963.3

$ 1,065.7

963.3

PSNH | FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

3.1

3.1

PSNH | Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

191

PSNH | Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

440

PSNH | Goodwill-related

Regulatory Assets [Line Items]

Regulatory assets

0

0

0

PSNH | Base Rate Adjustment

Regulatory Assets [Line Items]

Rate increase (decrease) requested

$ 181.9

Rate increase approved

$ 61.2

PSNH | Operation, Maintenance And Vegetation Expenses

Regulatory Assets [Line Items]

Purchase price of regulatory assets

$ 23.3

Regulatory assets

$ 16.9

CL&P

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

166.7

116.3

166.7

Deferred costs

64

47.2

64

Public utilities, approved rate, recovery of incurred and deferred program costs

$ 44.4

Public utilities, approved rate, expected program costs

24.3

Public utilities, approved rate, recovery of incurred and deferred program costs, carrying costs

$ 5.4

Public utilities, approved rate, recovery of incurred and deferred program costs, period

20 months

Public utilities, approved rate, expected program costs, period

8 months

Regulatory assets

2,143.2

2,325.5

2,143.2

CL&P | SBC

Regulatory Assets [Line Items]

Public utilities, approved rate, recovery, net of under recoveries

86.2

86.2

Public utilities, approved rate, recovery of expected net costs

254.4

254.4

CL&P | NBFMCC

Regulatory Assets [Line Items]

Public utilities, approved rate, recovery, net of under recoveries

264.9

264.9

Public utilities, approved rate, recovery of expected net costs

388.5

388.5

CL&P | 2024 Innovative Energy Solutions

Regulatory Assets [Line Items]

Public utilities, approved rate, incremental program costs

$ 3.5

CL&P | Connecticut Green Bank

Regulatory Assets [Line Items]

Public utilities, approved rate, incremental program costs

$ 1.5

CL&P | FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

21.4

21.4

CL&P | Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

134

CL&P | Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

1,120

CL&P | Deferred Storm Restoration Costs | Tropical Storm Isaias

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

232

CL&P | Catastrophic Storm Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

173

$ 634

CL&P | Goodwill-related

Regulatory Assets [Line Items]

Regulatory assets

0

0

0

NSTAR Electric

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

21.9

41.1

21.9

Deferred costs

7.3

$ 24.4

$ 7.3

Historical average term of capital additions (in years)

5 years

5 years

Rate increase approved

$ 104.9

Storms in a calendar year | storm

8

Regulatory assets

1,957.9

$ 2,107.1

$ 1,957.9

NSTAR Electric | FERC ROE Complaints

Regulatory Assets [Line Items]

Cumulative pre-tax reserves which include impact of refunds given to customers

14.6

14.6

NSTAR Electric | Deferred Pre-Staging And Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

85

NSTAR Electric | Deferred Storm Restoration Costs

Regulatory Assets [Line Items]

Amount of regulatory costs not yet approved

551

NSTAR Electric | Goodwill-related

Regulatory Assets [Line Items]

Regulatory assets

226.7

212.3

$ 226.7

NSTAR Electric | Inflation Based Adjustment

Regulatory Assets [Line Items]

Rate increase approved

$ 35.3

50.6

NSTAR Electric | K-Bar Adjustment

Regulatory Assets [Line Items]

Rate increase approved

$ 54.3

NSTAR Electric | Base Rate Adjustment

Regulatory Assets [Line Items]

Rate increase approved

55.8

NSTAR Electric | Capital Additions Adjustment

Regulatory Assets [Line Items]

Rate increase approved

$ 20.5

NSTAR Gas

Regulatory Assets [Line Items]

Rate increase approved

$ 12.7

$ 25.4

NSTAR Gas | Base Rate Adjustment

Regulatory Assets [Line Items]

Rate increase approved

$ 15.5

Yankee Gas

Regulatory Assets [Line Items]

Rate increase (decrease) requested

209

Yankee Gas | Base Rate Adjustment

Regulatory Assets [Line Items]

Rate increase (decrease) requested

274

Yankee Gas | Offsetting Adjustment

Regulatory Assets [Line Items]

Rate increase (decrease) requested

65

Yankee Gas | Rate Credit

Regulatory Assets [Line Items]

Rate increase (decrease) requested

$ 37.4

EGMA

Regulatory Assets [Line Items]

Rate increase approved

$ 76.8

EGMA | GSEP Investments

Regulatory Assets [Line Items]

Rate increase approved

8.8

34

EGMA | Base Rate Adjustment

Regulatory Assets [Line Items]

Rate increase approved

$ 85.6

$ 147.8

EGMA | Base Rate Adjustment | Subsequent Event

Regulatory Assets [Line Items]

Public utilities, return on rate base, remaining revenue requirement

$ 62.2

Rate Reduction Bonds | PSNH

Regulatory Assets [Line Items]

Amount of securitized rate reduction bonds issued

$ 635.7

REGULATORY ACCOUNTING - Compo_2

REGULATORY ACCOUNTING - Components of Regulatory Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 4,664,900	$ 4,614,700
Less:  Current Portion	632,282	591,750
Total Long-Term Regulatory Liabilities	4,032,564	4,022,923
EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	2,442,700	2,548,600
Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	702,400	668,300
Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	684,100	666,600
Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	427,100	354,000
AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	154,800	124,300
Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	69,300	51,000
Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	184,500	201,900
CL&P
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	1,520,000	1,418,100
Less:  Current Portion	124,122	102,239
Total Long-Term Regulatory Liabilities	1,395,883	1,315,928
CL&P | EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	956,600	969,200
CL&P | Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	180,300	154,000
CL&P | Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	212,800	157,900
CL&P | Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	61,600	49,900
CL&P | AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	65,100	56,100
CL&P | Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	4,500	600
CL&P | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	39,100	30,400
NSTAR Electric
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	2,079,400	1,953,400
Less:  Current Portion	436,312	368,070
Total Long-Term Regulatory Liabilities	1,643,079	1,585,311
NSTAR Electric | EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	877,600	905,100
NSTAR Electric | Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	413,600	347,200
NSTAR Electric | Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	451,300	420,900
NSTAR Electric | Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	211,600	175,900
NSTAR Electric | AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	89,700	68,200
NSTAR Electric | Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	21,400	22,200
NSTAR Electric | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	14,200	13,900
PSNH
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	516,100	511,100
Less:  Current Portion	121,058	117,515
Total Long-Term Regulatory Liabilities	394,982	393,574
PSNH | EDIT due to Tax Cuts and Jobs Act of 2017
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	330,600	339,300
PSNH | Regulatory Tracking Mechanisms
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	114,400	114,400
PSNH | Cost of Removal
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	20,100	16,200
PSNH | Deferred Portion of Non-Service Income Components of Pension, SERP and PBOP
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	42,600	36,600
PSNH | AFUDC - Transmission
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
PSNH | Benefit Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	3,900	0
PSNH | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 4,500	$ 4,600

PROPERTY, PLANT AND EQUIPMENT_3

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Investment in Utility Property, Plant and Equipment By Asset (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Distribution - Electric	$ 21,144,100	$ 19,656,500
Distribution - Natural Gas	8,922,200	8,155,300
Transmission - Electric	16,130,900	14,666,800
Distribution - Water (1)	0	2,280,100
Solar	201,000	201,100
Utility	46,398,200	44,959,800
Other	2,254,100	2,006,800
Property, Plant and Equipment, Gross	48,652,300	46,966,600
Less:  Accumulated Depreciation
Utility	(9,636,500)	(9,670,100)
Other	(1,044,100)	(869,600)
Total Accumulated Depreciation	(10,680,600)	(10,539,700)
Property, Plant and Equipment, Net	37,971,700	36,426,900
Construction Work in Progress	3,014,900	3,071,700
Total Property, Plant and Equipment, Net	40,986,578	39,498,607
CL&P
Property, Plant and Equipment [Line Items]
Distribution - Electric	8,437,900	7,897,100
Transmission - Electric	6,937,700	6,548,200
Solar	0	0
Property, Plant and Equipment, Gross	15,375,600	14,445,300
Less:  Accumulated Depreciation
Total Accumulated Depreciation	(2,928,000)	(2,670,500)
Property, Plant and Equipment, Net	12,447,600	11,774,800
Construction Work in Progress	554,600	565,400
Total Property, Plant and Equipment, Net	13,002,193	12,340,192
NSTAR Electric
Property, Plant and Equipment [Line Items]
Distribution - Electric	9,782,300	9,000,500
Transmission - Electric	6,375,200	5,630,800
Solar	201,000	201,100
Property, Plant and Equipment, Gross	16,358,500	14,832,400
Less:  Accumulated Depreciation
Total Accumulated Depreciation	(3,782,000)	(3,585,900)
Property, Plant and Equipment, Net	12,576,500	11,246,500
Construction Work in Progress	1,461,300	1,507,300
Total Property, Plant and Equipment, Net	14,037,828	12,753,787
PSNH
Property, Plant and Equipment [Line Items]
Distribution - Electric	2,964,200	2,799,200
Transmission - Electric	2,819,600	2,489,500
Solar	0	0
Property, Plant and Equipment, Gross	5,783,800	5,288,700
Less:  Accumulated Depreciation
Total Accumulated Depreciation	(1,032,300)	(984,000)
Property, Plant and Equipment, Net	4,751,500	4,304,700
Construction Work in Progress	338,400	270,000
Total Property, Plant and Equipment, Net	$ 5,089,943	$ 4,574,652

PROPERTY, PLANT AND EQUIPMENT_4

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Aggregate Composite Depreciation Rates (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	3.20%	3.10%	3%
CL&P
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	2.90%	2.80%	2.80%
NSTAR Electric
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	2.80%	2.70%	2.70%
PSNH
Property, Plant and Equipment [Line Items]
Composite depreciation rate for plant in service (in percent)	3%	3%	3%

PROPERTY, PLANT AND EQUIPMENT_5

PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Average Remaining Useful Lives of Depreciable Assets (Details)	12 Months Ended
	Dec. 31, 2024
Property, Plant and Equipment [Line Items]
Distribution - Electric	33 years 4 months 24 days
Distribution - Natural Gas	34 years 8 months 12 days
Transmission - Electric	39 years 8 months 12 days
Distribution - Water	45 years 2 months 12 days
Solar	22 years 9 months 18 days
Other	9 years 10 months 24 days
Computer Software, Hardware and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of property, plant and equipment (in years)	5 years
Computer Software, Hardware and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of property, plant and equipment (in years)	15 years
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life of property, plant and equipment (in years)	40 years
CL&P
Property, Plant and Equipment [Line Items]
Distribution - Electric	34 years 8 months 12 days
Transmission - Electric	35 years 9 months 18 days
NSTAR Electric
Property, Plant and Equipment [Line Items]
Distribution - Electric	33 years 4 months 24 days
Transmission - Electric	45 years 1 month 6 days
Solar	22 years 9 months 18 days
PSNH
Property, Plant and Equipment [Line Items]
Distribution - Electric	29 years 10 months 24 days
Transmission - Electric	39 years 9 months 18 days

DERIVATIVE INSTRUMENTS - Schedu

DERIVATIVE INSTRUMENTS - Schedule of Gross Fair Value of Contracts (Details) - CL&P - Level 2 - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Current Derivative Assets
Current and Long-Term Derivative Assets
Commodity Supply and Price Risk Management	$ 14.2	$ 16.4
Netting	(0.3)	(0.5)
Net Amount Recorded as a Derivative	13.9	15.9
Long-Term Derivative Assets
Current and Long-Term Derivative Assets
Commodity Supply and Price Risk Management	0	13.6
Netting	0	(0.5)
Net Amount Recorded as a Derivative	0	13.1
Current Derivative Liabilities
Current and Long-Term Derivative Liabilities
Commodity Supply and Price Risk Management	(71.1)	(81.9)
Netting	0	0
Net Amount Recorded as a Derivative	(71.1)	(81.9)
Long-Term Derivative Liabilities
Current and Long-Term Derivative Liabilities
Commodity Supply and Price Risk Management	0	(68)
Netting	0	0
Net Amount Recorded as a Derivative	$ 0	$ (68)

DERIVATIVE INSTRUMENTS - Narrat

DERIVATIVE INSTRUMENTS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) MW	Dec. 31, 2023 USD ($) MW	Dec. 31, 2022 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of costs or benefits borne under capacity-related contracts by United Illuminated Company (as a percentage)	20%
Amount of power to be purchased under capacity-related contract (up to) (in MW) | MW	610	682
Gain (loss) on deferred regulatory costs | $	$ (3.8)	$ (3.9)	$ 10.1
CL&P
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of costs or benefits borne under capacity-related contracts (as a percentage)	80%

DERIVATIVE INSTRUMENTS - Variat

DERIVATIVE INSTRUMENTS - Variations Using Significant unobservable Inputs (Details) - Level 3 - CL&P $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value as of Beginning of Period	$ (181.8)
Net Realized/Unrealized Losses Included in Regulatory Assets	(3.9)
Settlements	64.8
Transfer out of Level 3	120.9
Fair Value as of End of Period	$ 0

MARKETABLE SECURITIES - Narrati

MARKETABLE SECURITIES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Equity securities		$ 3.3
Equity securities, FV-NI, realized gain		1.1
Unrealized gains recorded in other income		0.6
Water assets held for sale	$ 4.1
Unrealized Losses on Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Losses recorded on securities intended to be sold	1.2
CYAPC and YAEC
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 163.1	$ 173.6

MARKETABLE SECURITIES - Availab

MARKETABLE SECURITIES - Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Amortized Cost	$ 163.2	$ 169.5
Pre-Tax Unrealized Gains	0.1	1.4
Pre-Tax Unrealized Losses	(6.1)	(6.6)
Fair Value	$ 157.2	$ 164.3

MARKETABLE SECURITIES - Contrac

MARKETABLE SECURITIES - Contractual Maturity (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Amortized Cost
Less than one year	$ 11.3
One to five years	35.6
Six to ten years	43.5
Greater than ten years	72.8
Amortized Cost	163.2	$ 169.5
Fair Value
Less than one year	11.7
One to five years	35.6
Six to ten years	42.6
Greater than ten years	67.3
Total Debt Securities	$ 157.2	$ 164.3

MARKETABLE SECURITIES - Fair Va

MARKETABLE SECURITIES - Fair Value Measurement (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	$ 320.3	$ 341.2
Level 1
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	173.1	190.6
Level 1 | Mutual Funds and Equities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	163.1	176.9
Level 1 | Money Market Funds
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	10	13.7
Level 2
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	147.2	150.6
Level 2 | U.S. Government Issued Debt Securities (Agency and Treasury)
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	92	90.1
Level 2 | Corporate Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	32.5	34
Level 2 | Asset-Backed Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	7.8	5.6
Level 2 | Municipal Bonds
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	6.8	9.8
Level 2 | Other Fixed Income Securities
Debt and Equity Securities, FV-NI [Line Items]
Total Marketable Securities	$ 8.1	$ 11.1

INVESTMENTS IN UNCONSOLIDATED_3

INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Summary of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Investments in Unconsolidated Affiliates	$ 168,652	$ 660,473
Offshore Wind Business
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	50%
Investments in Unconsolidated Affiliates	$ 22,200	515,500
Offshore Wind Business | Minimum
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	50%
Offshore Wind Business | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	100%
Natural Gas Pipeline - Algonquin Gas Transmission, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	15%
Investments in Unconsolidated Affiliates	$ 112,600	116,000
Other
Schedule of Equity Method Investments [Line Items]
Investments in Unconsolidated Affiliates	$ 33,900	$ 29,000

INVESTMENTS IN UNCONSOLIDATED_4

INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Narrative (Details) $ in Thousands				1 Months Ended	3 Months Ended			12 Months Ended
	Jul. 09, 2024 USD ($)	Feb. 13, 2024 USD ($)	Sep. 07, 2023 USD ($) a mile	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2024 USD ($) project company	Dec. 31, 2023 USD ($) company	Dec. 31, 2022 USD ($)	Jan. 24, 2024
Schedule of Equity Method Investments [Line Items]
Unrealized gain associated with investment								$ 51,900	$ 15,500	$ 22,900
Dividends received from equity method investees								$ 20,500	20,100	26,200
Number of offshore wind projects | project								3
Payments to acquire investments								$ 929,688	1,680,473	742,496
Investments in Unconsolidated Affiliates						$ 660,473		168,652	660,473
Investment tax credit, percent realized		0.10
Expected investment tax credit		$ 170,000
Equity method investment, other-than- temporary impairment						1,766,000	$ 401,000	$ 464,019	2,167,000	$ 0
Equity method investment, other than temporary impairment, after tax						1,622,000	$ 331,000		1,953,000
Proceeds from sale, land, held-for-investment									$ 318,000
Number of companies that transmit hydro electricity imported from The Hydro-Quebec System in Canada | company								2	2
South Fork Wind Holdings, LLC Class A
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)				100%
Investment tax credit								$ 459,000
Investments in Unconsolidated Affiliates						481,000			$ 481,000
Equity method investment, other-than- temporary impairment						4,000
Offshore Wind Business
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)								50%
Investments in Unconsolidated Affiliates						515,500		$ 22,200	515,500
Equity method investment, other-than- temporary impairment						1,766,000
Northeast Offshore LLC and South Fork Class B Member, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)								50%
Uncommitted Lease Area
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)			50%
Land subject to ground leases | a			175,000
Number of miles off south coast of Massachusetts | mile			25
Payments to acquire investments			$ 625,000
Tax Equity Capital Contribution Agreement
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)				100%
Payments to acquire investments				$ 528,000
Sunrise Wind, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	50%										50%
Investments in Unconsolidated Affiliates						(519,000)			$ (519,000)
Proceeds from sale of equity method investments	$ 118,000				$ 377,000			$ 377,000
Equity method investment, other-than- temporary impairment						$ 1,218,000
Sunrise Wind, LLC | Orsted
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)	50%
Proceeds from sale of equity method investments	$ 152,000
Sunrise Wind, LLC | Orsted
Schedule of Equity Method Investments [Line Items]
Equity method investment, remaining purchase price paid	$ 34,000
South Fork Wind, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)						50%		50%	50%
Renewable Energy Investment Fund
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of equity method investments									$ 147,600
Renewable Energy Investment Fund | Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Payments for charitable contributions									$ 20,000
Hydro-Quebec System
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)						14.50%		14.50%	14.50%
Payments to acquire investments								$ 11,500	$ 9,600
South Fork Wind And Revolution Wind
Schedule of Equity Method Investments [Line Items]
Ownership interest (in percent)		50%			50%
Proceeds from sale of equity method investments		$ 1,100,000			$ 745,000
Adjustments from sale of equity method investment					375,000
Adjustment from sale of equity method investment, capital expenses					150,000
Adjustments from sale of equity method investment, non-construction costs					225,000
Cost sharing agreement, threshold amount					240,000
Equity method investment, realized gain (loss) on disposal								$ 524,000
Equity method investment, aggregate cost					350,000
Equity method investment, post-closing sale costs					326,000
Effective income tax rate reconciliation, change in enacted tax rate, amount					60,000
Equity method investment, liability obligations					365,000
Investment tax credit, percent		40%
South Fork Wind And Revolution Wind | Current Derivative Liabilities
Schedule of Equity Method Investments [Line Items]
Equity method investment, liability obligations					$ 15,000

INVESTMENTS IN UNCONSOLIDATED_5

INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Summary of Impairment (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2024 USD ($) project	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of offshore wind projects | project			3
Impairment Charges, pre-tax	$ 1,766,000	$ 401,000	$ 464,019	$ 2,167,000	$ 0
Tax Benefit	(144,000)	(70,000)		(214,000)
Equity method investment, other than temporary impairment, after tax	1,622,000	331,000		1,953,000
Lower expected sales proceeds across all three wind projects
Schedule of Equity Method Investments [Line Items]
Impairment Charges, pre-tax	525,000	401,000		926,000
Expected cost overruns not recovered in the sales price
Schedule of Equity Method Investments [Line Items]
Impairment Charges, pre-tax	441,000	0		441,000
Loss of sales value from the sale price offered by GIP, including loss of ITC adders value, cancellation costs and other impacts assuming Sunrise Wind project is abandoned
Schedule of Equity Method Investments [Line Items]
Impairment Charges, pre-tax	$ 800,000	$ 0		$ 800,000

INVESTMENTS IN UNCONSOLIDATED_6

INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Summary of Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Loss on Offshore Wind Investments	$ (1,766,000)	$ (401,000)	$ (464,019)	$ (2,167,000)	$ 0
Carrying Value as of December 31, 2023	660,473		168,652	660,473
Sunrise Wind
Schedule of Equity Method Investments [Line Items]
Carrying Value as of December 31, 2023, before Impairment Charge	699,000			699,000
Loss on Offshore Wind Investments	(1,218,000)
Carrying Value as of December 31, 2023	(519,000)			(519,000)
Revolution Wind
Schedule of Equity Method Investments [Line Items]
Carrying Value as of December 31, 2023, before Impairment Charge	799,000			799,000
Loss on Offshore Wind Investments	(544,000)
Carrying Value as of December 31, 2023	255,000			255,000
South Fork Class B Member, LLC
Schedule of Equity Method Investments [Line Items]
Carrying Value as of December 31, 2023, before Impairment Charge	299,000			299,000
Loss on Offshore Wind Investments	0
Carrying Value as of December 31, 2023	299,000			299,000
South Fork Wind Holdings, LLC Class A
Schedule of Equity Method Investments [Line Items]
Carrying Value as of December 31, 2023, before Impairment Charge	485,000			485,000
Loss on Offshore Wind Investments	(4,000)
Carrying Value as of December 31, 2023	481,000			481,000
Total Offshore Wind Investments
Schedule of Equity Method Investments [Line Items]
Carrying Value as of December 31, 2023, before Impairment Charge	2,282,000			2,282,000
Loss on Offshore Wind Investments	(1,766,000)
Carrying Value as of December 31, 2023	$ 515,500		$ 22,200	$ 515,500

ASSET RETIREMENT OBLIGATIONS -

ASSET RETIREMENT OBLIGATIONS - Schedule of Reconciliation of Beginning and Ending Balance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	$ 505.8	$ 502.7
Liabilities Settled During the Year	(24.6)	(24.9)
Accretion	29.5	29.2
Revisions in Estimated Cash Flows	80.2	(1.2)
Balance as of End of Year	590.9	505.8
CL&P
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	39.9	37.4
Liabilities Settled During the Year	0	0
Accretion	2.6	2.5
Revisions in Estimated Cash Flows	0	0
Balance as of End of Year	42.5	39.9
NSTAR Electric
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	104.8	101.3
Liabilities Settled During the Year	0	0
Accretion	4.5	4.3
Revisions in Estimated Cash Flows	0	(0.8)
Balance as of End of Year	109.3	104.8
PSNH
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of Beginning of Year	5.2	4.9
Liabilities Settled During the Year	0	0
Accretion	0.4	0.3
Revisions in Estimated Cash Flows	0	0
Balance as of End of Year	$ 5.6	$ 5.2

ASSET RETIREMENT OBLIGATIONS _2

ASSET RETIREMENT OBLIGATIONS - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Asset Retirement Obligation [Line Items]
Asset retirement obligations	$ 590.9	$ 505.8	$ 502.7
CYAPC and YAEC
Schedule of Asset Retirement Obligation [Line Items]
Asset retirement obligations	$ 391.7	$ 315.8

SHORT-TERM DEBT - Narrative (De

SHORT-TERM DEBT - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 18, 2023	Nov. 30, 2023
Short-term Debt [Line Items]
Long-term debt	$ 25,701,627,000	$ 23,588,616,000
Eversource
Short-term Debt [Line Items]
Long-term debt	10,729,256,000	9,952,351,000
Commercial Paper
Short-term Debt [Line Items]
Long-term debt		990,900,000
Commercial Paper | Eversource
Short-term Debt [Line Items]
Maximum borrowing capacity	2,000,000,000
Line of Credit
Short-term Debt [Line Items]
Amount outstanding during period	0	0
Line of Credit | Eversource
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 2,000,000,000
Debt instrument term (in years)	5 years
CL&P
Short-term Debt [Line Items]
Short-term borrowing limit approved by regulatory agency				$ 600,000,000
Long-term debt	$ 5,108,173,000	4,814,429,000
Notes payable	280,000,000	249,670,000
CL&P | Related Party
Short-term Debt [Line Items]
Long-term debt		207,300,000
Notes payable	$ 280,000,000	457,000,000
CL&P | Unsecured Debt
Short-term Debt [Line Items]
Period of maturity restricting provisions of debt	10 years
Total capitalization (as a percentage)	10%
Capacity available under preferred stock provisions	$ 901,000,000
CL&P | Commercial Paper
Short-term Debt [Line Items]
Long-term debt		139,800,000
CL&P | Commercial Paper
Short-term Debt [Line Items]
Long-term debt		207,300,000
CL&P | Line of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	375,000,000
Borrowings outstanding	0
NSTAR Electric
Short-term Debt [Line Items]
Short-term borrowing limit approved by regulatory agency			$ 655,000,000
Long-term debt	4,844,920,000	4,496,947,000
Notes payable	504,782,000	365,847,000
NSTAR Electric | Unsecured Debt
Short-term Debt [Line Items]
Long-term debt	5,000,000,000	4,400,000,000
NSTAR Electric | Commercial Paper
Short-term Debt [Line Items]
Maximum borrowing capacity	650,000,000
NSTAR Electric | Line of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 650,000,000
Debt instrument term (in years)	5 years
PSNH
Short-term Debt [Line Items]
Short-term borrowing limit approved by regulatory agency	$ 526,700,000
Long-term debt	1,732,066,000	1,431,591,000
Notes payable	131,100,000	233,000,000
PSNH | Related Party
Short-term Debt [Line Items]
Notes payable	$ 131,100,000	$ 233,000,000
PSNH | Short Term Debt Authorization Calculation
Short-term Debt [Line Items]
Interest rate	10%
Short-term debt borrowing calculation approved by regulatory agency	$ 60,000,000
PSNH | Line of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	250,000,000
Borrowings outstanding	$ 0

SHORT-TERM DEBT - Schedule of D

SHORT-TERM DEBT - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Line of Credit Facility [Line Items]
Borrowings Outstanding as of December 31,	$ 2,042,793	$ 1,930,422
Eversource Parent Commercial Paper Program
Line of Credit Facility [Line Items]
Borrowings Outstanding as of December 31,	1,538,011	1,564,575
Commercial Paper | Eversource Parent Commercial Paper Program
Line of Credit Facility [Line Items]
Borrowings Outstanding as of December 31,	1,538,000	1,771,900
Available Borrowing Capacity as of December 31,	$ 462,000	$ 228,100
Weighted-Average Interest Rate as of December 31,	4.76%	5.60%
Commercial Paper | NSTAR Electric
Line of Credit Facility [Line Items]
Borrowings Outstanding as of December 31,	$ 504,800	$ 365,800
Available Borrowing Capacity as of December 31,	$ 145,200	$ 284,200
Weighted-Average Interest Rate as of December 31,	4.55%	5.40%

LONG-TERM DEBT - Schedule of Lo

LONG-TERM DEBT - Schedule of Long-Term Debt Outstanding (Details) - USD ($) $ in Thousands	Jan. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Long-Term Debt		$ 25,701,627	$ 23,588,616
Less Amounts due Within One Year		(1,003,150)	(824,847)
Current Portion Classified as Long-Term Debt		0	990,900
Senior Notes
Debt Instrument [Line Items]
Unamortized Premiums and Discounts, Net		41,700	49,700
Unamortized Debt Issuance Costs		(76,100)	(65,000)
Long-Term Debt		25,701,600	23,588,600
Pre-1983 Spent Nuclear Fuel Obligation (CYAPC)
Debt Instrument [Line Items]
Long-Term Debt		5,600	12,500
Fair Value Adjustment
Debt Instrument [Line Items]
Long-Term Debt		0	19,300
Fair Value Adjustment - Current Portion
Debt Instrument [Line Items]
Long-Term Debt		0	(5,500)
Loans Payable
Debt Instrument [Line Items]
Less Amounts due Within One Year		(750,300)	(1,810,200)
Total Other Long-Term Debt
Debt Instrument [Line Items]
Long-Term Debt		14,016,400	12,845,700
Commercial Paper
Debt Instrument [Line Items]
Long-Term Debt			990,900
Eversource
Debt Instrument [Line Items]
Long-Term Debt		10,729,256	9,952,351
Less Amounts due Within One Year		(600,000)	(364,653)
Eversource | Unsecured Debt | Eversource Parent - Senior Notes due 2025 - 2050
Debt Instrument [Line Items]
Long-Term Debt		$ 11,350,000	10,300,000
Eversource | Unsecured Debt | Eversource Parent - Senior Notes due 2025 - 2050 | Minimum
Debt Instrument [Line Items]
Interest rate		0.80%
Eversource | Unsecured Debt | Eversource Parent - Senior Notes due 2025 - 2050 | Maximum
Debt Instrument [Line Items]
Interest rate		5.95%
CL&P
Debt Instrument [Line Items]
Long-Term Debt		$ 5,108,173	4,814,429
Long-Term Debt, Due Within One Year		(400,000)	(139,800)
Less Amounts due Within One Year		(2,944)	0
CL&P | Subsequent Event
Debt Instrument [Line Items]
Current Portion Classified as Long-Term Debt	$ 397,100
CL&P | First Mortgage Bonds
Debt Instrument [Line Items]
Long-Term Debt		5,130,000	4,619,800
Current Portion Classified as Long-Term Debt		397,100	139,800
Unamortized Premiums and Discounts, Net		14,300	18,000
Unamortized Debt Issuance Costs		(33,200)	(30,700)
Long-Term Debt		$ 5,108,200	4,814,400
CL&P | First Mortgage Bonds | 1994 Series D due 2024
Debt Instrument [Line Items]
Interest rate		7.875%
Long-Term Debt		$ 0	139,800
CL&P | First Mortgage Bonds | 2004 Series B due 2034
Debt Instrument [Line Items]
Interest rate		5.75%
Long-Term Debt		$ 130,000	130,000
CL&P | First Mortgage Bonds | 2005 Series B due 2035
Debt Instrument [Line Items]
Interest rate		5.625%
Long-Term Debt		$ 100,000	100,000
CL&P | First Mortgage Bonds | 2006 Series A due 2036
Debt Instrument [Line Items]
Interest rate		6.35%
Long-Term Debt		$ 250,000	250,000
CL&P | First Mortgage Bonds | 2007 Series B due 2037
Debt Instrument [Line Items]
Interest rate		5.75%
Long-Term Debt		$ 150,000	150,000
CL&P | First Mortgage Bonds | 2007 Series D due 2037
Debt Instrument [Line Items]
Interest rate		6.375%
Long-Term Debt		$ 100,000	100,000
CL&P | First Mortgage Bonds | 2014 Series A due 2044
Debt Instrument [Line Items]
Interest rate		4.30%
Long-Term Debt		$ 475,000	475,000
CL&P | First Mortgage Bonds | 2015 Series A due 2045
Debt Instrument [Line Items]
Interest rate		4.15%
Long-Term Debt		$ 350,000	350,000
CL&P | First Mortgage Bonds | 2017 Series A due 2027
Debt Instrument [Line Items]
Interest rate		3.20%
Long-Term Debt		$ 500,000	500,000
CL&P | First Mortgage Bonds | 2018 Series A due 2048
Debt Instrument [Line Items]
Interest rate		4%
Long-Term Debt		$ 800,000	800,000
CL&P | First Mortgage Bonds | 2020 Series A due 2025
Debt Instrument [Line Items]
Interest rate		0.75%
Long-Term Debt		$ 400,000	400,000
CL&P | First Mortgage Bonds | 2021 Series A due 2031
Debt Instrument [Line Items]
Interest rate		2.05%
Long-Term Debt		$ 425,000	425,000
CL&P | First Mortgage Bonds | 2023 Series A due 2053
Debt Instrument [Line Items]
Interest rate		5.25%
Long-Term Debt		$ 500,000	500,000
CL&P | First Mortgage Bonds | 2023 Series B due 2033
Debt Instrument [Line Items]
Interest rate		4.90%
Long-Term Debt		$ 300,000	300,000
CL&P | First Mortgage Bonds | 2024 Series A due 2029
Debt Instrument [Line Items]
Interest rate		4.65%
Long-Term Debt		$ 350,000	0
CL&P | First Mortgage Bonds | 2024 Series B due 2034
Debt Instrument [Line Items]
Interest rate		4.95%
Long-Term Debt		$ 300,000	0
CL&P | Commercial Paper
Debt Instrument [Line Items]
Long-Term Debt			139,800
Current Portion Classified as Long-Term Debt		0	207,300
NSTAR Electric
Debt Instrument [Line Items]
Long-Term Debt		4,844,920	4,496,947
Less Amounts due Within One Year		(250,000)	0
NSTAR Electric | Unsecured Debt
Debt Instrument [Line Items]
Long-Term Debt		5,000,000	4,400,000
Less Amounts due Within One Year		(250,000)	0
Unamortized Premiums and Discounts, Net		(14,000)	(14,000)
Unamortized Debt Issuance Costs		(31,100)	(29,100)
Long-Term Debt		$ 4,844,900	4,496,900
NSTAR Electric | Unsecured Debt | 2006 Debentures due 2036
Debt Instrument [Line Items]
Interest rate		5.75%
Long-Term Debt		$ 200,000	200,000
NSTAR Electric | Unsecured Debt | 2010 Debentures due 2040
Debt Instrument [Line Items]
Interest rate		5.50%
Long-Term Debt		$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2014 Debentures due 2044
Debt Instrument [Line Items]
Interest rate		4.40%
Long-Term Debt		$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2015 Debentures due 2025
Debt Instrument [Line Items]
Interest rate		3.25%
Long-Term Debt		$ 250,000	250,000
NSTAR Electric | Unsecured Debt | 2016 Debentures due 2026
Debt Instrument [Line Items]
Interest rate		2.70%
Long-Term Debt		$ 250,000	250,000
NSTAR Electric | Unsecured Debt | 2017 Debentures due 2027
Debt Instrument [Line Items]
Interest rate		3.20%
Long-Term Debt		$ 700,000	700,000
NSTAR Electric | Unsecured Debt | 2019 Debentures due 2029
Debt Instrument [Line Items]
Interest rate		3.25%
Long-Term Debt		$ 400,000	400,000
NSTAR Electric | Unsecured Debt | 2020 Debentures due 2030
Debt Instrument [Line Items]
Interest rate		3.95%
Long-Term Debt		$ 400,000	400,000
NSTAR Electric | Unsecured Debt | 2021 Debentures due 2051
Debt Instrument [Line Items]
Interest rate		3.10%
Long-Term Debt		$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2021 Debentures due 2031
Debt Instrument [Line Items]
Interest rate		1.95%
Long-Term Debt		$ 300,000	300,000
NSTAR Electric | Unsecured Debt | 2022 Debentures due 2052
Debt Instrument [Line Items]
Interest rate		4.55%
Long-Term Debt		$ 450,000	450,000
NSTAR Electric | Unsecured Debt | 2022 Debentures due 2052
Debt Instrument [Line Items]
Interest rate		4.95%
Long-Term Debt		$ 400,000	400,000
NSTAR Electric | Unsecured Debt | 2023 Debentures due 2028
Debt Instrument [Line Items]
Interest rate		5.60%
Long-Term Debt		$ 150,000	150,000
NSTAR Electric | Unsecured Debt | 2024 Debentures due 2034
Debt Instrument [Line Items]
Interest rate		5.40%
Long-Term Debt		$ 600,000	0
NSTAR Electric | Senior Notes
Debt Instrument [Line Items]
Long-Term Debt		$ 140,000	140,000
NSTAR Electric | Senior Notes | 2004 Senior Notes Series B due 2034
Debt Instrument [Line Items]
Interest rate		5.90%
Long-Term Debt		$ 50,000	50,000
NSTAR Electric | Senior Notes | 2007 Senior Notes Series D due 2037
Debt Instrument [Line Items]
Interest rate		6.70%
Long-Term Debt		$ 40,000	40,000
NSTAR Electric | Senior Notes | 2016 Senior Notes Series H due 2026
Debt Instrument [Line Items]
Interest rate		2.75%
Long-Term Debt		$ 50,000	50,000
PSNH
Debt Instrument [Line Items]
Long-Term Debt		1,732,066	1,431,591
PSNH | First Mortgage Bonds
Debt Instrument [Line Items]
Long-Term Debt		1,750,000	1,450,000
Unamortized Premiums and Discounts, Net		(2,600)	(4,900)
Unamortized Debt Issuance Costs		(15,300)	(13,500)
Long-Term Debt		$ 1,732,100	1,431,600
PSNH | First Mortgage Bonds | 2005 Series M due 2035
Debt Instrument [Line Items]
Interest rate		5.60%
Long-Term Debt		$ 50,000	50,000
PSNH | First Mortgage Bonds | 2019 Series T due 2049
Debt Instrument [Line Items]
Interest rate		3.60%
Long-Term Debt		$ 300,000	300,000
PSNH | First Mortgage Bonds | 2020 Series U due 2050
Debt Instrument [Line Items]
Interest rate		2.40%
Long-Term Debt		$ 150,000	150,000
PSNH | First Mortgage Bonds | 2021 Series V due 2031
Debt Instrument [Line Items]
Interest rate		2.20%
Long-Term Debt		$ 350,000	350,000
PSNH | First Mortgage Bonds | 2023 Series W due 2053
Debt Instrument [Line Items]
Interest rate		5.15%
Long-Term Debt		$ 300,000	300,000
PSNH | First Mortgage Bonds | 2023 Series X due 2033
Debt Instrument [Line Items]
Interest rate		5.35%
Long-Term Debt		$ 600,000	300,000
Yankee Gas | First Mortgage Bonds | Yankee Gas - First Mortgage Bonds due 2025 - 2051
Debt Instrument [Line Items]
Long-Term Debt		$ 1,095,000	1,015,000
Yankee Gas | First Mortgage Bonds | Yankee Gas - First Mortgage Bonds due 2025 - 2051 | Minimum
Debt Instrument [Line Items]
Interest rate		1.38%
Yankee Gas | First Mortgage Bonds | Yankee Gas - First Mortgage Bonds due 2025 - 2051 | Maximum
Debt Instrument [Line Items]
Interest rate		5.74%
NSTAR Gas | First Mortgage Bonds | NSTAR Gas - First Mortgage Bonds due 2025 - 2051
Debt Instrument [Line Items]
Long-Term Debt		$ 905,000	705,000
NSTAR Gas | First Mortgage Bonds | NSTAR Gas - First Mortgage Bonds due 2025 - 2051 | Minimum
Debt Instrument [Line Items]
Interest rate		2.25%
NSTAR Gas | First Mortgage Bonds | NSTAR Gas - First Mortgage Bonds due 2025 - 2051 | Maximum
Debt Instrument [Line Items]
Interest rate		7.11%
EGMA | First Mortgage Bonds | Aquarion - Unsecured Notes due 2028 - 2052
Debt Instrument [Line Items]
Long-Term Debt		$ 808,000	708,000
EGMA | First Mortgage Bonds | Aquarion - Unsecured Notes due 2028 - 2052 | Minimum
Debt Instrument [Line Items]
Interest rate		2.11%
EGMA | First Mortgage Bonds | Aquarion - Unsecured Notes due 2028 - 2052 | Maximum
Debt Instrument [Line Items]
Interest rate		5.73%
Aquarion | Unsecured Debt | Aquarion - Unsecured Notes due 2028 - 2052
Debt Instrument [Line Items]
Long-Term Debt		$ 596,800	527,000
Aquarion | Unsecured Debt | Aquarion - Unsecured Notes due 2028 - 2052 | Minimum
Debt Instrument [Line Items]
Interest rate		3%
Aquarion | Unsecured Debt | Aquarion - Unsecured Notes due 2028 - 2052 | Maximum
Debt Instrument [Line Items]
Interest rate		6.43%
Aquarion | Secured Debt | Aquarion - Secured Debt due 2027 - 2045
Debt Instrument [Line Items]
Long-Term Debt		$ 40,700	39,000
Aquarion | Secured Debt | Aquarion - Secured Debt due 2027 - 2045 | Minimum
Debt Instrument [Line Items]
Interest rate		1.296%
Aquarion | Secured Debt | Aquarion - Secured Debt due 2027 - 2045 | Maximum
Debt Instrument [Line Items]
Interest rate		9.29%
Aquarion | Senior Notes | Aquarion - Senior Notes due 2024
Debt Instrument [Line Items]
Interest rate		4%
Long-Term Debt		$ 0	$ 360,000

LONG-TERM DEBT - Narrative (Det

LONG-TERM DEBT - Narrative (Details) - USD ($) $ in Thousands	Jan. 28, 2025	Dec. 31, 2024	Dec. 18, 2024	Aug. 12, 2024	Jul. 24, 2024	May 01, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Long-term debt		$ 25,701,627					$ 23,588,616
Interest included in payment to settle spent nuclear fuel obligation		4,300					9,500
NSTAR Electric
Debt Instrument [Line Items]
Long-term debt		4,844,920					4,496,947
Line of Credit | NSTAR Electric
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance						$ 2,400,000
Line of Credit | CL&P
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance					$ 1,000,000
Line of Credit | EGMA
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance				$ 325,000
Line of Credit | NSTAR Gas
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance			$ 475,000
Line of Credit | Yankee Gas | Subsequent Event
Debt Instrument [Line Items]
Amount of long-term debt requested for issuance	$ 360,000
Pre-1983 Spent Nuclear Fuel Obligation (CYAPC)
Debt Instrument [Line Items]
Long-term debt		$ 5,600					$ 12,500

LONG-TERM DEBT - Schedule of Is

LONG-TERM DEBT - Schedule of Issuances and Repayments (Details) - USD ($) $ in Thousands	1 Months Ended								12 Months Ended
	Jan. 31, 2025	Oct. 31, 2024	Aug. 31, 2024	Jul. 31, 2024	Jun. 30, 2024	May 31, 2024	Apr. 30, 2024	Jan. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Repayments of debt									$ (1,949,995)	$ (2,008,470)	$ (1,175,000)
CL&P
Debt Instrument [Line Items]
Repayments of debt									(139,800)	(400,000)	0
NSTAR Electric
Debt Instrument [Line Items]
Repayments of debt									0	(80,000)	(400,000)
PSNH
Debt Instrument [Line Items]
Repayments of debt									0	(325,000)	0
CL&P 2024 Series A First Mortgage Bonds | First Mortgage Bonds | CL&P
Debt Instrument [Line Items]
Interest rate								4.65%
Issuance								$ 350,000
CL&P Series B First Mortgage Bonds | First Mortgage Bonds | CL&P
Debt Instrument [Line Items]
Interest rate			4.95%
Issuance			$ 300,000
CL&P Series D First Mortgage Bonds | First Mortgage Bonds | CL&P
Debt Instrument [Line Items]
Interest rate		7.875%
Repayments of debt		$ (139,800)
CL&P 2025 Series A First Mortgage Bonds | First Mortgage Bonds | CL&P | Subsequent Event
Debt Instrument [Line Items]
Interest rate	4.95%
Issuance	$ 400,000
NSTAR Electric Debentures | Unsecured Debt | NSTAR Electric
Debt Instrument [Line Items]
Interest rate						5.40%
Issuance						$ 600,000
PSNH Series X First Mortgage Bonds | First Mortgage Bonds | PSNH
Debt Instrument [Line Items]
Interest rate							5.35%
Issuance							$ 300,000
NSTAR Gas Series W First Mortgage Bonds | First Mortgage Bonds | NSTAR Gas
Debt Instrument [Line Items]
Interest rate					5.29%
Issuance					$ 160,000
NSTAR Gas Series X First Mortgage Bonds | First Mortgage Bonds | NSTAR Gas
Debt Instrument [Line Items]
Interest rate					5.48%
Issuance					$ 40,000
Yankee Gas Series W First Mortgage Bonds | First Mortgage Bonds | Yankee Gas Services Company
Debt Instrument [Line Items]
Interest rate				5.50%
Issuance				$ 90,000
Yankee Gas Series X First Mortgage Bonds | First Mortgage Bonds | Yankee Gas Services Company
Debt Instrument [Line Items]
Interest rate				5.74%
Issuance				$ 90,000
Yankee Gas Series P First Mortgage Bonds | First Mortgage Bonds | Yankee Gas Services Company
Debt Instrument [Line Items]
Interest rate		2.23%
Repayments of debt		$ (100,000)
EGMA Series E First Mortgage Bonds | First Mortgage Bonds | Eversource Gas Company of Massachusetts
Debt Instrument [Line Items]
Interest rate		5.17%
Issuance		$ 100,000
Aquarion Senior Notes | Senior Notes | Aquarion Company and its Subsidiaries
Debt Instrument [Line Items]
Interest rate			4%
Repayments of debt			$ (360,000)
Aquarion Water Company of Connecticut Senior Notes | Senior Notes | Aquarion Company and its Subsidiaries
Debt Instrument [Line Items]
Interest rate			5.57%
Issuance			$ 70,000
Eversource
Debt Instrument [Line Items]
Repayments of debt									$ (1,350,000)	$ (1,200,000)	$ (750,000)
Eversource | Eversource Parent Series DD Senior Notes | Senior Notes
Debt Instrument [Line Items]
Interest rate								5%
Issuance								$ 350,000
Eversource | Eversource Parent Series EE Senior Notes | Senior Notes
Debt Instrument [Line Items]
Interest rate								5.50%
Issuance								$ 650,000
Eversource | Eversource Parent Series FF Senior Notes | Senior Notes
Debt Instrument [Line Items]
Interest rate							5.85%
Issuance							$ 700,000
Eversource | Eversource Parent Series GG Senior Notes | Senior Notes
Debt Instrument [Line Items]
Interest rate							5.95%
Issuance							$ 700,000
Eversource | Eversource Parent Series X Senior Notes | Senior Notes
Debt Instrument [Line Items]
Interest rate					4.20%
Repayments of debt					$ (900,000)
Eversource | Eversource Parent Series L Senior Notes | Senior Notes
Debt Instrument [Line Items]
Interest rate		2.90%
Repayments of debt		$ (450,000)
Eversource | Eversource Parent Series H Senior Notes | Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Interest rate	3.15%
Repayments of debt	$ (300,000)

LONG-TERM DEBT - Schedule of _2

LONG-TERM DEBT - Schedule of Long-term Debt Maturities (Details) $ in Millions	Dec. 31, 2024 USD ($)
Debt Instrument [Line Items]
2025	$ 1,400.3
2026	1,390.2
2027	2,889.2
2028	1,978.5
2029	2,300.3
Thereafter	16,857
Total	26,815.5
CL&P
Debt Instrument [Line Items]
2025	400
2026	0
2027	500
2028	0
2029	350
Thereafter	3,880
Total	5,130
NSTAR Electric
Debt Instrument [Line Items]
2025	250
2026	300
2027	700
2028	150
2029	400
Thereafter	3,340
Total	5,140
PSNH
Debt Instrument [Line Items]
2025	0
2026	0
2027	0
2028	0
2029	0
Thereafter	1,750
Total	$ 1,750

RATE REDUCTION BONDS AND VARI_3

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Narrative (Details) - PSNH - Rate Reduction Bonds $ in Millions	May 31, 2018 USD ($)
Debt Instrument [Line Items]
Amount of securitized rate reduction bonds issued	$ 635.7
Weighted average interest rate (in percent)	3.66%

RATE REDUCTION BONDS AND VARI_4

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	$ 7,070,700	$ 6,389,200
Regulatory Liabilities	4,032,564	4,022,923
Accrued Interest (included in Other Current Liabilities)	868,491	821,404
Rate Reduction Bonds - Current Portion	43,210	43,210
Rate Reduction Bonds - Long-Term Portion	$ 324,072	$ 367,282
Other Current Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash and Cash Equivalents, Statement of Financial Position [Extensible Enumeration]	Prepayments and Other Current Assets	Prepayments and Other Current Assets
Other Long-Term Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	$ 9,000	$ 17,300
Restricted Cash and Cash Equivalents, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Assets	Other Long-Term Assets
Securitized Stranded Costs
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	$ 349,300	$ 392,500
Other Regulatory Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	510,000	339,000
PSNH
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	1,065,700	963,300
Regulatory Liabilities	394,982	393,574
Accrued Interest (included in Other Current Liabilities)	92,018	72,328
Rate Reduction Bonds - Current Portion	43,210	43,210
Rate Reduction Bonds - Long-Term Portion	324,072	367,282
PSNH | Other Long-Term Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	3,100	3,200
PSNH | Securitized Stranded Costs
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	349,300	392,500
PSNH | Other Regulatory Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	3,700	8,000
Variable Interest Entity, Primary Beneficiary | PSNH
Condensed Balance Sheet Statements, Captions [Line Items]
Regulatory Liabilities	6,900	5,300
Accrued Interest (included in Other Current Liabilities)	5,700	6,300
Rate Reduction Bonds - Current Portion	43,200	43,200
Rate Reduction Bonds - Long-Term Portion	324,100	367,300
Variable Interest Entity, Primary Beneficiary | PSNH | Other Current Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	31,000	30,000
Variable Interest Entity, Primary Beneficiary | PSNH | Other Long-Term Assets
Condensed Balance Sheet Statements, Captions [Line Items]
Restricted Cash	3,100	3,200
Variable Interest Entity, Primary Beneficiary | PSNH | Securitized Stranded Costs
Condensed Balance Sheet Statements, Captions [Line Items]
Securitized Stranded Cost (included in Regulatory Assets)	$ 349,300	$ 392,500

RATE REDUCTION BONDS AND VARI_5

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Condensed Income Statements, Captions [Line Items]
Interest Expense on RRB Principal (included in Interest Expense)	$ 1,111,336	$ 855,441	$ 678,274
PSNH
Condensed Income Statements, Captions [Line Items]
Interest Expense on RRB Principal (included in Interest Expense)	77,770	72,786	59,548
Variable Interest Entity, Primary Beneficiary | PSNH | Rate Reduction Bonds
Condensed Income Statements, Captions [Line Items]
Amortization of RRB Principal (included in Amortization of Regulatory Assets/(Liabilities), Net)	43,200	43,200	43,200
Interest Expense on RRB Principal (included in Interest Expense)	$ 14,300	$ 15,700	$ 17,000

RATE REDUCTION BONDS AND VARI_6

RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES- Rate Reduction Bonds, Principal and Interest Payments (Details) - PSNH $ in Millions	Dec. 31, 2024 USD ($)
Debt Instrument [Line Items]
2025	$ 43.2
2026	43.2
2027	43.2
2028	43.2
2029	43.2
Thereafter	151.3
Total	$ 367.3

EMPLOYEE BENEFITS - Schedule of

EMPLOYEE BENEFITS - Schedule of Pension Benefit Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	$ (5,238.4)	$ (5,220.1)
Service Cost	(44.3)	(43.1)	$ (70.1)
Interest Cost	(250)	(254)	(154.5)
Actuarial Gain/(Loss)	280.2	(110.4)
Benefits Paid	320.9	317.3
Benefits Paid - Lump Sum	24	28.9
Benefits Paid - SERP	19.4	43
Employee Transfers	0	0
Reclassified to Assets Held for Sale	142.5	0
Benefit Obligation as of End of Year	(4,745.7)	(5,238.4)	(5,220.1)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	5,775	5,806.4
Employer Contributions	5	5
Actual Return on Plan Assets	227	309.8
Benefits Paid - Pension	(320.9)	(317.3)
Benefits Paid - Lump Sum	(24)	(28.9)
Employee Transfers	0	0
Reclassified to Assets Held for Sale	148.1	0
Fair Value of Plan Assets as of End of Year	5,514	5,775	5,806.4
Funded Status as of December 31st	768.3	536.6
PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(676)	(693.7)
Service Cost	(7)	(7.6)	(11.6)
Interest Cost	(31.9)	(33.8)	(20.2)
Actuarial Gain/(Loss)	41.3	5
Benefits Paid	51.7	52.7
Employee Transfers	0	0
Reclassified to Assets Held for Sale	34.5	0
Plan Amendment	0	1.4
Benefit Obligation as of End of Year	(587.4)	(676)	(693.7)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	1,024.4	970.1
Employer Contributions	0.9	1.9
Actual Return on Plan Assets	92.3	104.7
Benefits Paid - Pension	(51.8)	(52.3)
Employee Transfers	0	0
Reclassified to Assets Held for Sale	29.5	0
Fair Value of Plan Assets as of End of Year	1,036.3	1,024.4	970.1
Funded Status as of December 31st	448.9	348.4
CL&P | Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(1,048.5)	(1,030)
Service Cost	(12.7)	(12.3)	(18.7)
Interest Cost	(50.3)	(50.5)	(31.3)
Actuarial Gain/(Loss)	56.2	(19.7)
Benefits Paid	68.1	66.1
Benefits Paid - Lump Sum	0	0
Benefits Paid - SERP	0.3	0.3
Employee Transfers	4	(2.4)
Reclassified to Assets Held for Sale	0	0
Benefit Obligation as of End of Year	(982.9)	(1,048.5)	(1,030)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	1,170	1,172
Employer Contributions	0	0
Actual Return on Plan Assets	46.5	61.7
Benefits Paid - Pension	(68.1)	(66.1)
Benefits Paid - Lump Sum	0	0
Employee Transfers	(4)	2.4
Reclassified to Assets Held for Sale	0	0
Fair Value of Plan Assets as of End of Year	1,144.4	1,170	1,172
Funded Status as of December 31st	161.5	121.5
CL&P | PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(120.6)	(127.9)
Service Cost	(1.2)	(1.3)	(2)
Interest Cost	(5.6)	(6.2)	(3.7)
Actuarial Gain/(Loss)	8.9	4.4
Benefits Paid	9.4	10
Employee Transfers	0	0
Reclassified to Assets Held for Sale	0	0
Plan Amendment	0	0.4
Benefit Obligation as of End of Year	(109.1)	(120.6)	(127.9)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	123	120.6
Employer Contributions	0	0
Actual Return on Plan Assets	11.2	12.6
Benefits Paid - Pension	(9.4)	(10)
Employee Transfers	(0.4)	(0.2)
Reclassified to Assets Held for Sale	0	0
Fair Value of Plan Assets as of End of Year	124.4	123	120.6
Funded Status as of December 31st	15.3	2.4
NSTAR Electric | Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(1,107)	(1,110.4)
Service Cost	(7.7)	(7.8)	(13.8)
Interest Cost	(51.6)	(53.9)	(32.8)
Actuarial Gain/(Loss)	74.1	(17.6)
Benefits Paid	67.1	76.7
Benefits Paid - Lump Sum	7.6	5.3
Benefits Paid - SERP	0.2	0.2
Employee Transfers	13.8	0.5
Reclassified to Assets Held for Sale	0	0
Benefit Obligation as of End of Year	(1,003.5)	(1,107)	(1,110.4)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	1,411.6	1,418.8
Employer Contributions	0	0
Actual Return on Plan Assets	55.1	75.3
Benefits Paid - Pension	(67.1)	(76.7)
Benefits Paid - Lump Sum	(7.6)	(5.3)
Employee Transfers	(13.8)	(0.5)
Reclassified to Assets Held for Sale	0	0
Fair Value of Plan Assets as of End of Year	1,378.2	1,411.6	1,418.8
Funded Status as of December 31st	374.7	304.6
NSTAR Electric | PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(188.3)	(189.5)
Service Cost	(1.2)	(1.2)	(2)
Interest Cost	(8.8)	(9.2)	(5.3)
Actuarial Gain/(Loss)	10.7	(5.8)
Benefits Paid	15.9	16.7
Employee Transfers	0.3	0.5
Reclassified to Assets Held for Sale	0	0
Plan Amendment	0	0.2
Benefit Obligation as of End of Year	(171.4)	(188.3)	(189.5)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	490.4	456.1
Employer Contributions	0	0
Actual Return on Plan Assets	45.8	52.3
Benefits Paid - Pension	(15.9)	(16.7)
Employee Transfers	(1.1)	(1.3)
Reclassified to Assets Held for Sale	0	0
Fair Value of Plan Assets as of End of Year	519.2	490.4	456.1
Funded Status as of December 31st	347.8	302.1
PSNH | Pension and SERP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(562.3)	(556.2)
Service Cost	(4.3)	(4.3)	(6.9)
Interest Cost	(26.8)	(27.3)	(16.9)
Actuarial Gain/(Loss)	30.7	(11.6)
Benefits Paid	38	35.7
Benefits Paid - Lump Sum	0.1	1
Benefits Paid - SERP	0.4	0.4
Employee Transfers	2.7	0
Reclassified to Assets Held for Sale	0	0
Benefit Obligation as of End of Year	(521.5)	(562.3)	(556.2)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	614	618
Employer Contributions	0	0
Actual Return on Plan Assets	24.3	32.7
Benefits Paid - Pension	(38)	(35.7)
Benefits Paid - Lump Sum	(0.1)	(1)
Employee Transfers	(2.7)	0
Reclassified to Assets Held for Sale	0	0
Fair Value of Plan Assets as of End of Year	597.5	614	618
Funded Status as of December 31st	76	51.7
PSNH | PBOP
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation as of Beginning of Year	(72)	(74.6)
Service Cost	(0.6)	(0.7)	(1.1)
Interest Cost	(3.4)	(3.7)	(2.2)
Actuarial Gain/(Loss)	3.9	0.8
Benefits Paid	6.2	6.1
Employee Transfers	0	(0.1)
Reclassified to Assets Held for Sale	0	0
Plan Amendment	0	0.2
Benefit Obligation as of End of Year	(65.9)	(72)	(74.6)
Change in Pension Plan Assets:
Fair Value of Plan Assets as of Beginning of Year	74.7	72.3
Employer Contributions	0	0
Actual Return on Plan Assets	7.6	8.3
Benefits Paid - Pension	(6.1)	(6.1)
Employee Transfers	0.2	0.2
Reclassified to Assets Held for Sale	0	0
Fair Value of Plan Assets as of End of Year	76.4	74.7	$ 72.3
Funded Status as of December 31st	$ 10.5	$ 2.7

EMPLOYEE BENEFITS - Pension Pla

EMPLOYEE BENEFITS - Pension Plan Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Contribution Plan Disclosure [Line Items]
Expected long-term rate of return	8.25%	7.94%
Pension and SERP
Defined Contribution Plan Disclosure [Line Items]
Increase of liability as a result of change in discount rate	$ 332.9
Defined benefit plan, loss due to updated census data	$ 42.1
Decrease in liability as a result of a change in discount rate		$ 98.9
Expected long-term rate of return	8.25%	8.25%	8.25%
Employer Contributions	$ 5	$ 5
Pension and SERP | CL&P
Defined Contribution Plan Disclosure [Line Items]
Employer Contributions	0	0
Pension and SERP | PSNH
Defined Contribution Plan Disclosure [Line Items]
Employer Contributions	0	0
PBOP
Defined Contribution Plan Disclosure [Line Items]
Increase of liability as a result of change in discount rate	12
Decrease in liability as a result of a change in discount rate	$ 39.8	$ 17
Expected long-term rate of return	8.25%	8.25%	8.25%
Employer Contributions	$ 0.9	$ 1.9
PBOP | Aquarion
Defined Contribution Plan Disclosure [Line Items]
Expected long-term rate of return	7%	7%
PBOP | CL&P
Defined Contribution Plan Disclosure [Line Items]
Employer Contributions	$ 0	$ 0
PBOP | PSNH
Defined Contribution Plan Disclosure [Line Items]
Employer Contributions	$ 0	$ 0
Pre-65 Plan | PBOP
Defined Contribution Plan Disclosure [Line Items]
Health care trend rate	7.50%
Ultimate rate	5%
Pre-65 Plan | Minimum | PBOP | Aquarion
Defined Contribution Plan Disclosure [Line Items]
Health care trend rate	3.50%	3.50%
Pre-65 Plan | Maximum | PBOP | Aquarion
Defined Contribution Plan Disclosure [Line Items]
Health care trend rate	6.75%	7%
Post-65 Plan | PBOP
Defined Contribution Plan Disclosure [Line Items]
Ultimate rate	3.50%
Eversource Service Pension and PBOP Plans
Defined Contribution Plan Disclosure [Line Items]
Assumed rate of return	8.25%

EMPLOYEE BENEFITS - Schedule _2

EMPLOYEE BENEFITS - Schedule of Funded Status (Details) - Pension and SERP - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 4,617.1	$ 4,936.8
CL&P
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	953.9	977.8
NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	969.5	1,051.9
PSNH
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 507.4	$ 522.1

EMPLOYEE BENEFITS - Schedule _3

EMPLOYEE BENEFITS - Schedule of Prepaid Assets (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	$ 1,336.6	$ 1,028.2
Less: Accrued SERP - current portion	(24)	(19.4)
Accrued SERP and PBOP	95.4	123.8
CL&P
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	182.5	129.8
Less: Accrued SERP - current portion	(0.4)	(0.3)
Accrued SERP and PBOP	5.3	5.6
NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	724.7	608.6
Less: Accrued SERP - current portion	(0.2)	(0.2)
Accrued SERP and PBOP	2	1.7
PSNH
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	91	59
Less: Accrued SERP - current portion	(0.4)	(0.4)
Accrued SERP and PBOP	4.1	4.2
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	887.7	672.2
Pension Plan | CL&P
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	167.2	127.4
Pension Plan | NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	376.9	306.5
Pension Plan | PSNH
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	80.5	56.3
PBOP
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	448.9	356
Accrued liability, defined benefit pension plan	0	7.6
PBOP | CL&P
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	15.3	2.4
Accrued liability, defined benefit pension plan	0	0
PBOP | NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	347.8	302.1
Accrued liability, defined benefit pension plan	0	0
PBOP | PSNH
Defined Benefit Plan Disclosure [Line Items]
Prepaid asset	10.5	2.7
Accrued liability, defined benefit pension plan	0	0
SERP
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	119.4	135.6
SERP | CL&P
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	5.7	5.9
SERP | NSTAR Electric
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	2.2	1.9
SERP | PSNH
Defined Benefit Plan Disclosure [Line Items]
Accrued liability, defined benefit pension plan	$ 4.5	$ 4.6

EMPLOYEE BENEFITS - Schedule _4

EMPLOYEE BENEFITS - Schedule of Actuarial Assumptions (Details)	Dec. 31, 2024	Dec. 31, 2023
Pension and SERP | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	5.60%	4.90%
Compensation/Progression Rate	3.50%	3.50%
Pension and SERP | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	5.70%	5%
Compensation/Progression Rate	4%	4%
PBOP | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate	5.70%	5%
PBOP | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount Rate		5.20%

EMPLOYEE BENEFITS - Schedule _5

EMPLOYEE BENEFITS - Schedule of Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 44.3	$ 43.1	$ 70.1
Interest Cost	250	254	154.5
Expected Return on Plan Assets	(462.6)	(465)	(523.6)
Actuarial Loss/(Gain)	85.9	45.8	116
Prior Service Cost/(Credit)	1.3	1.3	1.4
Settlement Loss	4.3	12.4
Total Net Periodic Benefit Plan Income	(76.8)	$ (108.4)	$ (181.6)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Income, Net	Other Income, Net
PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	7	$ 7.6	$ 11.6
Interest Cost	31.9	33.8	20.2
Expected Return on Plan Assets	(81.2)	(77.1)	(89.9)
Actuarial Loss/(Gain)	(0.4)	0	0
Prior Service Cost/(Credit)	(21.6)	(21.6)	(21.7)
Settlement Loss	0	0
Total Net Periodic Benefit Plan Income	$ (64.3)	$ (57.3)	$ (79.8)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Income, Net	Other Income, Net	Other Income, Net
CL&P | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 12.7	$ 12.3	$ 18.7
Interest Cost	50.3	50.5	31.3
Expected Return on Plan Assets	(93.5)	(94.2)	(106.3)
Actuarial Loss/(Gain)	12.1	2.5	16.2
Prior Service Cost/(Credit)	0	0	0
Settlement Loss	0	0
Total Net Periodic Benefit Plan Income	(18.4)	(28.9)	(40.1)
Intercompany Income Allocations	(1.6)	(4)	(16)
CL&P | PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	1.2	1.3	2
Interest Cost	5.6	6.2	3.7
Expected Return on Plan Assets	(9.5)	(9.4)	(11.4)
Actuarial Loss/(Gain)	0	0	0
Prior Service Cost/(Credit)	1.1	1.1	1.1
Settlement Loss	0	0
Total Net Periodic Benefit Plan Income	(1.6)	(0.8)	(4.6)
Intercompany Income Allocations	(2.2)	(1.9)	(3.7)
NSTAR Electric | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	7.7	7.8	13.8
Interest Cost	51.6	53.9	32.8
Expected Return on Plan Assets	(112.4)	(113.8)	(128.4)
Actuarial Loss/(Gain)	25.6	17.1	32.8
Prior Service Cost/(Credit)	0.3	0.3	0.3
Settlement Loss	0	0
Total Net Periodic Benefit Plan Income	(27.2)	(34.7)	(48.7)
Intercompany Income Allocations	(1.3)	(3)	(12.4)
NSTAR Electric | PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	1.2	1.2	2
Interest Cost	8.8	9.2	5.3
Expected Return on Plan Assets	(39.5)	(36.9)	(42.4)
Actuarial Loss/(Gain)	0	0	0
Prior Service Cost/(Credit)	(17)	(17)	(17)
Settlement Loss	0	0
Total Net Periodic Benefit Plan Income	(46.5)	(43.5)	(52.1)
Intercompany Income Allocations	(2.6)	(2.1)	(3.6)
PSNH | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	4.3	4.3	6.9
Interest Cost	26.8	27.3	16.9
Expected Return on Plan Assets	(48.9)	(49.5)	(56.1)
Actuarial Loss/(Gain)	5	1.5	7.9
Prior Service Cost/(Credit)	0	0	0
Settlement Loss	0	0
Total Net Periodic Benefit Plan Income	(12.8)	(16.4)	(24.4)
Intercompany Income Allocations	(0.4)	(0.8)	(3.6)
PSNH | PBOP
Defined Benefit Plan Disclosure [Line Items]
Service Cost	0.6	0.7	1.1
Interest Cost	3.4	3.7	2.2
Expected Return on Plan Assets	(5.6)	(5.5)	(6.7)
Actuarial Loss/(Gain)	0	0	0
Prior Service Cost/(Credit)	0.4	0.4	0.4
Settlement Loss	0	0
Total Net Periodic Benefit Plan Income	(1.2)	(0.7)	(3)
Intercompany Income Allocations	$ (0.9)	$ (0.7)	$ (1.2)

EMPLOYEE BENEFITS - Schedule _6

EMPLOYEE BENEFITS - Schedule of Assumptions used To Calculate Pension and SERP and PBOP (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return (in percent)	8.25%	7.94%
Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return (in percent)	8.25%	8.25%	8.25%
PBOP
Defined Benefit Plan Disclosure [Line Items]
Expected Long-Term Rate of Return (in percent)	8.25%	8.25%	8.25%
Minimum | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	4.70%	4.90%	2.20%
Compensation/Progression Rate (in percent)	3.50%	3.50%	3.50%
Minimum | PBOP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	4.90%	5.10%	2.30%
Maximum | Pension and SERP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	5.10%	5.30%	3.20%
Compensation/Progression Rate (in percent)	4%	4%	4%
Maximum | PBOP
Defined Benefit Plan Disclosure [Line Items]
Discount rate (in percent)	5.20%	5.40%	3.30%

EMPLOYEE BENEFITS - Summary of

EMPLOYEE BENEFITS - Summary of Changes in Plan Assets and Benefit Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Pension and SERP
Net Regulatory Assets [Abstract]
Actuarial (Gain)/Loss Arising During the Year	$ (49.2)	$ 251.1
Actuarial (Loss)/Gain Reclassified as Net Periodic Benefit (Expense)/Income	(79.1)	(38.8)
Actuarial (Loss)/Gain Reclassified as Held for Sale	(16.6)	0
Settlement Loss	0	0
Prior Service Cost/(Credit) Arising During the Year	1.3	0
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	(1.2)	(1.2)
Prior Service Cost Reclassified as Held for Sale	(1.2)	0
Actuarial Loss	956.1	1,101
Prior Service (Credit)/Cost	1.8	2.9
OCI
Actuarial (Gain)/Loss Arising During the Year	2.3	14
Actuarial (Loss)/Gain Reclassified as Net Periodic Benefit (Expense)/Income	(6.8)	(7)
Actuarial (Loss)/Gain Reclassified as Held for Sale	0	0
Settlement Loss	(4.3)	(12.4)
Prior Service Cost/(Credit) Arising During the Year	0	0
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	(0.1)	(0.1)
Prior Service Cost Reclassified as Held for Sale	0	0
Actuarial Loss	47.7	56.5
Prior Service Cost	0.2	0.3
PBOP
Net Regulatory Assets [Abstract]
Actuarial (Gain)/Loss Arising During the Year	(50.9)	(32)
Actuarial (Loss)/Gain Reclassified as Net Periodic Benefit (Expense)/Income	0.4	0
Actuarial (Loss)/Gain Reclassified as Held for Sale	7.1	0
Settlement Loss	0	0
Prior Service Cost/(Credit) Arising During the Year	0	(0.9)
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	21.8	21.8
Prior Service Cost Reclassified as Held for Sale	0.6	0
Actuarial Loss	6.4	49.8
Prior Service (Credit)/Cost	(66.2)	(87.4)
OCI
Actuarial (Gain)/Loss Arising During the Year	(0.6)	(0.3)
Actuarial (Loss)/Gain Reclassified as Net Periodic Benefit (Expense)/Income	0	0
Actuarial (Loss)/Gain Reclassified as Held for Sale	0	0
Settlement Loss	0	0
Prior Service Cost/(Credit) Arising During the Year	0	0
Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income	(0.2)	(0.2)
Prior Service Cost Reclassified as Held for Sale	0	0
Actuarial Loss	1.8	2.4
Prior Service Cost	$ 0.5	$ 0.7

EMPLOYEE BENEFITS - Schedule _7

EMPLOYEE BENEFITS - Schedule of Estimated Future Benefit Payments (Details) $ in Millions	Dec. 31, 2024 USD ($)
Pension and SERP
Defined Contribution Plan Disclosure [Line Items]
2025	$ 367.3
2026	363.3
2027	369.5
2028	372.9
2029	375.4
2030 - 2034	1,879.4
PBOP
Defined Contribution Plan Disclosure [Line Items]
2025	51.3
2026	50.6
2027	49.8
2028	48.9
2029	48
2030 - 2034	$ 223.3

EMPLOYEE BENEFITS - Schedule _8

EMPLOYEE BENEFITS - Schedule of Long-term Rates of Return on Pension and PBOP (Details)	Dec. 31, 2024	Dec. 31, 2023
United States
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		0%
Assumed Rate of Return (in percent)	8.50%	8.50%
United States | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	0%
United States | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	20%	20%
Global
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		20%
Assumed Rate of Return (in percent)	8.80%	8.75%
Global | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	20%
Global | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	0%	0%
Non-United States
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		0%
Assumed Rate of Return (in percent)	8.50%	8.50%
Non-United States | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	0%
Non-United States | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	11%	11%
Emerging Markets
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		0%
Assumed Rate of Return (in percent)	10%	10%
Emerging Markets | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	0%
Emerging Markets | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	6%	6%
Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		16%
Assumed Rate of Return (in percent)	5.50%	5.50%
Fixed Income | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	16%
Fixed Income | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	17%	17%
Public High Yield Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		5%
Assumed Rate of Return (in percent)	7.50%	7.50%
Public High Yield Fixed Income | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	5%
Public High Yield Fixed Income | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	0%	0%
United States Treasuries
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		11%
Assumed Rate of Return (in percent)	4.50%	4.50%
United States Treasuries | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	11%
United States Treasuries | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	0%	0%
Private Debt
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		10%
Assumed Rate of Return (in percent)	10%	10%
Private Debt | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	10%
Private Debt | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	13%	13%
Private Equity
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		23%
Assumed Rate of Return (in percent)	12%	12%
Private Equity | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	23%
Private Equity | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	18%	18%
Real Assets
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)		15%
Assumed Rate of Return (in percent)	7.50%	7.50%
Real Assets | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	15%
Real Assets | PBOP
Defined Contribution Plan Disclosure [Line Items]
Target Asset Allocation (in percent)	15%	15%

EMPLOYEE BENEFITS - Schedule _9

EMPLOYEE BENEFITS - Schedule of Asset Category (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2022
Pension and SERP
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 5,775	$ 5,514	$ 5,806.4
Uncategorized	4,776.8	4,518.7
Pension and SERP | Total Assets Before 401
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	6,019.9	5,745.1
Pension and SERP | Equity Securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	1,227	1,149.6
Uncategorized	853	826
Pension and SERP | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	2,211.9	1,988.6
Uncategorized	1,516.4	1,329.6
Pension and SERP | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	1,685.3	1,710.9
Uncategorized	1,685.3	1,710.9
Pension and SERP | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	895.7	896
Uncategorized	722.1	652.2
Pension and SERP | 401 PBOP Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	(244.9)	(231.1)
Pension and SERP | Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	902.2	881.7
Pension and SERP | Level 1 | Equity Securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	374	323.6
Pension and SERP | Level 1 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	354.6	314.3
Pending redemption settlements	31
Pension and SERP | Level 1 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Pension and SERP | Level 1 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	173.6	243.8
Pension and SERP | Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	340.9	344.7
Pension and SERP | Level 2 | Equity Securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Pension and SERP | Level 2 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	340.9	344.7
Pension and SERP | Level 2 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
Pension and SERP | Level 2 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	1,024.4	1,036.3	$ 970.1
Uncategorized	493.5	430.3
PBOP | Total Assets Before 401
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	779.5	805.2
PBOP | Equity Securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	351.2	351.1
Uncategorized	212.1	166.3
PBOP | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	236.2	233.9
Uncategorized	159.8	127.5
PBOP | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	87.7	99
Uncategorized	87.7	99
PBOP | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	104.4	121.2
Uncategorized	33.9	37.5
PBOP | 401 PBOP Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	244.9	231.1
PBOP | Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	243	330.3
PBOP | Level 1 | Equity Securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	139.1	184.8
PBOP | Level 1 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	33.4	61.8
PBOP | Level 1 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP | Level 1 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	70.5	83.7
PBOP | Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	43	44.6
PBOP | Level 2 | Equity Securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP | Level 2 | Fixed Income
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	43	44.6
PBOP | Level 2 | Private Equity
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	0	0
PBOP | Level 2 | Real Assets
Defined Contribution Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 0	$ 0

EMPLOYEE BENEFITS - Defined Con

EMPLOYEE BENEFITS - Defined Contribution Plan Narrative (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Contribution Plan, 401K
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution (as a percentage)	100%	100%	100%
Percentage of employees' pay (up to)	3%	3%	3%
Defined Contribution Plan, Alternate Contribution 401K
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution (as a percentage)	50%	50%	50%
Percentage of employees' pay (up to)	8%	8%	8%

EMPLOYEE BENEFITS - Schedule_10

EMPLOYEE BENEFITS - Schedule of Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	$ 76.2	$ 67.3	$ 59.9
CL&P
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	10.6	9	7.7
NSTAR Electric
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	15.4	13.7	12.8
PSNH
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost recognized	$ 6	$ 5.4	$ 4.8

EMPLOYEE BENEFITS - Share-Based

EMPLOYEE BENEFITS - Share-Based Payments Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted in incentive plan (up to) (in shares)	7,400,000
Shares available for issuance under incentive plan (in shares)	3,790,353	4,587,376
Shares outstanding (in shares)	455,620
Weighted average grant date fair value of restricted stock units (in dollars per share)	$ 65.20
Total unrecognized compensation expense	$ 31.2
Period for recognition	1 year 9 months 3 days
Tax effect on total share-based payments (in percentage)	26%
Excess stock benefit	$ (2.3)	$ (0.5)	$ 2.1
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)	$ 57.93	$ 76.42	$ 85.96
Shares outstanding (in shares)		326,581
Weighted average shares outstanding (in dollars per share)	$ 65.29	$ 80.76
Restricted stock units available (in shares)	280,938
Restricted stock unit fully vested (in shares)	259,822
Additional restricted stock unit expected to vest (in shares)	432,839
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)	$ 55.87	$ 83.39	$ 83.34
Shares outstanding (in shares)	737,738	485,480
Weighted average shares outstanding (in dollars per share)	$ 69.12	$ 85.20
Restricted stock units available (in shares)	72,723
Weighted average grant date fair value of restricted stock units (in dollars per share)	$ 84.87
Restricted stock unit fully vested (in shares)	126,454
CL&P
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	$ 5.5
Period for recognition	1 year 9 months 3 days
Excess stock benefit	$ (0.8)	$ (0.2)	$ 0.7
NSTAR Electric
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	$ 8.8
Period for recognition	1 year 9 months 7 days
Excess stock benefit	$ (0.8)	(0.2)	0.8
PSNH
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	$ 2
Period for recognition	1 year 9 months 3 days
Excess stock benefit	$ (0.3)	$ (0.1)	$ 0.3
Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of graded vesting schedule under long-term incentive program	3 years
Board Members
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of graded vesting schedule under long-term incentive program	1 year

EMPLOYEE BENEFITS - Summary o_2

EMPLOYEE BENEFITS - Summary of RSU and Share Transactions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	672,242
Granted (in shares)	372,400
Shares issued (in shares)	(289,372)
Forfeited (in shares)	(39,828)
Ending balance (in shares)	715,442	672,242
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share)	$ 65.89
Granted (in dollars per share)	57.93	$ 76.42	$ 85.96
Shares issued (in dollars per share)	65.25
Forfeited (in dollars per share)	66.91
Ending balance (in dollars per share)	$ 61.95	$ 65.89
Performance Shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	664,424
Granted (in shares)	431,789
Shares issued (in shares)	(126,054)
Forfeited (in shares)	(105,967)
Ending balance (in shares)	864,192	664,424
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share)	$ 85.33
Granted (in dollars per share)	55.87	$ 83.39	$ 83.34
Shares issued (in dollars per share)	85.54
Forfeited (in dollars per share)	77.98
Ending balance (in dollars per share)	$ 71.48	$ 85.33

EMPLOYEE BENEFITS - Schedule_11

EMPLOYEE BENEFITS - Schedule of Compensation Expense and Income Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	$ 30	$ 27.8	$ 33.4
Future Income Tax Benefit	7.8	7.3	8.7
CL&P
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	9.3	8.7	10
Future Income Tax Benefit	2.4	2.3	2.6
NSTAR Electric
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	9.6	8.7	10.7
Future Income Tax Benefit	2.5	2.3	2.8
PSNH
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	3.6	3	3.6
Future Income Tax Benefit	$ 0.9	$ 0.8	$ 0.9

EMPLOYEE BENEFITS - Schedule_12

EMPLOYEE BENEFITS - Schedule of Other Retirement Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	$ 30.2	$ 32.6	$ 43.4
Other Retirement Benefits Expense	2.4	2.6	10.9
Retirement benefit payable		9.2
CL&P
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	0.1	0.2	0.2
Other Retirement Benefits Expense	0.8	0.8	4
NSTAR Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	0	0	0.1
Other Retirement Benefits Expense	0.8	0.8	3.7
PSNH
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarially-Determined Liability	1	1.1	1.3
Other Retirement Benefits Expense	$ 0.3	$ 0.4	$ 1.3

INCOME TAXES - Components of In

INCOME TAXES - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Current Income Taxes:
Federal	$ (23,400)	$ 75,800	$ 95,800
State	14,300	600	13,600
Total Current	(9,100)	76,400	109,400
Deferred Income Taxes, Net:
Federal	266,300	(900)	198,800
State	169,600	86,300	148,000
Total Deferred	435,889	85,405	346,779
Investment Tax Credits, Net	(2,100)	(2,100)	(2,600)
Income Tax Expense	424,664	159,684	453,574
CL&P
Current Income Taxes:
Federal	25,900	(10,800)	106,200
State	(6,800)	(2,300)	20,100
Total Current	19,100	(13,100)	126,300
Deferred Income Taxes, Net:
Federal	107,900	130,300	17,200
State	67,500	53,700	28,200
Total Deferred	175,424	184,037	45,381
Investment Tax Credits, Net	0	0	(500)
Income Tax Expense	194,459	170,909	171,198
NSTAR Electric
Current Income Taxes:
Federal	65,900	50,700	55,000
State	15,200	7,800	8,700
Total Current	81,100	58,500	63,700
Deferred Income Taxes, Net:
Federal	63,900	50,100	35,600
State	47,300	46,100	42,400
Total Deferred	111,177	96,224	78,039
Investment Tax Credits, Net	(1,700)	(1,700)	(1,700)
Income Tax Expense	190,576	152,996	139,977
PSNH
Current Income Taxes:
Federal	(1,700)	(40,000)	29,600
State	(5,200)	(20,000)	5,900
Total Current	(6,900)	(60,000)	35,500
Deferred Income Taxes, Net:
Federal	50,800	81,200	5,900
State	26,300	37,800	9,900
Total Deferred	77,082	118,970	15,765
Investment Tax Credits, Net	0	0	0
Income Tax Expense	$ 70,245	$ 59,014	$ 51,314

INCOME TAXES - Reconciliation B

INCOME TAXES - Reconciliation Between Income Tax Expense and Expected Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Contingency [Line Items]
Income/(Loss) Before Income Tax Benefit	$ 1,243,836	$ (275,037)	$ 1,865,968
Statutory Federal Income Tax Expense at 21%	261,200	(57,700)	391,900
Tax Effect of Differences:
Depreciation	(22,600)	(25,800)	(17,100)
Investment Tax Credit Amortization	(2,100)	(2,100)	(2,600)
Other Federal Tax Credits	67,000	42,500	0
State Income Taxes, Net of Federal Impact	43,200	(11,400)	75,900
Dividends on ESOP	(5,500)	(5,300)	(5,100)
Tax Asset Valuation   Allowance/Reserve Adjustments	278,600	295,800	51,600
Tax Deficiency/(Excess Stock Benefit)	2,300	500	(2,100)
EDIT Amortization	(37,000)	(51,500)	(49,100)
Other, Net	(26,400)	59,700	10,200
Income Tax Expense	$ 424,664	$ 159,684	$ 453,574
Effective Tax Rate	34.10%	(58.10%)	24.30%
CL&P
Income Tax Contingency [Line Items]
Income/(Loss) Before Income Tax Benefit	$ 707,057	$ 689,642	$ 704,118
Statutory Federal Income Tax Expense at 21%	148,500	144,900	147,900
Tax Effect of Differences:
Depreciation	400	(5,600)	(3,700)
Investment Tax Credit Amortization	0	0	(500)
State Income Taxes, Net of Federal Impact	(2,800)	(10,700)	(6,600)
Tax Asset Valuation   Allowance/Reserve Adjustments	50,800	51,300	44,700
Tax Deficiency/(Excess Stock Benefit)	800	200	(700)
EDIT Amortization	(9,200)	(10,500)	(9,200)
Other, Net	6,000	1,300	(700)
Income Tax Expense	$ 194,459	$ 170,909	$ 171,198
Effective Tax Rate	27.50%	24.80%	24.30%
NSTAR Electric
Income Tax Contingency [Line Items]
Income/(Loss) Before Income Tax Benefit	$ 826,929	$ 697,524	$ 632,405
Statutory Federal Income Tax Expense at 21%	173,700	146,500	132,800
Tax Effect of Differences:
Depreciation	(10,900)	(8,800)	(4,200)
Investment Tax Credit Amortization	(1,700)	(1,700)	(1,700)
State Income Taxes, Net of Federal Impact	49,400	42,500	40,300
Tax Asset Valuation   Allowance/Reserve Adjustments	0	0	0
Tax Deficiency/(Excess Stock Benefit)	800	200	(800)
EDIT Amortization	(20,000)	(28,400)	(29,200)
Other, Net	(700)	2,700	2,800
Income Tax Expense	$ 190,576	$ 152,996	$ 139,977
Effective Tax Rate	23%	21.90%	22.10%
PSNH
Income Tax Contingency [Line Items]
Income/(Loss) Before Income Tax Benefit	$ 285,128	$ 254,673	$ 222,884
Statutory Federal Income Tax Expense at 21%	59,900	53,500	46,800
Tax Effect of Differences:
Depreciation	(1,000)	(1,000)	900
Investment Tax Credit Amortization	0	0	0
State Income Taxes, Net of Federal Impact	16,700	14,100	12,500
Tax Asset Valuation   Allowance/Reserve Adjustments	0	0	0
Tax Deficiency/(Excess Stock Benefit)	300	100	(300)
EDIT Amortization	(6,500)	(6,800)	(7,700)
Other, Net	800	(900)	(900)
Income Tax Expense	$ 70,245	$ 59,014	$ 51,314
Effective Tax Rate	24.60%	23.20%	23%

INCOME TAXES - Temporary Differ

INCOME TAXES - Temporary Differences That Give Rise To Accumulated Deferred Income Tax Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Deferred Tax Assets:
Employee Benefits	$ 266.9	$ 244.5
Derivative Liabilities	19.6	33
Regulatory Deferrals - Liabilities	508.7	452
Allowance for Uncollectible Accounts	145.3	143.8
Tax Effect - Tax Regulatory Liabilities	720.8	739
Net Operating Loss Carryforwards	198.2	13.8
Purchase Accounting Adjustment	52.1	56.7
Equity Method Wind Investments	1,098.6	584.9
Other	267.1	200.1
Total Deferred Tax Assets	3,277.3	2,467.8
Less: Valuation Allowance	558.2	328.1
Net Deferred Tax Assets	2,719.1	2,139.7
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	5,493.3	5,103.3
Property Tax Accruals	107.4	95
Regulatory Amounts:
Regulatory Deferrals - Assets	1,709.1	1,512.3
Tax Effect - Tax Regulatory Assets	294.5	284
Goodwill-related Regulatory Asset - 1999 Merger	67.5	72.2
Employee Benefits	353	282
Derivative Assets	3.8	6.4
Other	101.7	88.2
Total Deferred Tax Liabilities	8,130.3	7,443.4
Offshore Wind Business
Regulatory Amounts:
Impairment charge	427	224
CL&P
Deferred Tax Assets:
Employee Benefits	33.7	29.9
Derivative Liabilities	19.6	33
Regulatory Deferrals - Liabilities	128	94.4
Allowance for Uncollectible Accounts	75.4	79.6
Tax Effect - Tax Regulatory Liabilities	317.6	320.7
Net Operating Loss Carryforwards	0	0
Purchase Accounting Adjustment	0	0
Equity Method Wind Investments	0	0
Other	134.7	125.3
Total Deferred Tax Assets	709	682.9
Less: Valuation Allowance	104.1	80.6
Net Deferred Tax Assets	604.9	602.3
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	1,820.3	1,703.4
Property Tax Accruals	49.8	42
Regulatory Amounts:
Regulatory Deferrals - Assets	522.9	470
Tax Effect - Tax Regulatory Assets	194.7	191.9
Goodwill-related Regulatory Asset - 1999 Merger	0	0
Employee Benefits	51	38.8
Derivative Assets	3.8	6.4
Other	15.2	9.9
Total Deferred Tax Liabilities	2,657.7	2,462.4
NSTAR Electric
Deferred Tax Assets:
Employee Benefits	83.5	66.8
Derivative Liabilities	0	0
Regulatory Deferrals - Liabilities	316.7	291.5
Allowance for Uncollectible Accounts	26.5	21.5
Tax Effect - Tax Regulatory Liabilities	214.3	227.1
Net Operating Loss Carryforwards	0	0
Purchase Accounting Adjustment	0	0
Equity Method Wind Investments	0	0
Other	31.5	25
Total Deferred Tax Assets	672.5	631.9
Less: Valuation Allowance	0	0
Net Deferred Tax Assets	672.5	631.9
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	1,845.2	1,728.6
Property Tax Accruals	44.5	39.8
Regulatory Amounts:
Regulatory Deferrals - Assets	519.9	474.5
Tax Effect - Tax Regulatory Assets	10	10.5
Goodwill-related Regulatory Asset - 1999 Merger	58	61.9
Employee Benefits	175.4	146.7
Derivative Assets	0	0
Other	24.9	19.5
Total Deferred Tax Liabilities	2,677.9	2,481.5
PSNH
Deferred Tax Assets:
Employee Benefits	14.5	13
Derivative Liabilities	0	0
Regulatory Deferrals - Liabilities	19.6	23.8
Allowance for Uncollectible Accounts	3.8	3.9
Tax Effect - Tax Regulatory Liabilities	93.2	95.5
Net Operating Loss Carryforwards	1.5	0
Purchase Accounting Adjustment	0	0
Equity Method Wind Investments	0	0
Other	24.1	23.4
Total Deferred Tax Assets	156.7	159.6
Less: Valuation Allowance	0	0
Net Deferred Tax Assets	156.7	159.6
Deferred Tax Liabilities:
Accelerated Depreciation and Other   Plant-Related Differences	618.4	566.5
Property Tax Accruals	6.5	6.3
Regulatory Amounts:
Regulatory Deferrals - Assets	277.8	250.3
Tax Effect - Tax Regulatory Assets	9.4	8.3
Goodwill-related Regulatory Asset - 1999 Merger	0	0
Employee Benefits	23.5	16.8
Derivative Assets	0	0
Other	2.7	2.9
Total Deferred Tax Liabilities	$ 938.3	$ 851.1

INCOME TAXES - Tax Credits and

INCOME TAXES - Tax Credits and Loss Carryforwards (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net Operating Loss	$ 214.1	$ 243.4
Tax Credit	238.3	228.5
State Charitable Contribution	15.2	7.9
State and Local Jurisdiction | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	2,700	0
Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net Operating Loss	877.7	0
Tax Credit	404.1	0
Internal Revenue Service (IRS) | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	2,700	0
CL&P | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net Operating Loss	0	0
Tax Credit	157.7	157.5
State Charitable Contribution	0	0
CL&P | State and Local Jurisdiction | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	0	0
CL&P | Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net Operating Loss	0	0
Tax Credit	0	0
CL&P | Internal Revenue Service (IRS) | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	0	0
NSTAR Electric | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net Operating Loss	0	0
Tax Credit	0	0
State Charitable Contribution	0	0
NSTAR Electric | State and Local Jurisdiction | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	0	0
NSTAR Electric | Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net Operating Loss	0	0
Tax Credit	0	0
NSTAR Electric | Internal Revenue Service (IRS) | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	0	0
PSNH | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net Operating Loss	0	0
Tax Credit	0	0
State Charitable Contribution	0	0
PSNH | State and Local Jurisdiction | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	0	0
PSNH | Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net Operating Loss	7.1	0
Tax Credit	0	0
PSNH | Internal Revenue Service (IRS) | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax Credit	$ 0	$ 0

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Loss Carryforwards [Line Items]
Interest expense on uncertain tax positions	$ 1,300,000	$ 300,000	$ 0
Accrued interest payable	1,700,000	400,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Valuation allowance for tax credit and operating loss carryforward	558,200,000	104,100,000
State and Local Jurisdiction | CL&P
Operating Loss Carryforwards [Line Items]
Change in valuation allowance	23,500,000	17,300,000
Eversource | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Change in valuation allowance	$ 27,300,000	$ 21,300,000

INCOME TAXES - Schedule of Unre

INCOME TAXES - Schedule of Unrecognized Tax Benefits Roll Forward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Unrecognized Tax Benefits [Roll Forward]
Beginning Balance	$ 81.3	$ 67.1	$ 65.8
Gross Increases - Current Year	14.2	23.4	11.5
Gross Increases - Prior Year	11	0.1
Gross Decreases - Prior Year	(0.2)	(0.1)	(2.4)
Lapse of Statute of Limitations	(12.6)	(9.2)	(7.8)
Ending Balance	93.7	81.3	67.1
CL&P
Unrecognized Tax Benefits [Roll Forward]
Beginning Balance	25.8	25.5	26.2
Gross Increases - Current Year	2.9	4	3.5
Gross Increases - Prior Year	0	0.1
Gross Decreases - Prior Year	(0.2)	0	(0.9)
Lapse of Statute of Limitations	(6.6)	(3.8)	(3.3)
Ending Balance	$ 21.9	$ 25.8	$ 25.5

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Schedule of Reconciliation of Activity in Environmental Reserve (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	$ 128.2	$ 122.6
Additions	11	16.8
Payments/Reductions	(11.2)	(11.2)
Accrual for Environmental Loss Contingencies, Ending Balance	128	$ 128.2
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]		Other Current Liabilities, Other Long-Term Liabilities
CL&P
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	13.8	$ 13.9
Additions	0.8	2.6
Payments/Reductions	(1.2)	(2.7)
Accrual for Environmental Loss Contingencies, Ending Balance	13.4	13.8
NSTAR Electric
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	5.4	3.4
Additions	1.9	2.5
Payments/Reductions	(0.7)	(0.5)
Accrual for Environmental Loss Contingencies, Ending Balance	6.6	5.4
PSNH
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies, Beginning Balance	7.6	6.1
Additions	0.2	1.7
Payments/Reductions	(1.5)	(0.2)
Accrual for Environmental Loss Contingencies, Ending Balance	$ 6.3	$ 7.6

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Schedule of Number of Sites and Reserves (Details) - site	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Loss Contingencies [Line Items]
Number of Sites	65	65
CL&P
Loss Contingencies [Line Items]
Number of Sites	15	16
NSTAR Electric
Loss Contingencies [Line Items]
Number of Sites	14	12
PSNH
Loss Contingencies [Line Items]
Number of Sites	8	8

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES - Environmental Matters Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) site	Dec. 31, 2023 USD ($) site	Dec. 31, 2022 USD ($)
Loss Contingencies [Line Items]
Number of sites | site	65	65
Reserve	$ 128	$ 128.2	$ 122.6
NSTAR Electric
Loss Contingencies [Line Items]
Number of sites | site	14	12
Reserve	$ 6.6	$ 5.4	3.4
CL&P
Loss Contingencies [Line Items]
Number of sites | site	15	16
Reserve	$ 13.4	$ 13.8	13.9
PSNH
Loss Contingencies [Line Items]
Number of sites | site	8	8
Reserve	$ 6.3	$ 7.6	$ 6.1
MGP Site accrual
Loss Contingencies [Line Items]
Reserve balances related to former MGP sites	$ 115.9	$ 117.1
Environmental Site for Which a Range is Too Early to Determine
Loss Contingencies [Line Items]
Number of sites | site	17
Reserve	$ 30.7
Environmental Site for Which a Range is Too Early to Determine | NSTAR Electric
Loss Contingencies [Line Items]
Number of sites | site	2
Reserve	$ 1.4
Environmental Site for Which a Range is Too Early to Determine | CL&P
Loss Contingencies [Line Items]
Number of sites | site	9
Reserve	$ 5.7
Environmental Sites for Which a Range of Loss Exists
Loss Contingencies [Line Items]
Number of sites | site	8
Reserve	$ 29.5
Best estimate of potential remediation costs (up to)	$ 17.5
Evironmental Sites with Best Estimate
Loss Contingencies [Line Items]
Number of sites | site	40
Reserve	$ 67.8
Evironmental Sites with Best Estimate | NSTAR Electric
Loss Contingencies [Line Items]
Reserve	$ 5.2
Environmental site quantity remaining | site	11
Evironmental Sites with Best Estimate | CL&P
Loss Contingencies [Line Items]
Reserve	$ 7.7
Environmental site quantity remaining | site	6
Evironmental Sites with Best Estimate | PSNH
Loss Contingencies [Line Items]
Reserve	$ 6.3
Environmental site quantity remaining | site	8

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES - Schedule of Estimated Future Annual Costs of Long term Contractual Agreement (Details) $ in Millions	Dec. 31, 2024 USD ($)
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	$ 1,425
2026	1,400.7
2027	1,330.3
2028	1,273
2029	1,128.6
Thereafter	7,403.8
Total	13,961.4
Renewable Energy Purchase Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	771.8
2026	865.2
2027	919.9
2028	918
2029	785.5
Thereafter	6,289.9
Total	10,550.3
Natural Gas Procurement
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	532.6
2026	486.1
2027	364.6
2028	308.1
2029	294.9
Thereafter	1,004.4
Total	2,990.7
Capacity and Purchased Power
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	75.2
2026	2.9
2027	2.7
2028	2.7
2029	2.3
Thereafter	2.3
Total	88.1
Peaker CfDs
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	28.3
2026	27.7
2027	23.1
2028	23.3
2029	24.1
Thereafter	84.6
Total	211.1
Transmission Support Commitments
Transmission Support Commitments
2025	17.1
2026	18.8
2027	20
2028	20.9
2029	21.8
Thereafter	22.6
Total	121.2
CL&P
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	758.5
2026	707.1
2027	754.7
2028	756.1
2029	621.1
Thereafter	3,567.1
Total	7,164.6
CL&P | Renewable Energy Purchase Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	651
2026	671.9
2027	723.7
2028	724.5
2029	588.4
Thereafter	3,473.6
Total	6,833.1
CL&P | Capacity and Purchased Power
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	72.4
2026	0.1
2027	0
2028	0
2029	0
Thereafter	0
Total	72.5
CL&P | Peaker CfDs
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	28.3
2026	27.7
2027	23.1
2028	23.3
2029	24.1
Thereafter	84.6
Total	211.1
CL&P | Transmission Support Commitments
Transmission Support Commitments
2025	6.8
2026	7.4
2027	7.9
2028	8.3
2029	8.6
Thereafter	8.9
Total	47.9
NSTAR Electric
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	130.3
2026	203.5
2027	206.8
2028	204.4
2029	208
Thereafter	2,827.5
Total	3,780.5
NSTAR Electric | Renewable Energy Purchase Contracts
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	120.8
2026	193.3
2027	196.2
2028	193.5
2029	197.1
Thereafter	2,816.3
Total	3,717.2
NSTAR Electric | Capacity and Purchased Power
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
2025	2.8
2026	2.8
2027	2.7
2028	2.7
2029	2.3
Thereafter	2.3
Total	15.6
NSTAR Electric | Transmission Support Commitments
Transmission Support Commitments
2025	6.7
2026	7.4
2027	7.9
2028	8.2
2029	8.6
Thereafter	8.9
Total	47.7
PSNH | Transmission Support Commitments
Transmission Support Commitments
2025	3.6
2026	4
2027	4.2
2028	4.4
2029	4.6
Thereafter	4.8
Total	$ 25.6

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES - Long-Term Contractual Arrangement Narrative (Details) MWh in Millions, $ in Millions				12 Months Ended
	Nov. 22, 2019	Mar. 15, 2019	Dec. 28, 2018 MWh	Dec. 31, 2024 USD ($) contract MW
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts				$ 13,961.4
Peaker Contracts For Differences
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts				$ 211.1
Percentage of costs and benefits borne by United Illuminated Company				20%
Period of payment to generation facility owner				30 years
NSTAR Electric
Long-term Purchase Commitment [Line Items]
Contract term (in years)				20 years
Estimated cost of energy purchase contracts				$ 3,780.5
NSTAR Electric | Construction in Progress
Long-term Purchase Commitment [Line Items]
Total construction contract cost				2,600
NSTAR Electric | Minimum
Long-term Purchase Commitment [Line Items]
Estimated costs under construction contract				100
NSTAR Electric | Maximum
Long-term Purchase Commitment [Line Items]
Estimated costs under construction contract				200
CL&P
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts				7,164.6
CL&P | Peaker Contracts For Differences
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts				$ 211.1
Number of capacity contracts | contract				3
Amount of peaking capacity contracts (in MW) | MW				500
Percentage of costs and benefits borne				80%
CL&P, NSTAR Electric and PSNH | Transmission Support Commitments
Long-term Purchase Commitment [Line Items]
Period of payment of annual operation and maintenance expense				20 years
Vineyard Wind Project | NSTAR Electric
Long-term Purchase Commitment [Line Items]
Contract term (in years)				20 years
Millstone Nuclear Power Station and Seabrook Nuclear Power Plant
Long-term Purchase Commitment [Line Items]
Estimated cost of energy purchase contracts				$ 2,600
Milestone Nuclear Power Station
Long-term Purchase Commitment [Line Items]
Annual purchase requirement (in MWh) | MWh			9
Percent of the facility's output required to be purchased		50%
Milestone Nuclear Power Station | CL&P
Long-term Purchase Commitment [Line Items]
Contract term (in years)			10 years
Percent of the facility's output required to be purchased		40%
Milestone Nuclear Power Station | UI
Long-term Purchase Commitment [Line Items]
Contract term (in years)			10 years
Seabrook Nuclear Power Plant
Long-term Purchase Commitment [Line Items]
Percent of the facility's output required to be purchased	18%
Seabrook Nuclear Power Plant | CL&P
Long-term Purchase Commitment [Line Items]
Contract term (in years)			8 years
Percent of the facility's output required to be purchased	15%
Seabrook Nuclear Power Plant | UI
Long-term Purchase Commitment [Line Items]
Contract term (in years)			8 years

COMMITMENTS AND CONTINGENCIES_6

COMMITMENTS AND CONTINGENCIES - Schedule of Total Costs Incurred (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	$ 591.4	$ 581.4	$ 678.1
Natural Gas Procurement	695	695.8	1,042.8
Capacity and Purchased Power	70.5	69	61.6
Peaker CfDs	23.1	20.1	13.4
Transmission Support Commitments	16.7	14.2	12.7
CL&P
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	529	474.1	513.2
Capacity and Purchased Power	67.6	65.5	57.7
Peaker CfDs	23.1	20.1	13.4
Transmission Support Commitments	6.6	5.6	5
NSTAR Electric
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	62.4	60	90.8
Capacity and Purchased Power	2.9	2.9	3
Peaker CfDs	0	0	0
Transmission Support Commitments	6.6	5.6	5
PSNH
Long-term Purchase Commitment [Line Items]
Renewable Energy Purchase Contracts	0	47.3	74.1
Capacity and Purchased Power	0	0.6	0.9
Peaker CfDs	0	0	0
Transmission Support Commitments	$ 3.5	$ 3	$ 2.7

COMMITMENTS AND CONTINGENCIES_7

COMMITMENTS AND CONTINGENCIES - Spent Nuclear Fuel Obligations Narrative (Details) - Yankee Companies - USD ($) $ in Millions			1 Months Ended
	Jun. 08, 2022	Mar. 25, 2021	Sep. 30, 2024
Guarantor Obligations [Line Items]
Damages sought	$ 33.1	$ 120.4
Litigation settlement, amount awarded from other party			$ 145

COMMITMENTS AND CONTINGENCIES_8

COMMITMENTS AND CONTINGENCIES - Guarantees and Obligations Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2024	Sep. 30, 2024	Jul. 09, 2024	Feb. 13, 2024	Jan. 24, 2024	Dec. 31, 2023
Loss Contingencies [Line Items]
Fair value of guarantees	$ 1.2					$ 4.4
Maximum exposure		$ 850
South Fork Wind And Revolution Wind
Loss Contingencies [Line Items]
Ownership interest (in percent)		50%		50%
Sunrise Wind, LLC
Loss Contingencies [Line Items]
Ownership interest (in percent)			50%		50%

COMMITMENTS AND CONTINGENCIES_9

COMMITMENTS AND CONTINGENCIES - Schedule of Guarantees and Indemnifications (Details) $ in Millions	Jan. 24, 2025 USD ($)	Dec. 31, 2024 USD ($) letterOfCredit	Sep. 30, 2024 USD ($)	Jul. 09, 2024	Jan. 24, 2024	Dec. 31, 2023 USD ($)
Guarantor Obligations [Line Items]
Maximum exposure guarantee		$ 1.2				$ 4.4
Maximum Exposure			$ 850
Eversource Investment LLC | Letter of Credit
Guarantor Obligations [Line Items]
Maximum Exposure		5.3
Amount of long-term debt requested for issuance		$ 25
Revolution Wind
Guarantor Obligations [Line Items]
Number of letter of credit | letterOfCredit		1
Revolution Wind | Letter of Credit | Subsequent Event
Guarantor Obligations [Line Items]
Borrowings outstanding	$ 1
South Fork Wind, LLC
Guarantor Obligations [Line Items]
Number of letter of credit | letterOfCredit		2
Sunrise Wind, LLC
Guarantor Obligations [Line Items]
Ownership interest (in percent)				50%	50%
South Fork Wind, LLC
Guarantor Obligations [Line Items]
Maximum Exposure		$ 7.1
Ownership interest (in percent)		50%				50%
South Fork Class B Member, LLC
Guarantor Obligations [Line Items]
Ownership interest (in percent)		50%
North East Offshore, Revolution Wind, LLC and South Fork Wind, LLC
Guarantor Obligations [Line Items]
Ownership interest (in percent)		50%
Eversource Investment Services Company LLC
Guarantor Obligations [Line Items]
Maximum Exposure			$ 100
Eversource Investment LLC, Eversource Investment Service Company LLC and South Fork Class B Member, LLC
Guarantor Obligations [Line Items]
Maximum Exposure		$ 1,620
Tax Equity | Eversource TEI LLC
Guarantor Obligations [Line Items]
Maximum Exposure		50
Revolution Wind, LLC and TurbineCo, LLC | Offshore wind construction-related purchase agreements with third-party contractors
Guarantor Obligations [Line Items]
Maximum Exposure		357
Revolution Wind, LLC and TurbineCo, LLC | Performance Guarantee
Guarantor Obligations [Line Items]
Maximum Exposure		935.6
Eversource Investment LLC, Eversource Investment Service Company LLC and South Fork Class B Member, LLC | Funding and Indemnification Obligations
Guarantor Obligations [Line Items]
Maximum Exposure		277.5
Eversource Investment LLC | Letters of Credit
Guarantor Obligations [Line Items]
Maximum Exposure		5.3
Eversource TEI LLC | South Fork Wind Tax Equity
Guarantor Obligations [Line Items]
Maximum Exposure		50
South Fork Wind, LLC | Power Purchase Agreement Security
Guarantor Obligations [Line Items]
Maximum Exposure		7.1
Various Eversource subsidiaries | Surety Bonds
Guarantor Obligations [Line Items]
Maximum Exposure		$ 30.7

COMMITMENTS AND CONTINGENCIE_10

COMMITMENTS AND CONTINGENCIES - FERC ROE Complaints Narrative (Details) $ in Millions			12 Months Ended	30 Months Ended	36 Months Ended
	Oct. 16, 2018 complaint	Apr. 29, 2016 complaint	Dec. 31, 2024 USD ($)	Apr. 14, 2017	Oct. 15, 2014	Dec. 31, 2023 USD ($)	Jul. 31, 2014 complaint
Loss Contingencies [Line Items]
Percentage of base ROE reasonably justified	10.41%
Percentage of incentive cap on total ROE	13.08%
FERC ROE Complaints
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | complaint	4	4
Period of complaint			15 months
Basis point change			0.10%
Estimate of possible loss for each 10 basis point change to base ROE			$ 3
Complaint period			15 months
FERC ROE First, Second and Third Complaints
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | complaint							3
Base ROE percentage challenged by complainants			11.14%
Percentage of ROE for any incentive project	13.08%
FERC ROE First Complaint
Loss Contingencies [Line Items]
Percentage of ROE for any incentive project				11.74%
Refund payments			$ 38.9
FERC ROE Second Complaint
Loss Contingencies [Line Items]
Percentage of base ROE of complaint period			10.57%	10.57%
Percentage of ROE for any incentive project			11.74%
Loss contingency, estimate of possible earnings impact			$ 39.1
FERC ROE Fourth Complaint
Loss Contingencies [Line Items]
Percentage of base ROE of complaint period		10.57%
Maximum percentage cap of ROE for incentive projects		11.74%
Percentage of ROE for any incentive project			10.57%
Original base ROE authorized by FERC at time of complaint			11.74%
FERC MISO Complaints
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | complaint	2
CL&P | FERC ROE First Complaint
Loss Contingencies [Line Items]
Refund payments			$ 22.4
CL&P | FERC ROE Second Complaint
Loss Contingencies [Line Items]
Loss contingency, estimate of possible earnings impact			21.4			$ 21.4
NSTAR Electric | FERC ROE First Complaint
Loss Contingencies [Line Items]
Refund payments			13.7
NSTAR Electric | FERC ROE Second Complaint
Loss Contingencies [Line Items]
Loss contingency, estimate of possible earnings impact			14.6			14.6
PSNH | FERC ROE First Complaint
Loss Contingencies [Line Items]
Refund payments			2.8
PSNH | FERC ROE Second Complaint
Loss Contingencies [Line Items]
Loss contingency, estimate of possible earnings impact			$ 3.1			$ 3.1
Minimum | FERC ROE First, Second and Third Complaints
Loss Contingencies [Line Items]
Percentage of ROE for any incentive project					11.14%
Maximum | FERC ROE First, Second and Third Complaints
Loss Contingencies [Line Items]
Percentage of ROE for any incentive project					13.10%

LEASES - Narrative (Details)

LEASES - Narrative (Details)	12 Months Ended
	Dec. 31, 2024
Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years
CL&P | Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
CL&P | Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years
NSTAR Electric | Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
NSTAR Electric | Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years
PSNH | Minimum
Lessee, Lease, Description [Line Items]
Renewal period	1 year
PSNH | Maximum
Lessee, Lease, Description [Line Items]
Renewal period	20 years

LEASES - Components of Lease Co

LEASES - Components of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	$ 6.4	$ 4.8	$ 8.3
Interest on Lease Liabilities	2.7	2	2
Total Finance Lease Cost	9.1	6.8	10.3
Operating Lease Cost	15.2	11.4	11.6
Variable Lease Cost	18.3	69.2	78.1
Total Lease Cost	42.6	87.4	100
CL&P
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	1.7	0	0
Interest on Lease Liabilities	0.8	0	0
Total Finance Lease Cost	2.5	0	0
Operating Lease Cost	2.6	0.7	0.3
Variable Lease Cost	18.9	21.9	25.6
Total Lease Cost	24	22.6	25.9
NSTAR Electric
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	0.2	0.2	0.2
Interest on Lease Liabilities	0.6	0.6	0.6
Total Finance Lease Cost	0.8	0.8	0.8
Operating Lease Cost	5.3	3	2.3
Variable Lease Cost	0	0	0
Total Lease Cost	6.1	3.8	3.1
PSNH
Lease, Cost [Abstract]
Amortization of Right-of-use-Assets	0	0	0.1
Interest on Lease Liabilities	0	0	0
Total Finance Lease Cost	0	0	0.1
Operating Lease Cost	1.8	0.4	0.1
Variable Lease Cost	(0.6)
Variable Lease Cost		47.3	52.5
Total Lease Cost	$ 1.2	$ 47.7	$ 52.7

LEASES - Supplemental Balance S

LEASES - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Operating Leases:
Right-of-use-Assets, Net	$ 56.1	$ 53.5
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Assets	Other Long-Term Assets
Current Portion	$ 10.4	$ 9.5
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other Current Liabilities	Other Current Liabilities
Long-Term	$ 45.7	$ 44
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Liabilities	Other Long-Term Liabilities
Total Operating Lease Liabilities	$ 56.1	$ 53.5
Finance Leases:
Right-of-use-Assets, Net	$ 61.9	$ 68.6
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Current Portion	$ 5.6	$ 5.4
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other Current Liabilities	Other Current Liabilities
Long-Term	$ 62.1	$ 67.3
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Long-Term Liabilities	Other Long-Term Liabilities
Total Finance Lease Liabilities	$ 67.7	$ 72.7
CL&P
Operating Leases:
Right-of-use-Assets, Net	7.7	2.2
Current Portion	2.2	0.8
Long-Term	5.5	1.4
Total Operating Lease Liabilities	7.7	2.2
Finance Leases:
Right-of-use-Assets, Net	16.6	18.3
Current Portion	1.5	1.4
Long-Term	15.6	16.9
Total Finance Lease Liabilities	17.1	18.3
NSTAR Electric
Operating Leases:
Right-of-use-Assets, Net	29.4	27.7
Current Portion	3.7	2.2
Long-Term	25.7	25.5
Total Operating Lease Liabilities	29.4	27.7
Finance Leases:
Right-of-use-Assets, Net	2.8	3
Current Portion	0	0
Long-Term	4.9	4.9
Total Finance Lease Liabilities	4.9	4.9
PSNH
Operating Leases:
Right-of-use-Assets, Net	3.3	4.7
Current Portion	1.7	1.5
Long-Term	1.6	3.2
Total Operating Lease Liabilities	3.3	4.7
Finance Leases:
Right-of-use-Assets, Net	0	0
Current Portion	0	0
Long-Term	0	0
Total Finance Lease Liabilities	$ 0	$ 0

LEASES - Other Information Rela

LEASES - Other Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Weighted-Average Remaining Lease Term (Years):
Operating Leases	9 years	9 years
Finance Leases	12 years	13 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	4.10%	4%
Finance Leases	3.30%	3.30%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 14.5	$ 10.5	$ 11.3
Operating Cash Flows from Finance Leases	2.6	2	2
Financing Cash Flows from Finance Leases	5.2	3.9	3.9
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	15.3	12.8	18.9
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 0.3	$ 18.5	3.5
CL&P
Weighted-Average Remaining Lease Term (Years):
Operating Leases	4 years	4 years
Finance Leases	8 years	9 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	5.20%	5.20%
Finance Leases	5.30%	5.30%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 2.5	$ 0.7	0.3
Operating Cash Flows from Finance Leases	0.7	0	0
Financing Cash Flows from Finance Leases	1.2	0	0
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	7.8	0.6	2.4
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 0	$ 18.3	0
NSTAR Electric
Weighted-Average Remaining Lease Term (Years):
Operating Leases	12 years	13 years
Finance Leases	17 years	18 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	4.20%	4.20%
Finance Leases	2.90%	2.90%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 4.9	$ 2.5	2.1
Operating Cash Flows from Finance Leases	0.7	0.6	0.6
Financing Cash Flows from Finance Leases	0	0	0
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	5.7	7	0
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 0	$ 0	0
PSNH
Weighted-Average Remaining Lease Term (Years):
Operating Leases	2 years	3 years
Weighted-Average Discount Rate (Percentage):
Operating Leases	5.20%	5.20%
Finance Leases	0%	0%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities:
Operating Cash Flows from Operating Leases	$ 1.8	$ 0.4	0.1
Operating Cash Flows from Finance Leases	0	0	0
Financing Cash Flows from Finance Leases	0	0	0.1
Supplemental Non-Cash Information on Lease Liabilities:
Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities	0.3	5	0
Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities	$ 0	$ 0	$ 0

LEASES - Future Minimum Lease P

LEASES - Future Minimum Lease Payments under Long-Term Leases (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Operating Leases
2025	$ 12.5
2026	11
2027	7
2028	6.6
2029	4.5
Thereafter	26.2
Future lease payments	67.8
Less amount representing interest	11.7
Present value of future minimum lease payments	56.1	$ 53.5
Finance Leases
2025	8.3
2026	7.9
2027	7.9
2028	7.3
2029	7.3
Thereafter	50.5
Future lease payments	89.2
Less amount representing interest	21.5
Present value of future minimum lease payments	67.7	72.7
CL&P
Operating Leases
2025	2.6
2026	2.3
2027	1.8
2028	1.8
2029	0
Thereafter	0
Future lease payments	8.5
Less amount representing interest	0.8
Present value of future minimum lease payments	7.7	2.2
Finance Leases
2025	2.3
2026	2.4
2027	2.5
2028	2.6
2029	2.6
Thereafter	8.9
Future lease payments	21.3
Less amount representing interest	4.2
Present value of future minimum lease payments	17.1	18.3
NSTAR Electric
Operating Leases
2025	4.9
2026	4.9
2027	2.9
2028	2.6
2029	2.5
Thereafter	22.2
Future lease payments	40
Less amount representing interest	10.6
Present value of future minimum lease payments	29.4	27.7
Finance Leases
2025	0.7
2026	0.7
2027	0.7
2028	0.7
2029	0.7
Thereafter	10.2
Future lease payments	13.7
Less amount representing interest	8.8
Present value of future minimum lease payments	4.9	4.9
PSNH
Operating Leases
2025	1.9
2026	1.5
2027	0.1
2028	0
2029	0
Thereafter	0
Future lease payments	3.5
Less amount representing interest	0.2
Present value of future minimum lease payments	3.3	4.7
Finance Leases
Present value of future minimum lease payments	$ 0	$ 0

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	$ 155,568	$ 155,569
Rate Reduction Bonds	324,072	367,282
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	155,600	155,600
Long-Term Debt	26,704,800	24,413,500
Rate Reduction Bonds	367,300	410,500
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	123,800	122,200
Long-Term Debt	24,791,400	22,855,200
Rate Reduction Bonds	352,100	395,000
CL&P
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	116,200	116,200
CL&P | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	116,200	116,200
Long-Term Debt	5,111,100	4,814,400
Rate Reduction Bonds	0	0
CL&P | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	90,300	90,400
Long-Term Debt	4,705,800	4,572,000
CL&P | Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rate Reduction Bonds	0	0
NSTAR Electric
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	43,000	43,000
NSTAR Electric | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	43,000	43,000
Long-Term Debt	5,094,900	4,496,900
Rate Reduction Bonds	0	0
NSTAR Electric | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	33,500	31,800
Long-Term Debt	4,759,400	4,273,700
NSTAR Electric | Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rate Reduction Bonds	0	0
PSNH
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rate Reduction Bonds	324,072	367,282
PSNH | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	0	0
Long-Term Debt	1,732,100	1,431,600
Rate Reduction Bonds	367,300	410,500
PSNH | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred Stock Not Subject to Mandatory Redemption	0	0
Long-Term Debt	1,529,700	1,292,600
Rate Reduction Bonds	$ 352,100	$ 395,000

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Changes in AOCI By Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 14,173,892	$ 15,473,158	$ 14,599,844
Ending balance	15,039,387	14,173,892	15,473,158
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(33,737)	(39,421)	(42,275)
OCI Before Reclassifications	(2,500)	(8,800)
Amounts Reclassified from AOCI	9,700	14,500
Other Comprehensive Income/(Loss), Net of Tax	7,200	5,700
Ending balance	(26,472)	(33,737)	(39,421)
Qualified Cash Flow Hedging Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(400)	(400)
OCI Before Reclassifications	0	0
Amounts Reclassified from AOCI	0	0
Other Comprehensive Income/(Loss), Net of Tax	0	0
Ending balance	(400)	(400)	(400)
Unrealized Losses on Marketable Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	0	(1,200)
OCI Before Reclassifications		0
Amounts Reclassified from AOCI		1,200
Other Comprehensive Income/(Loss), Net of Tax		1,200
Ending balance		0	(1,200)
Defined Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(33,300)	(37,800)
OCI Before Reclassifications	(2,500)	(8,800)
Amounts Reclassified from AOCI	9,700	13,300
Other Comprehensive Income/(Loss), Net of Tax	7,200	4,500
Ending balance	$ (26,100)	$ (33,300)	$ (37,800)

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Equity [Abstract]
Related tax effect recognized in AOCI	$ 0.4	$ 4.9	$ 1.3

ACCUMULATED OTHER COMPREHENSI_5

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Amounts Reclassified From AOCI By Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax Effect	$ (424,664)	$ (159,684)	$ (453,574)
Other Income, Net	410,482	348,069	346,088
Net Income/(Loss) Attributable to Common Shareholders	811,653	(442,240)	1,404,875
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net Income/(Loss) Attributable to Common Shareholders	(9,700)	(14,500)	(7,000)
Unrealized Losses on Marketable Securities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax Effect	0	400	0
Other Income, Net	0	(1,600)	0
Net Income/(Loss) Attributable to Common Shareholders	0	(1,200)	0
Defined Benefit Plans | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax Effect	1,700	6,400	2,300
Total pre-tax amount	(11,400)	(19,700)	(9,300)
Net Income/(Loss) Attributable to Common Shareholders	(9,700)	(13,300)	(7,000)
Amortization of Actuarial Losses | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	(6,800)	(7,000)	(9,000)
Amortization of Prior Service Cost | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	(300)	(300)	(300)
Settlement Losses | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Income, Net	$ (4,300)	$ (12,400)	$ 0

DIVIDEND RESTRICTIONS (Details)

DIVIDEND RESTRICTIONS (Details) $ in Millions	Dec. 31, 2024 USD ($)
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.70
Retained earnings subject to restrictions	$ 3,930
CL&P
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.65
Retained earnings subject to restrictions	$ 2,820
NSTAR Electric
Schedule of Restrictions on Retained Earnings [Line Items]
Retained earnings subject to restrictions	$ 3,130
PSNH
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.65
Retained earnings subject to restrictions	$ 808.7
Yankee Gas
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.65
EGMA
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.65
Aquarion Water Company
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.65
NSTAR Gas
Schedule of Restrictions on Retained Earnings [Line Items]
Consolidated total debt to total capital ratio (as a percentage)	0.65

COMMON SHARES - Common Shares A

COMMON SHARES - Common Shares Authorized and Issued (Details) - $ / shares	Dec. 31, 2024	Dec. 31, 2023	May 03, 2023	May 02, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 5	$ 5			$ 5
Authorized (in shares)	410,000,000	410,000,000	410,000,000	380,000,000
Issued (in shares)	375,724,367	359,984,073
CL&P
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 10	$ 10
Authorized (in shares)	24,500,000	24,500,000
Issued (in shares)	6,035,205	6,035,205
NSTAR Electric
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 1	$ 1
Authorized (in shares)	100,000,000	100,000,000
Issued (in shares)	200	200
PSNH
Class of Stock [Line Items]
Per share par value (in dollars per share)	$ 1	$ 1
Authorized (in shares)	100,000,000	100,000,000
Issued (in shares)	301	301

COMMON SHARES - Narrative (Deta

COMMON SHARES - Narrative (Details) - USD ($) $ in Thousands			12 Months Ended
	Oct. 03, 2022	May 11, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	May 03, 2023	May 02, 2023	Dec. 31, 2021
Class of Stock [Line Items]
Maximum amount of stock to be issued		$ 1,200,000
Equity offering (in shares)			15,740,294	0
Consideration received from sale of stock			$ 989,400
Treasury stock, common (in shares)			9,116,315	10,443,807
Common stock outstanding (in shares)			366,608,052	349,540,266
Issuance of treasury shares for acquisition	$ 72,100				$ 72,133
Authorized (in shares)			410,000,000	410,000,000		410,000,000	380,000,000
Common Shares
Class of Stock [Line Items]
Common stock outstanding (in shares)			366,608,052	349,540,266	348,443,855			344,403,196
Issuance of treasury shares for acquisition (in shares)	925,264				925,264

PREFERRED STOCK NOT SUBJECT T_3

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Narrative (Details)	Dec. 31, 2024 $ / shares shares
CL&P
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares) | shares	9,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 50
NSTAR Electric
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares) | shares	2,890,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 100

PREFERRED STOCK NOT SUBJECT T_4

PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Schedule of Preferred Stock by Class (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Preferred stock value outstanding	$ 155.6	$ 155.6
CL&P
Class of Stock [Line Items]
Shares outstanding (in shares)	2,324,000	2,324,000
Preferred stock value outstanding	$ 116.2	$ 116.2
CL&P | Series of 1947 Preferred Stock at $1.90
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 1,900,000	$ 1,900,000
Redemption Price Per Share (in dollars per share)	$ 52.50
Shares outstanding (in shares)	163,912	163,912
Preferred stock value outstanding	$ 8.2	$ 8.2
CL&P | Series of 1947 Preferred Stock at $2.00
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,000,000	$ 2,000,000
Redemption Price Per Share (in dollars per share)	$ 54
Shares outstanding (in shares)	336,088	336,088
Preferred stock value outstanding	$ 16.8	$ 16.8
CL&P | Series of 1949 Preferred Stock at $2.04
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,040,000	$ 2,040,000
Redemption Price Per Share (in dollars per share)	$ 52
Shares outstanding (in shares)	100,000	100,000
Preferred stock value outstanding	$ 5	$ 5
CL&P | Series of 1949 Preferred Stock at $2.20
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,200,000	$ 2,200,000
Redemption Price Per Share (in dollars per share)	$ 52.50
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
CL&P | Series of 1949 Preferred Stock at 3.90%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	3.90%	3.90%
Redemption Price Per Share (in dollars per share)	$ 50.50
Shares outstanding (in shares)	160,000	160,000
Preferred stock value outstanding	$ 8	$ 8
CL&P | Series E of 1954 Preferred Stock at $2.06
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,060,000	$ 2,060,000
Redemption Price Per Share (in dollars per share)	$ 51
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
CL&P | Series F of 1955 Preferred Stock at $2.09
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 2,090,000	$ 2,090,000
Redemption Price Per Share (in dollars per share)	$ 51
Shares outstanding (in shares)	100,000	100,000
Preferred stock value outstanding	$ 5	$ 5
CL&P | Series of 1956 Preferred Stock at 4.5%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.50%	4.50%
Redemption Price Per Share (in dollars per share)	$ 50.75
Shares outstanding (in shares)	104,000	104,000
Preferred stock value outstanding	$ 5.2	$ 5.2
CL&P | Series of 1958 Preferred Stock at 4.96%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.96%	4.96%
Redemption Price Per Share (in dollars per share)	$ 50.50
Shares outstanding (in shares)	100,000	100,000
Preferred stock value outstanding	$ 5	$ 5
CL&P | Series of 1963 Preferred Stock at 4.5%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.50%	4.50%
Redemption Price Per Share (in dollars per share)	$ 50.50
Shares outstanding (in shares)	160,000	160,000
Preferred stock value outstanding	$ 8	$ 8
CL&P | Series of 1967 Preferred Stock at 5.28%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	5.28%	5.28%
Redemption Price Per Share (in dollars per share)	$ 51.43
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
CL&P | Series G of 1968 Preferred Stock at $3.24
Class of Stock [Line Items]
Preferred stock, dividend rate, per-dollar-amount (in dollars per share)	$ 3,240,000	$ 3,240,000
Redemption Price Per Share (in dollars per share)	$ 51.84
Shares outstanding (in shares)	300,000	300,000
Preferred stock value outstanding	$ 15	$ 15
CL&P | Series of 1968 Preferred Stock at 6.56%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	6.56%	6.56%
Redemption Price Per Share (in dollars per share)	$ 51.44
Shares outstanding (in shares)	200,000	200,000
Preferred stock value outstanding	$ 10	$ 10
NSTAR Electric
Class of Stock [Line Items]
Shares outstanding (in shares)	430,000	430,000
Preferred stock value outstanding	$ 43	$ 43
NSTAR Electric | Preferred Stock 4.25%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.25%	4.25%
Redemption Price Per Share (in dollars per share)	$ 103.625
Shares outstanding (in shares)	180,000	180,000
Preferred stock value outstanding	$ 18	$ 18
NSTAR Electric | Preferred Stock 4.78%
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percentage)	4.78%	4.78%
Redemption Price Per Share (in dollars per share)	$ 102.80
Shares outstanding (in shares)	250,000	250,000
Preferred stock value outstanding	$ 25	$ 25
Fair Value Adjustment | NSTAR Electric
Class of Stock [Line Items]
Preferred stock value outstanding	$ 3.6	$ 3.6

COMMON SHAREHOLDERS' EQUITY A_2

COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Noncontrolling Interest [Line Items]
Dividends on preferred stock	$ 7,519	$ 7,519	$ 7,519
Noncontrolling interest - preferred stock of subsidiaries	155,568	155,569
CL&P and NSTAR Electric
Noncontrolling Interest [Line Items]
Dividends on preferred stock	$ 7,500	$ 7,500	$ 7,500

EARNINGS_(LOSS) PER SHARE - Nar

EARNINGS/(LOSS) PER SHARE - Narrative (Details) - shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Antidilutive share awards excluded from the EPS computation (in shares)	0	0	0

EARNINGS_(LOSS) PER SHARE - Com

EARNINGS/(LOSS) PER SHARE - Components of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Income/(Loss) Attributable to Common Shareholders	$ 811,653	$ (442,240)	$ 1,404,875
Weighted Average Common Shares Outstanding:
Basic (in shares)	357,482,965	349,580,638	346,783,444
Weighted Average Number of Shares Outstanding, Diluted, Adjustment [Abstract]
Share-Based Compensation Awards and Other (in shares)	296,443	259,843	463,324
Diluted (in shares)	357,779,408	349,840,481	347,246,768
Basic Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.27)	$ 4.05
Diluted Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.26)	$ 4.05

REVENUES - Operating Revenues D

REVENUES - Operating Revenues Disaggregated by Revenue Source (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	$ 11,801,800	$ 11,890,600	$ 12,270,200
Alternative Revenue Programs	74,900	(6,000)	5,300
Other Revenues	24,100	26,100	13,800
Operating Revenues	11,900,809	11,910,705	12,289,336
Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	6,184,300	6,344,300	6,142,700
Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,623,900	3,595,900	3,614,200
Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	543,800	524,000	559,200
Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	10,352,000	10,464,200	10,316,100
Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	503,100	467,000	436,000
Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	825,000	835,600	1,335,500
Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	123,600	119,500	110,600
Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(1,900)	4,300	72,000
CL&P
Disaggregation of Revenue [Line Items]
Operating Revenues	4,614,977	4,578,804	4,817,744
NSTAR Electric
Disaggregation of Revenue [Line Items]
Operating Revenues	3,720,877	3,515,539	3,583,070
PSNH
Disaggregation of Revenue [Line Items]
Operating Revenues	1,294,493	1,447,873	1,474,799
Operating Segments | Electric Distribution
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	9,018,200	9,007,400	9,409,500
Alternative Revenue Programs	28,700	(54,300)	(15,400)
Other Revenues	19,600	20,400	11,200
Operating Revenues	9,066,500	8,973,500	9,405,300
Operating Segments | Electric Distribution | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,904,800	5,054,200	4,796,100
Operating Segments | Electric Distribution | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,973,300	2,893,200	2,903,300
Operating Segments | Electric Distribution | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	389,000	352,400	374,900
Operating Segments | Electric Distribution | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	8,267,100	8,299,800	8,074,300
Operating Segments | Electric Distribution | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Distribution | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	658,900	625,000	1,190,900
Operating Segments | Electric Distribution | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	92,200	82,600	72,300
Operating Segments | Electric Distribution | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	72,000
Operating Segments | Natural Gas Distribution
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,056,600	2,182,200	2,199,500
Alternative Revenue Programs	44,500	35,500	14,800
Other Revenues	2,800	4,000	1,300
Operating Revenues	2,103,900	2,221,700	2,215,600
Operating Segments | Natural Gas Distribution | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,129,100	1,145,400	1,204,900
Operating Segments | Natural Gas Distribution | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	588,000	637,700	648,500
Operating Segments | Natural Gas Distribution | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	172,500	186,800	199,700
Operating Segments | Natural Gas Distribution | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,889,600	1,969,900	2,053,100
Operating Segments | Natural Gas Distribution | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Natural Gas Distribution | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	161,900	206,700	140,800
Operating Segments | Natural Gas Distribution | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	5,100	5,600	5,600
Operating Segments | Natural Gas Distribution | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,046,300	1,796,400	1,715,300
Alternative Revenue Programs	74,200	118,900	92,700
Other Revenues	500	600	700
Operating Revenues	2,121,000	1,915,900	1,808,700
Operating Segments | Electric Transmission | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,032,400	1,777,500	1,700,500
Operating Segments | Electric Transmission | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Electric Transmission | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	13,900	14,600	14,100
Operating Segments | Electric Transmission | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	4,300	700
Operating Segments | Water Distribution
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	233,400	231,000	224,400
Alternative Revenue Programs	(5,300)	400	(2,500)
Other Revenues	1,200	1,100	600
Operating Revenues	229,300	232,500	222,500
Operating Segments | Water Distribution | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	150,400	144,700	141,700
Operating Segments | Water Distribution | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	70,300	69,800	66,500
Operating Segments | Water Distribution | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,700	4,500	4,700
Operating Segments | Water Distribution | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	225,400	219,000	212,900
Operating Segments | Water Distribution | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | Water Distribution | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,200	3,900	3,800
Operating Segments | Water Distribution | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	5,700	8,100	8,400
Operating Segments | Water Distribution | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(1,900)	0	(700)
Operating Segments | CL&P
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	5,222,100	5,077,600	5,343,200
Alternative Revenue Programs	45,400	66,800	56,500
Other Revenues	9,000	9,600	1,800
Operating Segments | CL&P | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,493,700	2,597,800	2,397,200
Operating Segments | CL&P | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,164,800	1,082,100	1,067,900
Operating Segments | CL&P | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	164,200	137,200	146,400
Operating Segments | CL&P | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,822,700	3,817,100	3,611,500
Operating Segments | CL&P | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	870,800	794,700	755,100
Operating Segments | CL&P | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	491,900	429,100	873,700
Operating Segments | CL&P | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	36,700	32,400	30,200
Operating Segments | CL&P | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	4,300	72,700
Operating Segments | NSTAR Electric
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,332,000	4,129,400	4,127,300
Alternative Revenue Programs	36,700	(52,000)	700
Other Revenues	8,500	8,400	7,200
Operating Segments | NSTAR Electric | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,771,800	1,691,000	1,601,800
Operating Segments | NSTAR Electric | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,466,700	1,442,300	1,457,400
Operating Segments | NSTAR Electric | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	118,100	123,200	135,800
Operating Segments | NSTAR Electric | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,356,600	3,256,500	3,195,000
Operating Segments | NSTAR Electric | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	794,100	692,000	670,400
Operating Segments | NSTAR Electric | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	131,100	131,800	215,000
Operating Segments | NSTAR Electric | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	50,200	49,100	46,900
Operating Segments | NSTAR Electric | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Operating Segments | PSNH
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,514,200	1,600,000	1,659,600
Alternative Revenue Programs	20,800	49,800	20,100
Other Revenues	2,600	3,000	2,900
Operating Segments | PSNH | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	639,300	765,400	797,100
Operating Segments | PSNH | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	343,600	369,600	380,800
Operating Segments | PSNH | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	106,700	92,000	92,700
Operating Segments | PSNH | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,089,600	1,227,000	1,270,600
Operating Segments | PSNH | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	367,500	290,800	275,000
Operating Segments | PSNH | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	35,900	64,100	102,200
Operating Segments | PSNH | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	21,200	18,100	11,800
Operating Segments | PSNH | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,701,300	1,636,600	1,435,500
Alternative Revenue Programs	0	0	0
Other Revenues	0	0	0
Operating Revenues	1,701,300	1,636,600	1,435,500
Other | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Other | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,701,300	1,636,600	1,435,500
Other | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Eliminations
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(3,254,000)	(2,963,000)	(2,714,000)
Alternative Revenue Programs	(67,200)	(106,500)	(84,300)
Other Revenues	0	0	0
Operating Revenues	(3,321,200)	(3,069,500)	(2,798,300)
Eliminations | Residential
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Eliminations | Commercial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(7,700)	(4,800)	(4,100)
Eliminations | Industrial
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(22,400)	(19,700)	(20,100)
Eliminations | Total Retail Tariff Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(30,100)	(24,500)	(24,200)
Eliminations | Wholesale Transmission Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(1,529,300)	(1,310,500)	(1,264,500)
Eliminations | Wholesale Market Sales Revenues
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Eliminations | Other Revenues from Contracts with Customers
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	(1,694,600)	(1,628,000)	(1,425,300)
Eliminations | Reserve for Revenues Subject to Refund
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0	0
Consolidations Eliminations | CL&P
Disaggregation of Revenue [Line Items]
Operating Revenues	(661,500)	(575,200)	(583,800)
Consolidations Eliminations | NSTAR Electric
Disaggregation of Revenue [Line Items]
Operating Revenues	(656,300)	(570,300)	(552,100)
Consolidations Eliminations | PSNH
Disaggregation of Revenue [Line Items]
Operating Revenues	$ (243,100)	$ (204,900)	$ (207,800)

REVENUES - Narrative (Details)

REVENUES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Revenue	$ 11,801,800	$ 11,890,600	$ 12,270,200
Loss related to litigation settlement	0	0	(72,041)
Lease revenue	$ 2,500	$ 4,600	$ 4,000
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Income, Net	Other Income, Net	Other Income, Net
CL&P
Loss Contingencies [Line Items]
Loss related to litigation settlement	$ 0	$ 0	$ (72,041)
Lease revenue	500	700	800
NSTAR Electric
Loss Contingencies [Line Items]
Lease revenue	1,200	2,500	2,500
Reserve for Revenues Subject to Refund
Loss Contingencies [Line Items]
Revenue	(1,900)	4,300	72,000
Operating Segments | CL&P
Loss Contingencies [Line Items]
Revenue	5,222,100	5,077,600	5,343,200
Operating Segments | NSTAR Electric
Loss Contingencies [Line Items]
Revenue	4,332,000	4,129,400	4,127,300
Operating Segments | Reserve for Revenues Subject to Refund | CL&P
Loss Contingencies [Line Items]
Revenue	0	4,300	72,700
Operating Segments | Reserve for Revenues Subject to Refund | NSTAR Electric
Loss Contingencies [Line Items]
Revenue	$ 0	$ 0	$ 0
Unfavorable Regulatory Action | Operating Segments | Reserve for Revenues Subject to Refund | CL&P
Loss Contingencies [Line Items]
Revenue				$ 93,400

SEGMENT INFORMATION - Narrative

SEGMENT INFORMATION - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) reportableSegment
Segment Reporting Information [Line Items]
Number of reportable segments	1
Yankee Gas, NSTAR Gas and EGMA
Segment Reporting Information [Line Items]
Amount of natural gas transmission purchased | $	$ 77.7
CL&P
Segment Reporting Information [Line Items]
Number of reportable segments	1
NSTAR Electric
Segment Reporting Information [Line Items]
Number of reportable segments	1
PSNH
Segment Reporting Information [Line Items]
Number of reportable segments	1

SEGMENT INFORMATION - Schedule

SEGMENT INFORMATION - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Operating Revenues			$ 11,900,809	$ 11,910,705	$ 12,289,336
Depreciation and Amortization			(1,776,400)	(815,700)	(1,643,100)
Operations, Excluding Storm Costs
Corporate Shared Services, (General and Administrative)
Storm Costs
Employee Benefits
Uncollectible Expense
Operations and Maintenance			(2,012,926)	(1,895,703)	(1,865,328)
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2)			(5,405,800)	(6,800,000)	(6,582,700)
Loss on Pending Sale of Aquarion			(297,000)	0	0
Operating Income			2,408,709	2,399,335	2,198,154
Interest Expense			(1,111,336)	(855,441)	(678,274)
Loss on Offshore Wind Investments	$ (1,766,000)	$ (401,000)	(464,019)	(2,167,000)	0
Interest Income			138,200	94,200	50,500
Other Income/(Loss), Net			272,300	253,900	295,600
Income Tax (Expense)/Benefit			(424,664)	(159,684)	(453,574)
Net Income/(Loss)			819,172	(434,721)	1,412,394
Net Income Attributable to Noncontrolling Interests			(7,519)	(7,519)	(7,519)
Net Income Attributable to Common Shareholders			811,653	(442,240)	1,404,875
Total Assets (as of)	55,612,245		59,594,529	55,612,245
Cash Flows Used for Investments in Plant			4,480,500	4,336,800	3,441,900
CL&P
Segment Reporting Information [Line Items]
Operating Revenues			4,614,977	4,578,804	4,817,744
Operations and Maintenance			(815,345)	(733,287)	(707,162)
Operating Income			860,470	821,443	790,214
Interest Expense			(231,004)	(193,361)	(169,348)
Income Tax (Expense)/Benefit			(194,459)	(170,909)	(171,198)
Total Assets (as of)	15,849,624		16,839,845	15,849,624
NSTAR Electric
Segment Reporting Information [Line Items]
Operating Revenues			3,720,877	3,515,539	3,583,070
Operations and Maintenance			(735,019)	(668,466)	(640,834)
Operating Income			858,318	722,649	652,636
Interest Expense			(222,794)	(189,254)	(162,892)
Income Tax (Expense)/Benefit			(190,576)	(152,996)	(139,977)
Total Assets (as of)	16,271,513		18,075,248	16,271,513
PSNH
Segment Reporting Information [Line Items]
Operating Revenues			1,294,493	1,447,873	1,474,799
Operations and Maintenance			(288,342)	(284,442)	(255,991)
Operating Income			331,775	300,862	249,766
Interest Expense			(77,770)	(72,786)	(59,548)
Income Tax (Expense)/Benefit			(70,245)	(59,014)	(51,314)
Total Assets (as of)	5,993,451		6,641,941	5,993,451
Operating Segments | Electric Distribution
Segment Reporting Information [Line Items]
Operating Revenues			9,066,500	8,973,500	9,405,300
Depreciation and Amortization			(934,700)	(18,200)	(970,400)
Operations, Excluding Storm Costs			(447,300)	(418,200)	(416,000)
Corporate Shared Services, (General and Administrative)			(457,100)	(397,200)	(371,000)
Storm Costs			(76,800)	(71,100)	(74,400)
Employee Benefits			(202,500)	(175,600)	(189,600)
Uncollectible Expense			(182,800)	(161,900)	(107,300)
Other			(135,900)	(167,900)	(153,000)
Operations and Maintenance			(1,502,400)	(1,391,900)	(1,311,300)
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2)			(5,685,300)	(6,712,700)	(6,352,400)
Loss on Pending Sale of Aquarion			0
Operating Income			944,100	850,700	771,200
Interest Expense			(359,100)	(291,700)	(253,100)
Loss on Offshore Wind Investments			0	0
Interest Income			114,600	74,500	45,100
Other Income/(Loss), Net			134,700	136,200	180,400
Income Tax (Expense)/Benefit			(198,000)	(157,100)	(146,200)
Net Income/(Loss)			636,300	612,600	597,400
Net Income Attributable to Noncontrolling Interests			(4,600)	(4,600)	(4,600)
Net Income Attributable to Common Shareholders			631,700	608,000	592,800
Total Assets (as of)	29,426,400		32,031,900	29,426,400
Cash Flows Used for Investments in Plant			1,807,400	1,668,100	1,172,600
Operating Segments | Natural Gas Distribution
Segment Reporting Information [Line Items]
Operating Revenues			2,103,900	2,221,700	2,215,600
Depreciation and Amortization			(216,600)	(214,200)	(157,600)
Operations, Excluding Storm Costs			(180,900)	(172,800)	(182,500)
Corporate Shared Services, (General and Administrative)			(106,100)	(103,000)	(109,800)
Storm Costs			0	0	0
Employee Benefits			(76,900)	(76,600)	(79,800)
Uncollectible Expense			(48,400)	(64,800)	(36,000)
Other			(29,200)	(27,500)	(30,300)
Operations and Maintenance			(441,500)	(444,700)	(438,400)
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2)			(1,007,100)	(1,217,900)	(1,288,600)
Loss on Pending Sale of Aquarion			0
Operating Income			438,700	344,900	331,000
Interest Expense			(99,200)	(85,700)	(71,400)
Loss on Offshore Wind Investments			0	0
Interest Income			23,200	18,200	10,200
Other Income/(Loss), Net			22,400	20,400	33,600
Income Tax (Expense)/Benefit			(94,100)	(73,000)	(69,200)
Net Income/(Loss)			291,000	224,800	234,200
Net Income Attributable to Noncontrolling Interests			0	0	0
Net Income Attributable to Common Shareholders			291,000	224,800	234,200
Total Assets (as of)	8,775,300		9,786,700	8,775,300
Cash Flows Used for Investments in Plant			934,500	844,100	710,300
Operating Segments | Electric Transmission
Segment Reporting Information [Line Items]
Operating Revenues			2,121,000	1,915,900	1,808,700
Depreciation and Amortization			(405,100)	(371,200)	(337,400)
Operations, Excluding Storm Costs			(135,100)	(124,700)	(117,700)
Corporate Shared Services, (General and Administrative)			(74,600)	(62,500)	(58,400)
Storm Costs			0	(1,300)	(100)
Employee Benefits			(52,700)	(46,100)	(39,600)
Uncollectible Expense			0	0	0
Other			(71,100)	(57,400)	(72,600)
Operations and Maintenance			(333,500)	(292,000)	(288,400)
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2)			(276,000)	(258,500)	(260,000)
Loss on Pending Sale of Aquarion			0
Operating Income			1,106,400	994,200	922,900
Interest Expense			(172,400)	(163,700)	(145,500)
Loss on Offshore Wind Investments			0	0
Interest Income			300	400	500
Other Income/(Loss), Net			50,500	41,200	37,900
Income Tax (Expense)/Benefit			(257,300)	(225,800)	(216,300)
Net Income/(Loss)			727,500	646,300	599,500
Net Income Attributable to Noncontrolling Interests			(2,900)	(2,900)	(2,900)
Net Income Attributable to Common Shareholders			724,600	643,400	596,600
Total Assets (as of)	14,806,500		16,070,900	14,806,500
Cash Flows Used for Investments in Plant			1,343,300	1,406,300	1,144,000
Operating Segments | Water Distribution
Segment Reporting Information [Line Items]
Operating Revenues			229,300	232,500	222,500
Depreciation and Amortization			(32,300)	(56,000)	(50,900)
Operations, Excluding Storm Costs
Corporate Shared Services, (General and Administrative)
Storm Costs
Employee Benefits
Uncollectible Expense
Operations and Maintenance			(98,700)	(93,200)	(88,400)
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2)			(26,300)	(23,900)	(23,400)
Loss on Pending Sale of Aquarion			(297,000)
Operating Income			(225,000)	59,400	59,800
Interest Expense			(36,200)	(38,500)	(34,700)
Loss on Offshore Wind Investments			0	0
Interest Income			100	0	0
Other Income/(Loss), Net			7,200	5,900	8,500
Income Tax (Expense)/Benefit			200	6,300	3,200
Net Income/(Loss)			(253,700)	33,100	36,800
Net Income Attributable to Noncontrolling Interests			0	0	0
Net Income Attributable to Common Shareholders			(253,700)	33,100	36,800
Total Assets (as of)	2,944,800		2,515,800	2,944,800
Cash Flows Used for Investments in Plant			161,800	167,000	154,400
Other
Segment Reporting Information [Line Items]
Operating Revenues			1,701,300	1,636,600	1,435,500
Depreciation and Amortization			(198,700)	(158,800)	(132,600)
Operations, Excluding Storm Costs
Corporate Shared Services, (General and Administrative)
Storm Costs
Employee Benefits
Uncollectible Expense
Operations and Maintenance			(1,350,500)	(1,325,600)	(1,184,600)
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2)			(7,600)	(4,200)	(4,500)
Loss on Pending Sale of Aquarion			0
Operating Income			144,500	148,000	113,800
Interest Expense			(662,700)	(425,300)	(247,800)
Loss on Offshore Wind Investments			(464,000)	(2,167,000)
Interest Income			218,300	150,600	66,300
Other Income/(Loss), Net			1,416,900	(261,800)	1,600,800
Income Tax (Expense)/Benefit			124,500	289,900	(25,100)
Net Income/(Loss)			777,500	(2,265,600)	1,508,000
Net Income Attributable to Noncontrolling Interests			0	0	0
Net Income Attributable to Common Shareholders			777,500	(2,265,600)	1,508,000
Total Assets (as of)	26,337,700		29,041,100	26,337,700
Cash Flows Used for Investments in Plant			233,500	251,300	260,600
Eliminations
Segment Reporting Information [Line Items]
Operating Revenues			(3,321,200)	(3,069,500)	(2,798,300)
Depreciation and Amortization			11,000	2,700	5,800
Operations, Excluding Storm Costs
Corporate Shared Services, (General and Administrative)
Storm Costs
Employee Benefits
Uncollectible Expense
Operations and Maintenance			1,713,700	1,651,700	1,445,800
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (2)			1,596,500	1,417,200	1,346,200
Loss on Pending Sale of Aquarion			0
Operating Income			0	2,100	(500)
Interest Expense			218,300	149,500	74,200
Loss on Offshore Wind Investments			0	0
Interest Income			(218,300)	(149,500)	(71,600)
Other Income/(Loss), Net			(1,359,400)	312,000	(1,565,600)
Income Tax (Expense)/Benefit			0	0	0
Net Income/(Loss)			(1,359,400)	314,100	(1,563,500)
Net Income Attributable to Noncontrolling Interests			0	0	0
Net Income Attributable to Common Shareholders			(1,359,400)	314,100	(1,563,500)
Total Assets (as of)	$ (26,678,500)		(29,851,900)	(26,678,500)
Cash Flows Used for Investments in Plant			$ 0	$ 0	$ 0

Assets Held For Sale - Narrativ

Assets Held For Sale - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Jan. 27, 2025	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income Tax Benefit			$ 424,664	$ 159,684	$ 453,574
Disposal Group, Held-for-Sale, Not Discontinued Operations | Aquarion
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill, impairment loss		$ 297,000
Income Tax Benefit		$ 140,000
Disposal group, including discontinued operation, pre-tax income			$ 43,100	$ 26,800	$ 33,600
Disposal Group, Held-for-Sale, Not Discontinued Operations | Aquarion | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of business	$ 2,400,000
Disposal group, including discontinued operation, equity	1,600,000
Disposal group, including discontinues operation, debt	$ 800,000

Assets Held For Sale - Disposal

Assets Held For Sale - Disposal Groups, Including Discontinued Operations (Details) - Aquarion - Disposal Group, Held-for-Sale, Not Discontinued Operations $ in Millions	Dec. 31, 2024 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restricted Cash	$ 5.8
Receivables, Net	14.4
Unbilled Revenues	11.5
Prepayments and Other Current Assets	24.6
Total Current Assets Held for Sale	56.3
Property, Plant and Equipment, Net	1,885.2
Regulatory Assets	51.2
Goodwill	662.5
Other Long-Term Assets	12.2
Total Long-Term Assets Held for Sale	2,611.1
Accounts Payable	24.2
Other Current Liabilities	28.4
Current Liabilities Held for Sale	52.6
Regulatory Liabilities	132.2
Other Long-Term Liabilities	266.7
Total Long-Term Liabilities Held for Sale	$ 398.9

GOODWILL - Summary of Goodwill

GOODWILL - Summary of Goodwill by Reportable Segment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 4,532,100	$ 4,522,600
Goodwill, Rounding	3,571,400
Ending Balance	3,571,333	4,532,100
Water Acquisitions
Goodwill [Roll Forward]
Water Acquisitions		9,500
Water Sale and Acquisition, net	(1,200)
Water Goodwill Impairment	(297,000)
Water Goodwill Reclassified as Held for Sale	(662,500)
Electric Distribution
Goodwill [Roll Forward]
Beginning Balance	2,543,600	2,543,600
Ending Balance	2,543,600	2,543,600
Electric Distribution | Water Acquisitions
Goodwill [Roll Forward]
Water Acquisitions		0
Water Sale and Acquisition, net	0
Water Goodwill Impairment	0
Water Goodwill Reclassified as Held for Sale	0
Electric Transmission
Goodwill [Roll Forward]
Beginning Balance	576,800	576,800
Ending Balance	576,800	576,800
Electric Transmission | Water Acquisitions
Goodwill [Roll Forward]
Water Acquisitions		0
Water Sale and Acquisition, net	0
Water Goodwill Impairment	0
Water Goodwill Reclassified as Held for Sale	0
Natural Gas Distribution
Goodwill [Roll Forward]
Beginning Balance	451,000	451,000
Ending Balance	451,000	451,000
Natural Gas Distribution | Water Acquisitions
Goodwill [Roll Forward]
Water Acquisitions		0
Water Sale and Acquisition, net	0
Water Goodwill Impairment	0
Water Goodwill Reclassified as Held for Sale	0
Water Distribution
Goodwill [Roll Forward]
Beginning Balance	960,700	951,200
Water Acquisitions	4,200
Ending Balance	0	960,700
Water Distribution | Water Acquisitions
Goodwill [Roll Forward]
Water Acquisitions	9,500	$ 9,500
Water Sale and Acquisition, net	(1,200)
Water Goodwill Impairment	(297,000)
Water Goodwill Reclassified as Held for Sale	$ (662,500)

GOODWILL - Narrative (Details)

GOODWILL - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) acquistion	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Goodwill [Line Items]
Income Tax Expense	$ 424,664	$ 159,684	$ 453,574
Water Acquisitions
Goodwill [Line Items]
Water Acquisitions		9,500
Water Goodwill Impairment	297,000
Water Distribution
Goodwill [Line Items]
Water Acquisitions	4,200
Goodwill disposed of	$ 5,400
Water Distribution | Water Acquisitions
Goodwill [Line Items]
Number of water acquisitions | acquistion	2
Water Acquisitions	$ 9,500	$ 9,500
Water Goodwill Impairment	$ 297,000

SCHEDULE I - FINANCIAL INFORM_2

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - BALANCE SHEET (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current Assets:
Cash	$ 26,656	$ 53,873
Accounts Receivable from Subsidiaries	1,651,325	1,431,531
Prepayments and Other Current Assets, Including Assets Held for Sale	315,368	355,762
Total Current Assets	5,076,073	4,247,994
Deferred Debits and Other Assets:
Carrying Value as of December 31, 2023	168,652	660,473
Goodwill	3,571,333	4,532,100	$ 4,522,600
Long-Term Assets Held for Sale	2,611,145	0
Other Long-Term Assets	642,869	592,080
Total Deferred Debits and Other Assets	13,531,878	11,865,644
Total Assets (as of)	59,594,529	55,612,245
Current Liabilities:
Notes Payable	2,042,793	1,930,422
Long-Term Debt – Current Portion	1,003,150	824,847
Accounts Payable to Subsidiaries	1,736,880	1,869,187
Accrued Interest	341,558	260,577
Other Current Liabilities	868,491	821,404
Total Current Liabilities	6,720,957	6,341,397
Liabilities, Noncurrent [Abstract]
Long-Term Liabilities Held for Sale	398,859	0
Other Long-Term Liabilities	1,123,999	1,029,238
Total Deferred Credits and Other Liabilities	11,652,918	10,985,489
Capitalization:
Long-Term Debt	25,701,627	23,588,616
Common Shareholders' Equity:
Capital Surplus, Paid in	9,428,905	8,460,876
Retained Earnings	3,929,141	4,142,515
Accumulated Other Comprehensive Loss	(26,472)	(33,737)
Treasury Stock	(170,809)	(195,682)
Common Shareholders' Equity	15,039,387	14,173,892	$ 15,473,158	$ 14,599,844
Total Liabilities and Capitalization	59,594,529	55,612,245
Eversource
Current Assets:
Cash	1,083	542
Accounts Receivable from Subsidiaries	100,320	60,191
Notes Receivable from Subsidiaries	2,051,400	2,045,570
Prepayments and Other Current Assets, Including Assets Held for Sale	96,313	103,735
Total Current Assets	2,249,116	2,210,038
Deferred Debits and Other Assets:
Carrying Value as of December 31, 2023	20,080,215	17,977,812
Notes Receivable from Subsidiaries	2,296,500	2,296,500
Accumulated Deferred Income Taxes	113,718	10,131
Goodwill	3,231,811	3,852,524
Long-Term Assets Held for Sale	335,393	0
Other Long-Term Assets	24,582	28,287
Total Deferred Debits and Other Assets	26,082,219	24,165,254
Total Assets (as of)	28,331,335	26,375,292
Current Liabilities:
Notes Payable	1,538,011	1,564,575
Long-Term Debt – Current Portion	600,000	364,653
Accounts Payable to Subsidiaries	45,326	38,051
Accrued Interest	168,748	106,070
Other Current Liabilities	57,923	41,268
Total Current Liabilities	2,410,008	2,114,617
Liabilities, Noncurrent [Abstract]
Long-Term Liabilities Held for Sale	15,028	0
Other Long-Term Liabilities	137,656	134,432
Total Deferred Credits and Other Liabilities	152,684	134,432
Capitalization:
Long-Term Debt	10,729,256	9,952,351
Common Shareholders' Equity:
Common Shares	1,878,622	1,799,920
Capital Surplus, Paid in	9,428,905	8,460,876
Retained Earnings	3,929,141	4,142,515
Accumulated Other Comprehensive Loss	(26,472)	(33,737)
Treasury Stock	(170,809)	(195,682)
Common Shareholders' Equity	15,039,387	14,173,892
Total Liabilities and Capitalization	$ 28,331,335	$ 26,375,292

SCHEDULE I - FINANCIAL INFORM_3

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF INCOME(LOSS) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Condensed Income Statements, Captions [Line Items]
Operating Revenues	$ 11,900,809	$ 11,910,705	$ 12,289,336
Operating Expenses:
Other	2,012,926	1,895,703	1,865,328
Loss on Pending Sale of Aquarion	297,000	0	0
Total Operating Expenses	9,492,100	9,511,370	10,091,182
Operating Income (Loss)	2,408,709	2,399,335	2,198,154
Interest Expense	1,111,336	855,441	678,274
Other Income, Net:
Equity in Earnings/(Losses) of Subsidiaries	51,900	15,500	22,900
Other Income/(Loss), Net	410,482	348,069	346,088
Income/(Loss) Before Income Tax Benefit	1,243,836	(275,037)	1,865,968
Income Tax Benefit	$ 424,664	$ 159,684	$ 453,574
Basic Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.27)	$ 4.05
Diluted Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.26)	$ 4.05
Weighted Average Common Shares Outstanding:
Basic (in shares)	357,482,965	349,580,638	346,783,444
Diluted (in shares)	357,779,408	349,840,481	347,246,768
Eversource
Condensed Income Statements, Captions [Line Items]
Operating Revenues	$ 4,442	$ 840	$ 0
Operating Expenses:
Other	20	12,769	26,708
Loss on Pending Sale of Aquarion	297,000	0	0
Total Operating Expenses	297,020	12,769	26,708
Operating Income (Loss)	(292,578)	(11,929)	(26,708)
Interest Expense	549,511	397,281	237,773
Other Income, Net:
Equity in Earnings/(Losses) of Subsidiaries	1,359,297	(312,040)	1,565,474
Other, Net	214,444	188,003	79,383
Other Income/(Loss), Net	1,573,741	(124,037)	1,644,857
Income/(Loss) Before Income Tax Benefit	731,652	(533,247)	1,380,376
Income Tax Benefit	(80,001)	(91,007)	(24,499)
Net Income/(Loss)	$ 811,653	$ (442,240)	$ 1,404,875
Basic Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.27)	$ 4.05
Diluted Earnings/(Loss) Per Common Share (in dollars per share)	$ 2.27	$ (1.26)	$ 4.05
Weighted Average Common Shares Outstanding:
Basic (in shares)	357,482,965	349,580,638	346,783,444
Diluted (in shares)	357,779,408	349,840,481	347,246,768

SCHEDULE I - FINANCIAL INFORM_4

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF COMPREHENSIVE INCOME(LOSS) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	$ 20	$ 20	$ 20
Changes in Unrealized Gains/(Losses) on Marketable Securities	0	1,252	(1,636)
Changes in Funded Status of Pension, SERP and PBOP Benefit Plans	7,245	4,412	4,470
Other Comprehensive Income, Net of Tax	7,265	5,684	2,854
Comprehensive Income/(Loss)	818,918	(436,556)	1,407,729
Eversource
Condensed Statement of Income Captions [Line Items]
Net Income/(Loss)	811,653	(442,240)	1,404,875
Other Comprehensive Income/(Loss), Net of Tax:
Qualified Cash Flow Hedging Instruments	20	20	20
Changes in Unrealized Gains/(Losses) on Marketable Securities	0	1,252	(1,636)
Changes in Funded Status of Pension, SERP and PBOP Benefit Plans	7,245	4,412	4,470
Other Comprehensive Income, Net of Tax	7,265	5,684	2,854
Comprehensive Income/(Loss)	$ 818,918	$ (436,556)	$ 1,407,729

SCHEDULE I - FINANCIAL INFORM_5

SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENT OF CASH FLOWS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Equity in (Earnings)/Losses of Subsidiaries	$ (51,900)	$ (15,500)	$ (22,900)
Deferred Income Taxes	435,889	85,405	346,779
Loss on Pending Sale of Aquarion	297,000	0	0
Other	(102,450)	(53,026)	(39,192)
Receivables and Unbilled Revenues, Net	(432,620)	(124,393)	(470,593)
Taxes Receivable/Accrued, Net	55,502	36,357	18,358
Other Current Assets and Liabilities, Net	19,529	(66,202)	(45,583)
Net Cash Flows Provided by Operating Activities	2,159,737	1,646,161	2,401,293
Investing Activities:
Other Investing Activities	(13,365)	(2,897)	20,420
Net Cash Flows Used in Investing Activities	(4,535,664)	(4,870,732)	(4,130,490)
Financing Activities:
Issuance of Common Shares, Net of Issuance Costs	989,447	0	197,058
Cash Dividends on Common Shares	(1,001,488)	(918,995)	(860,033)
Issuance of Long-Term Debt	4,501,623	5,198,345	4,045,000
Retirement of Long-Term Debt	(1,949,995)	(2,008,470)	(1,175,000)
Other Financing Activities	(57,082)	(46,466)	(48,185)
Net Cash Flows Provided by Financing Activities	2,336,817	2,869,237	2,029,941
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	(39,110)	(355,334)	300,744
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	166,418	521,752	221,008
Cash, Cash Equivalents and Restricted Cash - End of Year	127,308	166,418	521,752
Cash Paid/(Received) During the Year for:
Interest	1,014,400	783,200	636,200
Income Taxes	(69,600)	39,200	77,900
Eversource
Operating Activities:
Net Income/(Loss)	811,653	(442,240)	1,404,875
Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:
Equity in (Earnings)/Losses of Subsidiaries	(1,359,297)	312,040	(1,565,474)
Cash Dividends Received from Subsidiaries	1,273,700	1,027,400	855,600
Deferred Income Taxes	(99,692)	(22,256)	25,823
Loss on Pending Sale of Aquarion	297,000	0	0
Other	57,469	(12,834)	26,455
Receivables and Unbilled Revenues, Net	(40,129)	(6,853)	(9,935)
Taxes Receivable/Accrued, Net	22,464	(80,968)	(21,627)
Accounts Payable to Subsidiaries	7,275	4,521	(4,079)
Other Current Assets and Liabilities, Net	58,572	35,357	35,090
Net Cash Flows Provided by Operating Activities	1,029,015	814,167	746,728
Investing Activities:
Capital Contributions to Subsidiaries	(2,026,500)	(1,369,700)	(1,499,300)
Return of Capital from Subsidiaries	17,000	438,000	12,000
Increase/(Decrease) in Notes Receivable from Subsidiaries	201,500	(1,578,100)	(724,400)
Other Investing Activities	0	147,567	(1,289)
Net Cash Flows Used in Investing Activities	(1,808,000)	(2,362,233)	(2,212,989)
Financing Activities:
Issuance of Common Shares, Net of Issuance Costs	989,447	0	197,058
Cash Dividends on Common Shares	(1,001,488)	(918,995)	(860,033)
Issuance of Long-Term Debt	2,400,000	3,350,000	2,800,000
Retirement of Long-Term Debt	(1,350,000)	(1,200,000)	(750,000)
Increase (Decrease) in Notes Payable to Eversource Parent	(233,894)	329,705	99,250
Other Financing Activities	(24,539)	(13,076)	(19,193)
Net Cash Flows Provided by Financing Activities	779,526	1,547,634	1,467,082
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash	541	(432)	821
Cash, Cash Equivalents and Restricted Cash - Beginning of Year	615	1,047	226
Cash, Cash Equivalents and Restricted Cash - End of Year	1,156	615	1,047
Cash Paid/(Received) During the Year for:
Interest	483,101	366,645	215,053
Income Taxes	$ 443	$ 23,984	$ (20,992)

SCHEDULE II - VALUATION AND Q_2

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 554,455	$ 486,297	$ 417,406
Additions, Charged to Costs and Expense	74,069	72,468	61,876
Additions, Charged to Other Accounts	119,659	158,205	112,533
Deductions	192,019	162,515	105,518
Balance at end of period	556,164	554,455	486,297
CL&P
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	296,030	225,320	181,319
Additions, Charged to Costs and Expense	17,190	11,675	15,578
Additions, Charged to Other Accounts	46,840	126,360	59,485
Deductions	80,952	67,325	31,062
Balance at end of period	279,108	296,030	225,320
NSTAR Electric
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	97,026	94,958	97,005
Additions, Charged to Costs and Expense	33,607	22,791	21,550
Additions, Charged to Other Accounts	37,653	17,488	12,412
Deductions	53,376	38,211	36,009
Balance at end of period	114,910	97,026	94,958
PSNH
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	14,322	29,236	24,331
Additions, Charged to Costs and Expense	4,688	3,989	9,211
Additions, Charged to Other Accounts	5,131	(8,735)	2,539
Deductions	10,051	10,168	6,845
Balance at end of period	$ 14,090	$ 14,322	$ 29,236