Volta (VLTA) 10-Q 12 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 11, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-439508
Entity Registrant Name	Volta Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	99-1550630
Entity Address, Address Line One	155 De Haro Street
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94103
City Area Code	888
Local Phone Number	264-2208
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001819584
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A Common Stock, par value of $0.0001 per share
Entity Information [Line Items]
Title of 12(b) Security	Class A Common Stock, par value of $0.0001 per share
Trading Symbol	VLTA
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		152,307,420
Warrants, each exercisable for one share of Class A Common Stock for $11.50 per share
Entity Information [Line Items]
Title of 12(b) Security	Warrants, each exercisable for one share of Class A Common Stock for $11.50 per share
Trading Symbol	VLTA WS
Security Exchange Name	NYSE
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		9,887,185

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 331,254	$ 58,806
Accounts receivable, less allowance for doubtful accounts; $53.2 and $53.2, respectively	8,662	6,150
Inventory	3,867	6,152
Prepaid partnership costs - current	9,692	9,625
Prepaid expenses and other current assets	9,932	921
Total current assets	363,407	81,654
Operating lease right-of-use assets, net	61,570	49,434
Property and equipment, net	82,389	49,358
Notes receivable - employee	0	1,019
Other non-current assets	3	327
Prepaid partnership costs - non-current	415	0
Intangible assets, net	845	0
Goodwill	221	0
Total assets	508,850	181,792
Current liabilities
Accounts payable	35,864	5,494
Accounts payable - due to related party	0	92
Accrued expenses and other current liabilities	13,898	21,533
Operating lease liability - current portion	9,267	7,484
Deferred revenue	6,928	7,625
Term loans payable - current	19,527	10,323
Warrant liability	37,269	698
Total current liabilities	122,753	53,249
Term loans payable, net of unamortized debt issuance costs and current term loan payable	27,662	40,697
Operating lease liability - non-current portion	47,844	37,146
Other non-current liabilities	6,944	7,004
Total liabilities	205,203	138,096
Redeemable convertible Legacy Volta Preferred Stock, $0.0001 par value: 86,845,643 shares authorized; 76,493,917 shares issued and outstanding as of and December 31, 2020. Volta Inc. Preferred Stock, $0.0001 par value: 10,000,000 shares authorized; no shares were outstanding as of September 30, 2021 (aggregate liquidation preference of $0 and $214,719,011 as of September 30, 2021 and December 31, 2020, respectively)	0	182,599
STOCKHOLDERS' (DEFICIT) EQUITY
Common Stock, $0.0001 par value: 400,000,000 and 152,901,000 shares authorized; 161,908,403 and 24,696,437 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	16	1
Additional paid-in capital	584,572	13,233
Accumulated deficit	(280,941)	(152,137)
Total stockholders’ (deficit) equity	303,647	(138,903)
Liabilities and Equity	$ 508,850	$ 181,792

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 53,200	$ 53,200
Redeemable convertible preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, shares authorized (in shares)	10,000,000	86,845,643
Redeemable convertible preferred stock, shares issued (in shares)	0	76,493,917
Redeemable convertible preferred stock, shares outstanding (in shares)	0	76,493,917
Redeemable convertible preferred stock, aggregate liquidation preference	$ 0	$ 214,719,011
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	400,000,000	152,901,000
Common stock, shares issued (in shares)	161,908,403	24,696,437
Common stock, shares outstanding (in shares)	161,908,403	24,696,437

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
REVENUES
Total revenues	$ 8,490	$ 4,795	$ 20,172	$ 11,076
COSTS AND EXPENSES
Selling, general and administrative	28,963	8,954	107,172	26,491
Depreciation and amortization	3,116	2,257	7,812	5,251
Other operating (income) expense	203	(13)	1,067	(361)
Total costs and expenses	38,157	16,421	132,019	44,320
Loss from operations	(29,667)	(11,626)	(111,847)	(33,244)
OTHER EXPENSES
Interest expense, net	1,639	2,778	5,030	5,695
Other expense, net	188	97	467	84
Change in fair value of warrant liability	11,554	(3)	11,436	(14)
Total other expenses	13,381	2,872	16,933	5,765
LOSS BEFORE INCOME TAXES	(43,048)	(14,498)	(128,780)	(39,009)
Income tax expense	0	19	24	23
NET LOSS	$ (43,048)	$ (14,517)	$ (128,804)	$ (39,032)
Weighted-average Common Stock outstanding, diluted (Note 12 - Net Loss Per Share) (in shares)	8,481,143	7,733,885	8,998,756	7,733,885
Class A Common Stock
OTHER EXPENSES
NET LOSS	$ (38,141)	$ (2,457)	$ (97,475)	$ (6,599)
Weighted-average Common Stock outstanding, basic (Note 12 - Net Loss Per Share) (in shares)	65,923,212	1,575,462	27,998,369	1,573,563
Weighted-average Common Stock outstanding, diluted (Note 12 - Net Loss Per Share) (in shares)	65,923,212	1,575,462	27,998,369	1,573,563
Net loss per Common Stock, basic (Note 12 - Net Loss Per Share) (in dollars per share)	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Net loss per Common Stock, diluted (Note 12 - Net Loss Per Share) (in dollars per share)	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Class B Common Stock
OTHER EXPENSES
NET LOSS	$ (4,907)	$ (12,060)	$ (31,329)	$ (32,433)
Weighted-average Common Stock outstanding, basic (Note 12 - Net Loss Per Share) (in shares)	8,481,143	7,733,885	8,998,756	7,733,885
Weighted-average Common Stock outstanding, diluted (Note 12 - Net Loss Per Share) (in shares)	8,481,143	7,733,885	8,998,756	7,733,885
Net loss per Common Stock, basic (Note 12 - Net Loss Per Share) (in dollars per share)	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Net loss per Common Stock, diluted (Note 12 - Net Loss Per Share) (in dollars per share)	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Service
REVENUES
Total revenues	$ 8,058	$ 4,043	$ 19,115	$ 8,907
COSTS AND EXPENSES
Costs (exclusive of depreciation and amortization shown below)	5,347	4,554	15,087	11,551
Product
REVENUES
Total revenues	372	752	670	1,463
COSTS AND EXPENSES
Costs (exclusive of depreciation and amortization shown below)	528	669	881	1,388
Other
REVENUES
Total revenues	$ 60	$ 0	$ 387	$ 706

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands	Total	Series D	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019	55,065,000
Beginning balance at Dec. 31, 2019	$ 75,608
Increase (Decrease) in Temporary Equity [Roll Forward]
Reverse recapitalization	$ 0
Ending balance (in shares) at Sep. 30, 2020	55,065,000
Ending balance at Sep. 30, 2020	$ 75,608
Beginning balance (in shares) at Dec. 31, 2019			13,186,000
Beginning balance at Dec. 31, 2019	(76,039)		$ 0	$ 5,542	$ (81,581)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beneficial conversion feature in convertible promissory notes	1,192			1,192
Issuance of Class B common stock warrants - related party	291			291
Issuance of Common Stock upon exercise of options (in shares)			12,000
Issuance of Common Stock upon exercise of options	7			7
Stock-based compensation expense - options	820			820
Net loss	(39,032)				(39,032)
Ending balance (in shares) at Sep. 30, 2020			13,198,000
Ending balance at Sep. 30, 2020	$ (112,761)		$ 0	7,852	(120,613)
Beginning balance (in shares) at Dec. 31, 2019	55,065,000
Beginning balance at Dec. 31, 2019	$ 75,608
Ending balance (in shares) at Dec. 31, 2020	76,493,917
Ending balance at Dec. 31, 2020	$ 182,599
Beginning balance (in shares) at Dec. 31, 2019			13,186,000
Beginning balance at Dec. 31, 2019	$ (76,039)		$ 0	5,542	(81,581)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock upon exercise of options (in shares)	259,070		9,271,877
Ending balance (in shares) at Dec. 31, 2020			24,696,000
Ending balance at Dec. 31, 2020	$ (138,903)		$ 1	13,233	(152,137)
Beginning balance (in shares) at Jun. 30, 2020	55,065,000
Beginning balance at Jun. 30, 2020	$ 75,608
Ending balance (in shares) at Sep. 30, 2020	55,065,000
Ending balance at Sep. 30, 2020	$ 75,608
Beginning balance (in shares) at Jun. 30, 2020			13,194,000
Beginning balance at Jun. 30, 2020	(99,403)		$ 0	6,693	(106,096)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beneficial conversion feature in convertible promissory notes	815			815
Issuance of Common Stock upon exercise of options (in shares)			4,000
Issuance of Common Stock upon exercise of options	3			3
Stock-based compensation expense - options	341			341
Net loss	(14,517)				(14,517)
Ending balance (in shares) at Sep. 30, 2020			13,198,000
Ending balance at Sep. 30, 2020	$ (112,761)		$ 0	7,852	(120,613)
Ending balance (in shares) at Dec. 31, 2020	76,493,917
Ending balance at Dec. 31, 2020	$ 182,599
Ending balance (in shares) at Dec. 31, 2020			24,696,000
Ending balance at Dec. 31, 2020	$ (138,903)		$ 1	13,233	(152,137)
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series D Preferred Stock (in shares)		4,722,000
Issuance of Series D Preferred Stock		$ 13,721
Issuance of Series D Preferred Stock - related party		15,000
Issuance Costs - Series D		$ (1,290)
Reverse recapitalization (in shares)	(81,216,000)
Reverse recapitalization	$ (210,030)
Ending balance (in shares) at Sep. 30, 2021	0
Ending balance at Sep. 30, 2021	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock awards - related party (in shares)			6,917,000
Issuance of restricted stock awards - related party	40,237		$ 1	40,236
Reverse recapitalization (in shares)			81,216,000
Reverse recapitalization	210,038		$ 8	210,030
TAC shares recapitalized, net of redemptions and equity issuance costs (in shares)			48,907,000
TAC shares recapitalized, net of redemptions and equity issuance costs	323,023		$ 5	323,018
Transaction costs related to reverse recapitalization	(8,307)			(8,307)
Recognition of exercise of options, net of forfeiture of shares, upon settlement of promissory notes (in shares)			(1,869,000)
Recognition of exercise of options, net of forfeiture of shares, upon settlement of promissory notes	(9,272)			(9,272)
Issuance of Common Stock upon exercise of options (in shares)			1,235,000
Issuance of Common Stock upon exercise of options	1,295		$ 1	1,294
Issuance of common stock upon net exercise of warrant (in shares)			442,000
Issuance of common stock upon net exercise of warrant	1,944			1,944
Stock-based compensation expense - options	11,175			11,175
Exercise of common stock warrants - related party	1		$ 182	1
Issuance of Common Stock for acquisition of 2Predict (in shares)			182,000
Issuance of Common Stock for acquisition of 2Predict	1,220			1,220
Net loss	(128,804)				(128,804)
Ending balance (in shares) at Sep. 30, 2021			161,908,000
Ending balance at Sep. 30, 2021	$ 303,647		$ 16	584,572	(280,941)
Beginning balance (in shares) at Jun. 30, 2021	81,216,000
Beginning balance at Jun. 30, 2021	$ 210,030
Increase (Decrease) in Temporary Equity [Roll Forward]
Reverse recapitalization (in shares)	(81,216,000)
Ending balance (in shares) at Sep. 30, 2021	0
Ending balance at Sep. 30, 2021	$ 0
Beginning balance (in shares) at Jun. 30, 2021			32,981,000
Beginning balance at Jun. 30, 2021	(175,550)		$ 3	62,340	(237,893)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reverse recapitalization (in shares)			81,216,000
Reverse recapitalization	210,038		$ 8	210,030
TAC shares recapitalized, net of redemptions and equity issuance costs (in shares)			48,907,000
TAC shares recapitalized, net of redemptions and equity issuance costs	323,023		$ 5	323,018
Transaction costs related to reverse recapitalization	(8,307)			(8,307)
Recognition of exercise of options, net of forfeiture of shares, upon settlement of promissory notes (in shares)			(1,869,000)
Recognition of exercise of options, net of forfeiture of shares, upon settlement of promissory notes	$ (9,272)		$ 0	(9,272)
Issuance of Common Stock upon exercise of options (in shares)	8,371,796		231,000
Issuance of Common Stock upon exercise of options	$ 208			208
Issuance of common stock upon net exercise of warrant (in shares)			442,000
Issuance of common stock upon net exercise of warrant	1,944			1,944
Stock-based compensation expense - options	4,611			4,611
Net loss	(43,048)				(43,048)
Ending balance (in shares) at Sep. 30, 2021			161,908,000
Ending balance at Sep. 30, 2021	$ 303,647		$ 16	$ 584,572	$ (280,941)

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Cash flows from operating activities
Net loss	$ (43,048)		$ (14,517)	$ (128,804)	$ (39,032)
Adjustments to reconcile net loss to net cash used in operating activities:
Reduction in the carrying amount of ROU assets				3,211	1,804
Depreciation and amortization	3,116		2,257	7,812	5,251
Stock-based compensation				51,411	818
Amortization of debt issuance costs				252	(9,001)
Non-cash interest expense				0	(496)
Revaluation of warrant liability to estimated fair value	11,554		(3)	11,436	(14)
Expenses related to invoices in dispute				624	0
Loss on abandonment of property and equipment				542	0
Changes in operating assets and liabilities:
Accounts receivable				(2,510)	7,099
Inventory				2,285	1,232
Prepaid expenses and other current assets				(8,914)	(893)
Prepaid partnership costs				(1,941)	(4,613)
Operating lease right-of-use asset				(14,699)	(10,895)
Other non-current assets				324	239
Accounts payable				30,371	(20,217)
Due to related party				(92)	45
Accrued expenses and other current liabilities				(7,506)	16,466
Deferred revenue				(697)	3,182
Lease incentive liability				(39)	(16)
Operating lease liability				12,482	9,471
Other noncurrent liabilities				504	(4,189)
Net cash used in operating activities				(43,948)	(43,759)
Cash flows from investing activities
Purchase of property and equipment				(41,470)	(12,753)
Capitalization of internal-use software				422	0
Incentive lease obligation				0	605
Acquisition of 2Predict				(200)	0
Net cash used in investing activities				(41,248)	(12,148)
Cash flows from financing activities
Due from employees for taxes paid on partial recourse notes				(8,340)	0
Proceeds from issuance of Class B Common Stock warrants				0	291
Proceeds from issuance of Series D Preferred Stock				28,721
Proceeds from issuance of Series D-1 convertible notes					20,205
Proceeds from issuance of Series D-1 convertible notes -related party					9,800
Proceeds from issuance of long term debt				0	22,042
Payments of long term debt				(4,084)	0
Proceeds from PPP loan					3,193
Proceeds from exercise of stock options				1,296	5
Payment of issuance costs related to Series D and D-1 Preferred Stock				(1,290)
Proceeds from financing activity				0	445
Payment of financing activity principal				(452)	(223)
Proceeds from reverse recapitalization and PIPE Financing				350,100	0
Payment of transaction costs related to reverse recapitalization				(8,307)	0
Net cash provided by financing activities				357,644	55,758
Net increase (decrease) in cash, cash equivalents, and restricted cash				272,448	(149)
Cash, cash equivalents, and restricted cash, beginning of period		$ 10,609		58,806	10,758	$ 10,758
Cash, cash equivalents, and restricted cash, end of period	$ 331,254	$ 58,806	$ 10,609	331,254	10,609	$ 58,806
Supplemental disclosures of cash flow information
Cash paid for interest				4,649	870
Non-cash investing and financing activities
Conversion of redeemable convertible Preferred Stock into common stock in connection with the reverse recapitalization				210,030	0
Beneficial conversion feature related to convertible notes				0	1,192
Transaction costs not yet paid				1,847	0
Cashless exercise of Legacy Volta Preferred Stock warrants				1,944	0
Forfeiture of shares to settle promissory notes collateralized to common stock				9,272	0
Initial recognition of operating lease right-of-use asset				14,860	10,895
Initial recognition of operating lease liability				14,211	10,337
Class B Common Stock warrants issued in satisfaction of services rendered				0	$ 291
Issuance of Common Stock in a reverse recapitalization				1,221
Fair value of 2Predict assets acquired				$ 1,200

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Note 1 - Description of Business Volta Inc. is a holding company for its wholly-owned subsidiaries, Volta Charging Industries, LLC, Volta Charging, LLC, Volta Charging Services, LLC, and Volta Media, LLC (inactive) (collectively, the “Company” or “Volta”). The Company is headquartered in San Francisco, California. The Company operates a network of smart media-enabled charging stations for electric vehicles across the United States (“U.S.”). In addition, the Company utilizes the network to decarbonize the transportation sector and accelerate electric vehicle adoption by providing sponsored or pay-to-use charging to drivers. Revenue is derived primarily by selling paid content on the media-enabled charging station network and selling, installing and maintaining charging stations. On August 26, 2021 ("Closing Date"), Tortoise Acquisition Corp. II (“TortoiseCorp II”) consummated the previously announced mergers, (the “reverse recapitalization”) contemplated by the Business Combination Agreement and Plan of Reorganization, dated as of February 7, 2021 (the "Business Combination Agreement"), by and among TortoiseCorp II, SNPR Merger Sub I, Inc., SNPR Merger Sub II, LLC, and Volta Industries, Inc. ("Legacy Volta"). On the Closing Date, and in connection with the closing of the Business Combination Agreement (the "Closing"), TortoiseCorp II was renamed Volta Inc. and began trading on the New York Stock Exchange ("NYSE") under the ticker symbol "VLTA". The Company's public warrants also trade on the NYSE under the ticker symbol "VLTA WS". On March 25, 2021, the Company formed a new wholly-owned subsidiary, Volta Canada Inc. On April 13, 2021, the Company formed two new, wholly-owned subsidiaries, Volta Charging Germany GmbH and Volta France SARL. In April 2021, the Company entered into and executed an acquisition agreement with 2Predict, Inc., pursuant to which the seller agreed to sell certain assets to the Company. The assets purchased consist primarily of intellectual property. The purchase price consisted of: (i) cash consideration of $0.2 million, and (ii) equity consideration of 150,134 shares of Legacy Volta Class B Common Stock. Substantially all of the Company’s operations and assets are located in the U.S., and all of its revenues are attributable to customers located in the U.S.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2 - Summary of Significant Accounting Policies Basis of presentation and consolidation The accompanying condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles ("GAAP") and include the accounts and operations of Volta Inc. and its wholly-owned subsidiaries. Volta Charging, LLC is the primary operating subsidiary of the Company. All intercompany accounts and transactions have been eliminated upon consolidation. Use of estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires the Company to make estimates, judgments and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Significant items subject to management’s estimates and assumptions include, but are not limited to, assumptions underlying the determination of the stand-alone selling prices for performance obligations within revenue arrangements, allowance for doubtful accounts, inventory valuation, stock-based compensation, tax valuation allowance, valuation and recognition of warrants, incremental borrowing rate for right-of-use ("ROU") assets and lease liabilities, lease term, the valuation and useful lives of property and equipment, goodwill and intangibles, and the valuation of assets acquired and liabilities assumed for reverse recapitalization. The Company believes that the estimates and judgments upon which it relies are reasonable based upon information available to the Company at the time that these estimates and judgments are made. The Company periodically evaluates such estimates and adjusts prospectively based upon such periodic evaluation. Actual results could differ materially from those estimates using different assumptions or under different conditions. Reclassifications Certain prior period amounts have been reclassified to conform to current period presentation. These reclassifications have no effect on previously reported results of operations or loss per share. Cash, cash equivalents, and restricted cash Cash and cash equivalents include on-demand deposits with banks and a mutual fund, respectively, for which cost approximates the fair value. Restricted cash as of September 30, 2021 includes $0.1 million held in escrow related to payments to contractors. Accounts receivable and allowance for doubtful accounts Accounts receivable primarily includes amounts related to receivables from our sales of media, site partnerships, and installation of stalls and stations. We provide an allowance against accounts receivable for the amount we expect to be uncollectible. We write-off accounts receivable against the allowance when they are deemed uncollectible. Unbilled receivables result from amounts recognized as revenues but not yet invoiced as of the condensed consolidated balance sheet date. As of September 30, 2021 and December 31, 2020, the company had $0.8 million and $0.8 million, respectively, in unbilled receivables related to network development revenue, which are included in the accounts receivable balance. Concentration of risk Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash and accounts receivable. The Company’s cash is held on deposit with high-credit quality financial institutions. Such deposits may at times exceed federally insured limits. The Company has not experienced losses in such amounts or accounts. As of September 30, 2021, two customers accounted for 45.4% and 10.9% of the Company's accounts receivable balance, respectively. As of December 31, 2020, one customer accounted for 59.5% of the Company's accounts receivable balance. For the three months ended September 30, 2021, two customers accounted for 39.5% and 12.2% of the Company's revenue, respectively. For the nine months ended September 30, 2021, two customers accounted for 29.1% and 11.7% of the Company's revenue, respectively. For the three months ended September 30, 2020, two customers accounted for 52.9% and 24.1% of the Company's revenue, respectively. For the nine months ended September 30, 2020, two customers accounted for 48.2% and 14.8% of the Company's revenue, respectively. Revenue generated by these customers arises from a portfolio of contracts with multiple, separate, legal entities. The Company mitigates concentration risk as all contracts are executed with these separate, legal entities. As of September 30, 2021, one supplier accounted for 10.5% of the Company's accounts payable orders. As of December 31, 2020, one supplier accounted for 19.5% of the Company's accounts payable orders. The Company mitigates concentration risk by maintaining contracts and agreements with alternative suppliers and is actively expanding its supplier network. Property and equipment Property and equipment are stated at cost, less accumulated depreciation and amortization. The cost of maintenance and repairs is expensed as incurred, and expenditures that extend the useful lives of assets are capitalized. Property and equipment are depreciated and amortized using the straight-line method over the estimated useful lives of the respective assets. Leasehold improvements are depreciated using the straight-line method over the shorter of the estimated useful lives of the assets or the lease term, ranging from two Asset Useful Lives (In Years) Charging stations and digital media screens 5-10 Capitalized research and development equipment 5 Computers and equipment 3-5 Furniture 5 Leasehold improvements 2-5 Internal-use software 0.5 Construction in progress includes all costs capitalized related to projects, primarily related to in-process engineering activities and installation of assets that have yet to be placed in service. When assets are retired or otherwise disposed of, the cost and accumulated depreciation or amortization are removed from the condensed consolidated balance sheets, and any resulting gain or loss is reflected in the condensed consolidated statements of operations and comprehensive loss in the period realized. Impairment of long-lived assets and intangibles Intangible assets with finite lives are amortized over their useful lives and reported net of accumulated amortization. The Company evaluates its long-lived assets and intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The recoverability of assets to be held and used is assessed by a comparison of the carrying amount of an asset to future net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. Although the Company has accumulated losses, the Company believes that the future cash flows will be sufficient to exceed the carrying value of the Company’s long-lived and intangible assets. As of September 30, 2021 and December 31, 2020, the Company determined that no events or changes in circumstances existed that would otherwise indicate any impairment of its long-lived or intangible assets. Goodwill Goodwill is evaluated for impairment at the end of each fiscal year or more frequently if impairment indicators are present. A qualitative assessment is performed to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of the reporting unit is less than its carrying amount. If, based on the evaluation, it is determined to be more likely than not that the fair value is less than the carrying value, then the goodwill is tested further for impairment. If the implied fair value of goodwill is lower than its carrying amount, an impairment loss is recognized in an amount equal to the difference. There was no impairment of goodwill for the three months ended September 30, 2021. Leases The Company determines if an arrangement contains a lease at inceptio n. The Company recognizes an ROU asset and a lease liability at the lease commencement date for operating leases with terms greater than 12 months. ROU assets represent the Company's right to use an underlying asset for the lease term, and lease liabilities represent the obligation to make lease payments arising from the lease . The initial measurement of ROU assets is comprised of the initial amount of the lease liability, adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred, less any lease incentives received. ROU assets are subsequently measured throughout the lease term at the carrying amount of the lease liability, plus any initial direct costs, plus (less) any prepaid (accrued) lease payments, less the unamortized balance of lease incentives received. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The interest rate used to determine the present value of the future lease payments is the Company's incremental borrowing rate as the Company generally cannot determine the implicit rate because it does not have access to the lessor's residual value or the amount of the lessor's deferred initial costs. The incremental borrowing rate is the interest rate the Company would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. Lease terms include the noncancellable period of the lease plus any additional periods covered by either an option to extend (or not to terminate) the lease that the Company is reasonably certain to exercise, or an option to extend (or not to terminate) the lease controlled by the lessor. Variable lease payments associated with the Company's leases are recognized when the event, activity, or circumstance in the lease agreement on which those payments are assessed occurs. Variable lease payments are recognized in other operating (income) expenses in the condensed consolidated statement of operations and comprehensive loss. The Company identifies separate lease and non-lease components within the contract. Non-lease components primarily include payments for electricity reimbursements made to the landlord. The Company has elected the practical expedient to combine lease and non-lease payments and account for them together as a single lease component, which increases the amount of the Company's ROU assets and lease liabilities. In April 2020, the Financial Accounting Standards Board ("FASB") provided for an optional practical expedient that simplifies how a lessee accounts for rent concessions that are a direct consequence of the COVID-19 pandemic. The practical expedient provides that, for eligible leases, the lessee may choose to forgo the evaluation of the enforceable rights and obligations of the original lease contract. Instead, lessees may account for COVID-19 related rent concessions either (i) as if they were part of the enforceable rights and obligations of the parties under the existing lease contract or (ii) as a lease modification. Eligible leases are those for which the concession is COVID-19 related and the changes to the lease do not result in a substantial increase to the rights of the lessor or the obligations of the lessee. The Company has elected to apply the practical expedient for all eligible lease modifications, resulting in the rent concession being recorded as a negative variable lease cost and recognized in the condensed consolidated statement of operations and comprehensive loss in that period. Equity issuance costs For the nine months ended September 30, 2020, the Company raised $9.5 million through sales of Legacy Volta Series D Preferred Stock resulting in $0.3 million of equity issuance costs, paid as Legacy Volta Class B Common Stock warrants. During the nine months ended September 30, 2021, the Company had raised $129 million through sales of Legacy Volta Series D and Legacy Volta D-1 Preferred Stock, resulting in $4.5 million of equity issuance costs, of which $3.8 million was paid in cash and $0.7 million was paid as Legacy Volta Class B Common Stock warrants. As a part of the Closing all Legacy Volta Series D and Legacy Volta D-1 Preferred Stock were converted to Class A Common Stock and Legacy Volta Class B Common Stock were converted to Class A Common Stock of Volta Inc. (Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation). Stock warrants The Company’s Common Stock warrants are freestanding warrants that were issued by Legacy Volta in connection with certain debt and equity financing transactions ("Legacy Volta Warrants"). At the Closing, the Legacy Volta Warrants were converted into warrants to purchase Volta Class A Common Stock ("Converted Warrants"). The Converted Warrants are classified as equity instruments at the grant date fair value calculated using the OPM Back solve approach and are not subject to revaluation at the condensed consolidated balance sheet date. Additionally, TortoiseCorp II sold warrants as a part of the units in TortoiseCorp's initial public offering of units, which closed on September 15, 2020 (the "IPO") (the "Public Warrants") and issued warrants to TortoiseEcofin Borrower, LLC ("Tortoise Borrower") in a private placement simultaneously with the closing of the IPO (the "Private Warrants"). As the Public Warrants and Private warrants do not meet the criteria for equity treatment, they are recorded as liabilities on the condensed consolidated balance sheets. Accordingly, the Company classifies the Private Warrants and Public Warrants as liabilities and records them at fair value. Revenue recognition ASC 606 Revenue is recognized when promised goods or services 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 by following a five-step process, (i) identify the contract with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price, and (v) recognize revenue when or as the Company satisfies a performance obligation. The Company generally considers a sales contract and/or agreement with an approved purchase order as a customer contract provided that collection is considered probable, which is assessed based on the creditworthiness of the customer. The Company combines contracts with a customer if contracts are entered into at or near the same time with the same customer and are negotiated with a single commercial substance or contain price dependencies. As it enters contracts with customers, the Company evaluates distinct goods and services promised in the contract to identify the appropriate performance obligations. The performance obligations include advertising services, charging stations, which include Level 2 ("L2") or Direct Current Fast Charging ("DCFC") stations, installation services, operation and maintenance services, installed infrastructure, regulatory credits and Software-as-a-Service ("SaaS"). The Company generally contracts with customers at fixed amounts and has not experienced significant returns or price concessions and discounts. To the extent the Company is entitled to variable consideration on the sale of goods or services, it will estimate the amount it expects to collect as part of the transaction price provided it is probable that a significant reversal of revenue will not occur when the uncertainty related to variable consideration is resolved. When a contract contains multiple performance obligations, the Company allocates the transaction price to each performance obligation using the relative standalone selling price (“SSP”) method. The determination of SSP is judgmental and is based on the price the Company would charge for the same good or service if it were sold separately in a standalone sale to similar customers in similar circumstances. As the charging stations, installation and operation and maintenance services are never sold separately, the Company utilizes an expected cost plus a margin approach to determine the SSP of each of the separate performance obligations. Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for promised goods or services. Disaggregation of revenue The Company's operations represent a single operating segment based on how the Company and its Chief Operating Decision Maker ("CODM") manages its business. The Company disaggregates revenue by major category in the table below based on what it believes are the primary economic factors that impact the nature, amount, timing, and uncertainty of revenue and cash flows from these customer contracts. Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenues (in thousands) Behavior and Commerce $ 7,360 $ 2,214 $ 17,373 $ 4,181 Network Development 1,071 2,581 2,412 6,189 Charging Network Operations (1) — — 706 Network Intelligence 60 — 387 — Total revenues $ 8,490 $ 4,795 $ 20,172 $ 11,076 Behavior and commerce Behavior and Commerce revenue is generated by displaying paid media content on the Company's network of media-enabled charging stations. National and regional businesses pay for content either directly or through their relationships with advertising agencies, based on the number of impressions delivered over the contract term, which is typically less than one year. Behavior and Commerce revenue is recognized ratably over time as the impressions are displayed on media-enabled charging stations over the contract term. The Company typically bills customers in advance on a monthly basis, and payments are typically due within one month after content delivery. Behavior and Commerce revenue is recorded in service revenue in the condensed consolidated statements of operations and comprehensive loss. Network development Network Development revenue consists of revenue generated through installation services, operation and maintenance services offered over the contract term (generally a 10-year term), installed infrastructure for utility companies and charging station products. Revenue from installation services is recognized over time using an input method based on costs incurred to measure progress toward complete satisfaction of the performance obligation. Revenue from operation and maintenance services is recognized ratably over the term of the arrangement as the services are performed. Revenue from the sale of installed infrastructure is recognized at a point in time when control of the installed infrastructure is transferred to the customer. Revenue from charging stations is recognized at the point in time when control of the charging station is transferred to the customer, which is typically when the charging station is delivered at the designated customer site. If the arrangement contains a lease, it is accounted for in accordance with Accounting Standards Codification ("ASC") 842, Leases . In some arrangements, the Company has executed a sale and leaseback of the digital media screens (sale leaseback) and has also acquired the right to control the use of the location to advertise over a set term (location lease) (see Note 10 - Debt Facilities). During the construction phase, the Company does not control the underlying asset on the customer’s property. As the leaseback qualifies as a financing arrangement, the Company will not record a sale for accounting purposes of the digital media screen and will depreciate that asset over its useful life. For contractual payments that do not exceed the fair value of the location lease obligation, the Company records a lease liability and an associated right-of-use asset based on the discounted lease payments. In some instances, the Company may receive a lease incentive from the lessor which is recorded as a reduction to the right-of-use asset. The determination of the transaction price for Network Development revenue may require judgment and can affect the amount and timing of revenue. The transaction price is based on the consideration that the Company expects to be entitled to for providing the Network Development products and services on a standalone basis. Almost all of the transaction price is based on fixed cash consideration received from customers. The transaction price is allocated between lease and non-lease components based on a relative-selling price basis. However, in arrangements where the Company pays consideration to a customer for a distinct good or service, the consideration payable to a customer is limited to the fair value of the distinct good or service received by the customer. If the contractual payments for the location lease of this arrangement are in excess of fair value, then the Company will estimate the excess contractual payments over fair value and record that amount as a reduction to the transaction price in the arrangement. The reduction to transaction price for consideration payable to a customer is recognized at the later of when the Company pays or promises to pay the consideration or when the Company recognizes the related revenue for the transferred products and services. The Company reduced the transaction price and recognized consideration payable to a customer of $0.1 million and $64.1 thousand for the three months ended September 30, 2021 and 2020, respectively, and $0.3 million and $0.1 million for the nine months ended September 30, 2021 and 2020, respectively. The Company typically bills the customer upon contract inception for charging stations and installation services and bills the customer on a quarterly basis for operation and maintenance services. Payments are typically due within one month after billing. Revenue generated through installation services, operation and maintenance services and installed infrastructure is recorded in service revenue in the condensed consolidated statements of operations and comprehensive loss. Revenue generated through charging station products is recorded in product revenue in the condensed consolidated statements of operations and comprehensive loss. Charging network operations Charging Network Operations revenue correlates to usage of stations, and are currently, primarily generated by selling regulatory credits or Low Carbon Fuel Standard credits to other regulated entities. The Company recognizes revenue from regulatory credits at the point in time when the regulatory credits are sold to the customer. Costs associated Charging Network Operations is comprised of a minor amount of personnel-related costs which is presented in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss. Charging Network Operations revenue is recorded in other revenue in the condensed consolidated statements of operations and comprehensive loss. Network intelligence Network Intelligence revenue is generated through the delivery of SaaS to the customer. The Company recognizes Network Intelligence revenue ratably over the contract term on a time-elapsed basis as the SaaS is performed. Network Intelligence revenue is recorded in other revenue in the condensed consolidated statements of operations and comprehensive loss. A majority of costs associated with Network Intelligence revenue qualify as internal use software and are capitalized and recorded within property and equipment, net on the condensed consolidated balance sheets. Practical expedient and policy elected The Company utilized the practical expedient to not adjust the promised amount of consideration for the effects of a significant financing component if the Company generally expects, at contract inception, that the period between when the Company transfers control of the promised good or service and when the Company receives payment from the customer is within one year or less. At contract inception, the Company expects to complete installation and transfer control of media-enabled charging stations to customers and receive payment within one year of contract execution. The Company generally expects to fulfill media campaigns and receive payment for advertising sales within one year. The Company has elected to present revenue net of sales taxes remitted to government authorities. Remaining performance obligations Transaction price allocated to the remaining performance obligation represents contracted revenue that has not yet been recognized, which includes deferred revenue and unbilled amounts that is expected to be recognized as revenue in future periods and excludes the performance obligations that are subject to cancellation terms. The remaining performance obligations related to advertising services, the sale of media-enabled charging stations, installation services and SaaS are expected to be recognized as revenue within the next twelve months and are recorded within deferred revenue on the condensed consolidated balance sheets. The unbilled amount was $0.8 million as of September 30, 2021 and December 31, 2020. The total remaining performance obligations, excluding advertising services contracts that have a duration of one year or less, was $22.0 million and $24.4 million as of September 30, 2021 and December 31, 2020, respectively. As of September 30, 2021, the Company expects to recognize approximately 37.4% of its remaining performance obligations as revenues in the next twelve months, and the remainder thereafter. Deferred revenue Deferred revenue primarily consists of billings or payments received from customers in advance of revenue recognized for the sale of media-enabled charging stations, installation and operation and maintenance services and is recognized as revenue upon transfer control or as services are performed. The Company generally invoices customers in advance or in milestone-based installments. Revenue recognized for the three months ended September 30, 2021 and 2020 that was included in the deferred revenue balance as of June 30, 2021 and 2020 was $0.8 million and $2.3 million, respectively. Revenue recognized for the nine months ended September 30, 2021 and 2020 that was included in the deferred revenue balance as of December 31, 2020 and 2019 was $1.8 million and $4.1 million, respectively. As of September 30, 2021, deferred revenue related to such customer payments amounted to $7.1 million, of which $6.9 million is expected to be recognized during the succeeding twelve-month period and is therefore presented as current. Costs to obtain a contract with a customer The Company elected to apply the practical expedient available under ASC 340-40, Other Assets and Deferred Costs - Contracts with Customer s, to not capitalize incremental costs of obtaining a contract, such as sales commissions, if the amortization period is less than one year. Commissions paid for certain sales of advertising are expensed as incurred because the amortization period would have been one year or less as the majority of media campaigns are scheduled to run less than one year. Sales commissions are also paid for obtaining a network development contract with a site host that purchases media-enabled charging stations and related services. As the typical contract term for these agreements exceeds one year, the Company does not apply this practical expedient. Sales commissions that are considered incremental and recoverable costs of obtaining a contract with a customer are capitalized and included in prepaid expenses and other current assets and other non-current assets on the condensed consolidated balance sheets. The deferred costs are then amortized over the period of benefit consistent with the transfer of the goods and services to the customer to which the asset relates and is included in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss. The ending balances of assets recognized from costs of obtaining a contract with a customer were $44.6 thousand and $0.1 million included in prepaid expenses and other current assets as of September 30, 2021 and December 31, 2020, respectively, and $0.3 million included in other non-current assets as of September 30, 2021 and December 31, 2020. Amortization expense related to assets recognized from costs to obtain a contract with a customer was $11.2 thousand and $0.2 million for the three months ended September 30, 2021 and 2020, respectively and $0.1 million and $0.3 million for the nine months ended September 30, 2021 and 2020, respectively. The Company did not recognize any contract cost impairment losses for the three and nine months ended September 30, 2021 and 2020. Cost of revenues (excluding depreciation and amortization) Costs of services Costs of services consist of costs attributable to the Network Development revenues and Behavior and Commerce revenue. Costs associated with Network Development consist of costs associated with providing installation, operations and maintenance services, including personnel-related costs associated with delivering services, such as salaries and benefits, and costs to install infrastructure for utility companies. Costs associated with Behavior and Commerce revenue consists of costs associated with providing advertising services, including related rental payments on location leases for the advertising displays, for charging sites, station electricity, and labor costs directly related to service revenue-generating activities. Cost of products Cost of products consists primarily of hardware cost and shipping cost. Hardware cost primarily relates to L2 and DCFC stations which includes the cost of station chassis, the electric vehicle chargers, routers, and computers. Advertising expenses The Company expenses advertising expenses as they are incurred. Advertising expenses for the three months ended September 30, 2021 were $0.4 million, and none were recognized for the three months ended September 30, 2020. For the nine months ended September 30, 2021 and 2020, advertising expenses were $0.6 million and $0.2 million, respectively, and are included in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss. The Company does not capitalize any advertising expenses. COVID-19 impact On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus (“COVID-19”). In March 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. The COVID-19 pandemic will continue to have a negative impact on the operations and customers of the Company. The impact on the business and the results of operations included decreased customer demand for advertising space due to the decrease in foot traffic at the site hosts as consumers were subject to shelter-in-place orders around the United States, as well as the temporary halting of construction activities of the media-enabled charging stations. In addition, the ability of the employees and the suppliers' and customers' employees to work may be impacted by individuals contracting or being exposed to COVID-19, which may significantly hamper the operations. Despite the adverse impacts, there are no indications that the COVID-19 pandemic has resulted in a material decline in the carrying value of any assets, or a material change in the estimate of any contingent amounts recorded in the condensed consolidated balance sheet as of September 30, 2021. However, there is uncertainty as to the duration and overall impact of the COVID-19 pandemic. The condensed consolidated financial statements reflect estimates and assumptions made by management as of September 30, 2021 and management continues to monitor the potential impact. Events and changes in circumstances arising after September 30, 2021, including those resulting from the impacts of the COVID-19 pandemic, will be reflected in management’s estimates for future periods. The Company applied for a loan under the Small Business Administration (“SBA”) Paycheck Protection Program ("PPP") of the Coronavirus Aid, Relief and Economic Security Act of 2020 (“CARES Act”). In April 2020, the Company received loan proceeds of $3.2 million under the SBA PPP of the CARES Act (see Note 10 - Debt Facilities). Recent accounting pronouncements Recently adopted accounting pronouncements In December 2019, the FASB issued Accounting Standards Update ("ASU") 2019-12, Income Taxes (Topic 740):

Liquidity

Liquidity	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liquidity	Note 3 - Liquidity The Company's condensed consolidated financial statements are prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. For the nine months ended September 30, 2021, the Company incurred a net loss of $128.8 million and had negative cash flows from operating activities of $43.9 million. As of September 30, 2021, the Company had an accumulated deficit of $280.9 million and cash of $331.3 million. In the quarter ended June 30, 2020, the Company’s revenues declined due to COVID-19. Customer demand for advertising space declined due to the decrease in foot traffic at the Company's site hosts as consumers were subject to shelter-in-place orders around the United States. Productivity and capital expenditures decreased as construction activities of the media-enabled charging stations were temporarily halted due to the shelter-in-place orders. In response, management implemented several plans to mitigate the impact of COVID-19 on the Company’s financial performance, including operating cost containment measures, payroll reductions, realignment of its commissions structure, reduced capital expenditures, re-prioritization of high-value and essential sites, and raising capital through debt and equity transactions. Most of the Company's media-enabled charging stations are located in close proximity to essential businesses, positioning the Company for recovery as shelter-in-place orders lift and consumers gradually return to in-person shopping. There are inherent uncertainties associated with predicting consumer behavior, particularly after the effects of COVID-19. Trends may or may not improve based on mitigating plans implemented by management. In April 2020, the Company received loan proceeds of $3.2 million under the PPP of the CARES Act as administered by the U.S. SBA (see Note 10 - Debt Facilities). Although the Company received full forgiveness for the PPP loan, as the entire amount was used for eligible expenses under the program, the Company repaid the entire loan balance of $3.2 million on October 12, 2021 (see Note 18 - Subsequent Events).

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Acquisitions	Note 4 - Acquisitions On April 21, 2021, the Company completed its acquisition of 2Predict, Inc. ("2Predict"), a Delaware corporation, from Praveen Mandal, the Company’s Chief Technology Officer. 2Predict uses artificial intelligence (“AI”) techniques to run next-level analytics on large data sets. 2Predict's data scientists provide advanced machine learning solutions and will continue to assist in developing Volta’s technology. The purchase price was $1.4 million, comprising $0.2 million cash and 150,134 issued shares of Legacy Volta Class B Common Stock valued at $8.13 per share, or $1.2 million, paid on the acquisition date. The acquisition of 2Predict was accounted for as a Business Combination according to ASC 805-10, Business Combinations . This method requires, among other things, that assets acquired and liabilities assumed in a Business Combination be recognized at their fair values as of the acquisition date. The Company recorded net assets acquired of $1.4 million, including definite-lived intangible assets of $1.2 million and goodwill of $0.2 million. Definite-lived intangible assets primarily consist of intellectual property of 2Predict, for which the weighted-average useful life is 1.5 years. Goodwill is primarily attributed to the future economic benefits arising from assets acquired that could not be individually identified and separately recognized, such as assembled workforce. The results of operations of 2Predict are included in the accompanying condensed consolidated statements of operations from the date of acquisition.

Immaterial Correction of An Err

Immaterial Correction of An Error	9 Months Ended
	Sep. 30, 2021
Accounting Changes and Error Corrections [Abstract]
Immaterial Correction of An Error	Note 5 - Immaterial Correction of An Error In September 2021, the Company revised its condensed consolidated statements of operations and comprehensive loss and condensed consolidated balance sheets to reflect the correction of immaterial errors for the years ended December 31, 2019 and 2020, and the quarter ended March 31, 2021. The corrections to hardware costs of products sold and media panel fixed assets within the property and equipment, net caption is attributable to clerical errors. As of December 31, 2019 and 2020, and March 31, 2021, respectively, the correction to media panel fixed assets resulted in a $1.1 million, $1.8 million, and $0.1 million decrease in costs of products (exclusive of depreciation and amortization) with a corresponding cumulative increase in property and equipment, net of $3.0 million. These corrections to property and equipment, net and comprehensive loss are attributable to clerical errors related to the number of stations sold to customers subject to failed-sale accounting. Pursuant to ASC 250, Accounting Changes and Error Corrections issued by the and Staff Accounting Bulletin 99, Materiality (“SAB 99”) issued by the SEC, the Company determined the impact of the error was immaterial to all periods. The correction was recorded as part of the activity within the condensed consolidated statements of operations and comprehensive losses and the condensed consolidated balance sheets for the years ended December 31, 2020 and 2019, and quarter ended March 31, 2021 as reflected herein. Adjustment resulting from these error corrections had an immaterial impact on the Company’s previously reported net loss, net loss per share, total assets, total liabilities and stockholder’s deficit.

Reverse Recapitalization

Reverse Recapitalization	9 Months Ended
	Sep. 30, 2021
Reverse Recapitalization [Abstract]
Reverse Recapitalization	Note 6 - Reverse Recapitalization As discussed in Note 1 - Description of Business, on the Closing Date, Volta Inc. (formerly TortoiseCorp II) consummated the reverse recapitalization and Legacy Volta received proceeds of $350 million. The proceeds included $300 million in proceeds from certain accredited investors that agreed to purchase 30,000,000 shares of Volta Class A Common Stock in a private placement in connection with the reverse recapitalization (the "PIPE Financing"), and is net of $242 million in redemptions from issuance of common stock upon the Closing and includes $61.0 million of transaction costs of which $8.3 million was paid by Legacy Volta as of September 30, 2021. These transaction costs consist of legal, accounting, and other professional services directly related to the reverse recapitalization. These one-time direct and incremental transaction costs incurred by the Company were recorded based on the activities to which the costs relate and the structure of the transaction; cost relating to the issuance of equity is recorded as a reduction of the amount of equity raised, presented in additional paid in capital, while all costs related to the warrants were estimated and charged to expense. The cash outflows related to these costs were presented as financing activities on the Company’s condensed consolidated statement of cash flows. On the Closing Date, each holder of Legacy Volta’s Class A common stock received approximately 1.2135 shares of Volta's Class B common stock, par value $0.0001 per share, and each holder of Legacy Volta’s Class B common stock received approximately 1.2135 shares of the Company’s Class A common stock, par value $0.0001 per share. See Note 11 - Warrants, and Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation for additional details of the Company’s stockholders’ equity prior to and subsequent to the reverse recapitalization. All equity awards of Legacy Volta . were assumed by the Company and converted into comparable equity awards that are settled or exercisable for shares of the Company’s Class A or Class B common stock based on an exchange ratio of approximately 1.2135. Each Public Warrant and Private Warrant was unexercised at the time of the reverse recapitalization and was assumed by the Company and represents the right to purchase shares of the Company’s Class A common stock. Refer to Note 11 - Warrants for additional detail. The reverse recapitalization was accounted for with Legacy Volta as the accounting acquirer and TortoiseCorp II as the acquired company for accounting purposes. Legacy Volta was determined to be the accounting acquirer since Legacy Volta’s stockholders prior to the reverse recapitalization had the greatest voting interest in the combined entity, Legacy Volta comprises all of the ongoing operations and Legacy Volta’s senior management directs operations of the combined entity. Accordingly, all historical financial information presented in the condensed consolidated financial statements represents the accounts Legacy Volta and its wholly owned subsidiaries. Net assets were stated at historical cost consistent with the treatment of the transaction as a reverse recapitalization of Volta, Inc.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 7 - Fair Value Measurements The Company uses a three-tier fair value hierarchy to prioritize the inputs used in the fair value measurements. All of the Company's cash and cash equivalents are classified within Level 1 as they are valued using quoted market prices or alternative pricing sources. The Public Warrants are classified as Level 1 due to the use of an observable market quote in an active market. The senior secured term loan and PPP loan and are classified within Level 2 as they are valued using market-based risk measurements that are indirectly observable, such as credit risk. Legacy Volta Preferred Stock warrant liabilities and the Private Warrants are classified within Level 3. The Preferred Stock warrant liabilities are measured by the OPM Back solve approach under the market method. In determining the fair value of the private placement warrant liability, the Company used the Binomial Lattice Model (“BLM”) that assumes optimal exercise of the Company’s redemption option at the earliest possible date. The following tables present information about the Company’s liabilities that are measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation techniques that the Company utilized to determine such fair value. Carrying Amount Total Level 1 Level 2 Level 3 December 31, 2020 (in thousands) Liabilities PPP loan $ 3,193 $ 3,193 $ — $ 3,193 $ — Senior secured term loan 47,827 50,960 — 50,960 — Preferred Stock warrant liability 698 698 — — 698 Total $ 51,718 $ 54,851 $ — $ 54,153 $ 698 September 30, 2021 Liabilities PPP loan $ 3,193 $ 3,193 $ — $ 3,193 $ — Senior secured term loan 43,996 46,264 — 46,264 — Public warrants 15,189 15,189 15,189 — — Private warrants 22,080 22,080 — — 22,080 Total $ 84,458 $ 86,726 $ 15,189 $ 49,457 $ 22,080 Level 2 valuation - senior secured term loan, PPP The Company measures the fair value of the senior secured term loan using discounted cash flows and market-based expectations for credit risk and market risk. The carrying amount of the PPP loan approximates fair value due to the expected short-term nature of the loan. Level 3 valuation - Legacy Volta P referred Stock warrants and Private Warrants The Company measures the value of its Legacy Volta Preferred Stock warrants on a recurring basis using the OPM Back solve approach. The OPM Back solve approach uses a Black-Scholes option pricing model to calculate the implied equity value of the Company. Once an overall equity value was determined, the aggregate amounts were allocated to the different classes of equity according to their rights and preferences. The inputs to the OPM Back solve approach include time to liquidation, a risk-free interest rate, an assumption for a discount for lack of marketability and an assumed volatility based on the volatility of similar publicly traded companies. The Legacy Volta Preferred Stock warrants were exercised as of September 30, 2021. The following table provides quantitative information regarding Level 3 Legacy Volta Preferred Stock warrants fair value measurements inputs at their measurement dates: December 31, 2020 Expected dividend yield — % Risk-free interest rate 0.53 % Expected volatility 50.00 % Expected term (in years) 4.50 The following table provides quantitative information regarding Level 3 Private Warrants fair value measurements inputs at their measurement dates: August 26, 2021 September 30, 2021 Expected dividend yield — % — % Risk-free interest rate 0.80 % 0.91 % Expected volatility 33.40 % 123.50 % Expected term (in years) 4.80 4.80 As of September 30, 2021, the Company has Private Warrants defined and discussed in Note 11 - Warrants. The warrants are measured at fair value on a recurring basis. The Binomial Lattice Model's primary unobservable input utilized in determining the fair value of the Private Warrants is the expected volatility of the common stock. The expected volatility as of the Closing was derived from observable Public Warrants pricing. The expected volatility as of subsequent valuation dates was implied from the Company’s own Public Warrants pricing. Accordingly, the Private Warrants are classified as Level 3 financial instruments. The Private Warrants were valued as of September 30, 2021 using the estimated fair value price of $2.56 per Private Warrants. The changes in the fair value of the Private Warrants, Public Warrants and Legacy Volta Preferred Stock warrants were as follows: (in thousands) December 31, 2020 $ 698 Increase (decrease) in fair value of warrants 1,246 Release of liability upon exercise of Preferred Stock Warrants (1,944) Addition of Private and Public Warrants 27,079 Increase (decrease) in Private and Public Warrants 10,190 September 30, 2021 $ 37,269 December 31, 2019 $ 288 Increase (decrease) in fair value of warrants (14) September 30, 2020 $ 274 There were no transfers of financial instruments between levels of the hierarchy for the three months ended September 30, 2021 and 2020 and for the nine months ended September 30, 2021 and 2020.

Property and equipment, net

Property and equipment, net	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and equipment, net	Note 8 - Property And Equipment, Net Property and equipment, net, as of September 30, 2021 and December 31, 2020, consist of the following: September 30, 2021 December 31, 2020 (in thousands) Charging stations and digital media screens $ 72,070 $ 43,799 Construction in progress 27,255 17,566 Capitalized research and development equipment 1,834 974 Leasehold improvements 866 552 Computer equipment and internal-use software 1,974 974 Other fixed assets 318 336 Capitalized software 45 — Total property and equipment 104,362 64,201 Less accumulated depreciation and amortization (21,973) (14,843) Property and equipment, net $ 82,389 $ 49,358

Accrued Expenses And Other Curr

Accrued Expenses And Other Current Liabilities	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Expenses And Other Current Liabilities	Note 9 - Accrued Expenses And Other Current Liabilities Accrued expenses and other current liabilities as of September 30, 2021 and December 31, 2020 consist of the following: September 30, 2021 December 31, 2020 (in thousands) Accrued billings on contracts $ 471 $ — Charging station expenses 4,619 4,812 Lease incentive liability 3,172 4,038 Employee related expenses 3,441 3,713 Financing transaction costs — 3,460 Other 1,302 1,575 Deposit liability 850 2,509 Accrued interest 43 1,426 Total accrued expenses and other liabilities $ 13,898 $ 21,533 Charging station expenses consist primarily of accrued installation costs and rent expenses. Accrued employee expenses consist of accrued bonuses and commissions. Financing transaction costs are in connection to the issuances of Legacy Volta Series D Preferred Stock for the year ended December 31, 2020. Lease incentive liability consists of payments received in excess of the SSP for performance obligations related to Network Development arrangements. These liabilities are recorded in ROU assets upon lease commencement.

Debt Facilities

Debt Facilities	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt Facilities	Note 10 - Debt Facilities The Company’s outstanding debt instruments as of September 30, 2021 and December 31, 2020 are as follows: September 30, 2021 December 31, 2020 (in thousands) Term loan $ 44,918 $ 49,000 PPP small business loan 3,193 3,193 Total outstanding principal amount 48,111 52,193 Less unamortized debt issuance fees 922 1,173 Less current maturities 19,527 10,323 Total long-term debt $ 27,662 $ 40,697 Term loan On June 19, 2019, the Company entered into a term loan agreement that provides for senior secured term loan facilities of up to $44.0 million, and on November 25, 2020, the maximum borrowings were increased to $49.0 million. $42.5 million of the principal amount was outstanding as of September 30, 2020. The Company drew on the remaining amount of the commitment of $16.7 million as of December 31, 2020. The term loan bears interest on the total outstanding balance at 12% per annum and is secured by certain qualifying assets of the Company. Principal payments are due in equal monthly installments beginning on July 1, 2021, and the term loan matures on June 19, 2024. These provisions expire on the earlier of loan termination, when the facility is fully drawn on, or two years after the closing date. As of September 30, 2021 and December 31, 2020, $44.9 million and $49.0 million respectively, of the principal was outstanding, and there was a debt discount of $0.9 million and $1.2 million, related to debt issuance costs, respectively. As of September 30, 2021 and December 31, 2020, accrued interest was $43.3 thousand and $1.4 million, respectively. As of September 30, 2021, Volta is in compliance of all debt covenants. The lenders agreed to waive their right to call the debt as a result of previous violations of certain covenants. PPP loan In April 2020 the Company applied for and received a small business loan of $3.2 million through the PPP (the "PPP Loan"). The loan principal and accrued interest are forgivable so long as the borrower maintains its payroll levels and uses the loan proceeds for eligible purposes during the covered period following disbursement, such as payroll, benefits, rent and utilities. Subject to certain qualifications and exclusions, the amount of loan forgiveness is reduced if the borrower terminates employees or reduces salaries during the covered period. Any portion of the loan that is not forgiven will carry interest at the stated rate of 1% per annum, and equal installment payments would be due monthly. Although the Company received full forgiveness for the loan as the entire amount was used for eligible expenses under the program, the Company has paid the entire balance of the PPP loan on October 12, 2021 (see Note 18 - Subsequent Events). Term loan and PPP loan payments by period as of September 30, 2021 are as follows: Fiscal Year (in thousands) Remainder of 2021 $ 5,163 2022 18,448 2023 16,333 2024 8,167 2025 — $ 48,111 Financing obligations For one customer, the Company has entered into multiple contracts to sell media-enabled charging stations and also leaseback the digital media screens for a period of up to 10 years. The leaseback of the digital media screen is in excess of its useful life of 5 years. Therefore, the consideration received equal to relative standalone selling price for the digital media screens has been recorded as a financing transaction. This financing arrangement has been amortized over its 5 year term at the Company’s incremental borrowing rate at the time of the transaction. As of September 30, 2021 and December 31, 2020, the current portions of the financing obligation were $0.8 million and $0.7 million, respectively, which were included within accrued expenses and other current liabilities. Non-current portions as of September 30, 2021 and December 31, 2020 were $3.3 million and $3.8 million, respectively, which were included within other non-current liabilities on the condensed consolidated balance sheets. The Company’s incremental borrowing rate for each of these transactions has ranged between 7.0%-16.7%. As of September 30, 2021 future payments under financing obligations were as follows: Fiscal Year (in thousands) Remainder of 2021 $ 264 2022 1,273 2023 1,305 2024 1,139 2025 726 Thereafter 354 Total future payments 5,061 Less amount representing interest 946 Total financing obligations $ 4,115

Warrants

Warrants	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Warrants	Note 11 - Warrants Legacy Volta Preferred Stock warrants In connection with the Company’s prior debt financing agreements, Legacy Volta issued Preferred Stock warrants to purchase shares of Legacy Volta Series B Preferred Stock. During December 2019, the Company issued warrants to purchase up to 209,029 shares of Series B Preferred Stock at an exercise price of $1.05 per warrant expiring in July 2025. On August 25, 2021, 208,993 shares of Legacy Volta Preferred Stock warrants were converted through a cashless exercise in accordance with the terms of the original warrant agreement. At Closing, each warrant to purchase Legacy Volta Common Stock or Legacy Volta Preferred Stock was automatically converted to a warrant to purchase a number of shares of Volta Class A Common Stock equal to the product of (a) the number of shares of Legacy Volta Common Stock or Legacy Volta Preferred Stock subject to such Legacy Volta warrant and (b) 1.2135, rounding down to the nearest whole number of shares, at an exercise price per share equal to (i) the exercise price per share for the shares of Legacy Volta Common Stock or Legacy Volta Preferred Stock subject to such Legacy Volta warrant divided by (ii) 1.2135, rounding up to the nearest whole cent. At Closing, the exercised outstanding Legacy Volta Class A common stock was increased to 253,613 due to the exchange ratio of approximately 1.2135. As of September 30, 2021, none of the Legacy Volta Preferred Stock warrants remain outstanding. As of December 31, 2020, all Legacy Volta Preferred Stock warrants remained outstanding. Legacy Volta Common stock warrants In connection with the Legacy Volta Series D issuance, the Company issued equity classified warrants to purchase 381,679 shares of Legacy Volta Class B common stock at an exercise price of $1.31, to the existing investors, during the nine months ended September 30, 2020. The Company valued the warrants at $0.76 per share upon issuance for a total amount of $0.3 million. As the warrants were issued in connection with the issuance of Legacy Volta Preferred Stock, the Legacy Volta Preferred Stock had equal and offsetting equity issuance costs of $0.3 million recorded in the condensed consolidated balance sheet as of September 30, 2020. During the nine months ended September 30, 2021, 182,025 shares of Legacy Volta Class B common stock warrants were exercised at an exercise price of $0.01 per share for an immaterial amount. During the nine months ended September 30, 2021, 188,638 shares of Class A common stock warrants were converted through a cashless exercise. As of September 30, 2021, 9,773,835 Class A common stock warrants remained outstanding. As of December 31, 2020, all Legacy Volta common stock warrants remained outstanding. Public and private warrants As the accounting acquirer, Legacy Volta, is deemed to have assumed 8,621,715 Public Warrants and 5,933,333 Private Warrants that were held by TortoiseCorp II at an exercise price of $11.50. In accordance with the Amended and Restated Warrant Agreement ("A&R Warrant Agreement"), dated August 26, 2021, between Volta, Computershare Inc. and Computershare Trust Company, N.A., collectively as warrant agent, the Public Warrants and Private Warrants will be exercisable on the later of (i) 30 days after the completion of the initial reverse recapitalization and (ii) 12 months from the closing of the Company’s IPO. The warrants will expire five years after the completion of the reverse recapitalization, or earlier upon redemption or liquidation. The public and private warrants do not meet the criteria for equity treatment and must be recorded as liabilities on the condensed consolidated balance sheets. Accordingly, the Company classifies the warrants as liabilities and records them at fair value. As of September 30, 2021, 75 public and no private warrants have been exercised. Additional charge to earning of $10.2 million immediately following the close of the transaction. Private Placement Warrants Public Warrants Total Common Stock Warrants Outstanding as of February 7, 2021 5,933,333 8,621,715 14,555,048 Common stock warrants as part of the merger 5,933,333 8,621,715 14,558,333 Warrants exercised — (75) (75) Outstanding as of September 30, 2021 5,933,333 8,621,640 14,554,973 The Private Warrants and the Public Warrants have substantially similar terms, except that the Private Warrants and Class A shares upon exercise of the Public Warrants were not transferable, assignable or salable until 30 days after the completion of the reverse recapitalization, subject to certain limited exceptions. Additionally, the Private Warrants will be non-redeemable so long as they are held by the initial purchasers or their permitted transferees. If the Private Warrants are held by someone other than the initial purchasers or their permitted transferees, the Private Warrants will be redeemable and exercisable by such holders and the same basis as the Public Warrants. Once the warrants become exercisable, the outstanding warrant can be redeemed in whole not in part and upon a minimum of 30 days’ prior written notice of redemption in the following two options: • If the last sale price of Class A shares equals or exceeds $18.00 per share (as adjusted for share sub-divisions, share dividends, reorganizations, recapitalizations and the like) for any 20 trading days within a 30-trading day period ending on the third trading day prior to the date on which the Company sends the notice of redemption to the warrant holders. In that case, the Company can redeem the outstanding warrants at a price of $0.01 per warrant. • Commencing 90 days after the warrants become exercisable, if the last sale price of Class A shares equal or exceeds $10.00 per share (as adjusted for share sub-divisions, share dividends, reorganizations, recapitalization and the like) on the trading day prior to the date on which the Company sends the notice of redemption to the warrant holders. In that case, the Company can redeem the outstanding warrants at a price equal to a number of Class A shares to be determined by reference to an agreed table based on the redemption date and the “fair market value” of Class A shares. No fractional shares will be issued upon exercise of the warrants. If, upon exercise of the warrants, a holder would be entitled to receive a fractional interest in a share, the Company will, upon exercise, round down to the nearest whole number the number of shares of Class A common stock to be issued to the warrant holder.

Stockholders_ (Deficit) Equity

Stockholders’ (Deficit) Equity And Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Stockholders’ (Deficit) Equity And Stock-Based Compensation	Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation Prior to the reverse recapitalization, Legacy Volta had two classes of authorized common stock: Legacy Volta Class A common stock and Legacy Volta Class B common stock. Shares issued on early exercise are not considered outstanding for accounting purposes because the employees holding these awards are not entitled to the rewards of stock ownership. The holders of Legacy Volta Class A common stock are entitled to one vote per share on any matter submitted to a vote of the stockholders of the Company; holders of Legacy Volta Class B common stock are entitled to receive dividends whenever funds are legally available and when declared by the Board of Directors. Reverse Recapitalization On the Closing Date and in accordance with the terms and subject to the conditions of the reverse recapitalization, each share of the Legacy Volta Class A common stock and Legacy Volta Class B common stock, par value $0.0001 per share, was canceled and converted into the right to receive the applicable portion of the reverse recapitalization comprised of the Company’s Class B common stock and Company's Class A common stock, par value $0.0001 per share, respectively, as determined pursuant to the share conversion ratio. The share conversion ratio is approximately 1.2135. PIPE Financing Concurrently with the execution of the Business Combination Agreement, certain accredited investors entered into subscription agreements, each dated February 7, 2021, pursuant to which the investors agreed to purchase 30,000,000 shares of Volta's Class A Common Stock in a private placement for aggregate gross proceeds of $300 million. Convertible Preferred Stock Prior to the closing, Legacy Volta had shares of Series A, Series B, Series C, Series C-1, Series C-2, Series D, and Series D-1 convertible Preferred Stock outstanding. Upon the Closing, the outstanding shares of Legacy Volta Preferred Stock were converted into Class A common stock of the Company at approximately 1.2135 per share, the exchange ratio established in connection thereof the reverse recapitalization. The following summarized the Company’s Preferred Stock conversion immediately after the reverse recapitalization: Preferred Shares Conversion Ratio Common Stock Series A redeemable convertible Preferred Stock 7,363,856 1.2135 8,936,039 Series B redeemable convertible Preferred Stock 11,090,568 1.2135 13,458,404 Series C redeemable convertible Preferred Stock 665,428 1.2135 807,497 Series C-1 redeemable convertible Preferred Stock 7,675,798 1.2135 9,314,581 Series C-2 redeemable convertible Preferred Stock 18,581,768 1.2135 22,548,975 Series D redeemable convertible Preferred Stock 8,283,574 1.2135 10,052,117 Series D-1 redeemable convertible Preferred Stock 13,266,042 1.2135 16,098,342 Total 66,927,034 81,215,955 Company’s common stock outstanding Authorized Shares Issued and Outstanding Shares September 30, 2021 Volta Class A common stock 350,000,000 152,021,218 Volta Class B common stock 50,000,000 9,887,185 Total common stock outstanding 400,000,000 161,908,403 December 31, 2020 Volta Class A common stock 48,540,000 13,185,808 Volta Class B common stock 104,361,000 11,510,629 Total common stock outstanding 152,901,000 24,696,437 Volta Class A and Volta Class B common stock Each holder of Volta Class A common stock has the right to one vote per share of Volta Class A common stock, and each holder of Volta Class B common stock has the right to ten votes per share of Volta Class B common stock held of record by such holder. Any dividends or distributions will be treated on a per share basis for each class. In the event a dividend is paid in the form of shares of Volta Class A common stock or Volta Class B common stock then holders of Volta Class A common stock will receive shares of Volta Class A common stock and holders of Volta Class B common stock will receive shares of Volta Class B common stock, with holders of shares of Volta Class A common stock and Volta Class B common stock receiving, on a per share basis, an identical number of shares of Volta Class A common stock or Volta Class B common stock, as applicable. Subject to any preferential or other rights of any holders of Volta Preferred Stock then outstanding, upon the liquidation, dissolution or winding up of Volta, whether voluntary or involuntary, holders of Volta Class A common stock and Volta Class B common stock are entitled to receive ratably all assets of Volta available for distribution to its stockholders. The holders of Volta Class A and Class B common stock do not have preemptive, subscription, redemption or conversion rights. The Volta Class B common stock is convertible into shares of Volta Class A common stock on a one-to-one basis at the option of the holders or automatically upon predetermined events of the Volta Class B common stock at any time upon written notice to Volta. Volta Preferred Stock The Certificate of Incorporation of Volta dated filed with the Secretary of State of the State of Delaware on August 26, 2021, as the same may be amended, supplemented or modified from time to time provides that shares of Volta Preferred Stock may be issued from time to time in one or more series up to 10,000,000 shares. No such shares have been issued as of September 30, 2021. Shares reserved for issuance The Company has the following shares of common stock reserved for future issuance, on an as-if converted basis: September 30, 2021 December 31, 2020 Redeemable Convertible Preferred Stock — 76,493,917 Outstanding Public Warrants 8,621,640 — Outstanding Private Warrants 5,933,333 — Preferred Stock Warrants — 190,210 Common stock warrants 9,773,835 10,156,090 Options and RSAs outstanding 11,881,500 6,307,307 Shares available for grant – 2014 Equity Incentive Plan — 14,301,980 Shares available for grant – 2021 Equity Incentive Plan 11,234,585 — Total shares of common stock reserved 47,444,893 107,449,504 Stock option activity Upon the Closing, Volta's board of directors, (the "Board") adopted a new plan (which amended and restated the prior plan), the 2021 Equity Incentive Plan (“2021 EIP”) effective as of August 26, 2021. As of September 30, 2021, 11,234,585 shares of common stock were available and reserved for issuance under the 2021 EIP. The amount of shares available and reserved for issuance under the 2021 EIP include the shares reserved for issuance under the Legacy Volta 2014 Equity Incentive Plan ("2014 EIP"). On the first day of each fiscal year beginning with the 2022 fiscal year and ending on (and including) the first day of the 2031 fiscal year, the number of shares available for issuance under the 2021 EIP will automatically increase in an amount equal to the lesser of (i) five percent (5%) of the outstanding shares on the last day of the immediately preceding fiscal year and (ii) such number of shares determined by the Board, with such shares to be Class A common stock. Under the 2021 EIP, the Company can grant stock options, stock appreciation rights, restricted stock, restricted stock units and certain other awards which are settled in the form of common shares under the 2021 EIP. No further awards will be granted under the Legacy Volta 2014 EIP. Stock option activity and activity regarding shares available for grant under the Plan is as follows: Number of options outstanding Weighted-average exercise price per share Weighted-average remaining contractual life (years) Aggregate intrinsic value (in thousands) January 1, 2020 12,890,557 $ 0.76 8.6 $ 5,836 Options granted 5,319,061 1.05 Options exercised (259,070) 0.49 Options forfeited (281,669) 0.97 Options expired (110,148) 0.76 December 31, 2020 17,558,731 $ 0.93 8.2 $ 30,881 Options granted 5,080,793 3.35 Options exercised (618,785) 1.70 Options forfeited (124,272) 1.76 Options expired — — March 31, 2021 21,896,467 $ 2.03 8.4 $ 108,590 Options granted 1,663,344 — Options exercised (384,199) 0.66 Options forfeited (81,095) 2.41 Options expired — — June 30, 2021 23,094,517 $ 2.88 8.3 $ 124,351 Options granted 459,310 8.46 Options exercised (8,371,796) 3.86 Options forfeited (170,652) 2.21 Options expired — Balance at September 30, 2021 15,011,379 $ 3.14 8.5 $ 63,228 Options vested and exercisable as of September 30, 2021 4,519,984 $ 1.55 7.6 $ 31,231 The aggregate intrinsic value of employee options exercised during the three months ended September 30, 2021 and September 30, 2020 was $45.6 million and immaterial, respectively. The aggregate intrinsic value of employee options exercised during the nine months ended September 30, 2021 and September 30, 2020 was $52.0 million and immaterial, respectively. The intrinsic value is the difference between the estimated fair value of the Company’s common stock at the date of the exercise and the exercise price for in-the-money options. The weighted-average grant-date fair value of employee options granted during the three months ended September 30, 2021 and September 30, 2020 was $5.42 and $0.37 per share, respectively. The weighted-average grant-date fair value of employee options granted during the nine months ended September 30, 2021 and September 30, 2020 was $4.29 and $0.37 per share, respectively. The weighted-average grant-date fair value of employee options forfeited during the three months ended September 30, 2021 and September 30, 2021 was $2.33 and $0.35 per share, respectively. The weighted-average grant-date fair value of employee options forfeited during the nine months ended September 30, 2021 and September 30, 2020 was $2.10 and $0.91 per share, respectively. The weighted-average grant-date fair value of options that vested during the three months ended September 30, 2021 and September 30, 2020 was $1.53 and $1.01 per share, respectively. The weighted-average grant-date fair value of options that vested during the nine months ended September 30, 2021 and September 30, 2020 was $1.77 and $0.79 per share, respectively. The total fair value of options vested during the three months ended September 30, 2021 and September 30, 2020 was $1.6 million and $1.0 million , respectively. The total fair value of options vested during the nine months ended September 30, 2021 and September 30, 2020 was $7.4 million and $1.7 million, respectively. Stock-based compensation Stock-based compensation is estimated using the Black-Scholes option pricing model on the date of grant. The fair value of all options is amortized on a ratable basis over the required service periods of the awards, which are generally the vesting periods. The weighted-average assumptions that were used in calculating such values during the three months ended September 30, 2021 and 2020 and for the nine months ended September 30, 2021 and 2020 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Expected dividend yield — % — % — % — % Risk-free interest rate 0.9 % 0.4 % 0.7 % 0.8 % Expected volatility 64.2 % 54.9 % 60.4 % 48.0 % Expected term (in years) 6.0 5.9 5.8 5.9 The Company has limited historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. Therefore, the expected term of options granted is based on the “simplified method” of expected life. The risk-free interest rate is based on the U.S. Treasury yield for a term consistent with the expected life of the awards in effect at the time of grant. As the Company does not have a trading history for its common stock prior to the reverse recapitalization, the expected stock price volatility for the Company’s common stock was estimated by taking the historic stock price volatility for industry peers based on their price observations over a period equivalent to the expected term of the stock option grants. The Company has no history or expectation of paying cash dividends on its common stock. As of September 30, 2021 and 2020, the Company had unrecognized employee stock-based compensation expense of $18.9 million and $2.4 million, respectively, related to unvested stock awards not yet recognized, which is expected to be recognized over an estimated weighted-average period of approximately 3.3 years and 1.7 years, respectively. Compensation expense Compensation expense related to stock-based awards was recorded in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss for $4.6 million and $0.3 million for the three months ended September 30, 2021 and 2020, respectively, and $51.4 million and $0.8 million for the nine months ended September 30, 2021, and 2020 respectively. Partial recourse promissory notes As of September 30, 2021 and December 31, 2020, the Company had $1.2 million and $10.4 million of promissory notes outstanding from employees and former employees, issued for 243,306 and 1,036,124 restricted stock purchases of Legacy Volta Class A common stock, respectively, and the exercise of 1,331,914 and 11,147,195 shares of stock options exercisable for Legacy Volta Class B common stock, respectively. Two of the remaining promissory notes for the exercise of stock options represent the aggregate exercise price of the options and carry an interest rate of 2.26%, and the principal and interest are due upon the earlier of (i) the tenth anniversary of the note’s issuance, or (ii) the date of a change of control. One of the promissory notes carries an interest rate of 3.25% and is due December 15, 2021. All promissory notes issued are collateralized by the shares issued in exchange for the note and were considered to be partial recourse as they may be surrendered at the then fair market value of a share of common stock as determined by the Board. The remainder up to 50% of the value of the original principal of the notes is collateralized by the assets of the borrowers. The amount payable is not limited to the fair value of the shares at the time of default or maturity. As such, the shares are not considered exercised for accounting purposes and the shares issued are not reflected as outstanding in the condensed consolidated financial statements until the notes are repaid and the underlying stock options have vested. The promissory notes with current employees were required to be settled upon the Closing. The notes associated with three former employees were not required to be settled upon the change of control and going public and remain outstanding as of September 30, 2021 in accordance with the terms of each respective Note. As of September 30, 2021, the Company had $0.1 million recorded in prepaid and other current assets related to one former employee’s tax portion that will not be settled until the repayment of the note in December 2021.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	Note 13 - Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the period. For stock options that were exercised by employees issuing promissory notes to the Company, the shares of common stock issued under such exercises are not included in the calculation of basic net loss per share until the underlying promissory notes are fully paid or forgiven. Diluted net loss per share is computed in a similar manner, but it also includes the effect of potential common shares outstanding during the period, when dilutive. Potential common shares include outstanding stock options, Legacy Volta convertible Preferred Stock, warrants for Legacy Volta Common Stock and warrants for Legacy Volta Preferred Stock. The dilutive effect of potentially dilutive common shares is reflected in diluted net loss per share by application of the treasury stock method for stock options and warrants, and by application of the if-converted method for the Legacy Volta Preferred Stock. Deposits received for the repayment of the promissory notes for the exercise of stock options are considered in the calculation of diluted net loss per share, in the event the effect is dilutive. To the extent these potential common shares are antidilutive, they are excluded from the calculation of diluted net loss per share. The following table presents the computation of basic and diluted net loss per share for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Class A Common Shares Class B Common Shares Class A Common Shares Class B Common Shares Class A Common Shares Class B Common Shares Class A Common Shares Class B Common Shares (in thousands except share and per share) Numerator: Net loss $ (38,141) $ (4,907) $ (2,457) $ (12,060) $ (97,475) $ (31,329) $ (6,599) $ (32,433) Denominator: Basic shares: Weighted-average common shares, basic 65,923,212 8,481,143 1,575,462 7,733,885 27,998,369 8,998,756 1,573,563 7,733,885 Diluted shares: Weighted-average common shares, diluted 65,923,212 8,481,143 1,575,462 7,733,885 27,998,369 8,998,756 1,573,563 7,733,885 Net loss per share attributable to common stockholders: Basic $ (0.58) $ (0.58) $ (1.56) $ (1.56) $ (3.48) $ (3.48) $ (4.19) $ (4.19) Diluted $ (0.58) $ (0.58) $ (1.56) $ (1.56) $ (3.48) $ (3.48) $ (4.19) $ (4.19) The following weighted average shares of the potentially dilutive outstanding securities for the three months ended and nine months ended September 30, 2021 were excluded from the computation of diluted net loss per share because their effect would have been anti-dilutive given the net loss attributable to common shares. Therefore, the diluted net loss per share is the same as the basic net loss per share for the periods presented. As a result of the reverse recapitalization, the Company has retroactively adjusted the weighted-average number of shares of common stock outstanding prior to the by multiplying them by the exchange ratio of approximately 1.2135 used to determine the number of shares of common stock into which they converted. The common stock issued as a result of the redeemable convertible Preferred Stock conversion on the Closing Date was included in the basic and diluted net loss per share calculation. Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Anti-dilutive securities Outstanding stock options - stock plan 11,692,733 15,763,501 11,692,733 15,763,501 Non plan option grants 188,767 — 188,767 — Convertible Preferred Stock — 55,065,497 — 55,065,497 Warrants for common stock 24,328,810 9,974,065 24,328,810 9,974,065 Warrants for Preferred Stock — 190,210 — 190,210 Options and RSAs exercised under notes receivables 1,911,529 3,885,298 1,911,529 3,885,298 Total anti-dilutive securities 38,121,839 84,878,571 38,121,839 84,878,571

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Lessee Disclosure [Abstract]
Leases	Note 14 - Leases The Company is a lessee in several noncancellable operating leases, primarily for office space and the use of spaces for the installation of its electric vehicle charging stations ("site leases"). These leases generally have an initial term ranging from five one Supplemental information related to leases within the condensed consolidated balance sheets is as follows: September 30, 2021 December 31, 2020 Other operating leases information Weighted-average remaining lease term (years) 7.7 7.9 Weighted-average discount rate 12.8 % 13.8 % Other financing leases information Weighted-average remaining lease term (years) 2.8 — Weighted-average discount rate 9.3 % — % The Company received COVID-19 related rent concessions indicating that (i) the Company was not obligated to pay rent, or the entirety of the contractual rent, or (ii) the Company received interest-free rent deferrals for the period affected by lockdown measures. The amount of such concessions recognized as negative variable lease cost for the three months and nine months ended September 30, 2020 was $0.1 million and $0.2 million, respectively. There were no such concessions recognized as negative variable lease cost for the three months or nine months ended September 30, 2021. The following lease costs were recognized in other operating (income) expenses within the condensed consolidated statements of operations and comprehensive loss: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) Operating lease costs Fixed lease cost $ 3,011 $ 1,926 $ 8,481 $ 3,436 Variable lease cost 122 (38) 320 (73) Total operating lease costs $ 3,133 $ 1,888 $ 8,801 $ 3,363 Finance lease costs Fixed lease cost $ 2 $ — $ 2 $ — Total finance lease costs $ 2 $ — $ 2 $ — Supplemental cash flow information related to leases is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) Cash paid for amounts included in the measurement of lease liabilities Operating cash outflows from operating leases $ 2,538 $ 1,537 $ 7,014 $ 2,874 Operating cash outflows from finance leases 1 — 1 — ROU assets obtained in exchange for lease obligations ROU assets obtained in exchange for operating lease liabilities 6,843 5,758 14,388 4,269 ROU assets obtained in exchange for finance liabilities $ — $ — $ 34 $ — Amounts disclosed for ROU assets obtained in exchange for lease obligations include amounts added to the carrying amount of ROU assets resulting from lease modifications and reassessments. Maturities of lease liabilities as of September 30, 2021 are as follows: Fiscal Year Operating Leases (in thousands) Remainder of 2021 $ 3,439 2022 11,798 2023 12,379 2024 11,849 2025 10,908 Thereafter 38,811 Total undiscounted lease payments 89,184 Less imputed interest (32,102) Total operating lease liabilities $ 57,082 Fiscal Year Finance Leases (in thousands) Remainder of 2021 $ 2 2022 5 2023 5 2024 23 2025 — Thereafter — Total undiscounted lease payments 35 Less imputed interest (6) Total financing lease liabilities $ 29 As of September 30, 2021, there are no material leases that are legally binding but have not yet commenced.
Leases	Note 14 - Leases The Company is a lessee in several noncancellable operating leases, primarily for office space and the use of spaces for the installation of its electric vehicle charging stations ("site leases"). These leases generally have an initial term ranging from five one Supplemental information related to leases within the condensed consolidated balance sheets is as follows: September 30, 2021 December 31, 2020 Other operating leases information Weighted-average remaining lease term (years) 7.7 7.9 Weighted-average discount rate 12.8 % 13.8 % Other financing leases information Weighted-average remaining lease term (years) 2.8 — Weighted-average discount rate 9.3 % — % The Company received COVID-19 related rent concessions indicating that (i) the Company was not obligated to pay rent, or the entirety of the contractual rent, or (ii) the Company received interest-free rent deferrals for the period affected by lockdown measures. The amount of such concessions recognized as negative variable lease cost for the three months and nine months ended September 30, 2020 was $0.1 million and $0.2 million, respectively. There were no such concessions recognized as negative variable lease cost for the three months or nine months ended September 30, 2021. The following lease costs were recognized in other operating (income) expenses within the condensed consolidated statements of operations and comprehensive loss: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) Operating lease costs Fixed lease cost $ 3,011 $ 1,926 $ 8,481 $ 3,436 Variable lease cost 122 (38) 320 (73) Total operating lease costs $ 3,133 $ 1,888 $ 8,801 $ 3,363 Finance lease costs Fixed lease cost $ 2 $ — $ 2 $ — Total finance lease costs $ 2 $ — $ 2 $ — Supplemental cash flow information related to leases is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) Cash paid for amounts included in the measurement of lease liabilities Operating cash outflows from operating leases $ 2,538 $ 1,537 $ 7,014 $ 2,874 Operating cash outflows from finance leases 1 — 1 — ROU assets obtained in exchange for lease obligations ROU assets obtained in exchange for operating lease liabilities 6,843 5,758 14,388 4,269 ROU assets obtained in exchange for finance liabilities $ — $ — $ 34 $ — Amounts disclosed for ROU assets obtained in exchange for lease obligations include amounts added to the carrying amount of ROU assets resulting from lease modifications and reassessments. Maturities of lease liabilities as of September 30, 2021 are as follows: Fiscal Year Operating Leases (in thousands) Remainder of 2021 $ 3,439 2022 11,798 2023 12,379 2024 11,849 2025 10,908 Thereafter 38,811 Total undiscounted lease payments 89,184 Less imputed interest (32,102) Total operating lease liabilities $ 57,082 Fiscal Year Finance Leases (in thousands) Remainder of 2021 $ 2 2022 5 2023 5 2024 23 2025 — Thereafter — Total undiscounted lease payments 35 Less imputed interest (6) Total financing lease liabilities $ 29 As of September 30, 2021, there are no material leases that are legally binding but have not yet commenced.

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Note 15 - Commitments And Contingencies Contingencies From time to time, the Company may become involved in claims and other legal matters, either asserted or unasserted, arising in the ordinary course of business. While the outcome of these claims cannot be predicted with certainty, management does not believe that the outcome of any of these ongoing legal matters, individually and in aggregate, will have a material adverse effect on the Company’s condensed consolidated financial statements. As of September 30, 2021 and December 31, 2020, the Company had $0.6 million in accrued expenses and other current liabilities on the condensed consolidated balance sheets for invoices totaling $1.4 million. In good faith, the Company disputed invoices for work performed in 2019. There are various disagreements between the Company and the vendor regarding these invoices. The Company disputes the underlying basis for these amounts and notified the vendor during the year ended December 31, 2020 of the Company’s intent not to pay. Employee benefit plan The Company has a 401(K) defined contribution savings plan that covers substantially all of its employees. The Company contributes a matching contribution of up to 4% of the employee's contribution under applicable safe harbor rules. Employee contribution is also limited by annual maximum amount determined by the Internal Revenue Service. The Company made contributions of $0.2 million and $0.1 million for the three months ended September 30, 2021 and 2020, respectively, and $0.7 million and $0.4 million for the nine months ended September 30, 2021 and 2020, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 16 - Income Taxes The provision for income taxes is recorded at the end of each interim period based on the Company’s best estimate of its effective income tax rate expected to be applicable for the full fiscal year in accordance with ASC 740-270. There is no provision for income taxes because the Company has incurred operating losses since inception and has projected losses for the current year. The Company’s effective income tax rate was 0% for the three months ended September 30, 2021 and 2020 and for the nine months ended September 30, 2021 and 2020, and the realization of any deferred tax assets does not satisfy the "is not more likely than not" threshold.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related party transactions	Note 17 - Related Party Transactions 2Predict, Inc. Prior to April 2021, the Company received consulting services from 2Predict, Inc., a firm where a Volta officer is co-founder and CEO, and recognized consulting service expenses of $0.2 million and $0.4 million for the three and nine months ended September 30, 2020, respectively, in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss. As of December 31, 2020, the Company maintained a balance of $0.1 million in accounts payable - due to related party for the consulting services received. As of September 30, 2021 the Company had no balance in accounts payable - due to related party for consulting services received. As of September 30, 2021, 2Predict, Inc., is no longer a related party as it was acquired by the Company in April 2021 (see Note 4 - Acquisitions). Related party loans Legacy Volta issued a total of $30.0 million in convertible notes for the nine months ended September 30, 2020, of which $9.8 million was issued to Activate Capital Partners, LP, an entity where a Volta Board member is the partner and co-founder, Virgo Hermes, LLC, an entity where a Volta Board member is a partner, Energize Ventures, LLC, where a Volta Board member is the Managing Partner, former Volta CFO Debra Crow, and Bauer Family Investments, a Volta Investor. From September 30, 2020 through December 31, 2020, the Company issued a total of $0.2 million in convertible notes, none of which were issued to related parties. As of December 31, 2020, the total $9.8 million convertible notes issued to related parties had been converted into 2,721,956 shares of Series D-1 Preferred Stock at a conversion price of $3.77 per share for total proceeds of $10.3 million. The Series D-1 Preferred Stock shares were issued, collectively, to Activate Capital Partners, LP, Virgo Hermes, LLC, and Energize Ventures, LLC, the former Volta CFO, Debra Crow, and Bauer Family Investments. At Closing, the outstanding shares of 2,721,956 Legacy Volta Series D-1 Preferred Stock were converted into 3,303,094 Class A common stock of the Company through a cashless exercise, as determined by pursuant to the share conversion ratio (see Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation). From September 30, 2020 through December 31, 2020, the Company issued 9,374,786 shares of Legacy Volta Series D Preferred Stock which at Closing, were converted into 11,376,303 Class A common stock of the Company through a cashless exercise. Of the 9,374,786 shares of Legacy Volta Series D Preferred Stock, 169,485 shares were to 19York Ventures, which is an entity founded by a Volta Board member, Activate Capital Partners, LP and Energize Ventures, LLC at $7.38 per share for total proceeds of $1.3 million. The 169,485 shares of Legacy Volta Series D Preferred Stock were converted into 205,670 Class A common stock of the Company through a cashless exercise. During the nine months ended September 30, 2021, the Company issued 3,891,256 shares of Legacy Volta Series D Preferred Stock which upon the Closing, were converted into 4,722,039 Class A common stock of the Company through a cashless exercise. Of the 3,891,256 shares of Legacy Volta Series D Preferred Stock, 2,262,594 shares were to 19York Ventures, Tire Rack, a Volta Investor, and Energize Ventures, LLC at $7.38 per share for total proceeds of $15.0 million, which upon the Closing, were converted into 2,745,658 shares of the Company's Class A common stock (see Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation). Common stock warrants During the nine months ended September 30, 2021, and as of December 31, 2020, in connection with Legacy Volta's Series D issuance (see Note 11 - Warrants), the Company issued 381,679 and 150,000 Legacy Volta Class B common stock warrants for a total value of $0.3 million and $0.5 million, which upon the date of the Closing, were converted into 463,167 and 182,025 of the Company's Class A common stock of the Company through a cashless exercise to Energize Ventures, LLC, and to Activate Capital Partners, LP for the consulting services provided during the fundraising, respectively (see Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation). Promissory notes All of the principal related to partial recourse promissory notes issued by the Company as of December 31, 2020 was used to exercise options for 9,271,877 shares of the Company’s common stock. The aggregate principal amount of promissory notes includes $0.7 million for taxes relating to 83(b) elections paid on the employees’ behalf and was recognized as notes receivable - employee on the condensed consolidated balance sheet as of December 31, 2020. As part of the reverse recapitalization, all promissory notes with employees were required to be settled. The remaining $0.1 million is related to a former employee within prepaid expense and other current assets as of September 30, 2021 (see Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation). During the nine months ended September 30, 2021, the Company entered into promissory note agreements with related parties where the Company loaned $8.3 million at an interest rate of 3.25%. The promissory notes with current employees were required to be settled upon the Closing. The notes associated with three former employees were not required to be settled upon the change of control and going public and remain outstanding as of September 30, 2021 in accordance with the terms of each respective Note (see Note 12 - Stockholders’ (Deficit) Equity And Stock-Based Compensation). Legacy Volta Class B common stock During the nine months ended September 30, 2021 the Company issued 5,700,000 shares of restricted stock awards of Legacy Volta Class B common stock, which upon the Closing, were converted into 6,916,950 Class A common stock of the Company to the CEO and President. The awards became fully vested upon issuance.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 18 - Subsequent Events The Company has evaluated events subsequent to September 30, 2021 and through the date the financials are made available. The following events occurring subsequent to the condensed consolidated balance sheet date merited recognition or disclosure in these statements. Early re-payment of PPP loan Although the Company received full forgiveness for the PPP Loan for the nine months ended September 30, 2021, as the entire amount was used for eligible expenses under the program, the Company paid the entire balance of $3.2 million loan on October 12, 2021. RSU grants On November 8, 2021, the Board of Directors approved the issuance of restricted stock units ("RSU's") under the Founder Plan covering 5,250,000 RSU's each to the Chief Executive Officer and President. Each RSU represents the right to receive one share of the Company's Class B common stock. Litigation On April 6, 2021, The Company was named as a defendant in an indemnity case, seeking costs and coverage for a slip and fall. While the primary case has been settled as of October 14, 2021 through payment by the Company's insurer, the claimant is seeking additional payment for costs, which could result in a loss of up to $150,000 for which coverage by the Company's insurer is uncertain.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of presentation	The accompanying condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles ("GAAP") and include the accounts and operations of Volta Inc. and its wholly-owned subsidiaries. Volta Charging, LLC is the primary operating subsidiary of the Company.
Consolidation	All intercompany accounts and transactions have been eliminated upon consolidation.
Use of estimates	The preparation of condensed consolidated financial statements in conformity with GAAP requires the Company to make estimates, judgments and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Significant items subject to management’s estimates and assumptions include, but are not limited to, assumptions underlying the determination of the stand-alone selling prices for performance obligations within revenue arrangements, allowance for doubtful accounts, inventory valuation, stock-based compensation, tax valuation allowance, valuation and recognition of warrants, incremental borrowing rate for right-of-use ("ROU") assets and lease liabilities, lease term, the valuation and useful lives of property and equipment, goodwill and intangibles, and the valuation of assets acquired and liabilities assumed for reverse recapitalization. The Company believes that the estimates and judgments upon which it relies are reasonable based upon information available to the Company at the time that these estimates and judgments are made. The Company periodically evaluates such estimates and adjusts prospectively based upon such periodic evaluation. Actual results could differ materially from those estimates using different assumptions or under different conditions.
Reclassifications	Certain prior period amounts have been reclassified to conform to current period presentation. These reclassifications have no effect on previously reported results of operations or loss per share.
Cash and cash equivalents	Cash and cash equivalents include on-demand deposits with banks and a mutual fund, respectively, for which cost approximates the fair value.
Restricted cash	Restricted cash as of September 30, 2021 includes $0.1 million held in escrow related to payments to contractors.
Accounts receivable and allowance for doubtful accounts	Unbilled receivables result from amounts recognized as revenues but not yet invoiced as of the condensed consolidated balance sheet date. As of September 30, 2021 and December 31, 2020, the company had $0.8 million and $0.8 million, respectively, in unbilled receivables related to network development revenue, which are included in the accounts receivable balance.
Concentration of risk	Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash and accounts receivable. The Company’s cash is held on deposit with high-credit quality financial institutions. Such deposits may at times exceed federally insured limits. The Company has not experienced losses in such amounts or accounts.
Property and equipment	Property and equipment are stated at cost, less accumulated depreciation and amortization. The cost of maintenance and repairs is expensed as incurred, and expenditures that extend the useful lives of assets are capitalized. Property and equipment are depreciated and amortized using the straight-line method over the estimated useful lives of the respective assets. Leasehold improvements are depreciated using the straight-line method over the shorter of the estimated useful lives of the assets or the lease term, ranging from two Asset Useful Lives (In Years) Charging stations and digital media screens 5-10 Capitalized research and development equipment 5 Computers and equipment 3-5 Furniture 5 Leasehold improvements 2-5 Internal-use software 0.5 Construction in progress includes all costs capitalized related to projects, primarily related to in-process engineering activities and installation of assets that have yet to be placed in service. When assets are retired or otherwise disposed of, the cost and accumulated depreciation or amortization are removed from the condensed consolidated balance sheets, and any resulting gain or loss is reflected in the condensed consolidated statements of operations and comprehensive loss in the period realized.
Impairment of long-lived assets and intangibles	Intangible assets with finite lives are amortized over their useful lives and reported net of accumulated amortization. The Company evaluates its long-lived assets and intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The recoverability of assets to be held and used is assessed by a comparison of the carrying amount of an asset to future net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. Although the Company has accumulated losses, the Company believes that the future cash flows will be sufficient to exceed the carrying value of the Company’s long-lived and intangible assets. As of September 30, 2021 and December 31, 2020, the Company determined that no events or changes in circumstances existed that would otherwise indicate any impairment of its long-lived or intangible assets.
Goodwill	Goodwill is evaluated for impairment at the end of each fiscal year or more frequently if impairment indicators are present. A qualitative assessment is performed to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of the reporting unit is less than its carrying amount. If, based on the evaluation, it is determined to be more likely than not that the fair value is less than the carrying value, then the goodwill is tested further for impairment. If the implied fair value of goodwill is lower than its carrying amount, an impairment loss is recognized in an amount equal to the difference.
Leases	The Company determines if an arrangement contains a lease at inceptio n. The Company recognizes an ROU asset and a lease liability at the lease commencement date for operating leases with terms greater than 12 months. ROU assets represent the Company's right to use an underlying asset for the lease term, and lease liabilities represent the obligation to make lease payments arising from the lease . The initial measurement of ROU assets is comprised of the initial amount of the lease liability, adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred, less any lease incentives received. ROU assets are subsequently measured throughout the lease term at the carrying amount of the lease liability, plus any initial direct costs, plus (less) any prepaid (accrued) lease payments, less the unamortized balance of lease incentives received. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The interest rate used to determine the present value of the future lease payments is the Company's incremental borrowing rate as the Company generally cannot determine the implicit rate because it does not have access to the lessor's residual value or the amount of the lessor's deferred initial costs. The incremental borrowing rate is the interest rate the Company would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. Lease terms include the noncancellable period of the lease plus any additional periods covered by either an option to extend (or not to terminate) the lease that the Company is reasonably certain to exercise, or an option to extend (or not to terminate) the lease controlled by the lessor. Variable lease payments associated with the Company's leases are recognized when the event, activity, or circumstance in the lease agreement on which those payments are assessed occurs. Variable lease payments are recognized in other operating (income) expenses in the condensed consolidated statement of operations and comprehensive loss. The Company identifies separate lease and non-lease components within the contract. Non-lease components primarily include payments for electricity reimbursements made to the landlord. The Company has elected the practical expedient to combine lease and non-lease payments and account for them together as a single lease component, which increases the amount of the Company's ROU assets and lease liabilities. In April 2020, the Financial Accounting Standards Board ("FASB") provided for an optional practical expedient that simplifies how a lessee accounts for rent concessions that are a direct consequence of the COVID-19 pandemic. The practical expedient provides that, for eligible leases, the lessee may choose to forgo the evaluation of the enforceable rights and obligations of the original lease contract. Instead, lessees may account for COVID-19 related rent concessions either (i) as if they were part of the enforceable rights and obligations of the parties under the existing lease contract or (ii) as a lease modification. Eligible leases are those for which the concession is COVID-19 related and the changes to the lease do not result in a substantial increase to the rights of the lessor or the obligations of the lessee. The Company has elected to apply the practical expedient for all eligible lease modifications, resulting in the rent concession being recorded as a negative variable lease cost and recognized in the condensed consolidated statement of operations and comprehensive loss in that period.
Stock warrants	The Company’s Common Stock warrants are freestanding warrants that were issued by Legacy Volta in connection with certain debt and equity financing transactions ("Legacy Volta Warrants"). At the Closing, the Legacy Volta Warrants were converted into warrants to purchase Volta Class A Common Stock ("Converted Warrants"). The Converted Warrants are classified as equity instruments at the grant date fair value calculated using the OPM Back solve approach and are not subject to revaluation at the condensed consolidated balance sheet date. Additionally, TortoiseCorp II sold warrants as a part of the units in TortoiseCorp's initial public offering of units, which closed on September 15, 2020 (the "IPO") (the "Public Warrants") and issued warrants to TortoiseEcofin Borrower, LLC ("Tortoise Borrower") in a private placement simultaneously with the closing of the IPO (the "Private Warrants"). As the Public Warrants and Private warrants do not meet the criteria for equity treatment, they are recorded as liabilities on the condensed consolidated balance sheets. Accordingly, the Company classifies the Private Warrants and Public Warrants as liabilities and records them at fair value.
Revenue recognition	ASC 606 Revenue is recognized when promised goods or services 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 by following a five-step process, (i) identify the contract with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price, and (v) recognize revenue when or as the Company satisfies a performance obligation. The Company generally considers a sales contract and/or agreement with an approved purchase order as a customer contract provided that collection is considered probable, which is assessed based on the creditworthiness of the customer. The Company combines contracts with a customer if contracts are entered into at or near the same time with the same customer and are negotiated with a single commercial substance or contain price dependencies. As it enters contracts with customers, the Company evaluates distinct goods and services promised in the contract to identify the appropriate performance obligations. The performance obligations include advertising services, charging stations, which include Level 2 ("L2") or Direct Current Fast Charging ("DCFC") stations, installation services, operation and maintenance services, installed infrastructure, regulatory credits and Software-as-a-Service ("SaaS"). The Company generally contracts with customers at fixed amounts and has not experienced significant returns or price concessions and discounts. To the extent the Company is entitled to variable consideration on the sale of goods or services, it will estimate the amount it expects to collect as part of the transaction price provided it is probable that a significant reversal of revenue will not occur when the uncertainty related to variable consideration is resolved. When a contract contains multiple performance obligations, the Company allocates the transaction price to each performance obligation using the relative standalone selling price (“SSP”) method. The determination of SSP is judgmental and is based on the price the Company would charge for the same good or service if it were sold separately in a standalone sale to similar customers in similar circumstances. As the charging stations, installation and operation and maintenance services are never sold separately, the Company utilizes an expected cost plus a margin approach to determine the SSP of each of the separate performance obligations. Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for promised goods or services. Disaggregation of revenue Behavior and commerce Behavior and Commerce revenue is generated by displaying paid media content on the Company's network of media-enabled charging stations. National and regional businesses pay for content either directly or through their relationships with advertising agencies, based on the number of impressions delivered over the contract term, which is typically less than one year. Behavior and Commerce revenue is recognized ratably over time as the impressions are displayed on media-enabled charging stations over the contract term. The Company typically bills customers in advance on a monthly basis, and payments are typically due within one month after content delivery. Behavior and Commerce revenue is recorded in service revenue in the condensed consolidated statements of operations and comprehensive loss. Network development Network Development revenue consists of revenue generated through installation services, operation and maintenance services offered over the contract term (generally a 10-year term), installed infrastructure for utility companies and charging station products. Revenue from installation services is recognized over time using an input method based on costs incurred to measure progress toward complete satisfaction of the performance obligation. Revenue from operation and maintenance services is recognized ratably over the term of the arrangement as the services are performed. Revenue from the sale of installed infrastructure is recognized at a point in time when control of the installed infrastructure is transferred to the customer. Revenue from charging stations is recognized at the point in time when control of the charging station is transferred to the customer, which is typically when the charging station is delivered at the designated customer site. If the arrangement contains a lease, it is accounted for in accordance with Accounting Standards Codification ("ASC") 842, Leases . In some arrangements, the Company has executed a sale and leaseback of the digital media screens (sale leaseback) and has also acquired the right to control the use of the location to advertise over a set term (location lease) (see Note 10 - Debt Facilities). During the construction phase, the Company does not control the underlying asset on the customer’s property. As the leaseback qualifies as a financing arrangement, the Company will not record a sale for accounting purposes of the digital media screen and will depreciate that asset over its useful life. For contractual payments that do not exceed the fair value of the location lease obligation, the Company records a lease liability and an associated right-of-use asset based on the discounted lease payments. In some instances, the Company may receive a lease incentive from the lessor which is recorded as a reduction to the right-of-use asset. The determination of the transaction price for Network Development revenue may require judgment and can affect the amount and timing of revenue. The transaction price is based on the consideration that the Company expects to be entitled to for providing the Network Development products and services on a standalone basis. Almost all of the transaction price is based on fixed cash consideration received from customers. The transaction price is allocated between lease and non-lease components based on a relative-selling price basis. However, in arrangements where the Company pays consideration to a customer for a distinct good or service, the consideration payable to a customer is limited to the fair value of the distinct good or service received by the customer. If the contractual payments for the location lease of this arrangement are in excess of fair value, then the Company will estimate the excess contractual payments over fair value and record that amount as a reduction to the transaction price in the arrangement. The reduction to transaction price for consideration payable to a customer is recognized at the later of when the Company pays or promises to pay the consideration or when the Company recognizes the related revenue for the transferred products and services. The Company reduced the transaction price and recognized consideration payable to a customer of $0.1 million and $64.1 thousand for the three months ended September 30, 2021 and 2020, respectively, and $0.3 million and $0.1 million for the nine months ended September 30, 2021 and 2020, respectively. The Company typically bills the customer upon contract inception for charging stations and installation services and bills the customer on a quarterly basis for operation and maintenance services. Payments are typically due within one month after billing. Revenue generated through installation services, operation and maintenance services and installed infrastructure is recorded in service revenue in the condensed consolidated statements of operations and comprehensive loss. Revenue generated through charging station products is recorded in product revenue in the condensed consolidated statements of operations and comprehensive loss. Charging network operations Charging Network Operations revenue correlates to usage of stations, and are currently, primarily generated by selling regulatory credits or Low Carbon Fuel Standard credits to other regulated entities. The Company recognizes revenue from regulatory credits at the point in time when the regulatory credits are sold to the customer. Costs associated Charging Network Operations is comprised of a minor amount of personnel-related costs which is presented in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss. Charging Network Operations revenue is recorded in other revenue in the condensed consolidated statements of operations and comprehensive loss. Network intelligence Network Intelligence revenue is generated through the delivery of SaaS to the customer. The Company recognizes Network Intelligence revenue ratably over the contract term on a time-elapsed basis as the SaaS is performed. Network Intelligence revenue is recorded in other revenue in the condensed consolidated statements of operations and comprehensive loss. A majority of costs associated with Network Intelligence revenue qualify as internal use software and are capitalized and recorded within property and equipment, net on the condensed consolidated balance sheets. Practical expedient and policy elected The Company utilized the practical expedient to not adjust the promised amount of consideration for the effects of a significant financing component if the Company generally expects, at contract inception, that the period between when the Company transfers control of the promised good or service and when the Company receives payment from the customer is within one year or less. At contract inception, the Company expects to complete installation and transfer control of media-enabled charging stations to customers and receive payment within one year of contract execution. The Company generally expects to fulfill media campaigns and receive payment for advertising sales within one year. The Company has elected to present revenue net of sales taxes remitted to government authorities. Remaining performance obligations Transaction price allocated to the remaining performance obligation represents contracted revenue that has not yet been recognized, which includes deferred revenue and unbilled amounts that is expected to be recognized as revenue in future periods and excludes the performance obligations that are subject to cancellation terms. The remaining performance obligations related to advertising services, the sale of media-enabled charging stations, installation services and SaaS are expected to be recognized as revenue within the next twelve months and are recorded within deferred revenue on the condensed consolidated balance sheets. The unbilled amount was $0.8 million as of September 30, 2021 and December 31, 2020. The total remaining performance obligations, excluding advertising services contracts that have a duration of one year or less, was $22.0 million and $24.4 million as of September 30, 2021 and December 31, 2020, respectively. As of September 30, 2021, the Company expects to recognize approximately 37.4% of its remaining performance obligations as revenues in the next twelve months, and the remainder thereafter. Deferred revenue Deferred revenue primarily consists of billings or payments received from customers in advance of revenue recognized for the sale of media-enabled charging stations, installation and operation and maintenance services and is recognized as revenue upon transfer control or as services are performed. The Company generally invoices customers in advance or in milestone-based installments. Revenue recognized for the three months ended September 30, 2021 and 2020 that was included in the deferred revenue balance as of June 30, 2021 and 2020 was $0.8 million and $2.3 million, respectively. Revenue recognized for the nine months ended September 30, 2021 and 2020 that was included in the deferred revenue balance as of December 31, 2020 and 2019 was $1.8 million and $4.1 million, respectively. As of September 30, 2021, deferred revenue related to such customer payments amounted to $7.1 million, of which $6.9 million is expected to be recognized during the succeeding twelve-month period and is therefore presented as current. Costs to obtain a contract with a customer The Company elected to apply the practical expedient available under ASC 340-40, Other Assets and Deferred Costs - Contracts with Customer s, to not capitalize incremental costs of obtaining a contract, such as sales commissions, if the amortization period is less than one year. Commissions paid for certain sales of advertising are expensed as incurred because the amortization period would have been one year or less as the majority of media campaigns are scheduled to run less than one year. Sales commissions are also paid for obtaining a network development contract with a site host that purchases media-enabled charging stations and related services. As the typical contract term for these agreements exceeds one year, the Company does not apply this practical expedient. Sales commissions that are considered incremental and recoverable costs of obtaining a contract with a customer are capitalized and included in prepaid expenses and other current assets and other non-current assets on the condensed consolidated balance sheets. The deferred costs are then amortized over the period of benefit consistent with the transfer of the goods and services to the customer to which the asset relates and is included in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss. The ending balances of assets recognized from costs of obtaining a contract with a customer were $44.6 thousand and $0.1 million included in prepaid expenses and other current assets as of September 30, 2021 and December 31, 2020, respectively, and $0.3 million included in other non-current assets as of September 30, 2021 and December 31, 2020. Amortization expense related to assets recognized from costs to obtain a contract with a customer was $11.2 thousand and $0.2 million for the three months ended September 30, 2021 and 2020, respectively and $0.1 million and $0.3 million for the nine months ended September 30, 2021 and 2020, respectively. The Company did not recognize any contract cost impairment losses for the three and nine months ended September 30, 2021 and 2020.
Cost of revenues (excluding depreciation and amortization)	Costs of services Costs of services consist of costs attributable to the Network Development revenues and Behavior and Commerce revenue. Costs associated with Network Development consist of costs associated with providing installation, operations and maintenance services, including personnel-related costs associated with delivering services, such as salaries and benefits, and costs to install infrastructure for utility companies. Costs associated with Behavior and Commerce revenue consists of costs associated with providing advertising services, including related rental payments on location leases for the advertising displays, for charging sites, station electricity, and labor costs directly related to service revenue-generating activities. Cost of products Cost of products consists primarily of hardware cost and shipping cost. Hardware cost primarily relates to L2 and DCFC stations which includes the cost of station chassis, the electric vehicle chargers, routers, and computers.
Advertising expenses	The Company expenses advertising expenses as they are incurred. Advertising expenses for the three months ended September 30, 2021 were $0.4 million, and none were recognized for the three months ended September 30, 2020. For the nine months ended September 30, 2021 and 2020, advertising expenses were $0.6 million and $0.2 million, respectively, and are included in selling, general and administrative in the condensed consolidated statements of operations and comprehensive loss. The Company does not capitalize any advertising expenses.
Recent accounting pronouncements	Recently adopted accounting pronouncements In December 2019, the FASB issued Accounting Standards Update ("ASU") 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes . This standard simplifies the accounting for income taxes by, among other things, eliminating certain exceptions related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 is effective for public business entities for fiscal years beginning after December 15, 2020, with early adoption permitted. Upon adoption, the Company must apply certain aspects of this standard retrospectively for all periods presented while other aspects are applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The Company adopted the new standard on January 1, 2021. The adoption of this new standard did not have a significant effect on the condensed consolidated financial statements. Recently issued accounting pronouncements not yet adopted In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326) : Measurement of Credit Losses on Financial Instruments . The ASU was subsequently amended by ASU No. 2018-19, ASU No. 2019-05 and ASU No. 2019-10. The guidance amended reporting requirements for credit losses for assets held at amortized cost basis and available-for-sale debt securities. For available-for-sale debt securities, credit losses will be presented as an allowance rather than as a write-down. In addition, the length of time a security has been in an unrealized loss position will no longer impact the determination of whether a credit loss exists. ASU No. 2016-13, as subsequently amended for various technical issues, is effective for emerging growth companies following private company adoption dates for fiscal years beginning after December 15, 2022, and for interim periods within those fiscal years. If the Company were to lose EGC status in 2021, the standard would be effective for the fiscal year beginning after December 15, 2021. The Company has not yet determined the potential effects of this ASU on its condensed consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Schedule of property and equipment	Asset Useful Lives (In Years) Charging stations and digital media screens 5-10 Capitalized research and development equipment 5 Computers and equipment 3-5 Furniture 5 Leasehold improvements 2-5 Internal-use software 0.5 Property and equipment, net, as of September 30, 2021 and December 31, 2020, consist of the following: September 30, 2021 December 31, 2020 (in thousands) Charging stations and digital media screens $ 72,070 $ 43,799 Construction in progress 27,255 17,566 Capitalized research and development equipment 1,834 974 Leasehold improvements 866 552 Computer equipment and internal-use software 1,974 974 Other fixed assets 318 336 Capitalized software 45 — Total property and equipment 104,362 64,201 Less accumulated depreciation and amortization (21,973) (14,843) Property and equipment, net $ 82,389 $ 49,358
Schedule of disaggregation of revenue	The Company disaggregates revenue by major category in the table below based on what it believes are the primary economic factors that impact the nature, amount, timing, and uncertainty of revenue and cash flows from these customer contracts. Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenues (in thousands) Behavior and Commerce $ 7,360 $ 2,214 $ 17,373 $ 4,181 Network Development 1,071 2,581 2,412 6,189 Charging Network Operations (1) — — 706 Network Intelligence 60 — 387 — Total revenues $ 8,490 $ 4,795 $ 20,172 $ 11,076

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of financial instruments measured at fair value	Carrying Amount Total Level 1 Level 2 Level 3 December 31, 2020 (in thousands) Liabilities PPP loan $ 3,193 $ 3,193 $ — $ 3,193 $ — Senior secured term loan 47,827 50,960 — 50,960 — Preferred Stock warrant liability 698 698 — — 698 Total $ 51,718 $ 54,851 $ — $ 54,153 $ 698 September 30, 2021 Liabilities PPP loan $ 3,193 $ 3,193 $ — $ 3,193 $ — Senior secured term loan 43,996 46,264 — 46,264 — Public warrants 15,189 15,189 15,189 — — Private warrants 22,080 22,080 — — 22,080 Total $ 84,458 $ 86,726 $ 15,189 $ 49,457 $ 22,080
Schedule of fair value measurement inputs and valuation techniques	The following table provides quantitative information regarding Level 3 Legacy Volta Preferred Stock warrants fair value measurements inputs at their measurement dates: December 31, 2020 Expected dividend yield — % Risk-free interest rate 0.53 % Expected volatility 50.00 % Expected term (in years) 4.50 The following table provides quantitative information regarding Level 3 Private Warrants fair value measurements inputs at their measurement dates: August 26, 2021 September 30, 2021 Expected dividend yield — % — % Risk-free interest rate 0.80 % 0.91 % Expected volatility 33.40 % 123.50 % Expected term (in years) 4.80 4.80
Schedule of Warrants	The changes in the fair value of the Private Warrants, Public Warrants and Legacy Volta Preferred Stock warrants were as follows: (in thousands) December 31, 2020 $ 698 Increase (decrease) in fair value of warrants 1,246 Release of liability upon exercise of Preferred Stock Warrants (1,944) Addition of Private and Public Warrants 27,079 Increase (decrease) in Private and Public Warrants 10,190 September 30, 2021 $ 37,269 December 31, 2019 $ 288 Increase (decrease) in fair value of warrants (14) September 30, 2020 $ 274 Private Placement Warrants Public Warrants Total Common Stock Warrants Outstanding as of February 7, 2021 5,933,333 8,621,715 14,555,048 Common stock warrants as part of the merger 5,933,333 8,621,715 14,558,333 Warrants exercised — (75) (75) Outstanding as of September 30, 2021 5,933,333 8,621,640 14,554,973

Property and equipment, net (Ta

Property and equipment, net (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	Asset Useful Lives (In Years) Charging stations and digital media screens 5-10 Capitalized research and development equipment 5 Computers and equipment 3-5 Furniture 5 Leasehold improvements 2-5 Internal-use software 0.5 Property and equipment, net, as of September 30, 2021 and December 31, 2020, consist of the following: September 30, 2021 December 31, 2020 (in thousands) Charging stations and digital media screens $ 72,070 $ 43,799 Construction in progress 27,255 17,566 Capitalized research and development equipment 1,834 974 Leasehold improvements 866 552 Computer equipment and internal-use software 1,974 974 Other fixed assets 318 336 Capitalized software 45 — Total property and equipment 104,362 64,201 Less accumulated depreciation and amortization (21,973) (14,843) Property and equipment, net $ 82,389 $ 49,358

Accrued Expenses And Other Cu_2

Accrued Expenses And Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities as of September 30, 2021 and December 31, 2020 consist of the following: September 30, 2021 December 31, 2020 (in thousands) Accrued billings on contracts $ 471 $ — Charging station expenses 4,619 4,812 Lease incentive liability 3,172 4,038 Employee related expenses 3,441 3,713 Financing transaction costs — 3,460 Other 1,302 1,575 Deposit liability 850 2,509 Accrued interest 43 1,426 Total accrued expenses and other liabilities $ 13,898 $ 21,533

Debt Facilities (Tables)

Debt Facilities (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of long-term debt	The Company’s outstanding debt instruments as of September 30, 2021 and December 31, 2020 are as follows: September 30, 2021 December 31, 2020 (in thousands) Term loan $ 44,918 $ 49,000 PPP small business loan 3,193 3,193 Total outstanding principal amount 48,111 52,193 Less unamortized debt issuance fees 922 1,173 Less current maturities 19,527 10,323 Total long-term debt $ 27,662 $ 40,697
Schedule of maturities of long-term debt	Term loan and PPP loan payments by period as of September 30, 2021 are as follows: Fiscal Year (in thousands) Remainder of 2021 $ 5,163 2022 18,448 2023 16,333 2024 8,167 2025 — $ 48,111 Fiscal Year (in thousands) Remainder of 2021 $ 264 2022 1,273 2023 1,305 2024 1,139 2025 726 Thereafter 354 Total future payments 5,061 Less amount representing interest 946 Total financing obligations $ 4,115

Warrants (Tables)

Warrants (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Warrants	The changes in the fair value of the Private Warrants, Public Warrants and Legacy Volta Preferred Stock warrants were as follows: (in thousands) December 31, 2020 $ 698 Increase (decrease) in fair value of warrants 1,246 Release of liability upon exercise of Preferred Stock Warrants (1,944) Addition of Private and Public Warrants 27,079 Increase (decrease) in Private and Public Warrants 10,190 September 30, 2021 $ 37,269 December 31, 2019 $ 288 Increase (decrease) in fair value of warrants (14) September 30, 2020 $ 274 Private Placement Warrants Public Warrants Total Common Stock Warrants Outstanding as of February 7, 2021 5,933,333 8,621,715 14,555,048 Common stock warrants as part of the merger 5,933,333 8,621,715 14,558,333 Warrants exercised — (75) (75) Outstanding as of September 30, 2021 5,933,333 8,621,640 14,554,973

Stockholders_ (Deficit) Equit_2

Stockholders’ (Deficit) Equity And Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Schedule of Stock by Class	The following summarized the Company’s Preferred Stock conversion immediately after the reverse recapitalization: Preferred Shares Conversion Ratio Common Stock Series A redeemable convertible Preferred Stock 7,363,856 1.2135 8,936,039 Series B redeemable convertible Preferred Stock 11,090,568 1.2135 13,458,404 Series C redeemable convertible Preferred Stock 665,428 1.2135 807,497 Series C-1 redeemable convertible Preferred Stock 7,675,798 1.2135 9,314,581 Series C-2 redeemable convertible Preferred Stock 18,581,768 1.2135 22,548,975 Series D redeemable convertible Preferred Stock 8,283,574 1.2135 10,052,117 Series D-1 redeemable convertible Preferred Stock 13,266,042 1.2135 16,098,342 Total 66,927,034 81,215,955
Schedule Of Common Stock Shares Outstanding	Company’s common stock outstanding Authorized Shares Issued and Outstanding Shares September 30, 2021 Volta Class A common stock 350,000,000 152,021,218 Volta Class B common stock 50,000,000 9,887,185 Total common stock outstanding 400,000,000 161,908,403 December 31, 2020 Volta Class A common stock 48,540,000 13,185,808 Volta Class B common stock 104,361,000 11,510,629 Total common stock outstanding 152,901,000 24,696,437
Schedule of common stock, capital shares reserved for future issuance	The Company has the following shares of common stock reserved for future issuance, on an as-if converted basis: September 30, 2021 December 31, 2020 Redeemable Convertible Preferred Stock — 76,493,917 Outstanding Public Warrants 8,621,640 — Outstanding Private Warrants 5,933,333 — Preferred Stock Warrants — 190,210 Common stock warrants 9,773,835 10,156,090 Options and RSAs outstanding 11,881,500 6,307,307 Shares available for grant – 2014 Equity Incentive Plan — 14,301,980 Shares available for grant – 2021 Equity Incentive Plan 11,234,585 — Total shares of common stock reserved 47,444,893 107,449,504
Schedule of option award activity	Stock option activity and activity regarding shares available for grant under the Plan is as follows: Number of options outstanding Weighted-average exercise price per share Weighted-average remaining contractual life (years) Aggregate intrinsic value (in thousands) January 1, 2020 12,890,557 $ 0.76 8.6 $ 5,836 Options granted 5,319,061 1.05 Options exercised (259,070) 0.49 Options forfeited (281,669) 0.97 Options expired (110,148) 0.76 December 31, 2020 17,558,731 $ 0.93 8.2 $ 30,881 Options granted 5,080,793 3.35 Options exercised (618,785) 1.70 Options forfeited (124,272) 1.76 Options expired — — March 31, 2021 21,896,467 $ 2.03 8.4 $ 108,590 Options granted 1,663,344 — Options exercised (384,199) 0.66 Options forfeited (81,095) 2.41 Options expired — — June 30, 2021 23,094,517 $ 2.88 8.3 $ 124,351 Options granted 459,310 8.46 Options exercised (8,371,796) 3.86 Options forfeited (170,652) 2.21 Options expired — Balance at September 30, 2021 15,011,379 $ 3.14 8.5 $ 63,228 Options vested and exercisable as of September 30, 2021 4,519,984 $ 1.55 7.6 $ 31,231
Schedule of share-based payment award, stock options, valuation assumptions	The weighted-average assumptions that were used in calculating such values during the three months ended September 30, 2021 and 2020 and for the nine months ended September 30, 2021 and 2020 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Expected dividend yield — % — % — % — % Risk-free interest rate 0.9 % 0.4 % 0.7 % 0.8 % Expected volatility 64.2 % 54.9 % 60.4 % 48.0 % Expected term (in years) 6.0 5.9 5.8 5.9

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of earnings per share, basic and diluted	The following table presents the computation of basic and diluted net loss per share for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Class A Common Shares Class B Common Shares Class A Common Shares Class B Common Shares Class A Common Shares Class B Common Shares Class A Common Shares Class B Common Shares (in thousands except share and per share) Numerator: Net loss $ (38,141) $ (4,907) $ (2,457) $ (12,060) $ (97,475) $ (31,329) $ (6,599) $ (32,433) Denominator: Basic shares: Weighted-average common shares, basic 65,923,212 8,481,143 1,575,462 7,733,885 27,998,369 8,998,756 1,573,563 7,733,885 Diluted shares: Weighted-average common shares, diluted 65,923,212 8,481,143 1,575,462 7,733,885 27,998,369 8,998,756 1,573,563 7,733,885 Net loss per share attributable to common stockholders: Basic $ (0.58) $ (0.58) $ (1.56) $ (1.56) $ (3.48) $ (3.48) $ (4.19) $ (4.19) Diluted $ (0.58) $ (0.58) $ (1.56) $ (1.56) $ (3.48) $ (3.48) $ (4.19) $ (4.19)
Schedule of antidilutive securities excluded from computation of earnings per share	The following weighted average shares of the potentially dilutive outstanding securities for the three months ended and nine months ended September 30, 2021 were excluded from the computation of diluted net loss per share because their effect would have been anti-dilutive given the net loss attributable to common shares. Therefore, the diluted net loss per share is the same as the basic net loss per share for the periods presented. As a result of the reverse recapitalization, the Company has retroactively adjusted the weighted-average number of shares of common stock outstanding prior to the by multiplying them by the exchange ratio of approximately 1.2135 used to determine the number of shares of common stock into which they converted. The common stock issued as a result of the redeemable convertible Preferred Stock conversion on the Closing Date was included in the basic and diluted net loss per share calculation. Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Anti-dilutive securities Outstanding stock options - stock plan 11,692,733 15,763,501 11,692,733 15,763,501 Non plan option grants 188,767 — 188,767 — Convertible Preferred Stock — 55,065,497 — 55,065,497 Warrants for common stock 24,328,810 9,974,065 24,328,810 9,974,065 Warrants for Preferred Stock — 190,210 — 190,210 Options and RSAs exercised under notes receivables 1,911,529 3,885,298 1,911,529 3,885,298 Total anti-dilutive securities 38,121,839 84,878,571 38,121,839 84,878,571

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Lessee Disclosure [Abstract]
Schedule of Assets and Liabilities, Lessee	Supplemental information related to leases within the condensed consolidated balance sheets is as follows: September 30, 2021 December 31, 2020 Other operating leases information Weighted-average remaining lease term (years) 7.7 7.9 Weighted-average discount rate 12.8 % 13.8 % Other financing leases information Weighted-average remaining lease term (years) 2.8 — Weighted-average discount rate 9.3 % — %
Schedule of lease cost	The following lease costs were recognized in other operating (income) expenses within the condensed consolidated statements of operations and comprehensive loss: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) Operating lease costs Fixed lease cost $ 3,011 $ 1,926 $ 8,481 $ 3,436 Variable lease cost 122 (38) 320 (73) Total operating lease costs $ 3,133 $ 1,888 $ 8,801 $ 3,363 Finance lease costs Fixed lease cost $ 2 $ — $ 2 $ — Total finance lease costs $ 2 $ — $ 2 $ — Supplemental cash flow information related to leases is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) Cash paid for amounts included in the measurement of lease liabilities Operating cash outflows from operating leases $ 2,538 $ 1,537 $ 7,014 $ 2,874 Operating cash outflows from finance leases 1 — 1 — ROU assets obtained in exchange for lease obligations ROU assets obtained in exchange for operating lease liabilities 6,843 5,758 14,388 4,269 ROU assets obtained in exchange for finance liabilities $ — $ — $ 34 $ —
Schedule of maturity of operating lease liability	Maturities of lease liabilities as of September 30, 2021 are as follows: Fiscal Year Operating Leases (in thousands) Remainder of 2021 $ 3,439 2022 11,798 2023 12,379 2024 11,849 2025 10,908 Thereafter 38,811 Total undiscounted lease payments 89,184 Less imputed interest (32,102) Total operating lease liabilities $ 57,082
Schedule of maturity of finance lease liability	Fiscal Year Finance Leases (in thousands) Remainder of 2021 $ 2 2022 5 2023 5 2024 23 2025 — Thereafter — Total undiscounted lease payments 35 Less imputed interest (6) Total financing lease liabilities $ 29

Description of Business (Detail

Description of Business (Details) $ in Millions	1 Months Ended
	Apr. 30, 2021USD ($)shares	Apr. 13, 2021subsidiary
Asset Acquisition [Line Items]
Number of wholly-owned subsidiaries formed (in subsidiary) | subsidiary		2
2Predict, Inc.
Asset Acquisition [Line Items]
Cash consideration | $	$ 0.2
2Predict, Inc. | Class B Common Stock
Asset Acquisition [Line Items]
Equity consideration (in shares) | shares	150,134

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Accounting Policies [Abstract]
Restricted cash		$ 100,000		$ 100,000
Unbilled receivables		800,000		800,000		$ 800,000
Impairment of goodwill		0
Consideration payables to customers		(100,000)	$ (64,100)	(300,000)	$ (100,000)
Advertising expense		$ 400,000	$ 0	$ 600,000	200,000
Debt Instrument [Line Items]
Proceeds from PPP loan					$ 3,193,000
PPP loan
Debt Instrument [Line Items]
Proceeds from PPP loan	$ 3,200,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Concentration of risk (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Customer Concentration Risk | Accounts Receivable | Customer One
Concentration Risk [Line Items]
Concentration risk, percentage			45.40%		59.50%
Customer Concentration Risk | Accounts Receivable | Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage			10.90%
Customer Concentration Risk | Revenue from Contract with Customer | Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	39.50%	52.90%	29.10%	48.20%
Customer Concentration Risk | Revenue from Contract with Customer | Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage	12.20%	24.10%	11.70%	14.80%
Supplier Concentration Risk | Accounts Payable | Supplier One
Concentration Risk [Line Items]
Concentration risk, percentage			10.50%		19.50%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Property and equipment (Details)	9 Months Ended
	Sep. 30, 2021
Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	2 years
Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	5 years
Charging stations and digital media screens | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	5 years
Charging stations and digital media screens | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	10 years
Capitalized research and development equipment
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	5 years
Computers and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	3 years
Computers and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	5 years
Furniture
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	5 years
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	2 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	5 years
Internal-use software
Property, Plant and Equipment [Line Items]
Useful Lives (In Years)	6 months

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Equity issuance costs (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Proceeds from issuance of preferred stock		$ 28,721
Payments of stock issuance costs		1,290
Payments of stock issuance cost in warrants	$ 1,944	1,944
Series D
Class of Stock [Line Items]
Proceeds from issuance of preferred stock			$ 9,500
Stock issuance costs			$ 300
Series D and D-1 Preferred Stock
Class of Stock [Line Items]
Proceeds from issuance of preferred stock		129,000
Stock issuance costs		4,500
Payments of stock issuance costs		3,800
Class B Common Stock Warrants | Legacy Volta
Class of Stock [Line Items]
Payments of stock issuance cost in warrants		$ 700

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Disaggregation of revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 8,490	$ 4,795	$ 20,172	$ 11,076
Behavior and Commerce
Disaggregation of Revenue [Line Items]
Total revenues	7,360	2,214	17,373	4,181
Network Development
Disaggregation of Revenue [Line Items]
Total revenues	1,071	2,581	2,412	6,189
Charging Network Operations
Disaggregation of Revenue [Line Items]
Total revenues	(1)	0	0	706
Network Intelligence
Disaggregation of Revenue [Line Items]
Total revenues	$ 60	$ 0	$ 387	$ 0

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Remaining performance obligations (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 7.1
Remaining performance obligation	$ 22	$ 24.4
Expected percent of remaining performance obligations to be recognized as revenues	37.40%
Unbilled
Disaggregation of Revenue [Line Items]
Revenue	$ 0.8	$ 0.8

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Costs to obtain a contract with a customer (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Amortization expense	$ 11,200	$ 200,000	$ 100,000	$ 300,000
Impairment loss	$ 0	$ 0	0	$ 0
Prepaid expenses and other current assets
Disaggregation of Revenue [Line Items]
Assets recognized from costs of obtaining a contract with a customer			44,600		$ 100,000
Other non-current assets
Disaggregation of Revenue [Line Items]
Assets recognized from costs of obtaining a contract with a customer			$ 300,000		$ 300,000

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Deferred revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Accounting Policies [Abstract]
Revenue recognized	$ 800	$ 2,300	$ 1,800	$ 4,100
Deferred revenue	7,100		7,100
Deferred revenue, current	$ 6,928		$ 6,928		$ 7,625

Liquidity (Details)

Liquidity (Details) - USD ($) $ in Thousands	Oct. 12, 2021	Apr. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss			$ (43,048)	$ (14,517)	$ (128,804)	$ (39,032)
Net cash used in operating activities					(43,948)	(43,759)
Accumulated deficit			(280,941)		(280,941)		$ (152,137)
Cash and cash equivalents			$ 331,254		$ 331,254		$ 58,806
Subsequent Event [Line Items]
Proceeds from PPP loan						$ 3,193
PPP loan
Subsequent Event [Line Items]
Proceeds from PPP loan		$ 3,200
Subsequent Event | PPP loan
Subsequent Event [Line Items]
Repayments of debt	$ 3,200

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 21, 2021	Sep. 30, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill		$ 221	$ 0
2Predict, Inc.
Business Acquisition [Line Items]
Purchase price	$ 1,400
Cash paid	$ 200
Number of shares issued (in shares)	150,134
Price per share (in dollars per share)	$ 8.13
Equity issued	$ 1,200
Net assets acquired	1,400
Definite-lived intangible assets	1,200
Goodwill	$ 200
Weighted average useful life	1 year 6 months

Immaterial Correction of An E_2

Immaterial Correction of An Error (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2021
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Property and equipment, net		$ 49,358		$ 82,389
Error Correction, Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of products	$ 100	$ 1,800	$ 1,100
Property and equipment, net	$ 3,000

Reverse Recapitalization (Detai

Reverse Recapitalization (Details) $ / shares in Units, $ in Thousands	Feb. 07, 2021USD ($)$ / sharesshares	Sep. 30, 2021USD ($)$ / shares	Sep. 30, 2021USD ($)$ / shares	Aug. 27, 2021	Aug. 25, 2021	Dec. 31, 2020$ / shares
Schedule Of Reverse Recapitalization [Line Items]
Consideration received	$ 350,000
Proceeds from issuance of private placement	$ 300,000
Private placement purchase (in shares) | shares	30,000,000
Redemptions from issuance of common stock	$ 242,000
Transaction costs			$ 61,000
Transaction costs related to reverse recapitalization		$ 8,307	$ 8,307
Exchange ratio	1.2135			1.2135	1.2135
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001	$ 0.0001			$ 0.0001
Additional Paid-in Capital
Schedule Of Reverse Recapitalization [Line Items]
Transaction costs related to reverse recapitalization		$ 8,307	$ 8,307
Class A Common Stock
Schedule Of Reverse Recapitalization [Line Items]
Exchange ratio	1.2135
Common stock, par value (in dollars per share) | $ / shares	$ 0.0001
Class B Common Stock
Schedule Of Reverse Recapitalization [Line Items]
Exchange ratio	1.2135
Common stock, par value (in dollars per share) | $ / shares	$ 0.0001

Fair Value Measurements - Deriv

Fair Value Measurements - Derivative Instruments at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	$ 37,269	$ 698	$ 274	$ 288
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	15,189	0
Level 1 | Public Warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	15,189
Level 1 | Private warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	0
Level 1 | Preferred Stock warrant liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability		0
Level 1 | PPP loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	0	0
Level 1 | Senior secured term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	49,457	54,153
Level 2 | Public Warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	0
Level 2 | Private warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	0
Level 2 | Preferred Stock warrant liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability		0
Level 2 | PPP loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	3,193	3,193
Level 2 | Senior secured term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	46,264	50,960
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	22,080	698
Level 3 | Public Warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	0
Level 3 | Private warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	22,080
Level 3 | Preferred Stock warrant liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability		698
Level 3 | PPP loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	0	0
Level 3 | Senior secured term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	0	0
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	84,458	51,718
Carrying Amount | Public Warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	15,189
Carrying Amount | Private warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	22,080
Carrying Amount | Preferred Stock warrant liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability		698
Carrying Amount | PPP loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	3,193	3,193
Carrying Amount | Senior secured term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	43,996	47,827
Total
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	86,726	54,851
Total | Public Warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	15,189
Total | Private warrants
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability	22,080
Total | Preferred Stock warrant liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability		698
Total | PPP loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	3,193	3,193
Total | Senior secured term loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans payable	$ 46,264	$ 50,960

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	Sep. 30, 2021$ / shares
Private warrants
Class of Warrant or Right [Line Items]
Trading price (in dollars per share)	$ 2.56

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information (Details)	Sep. 30, 2021	Aug. 26, 2021	Feb. 07, 2021	Dec. 31, 2020
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (in years)			5 years
Legacy Volta Preferred Stock Warrants | Level 3 | Expected dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input				0
Legacy Volta Preferred Stock Warrants | Level 3 | Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input				0.0053
Legacy Volta Preferred Stock Warrants | Level 3 | Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input				0.5000
Legacy Volta Preferred Stock Warrants | Level 3 | Expected term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (in years)				4 years 6 months
Private warrants | Level 3 | Expected dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0	0
Private warrants | Level 3 | Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0091	0.0080
Private warrants | Level 3 | Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	1.2350	0.3340
Private warrants | Level 3 | Expected term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (in years)	4 years 9 months 18 days	4 years 9 months 18 days

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Changes In Fair Value Of Warrant Liabilities [Roll Forward]
Beginning balance	$ 698	$ 288
Increase (decrease) in fair value of warrants	1,246	(14)
Release of liability upon exercise of Preferred Stock Warrants	(1,944)
Addition of Private and Public Warrants	27,079
Increase (decrease) in Private and Public Warrants	10,190
Ending balance	$ 37,269	$ 274

Property and equipment, net (De

Property and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Property and Equipment
Total property and equipment	$ 104,362		$ 104,362		$ 64,201
Less accumulated depreciation and amortization	(21,973)		(21,973)		(14,843)
Property and equipment, net	82,389		82,389		49,358
Depreciation and amortization	3,116	$ 2,257	7,812	$ 5,251
Charging stations and digital media screens
Property and Equipment
Total property and equipment	72,070		72,070		43,799
Construction in progress
Property and Equipment
Total property and equipment	27,255		27,255		17,566
Capitalized research and development equipment
Property and Equipment
Total property and equipment	1,834		1,834		974
Leasehold improvements
Property and Equipment
Total property and equipment	866		866		552
Computer equipment and internal-use software
Property and Equipment
Total property and equipment	1,974		1,974		974
Other fixed assets
Property and Equipment
Total property and equipment	318		318		336
Capitalized software
Property and Equipment
Total property and equipment	$ 45		$ 45		$ 0

Accrued Expenses And Other Cu_3

Accrued Expenses And Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued billings on contracts	$ 471	$ 0
Charging station expenses	4,619	4,812
Lease incentive liability	3,172	4,038
Employee related expenses	3,441	3,713
Financing transaction costs	0	3,460
Other	1,302	1,575
Deposit liability	850	2,509
Accrued interest	43	1,426
Accrued expenses and other current liabilities	$ 13,898	$ 21,533

Debt Facilities - Schedule of D

Debt Facilities - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total outstanding principal amount	$ 48,111	$ 52,193
Less unamortized debt issuance fees	922	1,173
Less current maturities	19,527	10,323
Total long-term debt	27,662	40,697
Term loan
Debt Instrument [Line Items]
Total outstanding principal amount	44,918	49,000
PPP small business loan
Debt Instrument [Line Items]
Total outstanding principal amount	$ 3,193	$ 3,193

Debt Facilities - Additional In

Debt Facilities - Additional Information (Details) - USD ($)	Jun. 19, 2019	Sep. 30, 2021	Dec. 31, 2020	Nov. 25, 2020	Sep. 30, 2020	Apr. 30, 2020
Debt Instrument [Line Items]
Total outstanding principal amount		$ 48,111,000	$ 52,193,000
Debt issuance costs		922,000	1,173,000
Financing obligation, current portions		6,928,000	7,625,000
Accrued Expenses and Other Current Liabilities
Debt Instrument [Line Items]
Financing obligation, current portions		800,000	700,000
Non-current Liabilities
Debt Instrument [Line Items]
Financing obligation, non-current portions		$ 3,300,000	3,800,000
Minimum
Debt Instrument [Line Items]
Useful life		2 years
Incremental borrowing rate		7.00%
Maximum
Debt Instrument [Line Items]
Useful life		5 years
Incremental borrowing rate		16.70%
Digital Media Screen
Debt Instrument [Line Items]
Useful life		5 years
Amortization period		5 years
Digital Media Screen | Maximum
Debt Instrument [Line Items]
Period of sale agreement		10 years
Term loan
Debt Instrument [Line Items]
Total outstanding principal amount		$ 44,918,000	49,000,000
PPP loan
Debt Instrument [Line Items]
Face amount of debt						$ 3,200,000
Interest rate						1.00%
Secured Debt
Debt Instrument [Line Items]
Total outstanding principal amount		44,900,000
Secured Debt | Term loan
Debt Instrument [Line Items]
Face amount of debt	$ 44,000,000			$ 49,000,000
Total outstanding principal amount			49,000,000		$ 42,500,000
Total financing obligations			16,700,000
Interest rate	12.00%
Debt issuance costs		900,000	1,200,000
Accrued interest		$ 43,300	$ 1,400,000
Secured Debt | Term loan | After Closing Date
Debt Instrument [Line Items]
Debt instrument, term	2 years

Debt Facilities - PPP Loan Paym

Debt Facilities - PPP Loan Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Remainder of 2021	$ 5,163
2022	18,448
2023	16,333
2024	8,167
2025	0
Total outstanding principal amount	$ 48,111	$ 52,193

Debt Facilities - Future Maturi

Debt Facilities - Future Maturities (Details) $ in Thousands	Sep. 30, 2021USD ($)
Debt Disclosure [Abstract]
Remainder of 2021	$ 264
2022	1,273
2023	1,305
2024	1,139
2025	726
Thereafter	354
Total future payments	5,061
Less amount representing interest	946
Total financing obligations	$ 4,115

Warrants - Additional Informati

Warrants - Additional Information (Details) $ / shares in Units, $ in Thousands	Aug. 25, 2021shares	Feb. 07, 2021USD ($)$ / sharesshares	Dec. 31, 2019$ / sharesshares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)$ / shares	Sep. 30, 2021$ / sharesshares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)$ / sharesshares	Aug. 27, 2021	Dec. 31, 2020shares
Class of Warrant or Right [Line Items]
Exchange ratio	1.2135	1.2135							1.2135
Warrants outstanding (in shares)		14,555,048		14,554,973		14,554,973	14,554,973
Warrants exercised (in shares)						(75)
Exercisable period after completion of business combination		30 days
Exercisable period from IPO closing		12 months
Expiration period		5 years
Change in fair value of warrant liability | $		$ 10,200		$ 11,554	$ (3)		$ 11,436	$ (14)
Notice period to redeem warrants		30 days
Option One
Class of Warrant or Right [Line Items]
Trading price (in dollars per share) | $ / shares		$ 0.01
Trading period		20 days
Threshold trading days		30 days
Option One | Minimum
Class of Warrant or Right [Line Items]
Trigger price (in dollars per share) | $ / shares		$ 18
Option Two
Class of Warrant or Right [Line Items]
Period when warrants become exercisable		90 days
Option Two | Minimum
Class of Warrant or Right [Line Items]
Trigger price (in dollars per share) | $ / shares		$ 10
Preferred Stock Warrants | Legacy Volta
Class of Warrant or Right [Line Items]
Warrants converted (in shares)	208,993
Warrants outstanding (in shares)				0		0	0
Class B Common Stock Warrants | Legacy Volta
Class of Warrant or Right [Line Items]
Trading price (in dollars per share) | $ / shares				$ 0.01		$ 0.01	$ 0.01
Warrants exercised (in shares)							(182,025)
Class A Common Stock warrants
Class of Warrant or Right [Line Items]
Trading price (in dollars per share) | $ / shares		$ 11.50
Warrants converted (in shares)				188,638		188,638	188,638
Warrants outstanding (in shares)				9,773,835		9,773,835	9,773,835			9,773,835
Public Warrants
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)		8,621,715		8,621,640		8,621,640	8,621,640
Warrants exercised (in shares)						(75)
Private Placement Warrants
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)		5,933,333		5,933,333		5,933,333	5,933,333
Warrants exercised (in shares)						0
Period of certain limited exceptions		30 days
Preferred Class B
Class of Warrant or Right [Line Items]
Trading price (in dollars per share) | $ / shares			$ 1.05
Warrants issued (in shares)			209,029
Class A Common Stock
Class of Warrant or Right [Line Items]
Exchange ratio		1.2135
Class A Common Stock | Legacy Volta
Class of Warrant or Right [Line Items]
Exercised outstanding shares (in shares)	253,613
Class B Common Stock
Class of Warrant or Right [Line Items]
Exchange ratio		1.2135
Class B Common Stock | Legacy Volta
Class of Warrant or Right [Line Items]
Trading price (in dollars per share) | $ / shares					$ 1.31			$ 1.31
Warrants issued (in shares)								381,679
Valued price of warrants (in dollars per share) | $ / shares					$ 0.76			$ 0.76
Proceeds from warrant exercises | $								$ 300

Warrants - Schedule of Activiti

Warrants - Schedule of Activities (Details)	8 Months Ended
	Sep. 30, 2021shares
Class of Warrant or Right, Outstanding [Roll Forward]
Beginning balance (in shares)	14,555,048
Common Stock Warrants as Part of the Merger (in shares)	14,558,333
Warrants exercised (in shares)	(75)
Ending balance (in shares)	14,554,973
Private Placement Warrants
Class of Warrant or Right, Outstanding [Roll Forward]
Beginning balance (in shares)	5,933,333
Common Stock Warrants as Part of the Merger (in shares)	5,933,333
Warrants exercised (in shares)	0
Ending balance (in shares)	5,933,333
Public Warrants
Class of Warrant or Right, Outstanding [Roll Forward]
Beginning balance (in shares)	8,621,715
Common Stock Warrants as Part of the Merger (in shares)	8,621,715
Warrants exercised (in shares)	(75)
Ending balance (in shares)	8,621,640

Stockholders_ (Deficit) Equit_3

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Business Combination and PIPE Investment (Details) $ / shares in Units, $ in Millions	Feb. 07, 2021USD ($)subsidiary$ / sharesshares	Sep. 30, 2021$ / shares	Aug. 27, 2021	Aug. 25, 2021	Dec. 31, 2020$ / shares
Class of Stock [Line Items]
Common stock, par value (in dollars per share)		$ 0.0001			$ 0.0001
Exchange ratio	1.2135		1.2135	1.2135
Sale of stock, number of shares issued in transaction (in shares) | shares	30,000,000
Consideration received | $	$ 350
Proceeds from PIPE investment | $	$ 300
Class A Common Stock
Class of Stock [Line Items]
Votes per share | subsidiary	1
Common stock, par value (in dollars per share)	$ 0.0001
Exchange ratio	1.2135
Class B Common Stock
Class of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.0001
Exchange ratio	1.2135

Stockholders_ (Deficit) Equit_4

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Convertible Preferred Stock (Details)	9 Months Ended
	Sep. 30, 2021shares	Aug. 27, 2021	Aug. 25, 2021	Feb. 07, 2021
Class of Stock [Line Items]
Conversion Ratio		1.2135	1.2135	1.2135
Series A redeemable convertible Preferred Stock
Class of Stock [Line Items]
Conversion Ratio	1.2135
Series B redeemable convertible Preferred Stock
Class of Stock [Line Items]
Conversion Ratio	1.2135
Series C redeemable convertible Preferred Stock
Class of Stock [Line Items]
Conversion Ratio	1.2135
Series C-1 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Conversion Ratio	1.2135
Series C-2 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Conversion Ratio	1.2135
Series D redeemable convertible Preferred Stock
Class of Stock [Line Items]
Conversion Ratio	1.2135
Series D-1 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Conversion Ratio	1.2135
Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	66,927,034
Preferred Stock | Series A redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	7,363,856
Preferred Stock | Series B redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	11,090,568
Preferred Stock | Series C redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	665,428
Preferred Stock | Series C-1 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	7,675,798
Preferred Stock | Series C-2 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	18,581,768
Preferred Stock | Series D redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	8,283,574
Preferred Stock | Series D-1 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Converted (in shares)	13,266,042
Common Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	81,215,955
Common Stock | Series A redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	8,936,039
Common Stock | Series B redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	13,458,404
Common Stock | Series C redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	807,497
Common Stock | Series C-1 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	9,314,581
Common Stock | Series C-2 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	22,548,975
Common Stock | Series D redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	10,052,117
Common Stock | Series D-1 redeemable convertible Preferred Stock
Class of Stock [Line Items]
Shares Issued upon Conversion (in shares)	16,098,342

Stockholders_ (Deficit) Equit_5

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Common sock activity (Details) - shares	Sep. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	400,000,000	152,901,000
Common stock, shares issued (in shares)	161,908,403	24,696,437
Common stock, shares outstanding (in shares)	161,908,403	24,696,437
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	350,000,000	48,540,000
Common stock, shares issued (in shares)	152,021,218	13,185,808
Common stock, shares outstanding (in shares)	152,021,218	13,185,808
Class B Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	50,000,000	104,361,000
Common stock, shares issued (in shares)	9,887,185	11,510,629
Common stock, shares outstanding (in shares)	9,887,185	11,510,629

Stockholders_ (Deficit) Equit_6

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Volta Common and Preferred Stock (Details)	9 Months Ended
	Sep. 30, 2021subsidiaryshares	Feb. 07, 2021subsidiary
Class A Common Stock
Class of Stock [Line Items]
Votes per share		1
Common Stock
Class of Stock [Line Items]
Conversion ratio	1
Common Stock | Class A Common Stock
Class of Stock [Line Items]
Votes per share	1
Common Stock | Class B Common Stock
Class of Stock [Line Items]
Votes per share	10
Preferred Stock | Volta Charter
Class of Stock [Line Items]
Number of shares authorized (in shares) | shares	10,000,000
Stock issued (in shares) | shares	0

Stockholders_ (Deficit) Equit_7

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Shares reserved for issuance (Details) - shares	Sep. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	47,444,893	107,449,504
Shares available for grant – 2014 Equity Incentive Plan
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	0	14,301,980
Shares available for grant – 2021 Equity Incentive Plan
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	11,234,585	0
Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	0	76,493,917
Outstanding Public Warrants
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	8,621,640	0
Outstanding Private Warrants
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	5,933,333	0
Preferred Stock Warrants
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	0	190,210
Common stock warrants
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	9,773,835	10,156,090
Options and RSAs outstanding
Class of Stock [Line Items]
Shares reserved for issuance (in shares)	11,881,500	6,307,307

Stockholders_ (Deficit) Equit_8

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Stock option activity, narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Total fair value of options vested	$ 1.6	$ 1	$ 7.4	$ 1.7
Employees
Class of Stock [Line Items]
Aggregate intrinsic value of options exercised	$ 45.6		$ 52
Weighted-average grant-date fair value of options granted (in dollars per share)	$ 5.42	$ 0.37	$ 4.29	$ 0.37
Weighted-average grant-date fair value of options forfeited (in dollars per share)	2.33	0.35	2.10	0.91
Weighted-average grant-date fair value of options vested (in dollars per share)	$ 1.53	$ 1.01	$ 1.77	$ 0.79
Common Stock | 2021 Equity Incentive Plan
Class of Stock [Line Items]
Number of shares authorized (in shares)	11,234,585		11,234,585
Percent of possible increase in shares available for issuance	5.00%		5.00%

Stockholders_ (Deficit) Equit_9

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Option reward activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended	12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of options outstanding
Beginning balance (in shares)	23,094,517	21,896,467	17,558,731	17,558,731	12,890,557
Options granted (in shares)	459,310	1,663,344	5,080,793		5,319,061
Options exercised (in shares)	(8,371,796)	(384,199)	(618,785)		(259,070)
Options forfeited (in shares)	(170,652)	(81,095)	(124,272)		(281,669)
Options expired (in shares)	0	0	0		(110,148)
Ending balance (in shares)	15,011,379	23,094,517	21,896,467	15,011,379	17,558,731	12,890,557
Weighted-average exercise price per share
Beginning balance (in dollars per share)	$ 2.88	$ 2.03	$ 0.93	$ 0.93	$ 0.76
Options granted (in dollars per share)	8.46	0	3.35		1.05
Options exercised (in dollars per share)	3.86	0.66	1.70		0.49
Options forfeited (in dollars per share)	2.21	2.41	1.76		0.97
Options expired (in dollars per share)		0	0		0.76
Ending balance (in dollars per share)	$ 3.14	$ 2.88	$ 2.03	$ 3.14	$ 0.93	$ 0.76
Weighted-average remaining contractual life (years)		8 years 3 months 18 days	8 years 4 months 24 days	8 years 6 months	8 years 2 months 12 days	8 years 7 months 6 days
Aggregate intrinsic value	$ 63,228	$ 124,351	$ 108,590	$ 63,228	$ 30,881	$ 5,836
Options vested, Number of options outstanding (in shares)	4,519,984			4,519,984
Options exercisable, Number of options outstanding (in shares)	4,519,984			4,519,984
Options vested, Weighted-average exercise price per share (in dollars per share)	$ 1.55			$ 1.55
Options exercisable, Weighted-average exercise price per share (in dollars per share)	$ 1.55			$ 1.55
Options vested, Weighted-average remaining contractual life (years)	7 years 7 months 6 days
Options exercisable, Weighted-average remaining contractual life (years)	7 years 7 months 6 days
Options vested, Aggregate intrinsic value	$ 31,231			$ 31,231
Options exercisable, Aggregate intrinsic value	$ 31,231			$ 31,231

Stockholders_ (Deficit) Equi_10

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Assumptions (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Risk-free interest rate	0.90%	0.40%	0.70%	0.80%
Expected volatility	64.20%	54.90%	60.40%	48.00%
Expected term (in years)	6 years	5 years 10 months 24 days	5 years 9 months 18 days	5 years 10 months 24 days

Stockholders_ (Deficit) Equi_11

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Stock-based compensation and expense, narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Total unrecognized compensation cost	$ 18.9		$ 18.9		$ 2.4
Weighted-average period of total unrecognized compensation cost, in years			3 years 3 months 18 days		1 year 8 months 12 days
Compensation expense	$ 4.6	$ 0.3	$ 51.4	$ 0.8

Stockholders_ (Deficit) Equi_12

Stockholders’ (Deficit) Equity And Stock-Based Compensation - Partial recourse promissory notes (Details) $ in Millions	3 Months Ended			9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)debt_instrumentshares	Jun. 30, 2021shares	Mar. 31, 2021shares	Sep. 30, 2021USD ($)debt_instrumentshares	Dec. 31, 2020USD ($)shares
Class of Stock [Line Items]
Due from employees | $	$ 0.1			$ 0.1	$ 0.7
Issuance of Common Stock upon exercise of options (in shares) | shares	8,371,796	384,199	618,785		259,070
Accounts Receivable
Class of Stock [Line Items]
Due from employees | $	$ 0.1			$ 0.1
Class B Common Stock
Class of Stock [Line Items]
Issuance of Common Stock upon exercise of options (in shares) | shares				1,331,914	11,147,195
Restricted Stock | Class A Common Stock
Class of Stock [Line Items]
Stock issued (in shares) | shares				243,306	1,036,124
Partial Recourse Promissory Notes
Class of Stock [Line Items]
Due from employees | $	$ 1.2			$ 1.2	$ 10.4
Percent of original principal of notes collateralized	50.00%			50.00%
Two Remaining Promissory Notes | Employees and Former Employees
Class of Stock [Line Items]
Interest rate	2.26%			2.26%
Number of instruments (in instruments) | debt_instrument	2			2
One Remaining Promissory Note | Employees and Former Employees
Class of Stock [Line Items]
Interest rate	3.25%			3.25%
Number of instruments (in instruments) | debt_instrument	1			1

Net Loss Per Share (Details)

Net Loss Per Share (Details) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)$ / sharesshares	Aug. 27, 2021	Aug. 25, 2021	Feb. 07, 2021
Class of Stock [Line Items]
Net loss | $	$ (43,048)	$ (14,517)	$ (128,804)	$ (39,032)
Weighted-average common shares, diluted (in shares)	8,481,143	7,733,885	8,998,756	7,733,885
Net loss per share attributable to common stockholders:
Exchange ratio					1.2135	1.2135	1.2135
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	38,121,839	84,878,571	38,121,839	84,878,571
Class A Common Stock
Class of Stock [Line Items]
Net loss | $	$ (38,141)	$ (2,457)	$ (97,475)	$ (6,599)
Weighted-average common shares, basic (in shares)	65,923,212	1,575,462	27,998,369	1,573,563
Weighted-average common shares, diluted (in shares)	65,923,212	1,575,462	27,998,369	1,573,563
Net loss per share attributable to common stockholders:
Basic (in dollars per share) | $ / shares	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Diluted (in dollars per share) | $ / shares	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Exchange ratio							1.2135
Class B Common Stock
Class of Stock [Line Items]
Net loss | $	$ (4,907)	$ (12,060)	$ (31,329)	$ (32,433)
Weighted-average common shares, basic (in shares)	8,481,143	7,733,885	8,998,756	7,733,885
Weighted-average common shares, diluted (in shares)	8,481,143	7,733,885	8,998,756	7,733,885
Net loss per share attributable to common stockholders:
Basic (in dollars per share) | $ / shares	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Diluted (in dollars per share) | $ / shares	$ (0.58)	$ (1.56)	$ (3.48)	$ (4.19)
Exchange ratio							1.2135
Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	188,767	0	188,767	0
Option | Stock Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	11,692,733	15,763,501	11,692,733	15,763,501
Convertible Preferred Stock | Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	55,065,497	0	55,065,497
Warrants | Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	24,328,810	9,974,065	24,328,810	9,974,065
Warrants | Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	190,210	0	190,210
Options and RSAs exercised under notes receivables
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	1,911,529	3,885,298	1,911,529	3,885,298

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Lessee, Lease, Description [Line Items]
Asset retirement obligation			$ 0.8	$ 1.1
Variable lease cost, COVID-19	$ 0.1	$ 0.2
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, term of contract	5 years	5 years
Operating lease, renewal term	1 year	1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, term of contract	10 years	10 years
Operating lease, renewal term	5 years	5 years

Leases - Balance Sheets (Detail

Leases - Balance Sheets (Details)	Sep. 30, 2021	Dec. 31, 2020
Other operating leases information
Weighted-average remaining lease term (years)	7 years 8 months 12 days	7 years 10 months 24 days
Other financing leases information
Weighted-average remaining lease term (years)	2 years 9 months 18 days
Weighted-average discount rate	9.30%	0.00%
Weighted-average discount rate	12.80%	13.80%

Leases - Costs (Details)

Leases - Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating lease costs
Fixed lease cost	$ 3,011	$ 1,926	$ 8,481	$ 3,436
Variable lease cost	122	(38)	320	(73)
Total operating lease costs	3,133	1,888	8,801	3,363
Finance lease costs
Fixed lease cost	2	0	2	0
Total finance lease costs	$ 2	$ 0	$ 2	$ 0

Leases - Cash Flows (Details)

Leases - Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lessee Disclosure [Abstract]
Operating cash outflows from operating leases	$ 2,538	$ 1,537	$ 7,014	$ 2,874
Operating cash outflows from finance leases	1	0	1	0
ROU assets obtained in exchange for operating lease liabilities	6,843	5,758	14,388	4,269
ROU assets obtained in exchange for finance liabilities	$ 0	$ 0	$ 34	$ 0

Leases - Maturities (Details)

Leases - Maturities (Details) $ in Thousands	Sep. 30, 2021USD ($)
Operating Leases
Remainder of 2021	$ 3,439
2022	11,798
2023	12,379
2024	11,849
2025	10,908
Thereafter	38,811
Total undiscounted lease payments	89,184
Less imputed interest	(32,102)
Total operating lease liabilities	57,082
Finance Leases
Remainder of 2021	2
2022	5
2023	5
2024	23
2025	0
Thereafter	0
Total undiscounted lease payments	35
Less imputed interest	(6)
Total financing lease liabilities	$ 29

Commitments And Contingencies (

Commitments And Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Loss Contingencies [Line Items]
Accrued expenses and other current liabilities	$ 13,898		$ 13,898		$ 21,533
Employer matching contribution			4.00%
Contributions by employer	200	$ 100	$ 700	$ 400
Invoices
Loss Contingencies [Line Items]
Accrued expenses and other current liabilities	600		600		600
Invoices	$ 1,400		$ 1,400		$ 1,400

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate	0.00%	0.00%	0.00%	0.00%

Related Party Transactions - 2P

Related Party Transactions - 2Predict, Inc (Details) - Affiliated Entity - 2Predict, Inc. - Consulting Service - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Expenses from transactions with related party	$ 200,000	$ 400,000
Accounts payable			$ 0	$ 100,000

Related Party Transactions - Re

Related Party Transactions - Related party loans (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Proceeds from issuance of preferred stock		$ 28,721
Series D
Related Party Transaction [Line Items]
Issuance of convertible notes		$ 13,721
Proceeds from issuance of preferred stock			$ 9,500
Affiliated Entity | Activate Capital Partners, LP | Class A Common Stock
Related Party Transaction [Line Items]
Shares converted (in shares)		182,025
Related Party Loans | Affiliated Entity
Related Party Transaction [Line Items]
Issuance of convertible notes	$ 200		30,000
Related Party Loans | Affiliated Entity | Series D-1
Related Party Transaction [Line Items]
Shares converted (in shares)				2,721,956
Conversion price (in dollars per share)	$ 3.77			$ 3.77
Proceeds from issuance of preferred stock				$ 10,300
Related Party Loans | Affiliated Entity | Class A Common Stock
Related Party Transaction [Line Items]
Shares converted (in shares)	11,376,303	2,745,658		3,303,094
Related Party Loans | Affiliated Entity | Series D
Related Party Transaction [Line Items]
Shares converted (in shares)		4,722,039
Stock issued (in shares)	9,374,786	3,891,256
Related Party Loans | Affiliated Entity | Activate Capital Partners, LP
Related Party Transaction [Line Items]
Issuance of convertible notes			$ 9,800	$ 9,800
Related Party Loans | Affiliated Entity | 19York Ventures | Class A Common Stock
Related Party Transaction [Line Items]
Shares converted (in shares)	205,670
Related Party Loans | Affiliated Entity | 19York Ventures | Series D
Related Party Transaction [Line Items]
Conversion price (in dollars per share)	$ 7.38			$ 7.38
Proceeds from issuance of preferred stock	$ 1,300	$ 15,000
Stock issued (in shares)	169,485	2,262,594

Related Party Transactions - Pu

Related Party Transactions - Public placement warrants (Details) - Public Warrants - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Class A Common Stock
Related Party Transaction [Line Items]
Shares converted (in shares)	463,167	182,025
Legacy Volta | Class B Common Stock
Related Party Transaction [Line Items]
Stock issued (in shares)	381,679	150,000
Stock issued	$ 0.3	$ 0.5

Related Party Transactions - Pr

Related Party Transactions - Promissory notes (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Issuance of Common Stock upon exercise of options (in shares)	8,371,796	384,199	618,785				259,070
Due from employees	$ 0.1				$ 0.1		$ 0.7
Promissory Note Agreement
Related Party Transaction [Line Items]
Amounts of transaction					$ 8.3
Transaction, interest rate					3.25%
Common Stock
Related Party Transaction [Line Items]
Issuance of Common Stock upon exercise of options (in shares)	231,000			4,000	1,235,000	12,000	9,271,877

Related Party Transactions - Le

Related Party Transactions - Legacy Volta Class B common stock (Details) - USD ($)	8 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020	Feb. 07, 2021
Related Party Transaction [Line Items]
Warrants exercised (in shares)	75
Class A Common Stock warrants
Related Party Transaction [Line Items]
Trading price (in dollars per share)				$ 11.50
Warrants converted (in shares)	188,638	188,638
Class A Common Stock | Restricted Stock
Related Party Transaction [Line Items]
Stock issued (in shares)		243,306	1,036,124
Class A Common Stock | Restricted Stock | Affiliated Entity
Related Party Transaction [Line Items]
Shares converted (in shares)		6,916,950
Legacy Volta | Class B Common Stock | Restricted Stock | Affiliated Entity
Related Party Transaction [Line Items]
Stock issued (in shares)		5,700,000
Activate Capital Partners, LP | Affiliated Entity | Class B Common Stock Warrants
Related Party Transaction [Line Items]
Warrants exercised (in shares)		150,000
Trading price (in dollars per share)	$ 0.01	$ 0.01
Proceeds from warrant exercises		$ 1,500
Activate Capital Partners, LP | Class A Common Stock | Affiliated Entity
Related Party Transaction [Line Items]
Shares converted (in shares)		182,025

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event $ in Thousands	Nov. 08, 2021shares	Oct. 14, 2021USD ($)	Oct. 12, 2021USD ($)
Pending Litigation | Additional Payment for Costs
Subsequent Event [Line Items]
Damages sought | $		$ 150
Restricted Stock Units | Class B Common Stock
Subsequent Event [Line Items]
Right to reserve ratio per common stock	1
Restricted Stock Units | Chief Executive Officer
Subsequent Event [Line Items]
Number of shares authorized (in shares) | shares	5,250,000
Restricted Stock Units | President
Subsequent Event [Line Items]
Number of shares authorized (in shares) | shares	5,250,000
PPP loan
Subsequent Event [Line Items]
Repayments of debt | $			$ 3,200