Tecogen (TGEN) 10-Q 10 Aug 23 2023 Q2 Quarterly report Financial data

Cover

Cover	6 Months Ended
	Jun. 30, 2023 shares
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-36103
Entity Registrant Name	TECOGEN INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3536131
Entity Address, Address Line One	45 First Avenue
Entity Address, City or Town	Waltham
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02451
City Area Code	781
Local Phone Number	466-6402
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	24,850,261
Entity Central Index Key	0001537435
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Current assets:
Cash and cash equivalents	$ 1,871,063	$ 1,913,969
Accounts receivable, net	5,614,291	6,714,122
Unbilled revenue	1,748,336	1,805,330
Employee retention credit receivable	46,148	713,269
Inventories, net	12,027,525	10,482,729
Prepaid and other current assets	467,390	401,189
Total current assets	21,774,753	22,030,608
Property, plant and equipment, net	1,352,318	1,407,720
Right of use assets	920,690	1,245,549
Intangible assets, net	2,421,379	997,594
Goodwill	3,129,147	2,406,156
Other assets	201,898	165,230
TOTAL ASSETS	29,800,185	28,252,857	$ 30,333,724
Current liabilities:
Accounts payable	4,212,914	3,261,952
Accrued expenses	2,554,000	2,384,447
Deferred revenue, current	2,086,174	1,115,627
Lease obligations, current	513,811	687,589
Acquisition liabilities, current	649,241	0
Unfavorable contract liability, current	213,559		236,705
Total current liabilities	10,229,699	7,686,320
Long-term liabilities:
Deferred revenue, net of current portion	154,149	371,823
Lease obligations, net of current portion	459,372	623,452
Acquisition liabilities, net of current portion	1,643,567	0
Unfavorable contract liability, net of current portion	490,802	583,512
Total liabilities	12,977,589	9,265,107
Commitments and contingencies (Note 12)
Tecogen Inc. shareholders’ equity:
Common stock, $0.001 par value; 100,000,000 shares authorized; 24,850,261 and 24,850,261 issued and outstanding at June 30,2021 and December 31, 2020, respectively	24,850	24,850
Additional paid-in capital	57,456,945	57,351,008
Accumulated deficit	(40,551,687)	(38,281,548)
Total Tecogen Inc. stockholders’ equity	16,930,108	19,094,310
Non-controlling interest	(107,512)	(106,560)
Total stockholders’ equity	16,822,596	18,987,750	$ 20,542,673
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 29,800,185	$ 28,252,857
Common stock, shares outstanding	24,850,261	24,850,261
Common stock, shares issued		24,850,261

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued		24,850,261
Common stock, shares outstanding	24,850,261	24,850,261

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total revenues	$ 6,748,758	$ 6,414,593	$ 12,128,576	$ 13,852,916
Total cost of sales	3,914,332	3,711,144	7,202,241	8,058,678
Gross profit	2,834,426	2,703,449	4,926,335	5,794,238
Operating expenses
General and administrative	2,917,283	2,824,832	5,709,766	5,298,735
Selling	480,786	503,601	1,000,856	1,004,692
Research and development	236,556	194,853	465,658	334,988
Gain on disposition of assets	(19,950)	(2,500)	(19,950)	(36,445)
Gain on termination of unfavorable contract liability			0	(71,375)
Total operating expenses	3,614,675	3,520,786	7,156,330	6,530,595
Loss from operations	(780,249)	(817,337)	(2,229,995)	(736,357)
Other income (expense)
Interest and other income (expense), net	(21,061)	(1,265)	(20,231)	(15,416)
Interest expense	(1,857)	(12,733)	(2,272)	(13,561)
Unrealized gain (loss) on investment securities	37,497	0	37,497	37,497
Total other income (expense), net	14,579	(13,998)	14,994	8,520
Loss before provision for state income taxes	(765,670)	(831,335)	(2,215,001)	(727,837)
Provision for state income taxes	9,614	6,500	32,252	10,430
Consolidated net loss	(775,284)	(837,835)	(2,247,253)	(738,267)
Income attributable to the non-controlling interest	(4,826)	(18,383)	(22,886)	(28,542)
Net loss attributable to Tecogen Inc.	$ (780,110)	$ (856,218)	$ (2,270,139)	$ (766,809)
Earnings Per Share [Abstract]
Net income (loss) per share - basic (in USD per share)	$ (0.03)	$ (0.03)	$ (0.09)	$ (0.03)
Net income (loss) per share - diluted (in usd per share)	$ (0.03)	$ (0.03)	$ (0.09)	$ (0.03)
Weighted average shares outstanding - basic	24,850,261	24,850,261	24,850,261	24,850,261
Weighted average shares outstanding - diluted	24,850,261	24,850,261	24,850,261	24,850,261
Products
Total revenues	$ 2,445,631	$ 3,010,115	$ 4,155,767	$ 6,949,596
Total cost of sales	1,618,456	2,015,466	2,831,024	4,660,221
Services
Total revenues	3,952,971	3,050,191	7,089,144	5,967,471
Total cost of sales	2,075,869	1,473,586	3,813,471	2,840,338
Energy production
Total revenues	350,156	354,287	883,665	935,849
Total cost of sales	$ 220,007	$ 222,092	$ 557,746	$ 558,119

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity Statement - USD ($)	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Noncontrolling Interest
Beginning balance (shares) at Dec. 31, 2021		24,850,261
Beginning balance at Dec. 31, 2021	$ 21,128,149	$ 24,850	$ 57,016,859	$ (35,833,621)	$ (79,939)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	185,600		185,600
Distributions to Noncontrolling interests	(32,809)				32,809
Net income	(28,542)			766,809
Net income (loss)	(738,267)				28,542
Ending balance (shares) at Jun. 30, 2022		24,850,261
Ending balance at Jun. 30, 2022	20,542,673	$ 24,850	57,202,459	(36,600,430)	(84,206)
Beginning balance (shares) at Mar. 31, 2022		24,850,261
Beginning balance at Mar. 31, 2022	21,307,784	$ 24,850	57,112,566	(35,744,212)	(85,420)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	89,893		89,893
Distributions to Noncontrolling interests	(17,169)				17,169
Net income	(18,383)			856,218
Net income (loss)	(837,835)				18,383
Ending balance (shares) at Jun. 30, 2022		24,850,261
Ending balance at Jun. 30, 2022	20,542,673	$ 24,850	57,202,459	(36,600,430)	(84,206)
Beginning balance (shares) at Dec. 31, 2022		24,850,261
Beginning balance at Dec. 31, 2022	18,987,750	$ 24,850	57,351,008	(38,281,548)	(106,560)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	105,937		105,937
Distributions to Noncontrolling interests	(23,838)				23,838
Net income	(22,886)			2,270,139
Net income (loss)	(2,247,253)				22,886
Ending balance (shares) at Jun. 30, 2023		24,850,261
Ending balance at Jun. 30, 2023	16,822,596	$ 24,850	57,456,945	(40,551,687)	(107,512)
Beginning balance (shares) at Mar. 31, 2023		24,850,261
Beginning balance at Mar. 31, 2023	17,593,129	$ 24,850	57,428,356	(39,771,577)	(88,500)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	28,589		28,589
Distributions to Noncontrolling interests	(23,838)				(23,838)
Net income	(4,826)			780,110
Net income (loss)	(775,284)				4,826
Ending balance (shares) at Jun. 30, 2023		24,850,261
Ending balance at Jun. 30, 2023	$ 16,822,596	$ 24,850	$ 57,456,945	$ (40,551,687)	$ (107,512)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Consolidated net loss	$ (2,247,253)	$ (738,267)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization, net	291,095	217,718
Stock-based compensation	105,937	185,600
Provision for doubtful accounts	44,000	46,000
Gain on disposition of assets	(19,950)	(36,445)
Unrealized gain on investment securities	(37,497)	(37,497)
Gain on termination of unfavorable contract liability	0	(71,375)
Changes in operating assets and liabilities
Accounts receivable	755,831	(444,541)
Employee retention credit receivable	667,121	562,752
Unbilled revenue	56,994	1,117,057
Inventory	(1,133,618)	(438,102)
Prepaid expenses and other current assets	(66,201)	(22,618)
Other assets	325,688	308,282
Increase (decrease) in:
Accounts payable	839,784	(247,876)
Accrued expenses and other current liabilities	178,241	(74,490)
Deferred revenue	752,873	(589,158)
Other liabilities	(359,369)	(316,217)
Net cash provided by (used in) operating activities	153,676	(579,177)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(19,607)	(209,034)
Payment for business acquisition	(170,000)	0
Purchases of intangible assets	0	(29,505)
Proceeds from disposition of assets	16,863	67,169
Distributions to non-controlling interest	(23,838)	(32,809)
Net cash used in investing activities	(196,582)	(204,179)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net cash provided by financing activities	0	0
Change in cash and cash equivalents	(42,906)	(783,356)
Cash and cash equivalents, beginning of the period	1,913,969	3,614,463
Cash and cash equivalents, end of the period	1,871,063	2,831,107
Non-cash investing and financing activities:
Cash paid for interest	1,443	12,733
Cash paid for taxes	$ 32,252	$ 10,430

Description of business and bas

Description of business and basis of presentation	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Description of business and basis of presentation	Description of Business and Basis of Presentation Description of Business Tecogen Inc. (together with its subsidiaries, “we,” “our,” or “us,” or “Tecogen”) designs, manufactures, markets, and maintains high efficiency, ultra-clean cogeneration products. These include natural gas engine driven combined heat and power (CHP) systems, chillers and heat pumps for multi-family residential, commercial, recreational and industrial use. We are known for products that provide customers with substantial energy savings, resiliency from utility power outages and for significantly reducing a customer’s carbon footprint. Our products are sold with our patented Ultera® emissions technology which nearly eliminates all criteria pollutants such as nitrogen oxide ("NOx") and carbon monoxide ("CO"). We developed Ultera® for other applications including stationary engines and forklifts. We were incorporated in the State of Delaware on September 15, 2000. We have wholly-owned subsidiaries American DG Energy, Inc. ("ADGE") and Tecogen CHP Solutions, Inc., and we own a 51% interest in American DG New York, LLC ("ADGNY"), a joint venture. ADGE and ADGNY distribute, own, and operate clean, on-site energy systems that produce electricity, hot water, heat and cooling. ADGE and ADGNY own the equipment that is installed at customers' facilities and sell the energy produced to the customer on a long-term contractual basis. Our operations are comprised of three business segments: • our Products segment, which designs, manufactures and sells industrial and commercial cogeneration systems; • our Services segment, which provides operations and maintenance ("O&M") services for our products under long term service contracts, and • our Energy Production segment, which sells energy in the form of electricity, heat, hot water and cooling to our customers under long-term energy sales agreements. The majority of our customers are located in regions with the highest utility rates, typically California, the Midwest and the Northeast. On July 20, 2022, we announced our intention to increase focus on opportunities relating to Controlled Environment Agriculture (CEA). Tecogen believes that CEA offers an exciting opportunity to apply the company’s expertise in clean cooling, power generation, and greenhouse gas reduction to address critical issues affecting food and energy security. Our common stock is quoted on OTC Markets Group, Inc.'s OTCQX Best Market tier and trades under the symbol "TGEN." On May 18, 2017, we acquired 100% of the outstanding common stock of American DG Energy Inc., formerly a related entity, in a stock-for-stock merger. On March 15, 2023, we entered into an agreement ("Agreement") with Aegis Energy Services, LLC (“Aegis”) pursuant to which Aegis agreed to assign to us and we agreed to assume certain Aegis maintenance agreements, we agreed to purchase certain assets, and related matters (“Acquisition”). On April 1, 2023, the Acquisition closed. Under the Agreement, we agreed to acquire from Aegis and assume Aegis rights and obligations arising on or after April 1, 2023, under maintenance agreements pursuant to which Aegis provided maintenance services for approximately 200 cogeneration systems, and acquired certain vehicles and inventory used by Aegis in connection with the performance of such maintenance services, and, following closing hired eight (8) Aegis employees to provide services with respect to such maintenance agreements. At closing, we acquired eight (8) Aegis vehicles for consideration consisting of $170,000 in cash. Also, we issued credits against outstanding accounts receivable due from Aegis in the amount of $300,000 for the acquisition of inventory that Aegis used to provide maintenance services. See Note 8. - Aegis Contract and Related Asset Acquisition. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 8 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation have been included. Operating results for the six months ended June 30, 2023 are not necessarily indicative of the results that may be expected for the year ending December 31, 2023. The condensed consolidated balance sheet at December 31, 2022 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. For further information, refer to the consolidated financial statements and footnotes thereto included in Tecogen's Annual Report on Form 10-K for the year ended December 31, 2022. The accompanying unaudited condensed consolidated financial statements include our accounts and the accounts of entities in which we have a controlling financial interest. Those entities include our wholly-owned subsidiaries American DG Energy Inc., Tecogen CHP Solutions, Inc., and a joint venture, American DG New York, LLC, in which American DG Energy Inc. holds a 51% interest. Investments in partnerships and companies in which we do not have a controlling financial interest but where we have significant influence are accounted for under the equity method. Any intercompany transactions have been eliminated in consolidation. Our operations are comprised of three business segments. Our Products segment designs, manufactures and sells industrial and commercial cogeneration systems as described above. Our Services segment provides operation and maintenance services to customers for our products. Our Energy Production segment sells energy in the form of electricity, heat, hot water and cooling to our customers under long-term sales agreements. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Income Taxes The provisions for income taxes in the accompanying unaudited consolidated statements of operations differ from that which would be expected by applying the federal statutory tax rate primarily due to losses for which no benefit is recognized. Employee Retention Credit On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) was signed into law providing numerous tax provisions and other stimulus measures, including an employee retention credit (“ERC”), which is a refundable tax credit against certain employment taxes. The Taxpayer Certainty and Disaster Tax Relief Act of 2020 and the American Rescue Plan Act of 2021 extended and expanded the availability of the ERC. As a result of our election to use an alternative quarter, we qualified for the ERC in the first, second and third quarters of 2021 because our gross receipts decreased by more than 20% from the first, second and third quarters of 2019. As a result of averaging 100 or fewer full-time employees in 2019, all wages paid to employees in the first, second and third quarters of 2021, excluding the wages applied to the Paycheck Protection Program Second Draw Loan, were eligible for the ERC.

Income (Loss) Per Common Share

Income (Loss) Per Common Share	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Income (Loss) Per Common Share	Income Per Common Share Basic and diluted loss per share for the three and six months ended June 30, 2023 and 2022, respectively, were as follows: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Numerator: Net loss available to stockholders $ (780,110) $ (856,218) $ (2,270,139) $ (766,809) Denominator: Weighted average shares outstanding - Basic 24,850,261 24,850,261 24,850,261 24,850,261 Effect of dilutive securities: Stock options — — — — Weighted average shares outstanding - Diluted 24,850,261 24,850,261 24,850,261 24,850,261 Basic loss per share $ (0.03) $ (0.03) $ (0.09) $ (0.03) Diluted loss per share $ (0.03) $ (0.03) $ (0.09) $ (0.03) Anti-dilutive shares underlying stock options outstanding 1,831,851 925,396 1,831,851 925,396

Inventories, net

Inventories, net	6 Months Ended
	Jun. 30, 2023
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net Inventories at June 30, 2023 and December 31, 2022 consisted of the following: June 30, 2023 December 31, 2022 Raw materials, net $ 9,895,804 $ 9,001,491 Work-in-process 1,001,676 498,139 Finished goods 1,130,045 983,099 Total inventories, net $ 12,027,525 $ 10,482,729

Property, Plant and Equipment,

Property, Plant and Equipment, net	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, net	Property, Plant and Equipment, net Property, plant and equipment at June 30, 2023 and December 31, 2022 consisted of the following: Estimated Useful June 30, 2023 December 31, 2022 Energy systems 1 - 15 years $ 2,810,232 $ 2,810,232 Machinery and equipment 5 - 7 years 1,766,945 1,624,885 Furniture and fixtures 5 years 198,170 196,007 Computer software 3 - 5 years 192,865 192,865 Leasehold improvements * 466,789 466,789 5,435,001 5,290,778 Less - accumulated depreciation and amortization (4,082,683) (3,883,058) $ 1,352,318 $ 1,407,720 * Lesser of estimated useful life of asset or lease term Depreciation and amortization expense on property and equipment for the three and six months ended June 30, 2023 and 2022 was $161,701 and $279,193 and $123,818 and $250,610, respectively. During the six months ended June 30, 2023, we received proceeds of $16,863 from the disposition of certain assets and reversed $8,687 of accrued decomissioning costs from a former ADG energy site, realizing a gain of $19,950. During the six months ended June 30, 2022, we received proceeds of $67,169 from the disposition of certain assets, realizing a gain of $36,445.

Intangible Assets and Liabiliti

Intangible Assets and Liabilities Other Than Goodwill	6 Months Ended
	Jun. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Liabilities Other Than Goodwill	Intangible Assets and Liabilities Other Than Goodwill As of June 30, 2023 and December 31, 2022 we had the following amounts related to intangible assets and liabilities other than goodwill: June 30, 2023 December 31, 2022 Intangible assets Cost Accumulated Amortization Total Cost Accumulated Amortization Total Product certifications $ 777,465 $ (618,749) $ 158,716 $ 777,465 $ (584,863) $ 192,602 Patents 888,910 (452,914) 435,996 888,910 (405,140) 483,770 Developed technology 240,000 (164,000) 76,000 240,000 (156,000) 84,000 Trademarks 26,896 — 26,896 26,896 — 26,896 In Process R&D 263,936 (84,837) 179,099 263,936 (65,984) 197,952 Favorable contract asset 384,465 (374,287) 10,178 384,465 (372,091) 12,374 Customer contract 1,591,327 (56,833) 1,534,494 — — — $ 4,172,999 $ (1,751,620) $ 2,421,379 $ 2,581,672 $ (1,584,078) $ 997,594 Intangible liability Unfavorable contract liability $ 2,618,168 $ (1,913,807) $ 704,361 $ 2,618,168 $ (1,797,951) $ 820,217 The aggregate amortization expense related to intangible assets and liabilities exclusive of unfavorable contract related intangibles for the three and six months ended June 30, 2023 and 2022 was $117,833 and $167,194 and $50,469 and $100,491, respectively. The net credit to cost of sales related to the amortization of the unfavorable contract related intangible asset and liability for the three and six months ended June 30, 2023 and 2022 was $54,575 and $115,508 and $62,857 and $133,383, respectively. Favorable/Unfavorable Contract Assets and Liabilities and Customer Contract Assets The favorable contract asset and unfavorable contract liability in the foregoing table represent the estimated fair value of American DG Energy's customer contracts (both positive for favorable contracts and negative for unfavorable contracts) which were acquired by us in May 2017 and include the customer relationship contract acquired by us in April 2023 as part of the Aegis acquisition. The Aegis customer relationship contract is being amortized on a straight-line basis over a period of seven (7) years which is consistent with the projected revenue recognition. Amortization of intangibles including contract related amounts is calculated using the straight-line method over the remaining useful life or contract term. Aggregate future amortization over the next five years and thereafter as of June 30, 2023 is estimated to be as follows: Non-contract Related Intangibles Contract Related Intangibles Total Year 1 $ 183,504 $ 13,774 $ 197,278 Year 2 179,922 95,572 275,494 Year 3 176,029 143,370 319,399 Year 4 172,418 165,490 337,908 Year 5 100,048 174,871 274,919 Thereafter 48,068 237,056 285,124 Total $ 859,989 830,133 $ 1,690,122 We recognized a gain on termination of unfavorable contract liability of $71,375 in the six months ended June 30, 2022 due to the closing of certain energy production sites.

Sale of Energy Producing Assets

Sale of Energy Producing Assets and Goodwill Impairment	6 Months Ended
	Jun. 30, 2023
Discontinued Operations and Disposal Groups [Abstract]
Sale of Energy Producing Assets and Goodwill Impairment	Sale of Energy Producing Assets and Goodwill ImpairmentDuring the first quarter of 2019 we recognized two individual sales of energy producing assets, for a total of eight power purchase agreements, including the associated energy production contracts for total consideration of $7 million. In connection with these assets sales, we entered into agreements with the purchaser to maintain and operate the assets over the remaining periods of the associated energy production contracts (through August 2033 and January 2034, respectively) in exchange for monthly maintenance and operating fees. These agreements contain provisions whereby we have guaranteed to the purchaser a minimum level or threshold of cash flows from the associated energy production contracts. In October 2021 the minimum guarantee with respect to one of the energy purchase agreements was modified by reducing the guaranteed minimum collections by $35,000 per year, the guaranteed minimum collection amount associated with one site that was sold by the customer. Actual results are compared to the minimum threshold bi-annually and we are contractually obligated to reimburse any shortfall to the purchaser. To the extent actual cash flow results exceed the minimum threshold, we are entitled to fifty percent of such excess under the agreements. Based upon an analysis of these energy producing assets expected future performance, as of June 30, 2023 we do not expect to make any material payments under the guarantee. At June 30, 2023, we were due $22,229 under the energy production contracts, representing outstanding accounts receivable balances that were due from the purchaser's customers which were past due at December 31, 2022 and have since been collected. We expect to receive these funds in the third quarter of 2023 when the bi-annual reconciliation for the period ended June 30, 2023 is prepared. The foregoing agreements also contain provisions whereby we have agreed to make whole the purchaser in the event the counterparty to the energy production contract(s) defaults on or otherwise terminates before the stated expiration of the energy production contract. Should we be required to make whole the purchaser under such provisions, we would be entitled to seek recovery from the counterparty to the energy production contract(s) under a similar provision contained in those contracts in respect of early termination.

Leases

Leases	6 Months Ended
	Jun. 30, 2023
Leases [Abstract]
Leases	Leases Our leases principally consist of operating leases related to our corporate office, field offices, and our research, manufacturing, and storage facilities. At inception, we determine if an arrangement contains a lease and whether that lease meets the classification criteria of a finance or operating lease. Some of our lease agreements contain lease components (e.g. minimum rent payments) and non-lease components (e.g. maintenance, labor charges, etc.). We account for each component separately based on the estimated standalone price of each component. Operating leases are included in Right-of-use assets, Lease obligations, current and Lease obligations, long term on the condensed consolidated balance sheets. These assets and liabilities are recognized at the commencement date based on the present value of remaining lease payments over the lease term and using an incremental borrowing rate consistent with the lease terms or implicit rates, when readily determinable. For those leases where it is reasonably certain at the commencement date that we will exercise the option to extend the lease, then the lease term will include the lease extension term. Short-term operating leases, which have an initial term of 12 months or less, are not recorded on the balance sheet. Lease expense for operating leases, which principally consist of fixed payments for base rent, is recognized on a straight-line basis over the lease term. Lease expense for the three and six months ended June 30, 2023 and 2022 was $216,841 and $406,556 and $210,155 and $407,074, respectively. Supplemental information related to leases for the six months ended June 30, 2023 was as follows: Six Months Ended June 30, 2023 2022 Cash paid for amounts included in the measurement of operating lease liabilities $ 371,264 $ 365,509 Right-of-use assets obtained in exchange for operating lease liabilities $ — $ — Weighted-average remaining lease term - operating leases 3.70 years 3.70 years Weighted-average discount rate - operating leases 6 % 6 % Supplemental information related to operating leases as of June 30, 2023 and December 31, 2022 was as follows: June 30, 2023 December 31, 2022 Operating leases Right-of-use assets $ 920,690 $ 1,245,549 Operating lease liability, current $ 513,811 $ 687,589 Operating lease liability, long-term 459,372 623,452 Total operating lease liability $ 973,183 $ 1,311,041 Future minimum lease commitments under non-cancellable operating leases as of June 30, 2023 were as follows: Operating Leases Year 1 $ 550,785 Year 2 132,569 Year 3 121,565 Year 4 76,818 Year 5 53,422 Thereafter 144,100 Total lease payments 1,079,259 Less: imputed interest 106,076 Total $ 973,183 The lease on our headquarters located in Waltham, Massachusetts which consists of approximately 43,000 square feet of manufacturing, storage and office space, expires on March 31, 2024. Currently, our monthly base rent is $44,254. On March 31, 2023, we entered into two lease agreements for two adjoining buildings, located in Billerica, Massachusetts, containing approximately 26,412 square feet of manufacturing, storage and offices space to serve as our headquarters and manufacturing facilities. The lease agreements provide for initial lease terms of five (5) years with two successive options to renew for additional terms of five (5) years. Both leases commence on January 1, 2024 and require payment of the base rent, real estate taxes, common maintenance expenses and aggregate deposits of $38,200. Our costs for initial improvements required to the leased premises is estimated to range between $1,000,000 and $1,250,000. The estimated straight-line monthly rent expense for the initial term of the lease is approximately $24,800 per month. In accordance with ASC 842-20-30-1, we will record the lease liability and right-of-use asset using the discount rate for the lease upon the lease commencement date.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Stock-Based Compensation	Stock-Based Compensation Stock-Based Compensation We adopted a 2006 Stock Option and Incentive Plan, or the Plan, under which the Board of Directors may grant incentive or non-qualified stock options and stock grants to key employees, directors, advisors and consultants. The Plan was amended at various dates by the Board of Directors to increase the reserved shares of common stock issuable under the Amended Plan to 3,838,750 as of June 30, 2023, and in June 2017 stockholders approved an amendment to extend the termination date of the Plan to January 1, 2026 and ratified all of our option grants issued after January 1, 2016 (the "Amended Plan"). Stock options vest based upon the terms within the individual option grants, with an acceleration of the unvested portion of such options upon a change in control event, as defined in the Amended Plan. The options are not transferable except by will or by the laws of descent and distribution. The option price per share under the Amended Plan cannot be less than the fair market value of the underlying shares on the date of the grant. The number of shares remaining available for future issuance under the Amended Plan as of June 30, 2023 was 188,393. During the six months ended June 30, 2023, we did not grant any options to purchase shares of common stock under the Amended Plan. We adopted the 2022 Stock Incentive Plan (the "2022 Plan"), under which the Board of Directors may grant incentive or non-qualified stock options and stock grants to key employees, directors, advisors and consultants. We have reserved 3,800,000 shares of our common stock for issuance pursuant to awards under the 2022 Plan. The adoption of the 2022 Plan was approved by our shareholders on June 9, 2022. Under the 2022 Plan, stock options vest based upon the terms within the individual option grants, with an acceleration of the unvested portion of such options upon a change in control event, as defined in the 2022 Plan. The options are not transferable except by will or domestic relations order. The option price per share under the 2022 Plan cannot be less than the fair market value of the underlying shares on the date of the grant. The number of shares remaining available for future issuance under the Plan as of June 30, 2023 was 3,475,000. During the six months ended June 30, 2023, we granted non-qualified options to purchase an aggregate of 125,000 shares of common stock at $1.10 per share to certain directors. These options have a vesting schedule of four years and expire in ten years. The fair value of the options issued in 2023 was $62,500. The weighted-average grant date fair value of stock options granted during 2023 was $0.50 per share. Stock option activity for the six months ended June 30, 2023 was as follows: Common Stock Options Number of Exercise Weighted Weighted Aggregate Outstanding, December 31, 2022 3,204,297 $0.71-$10.33 $ 1.61 7.30 years $ 882,074 Granted 125,000 $1.10 $ 1.11 Exercised — Canceled and forfeited (42,000) $1.10-$3.20 $ 2.98 Outstanding, June 30, 2023 3,287,297 $0.71-$10.33 $ 1.57 7.00 years $ 406,845 Exercisable, June 30, 2023 1,788,972 $ 2.06 $ 206,145 Vested and expected to vest, June 30, 2023 3,062,548 $ 1.61 $ 376,740 Consolidated stock-based compensation expense for the three and six months ended June 30, 2023 and 2022 was $28,589 and $105,937 and $89,893 and $185,600, respectively. No tax benefit was recognized related to the stock-based compensation recorded during the period.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The fair value topic of the FASB Accounting Standards Codification defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The accounting guidance also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value: Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities. We currently do not have any Level 1 financial assets or liabilities. Level 2 - Observable inputs other than quoted prices included in Level 1. Level 2 inputs include quoted prices for identical assets or liabilities in non-active markets, quoted prices for similar assets or liabilities in active markets and inputs other than quoted prices that are observable for substantially the full term of the asset or liability. We have Level 2 financial assets and liabilities as provided below. Level 3 - Unobservable inputs reflecting management’s own assumptions about the input used in pricing the asset or liability. We do not currently have any Level 3 financial assets or liabilities. The following tables present the asset reported in "other assets" in the consolidated balance sheet measured at its fair value on a recurring basis as of June 30, 2023 and 2022 by level within the fair value hierarchy. June 30, 2023 Quoted prices in active markets for identical assets Significant other observable inputs Significant unobservable inputs Unrealized Description Total Level 1 Level 2 Level 3 Gains Recurring fair value measurements Marketable equity securities EuroSite Power Inc. $ 131,241 $ — $ 131,241 $ — $ 37,497 Total recurring fair value measurements $ 131,241 $ — $ 131,241 $ — $ 37,497 June 30, 2022 Quoted prices in active markets for identical assets Significant other observable inputs Significant unobservable inputs Unrealized Description Total Level 1 Level 2 Level 3 Gains Recurring fair value measurements Marketable equity securities EuroSite Power Inc. $ 112,492 $ — $ 112,492 $ — $ 37,497 Total recurring fair value measurements $ 112,492 $ — $ 112,492 $ — $ 37,497 We utilize a Level 2 category fair value measurement to value our investment in EuroSite Power, Inc. as a marketable equity security at period end. That measurement is equal to the quoted market closing price at period end. Since this security is not actively traded we classify it as Level 2. The following table summarizes changes in Level 2 assets which are comprised of marketable equity securities for the six months ended June 30, 2023 and 2022: Fair value at December 31, 2022 $ 93,744 Unrealized gains 37,497 Fair value at June 30, 2023 $ 131,241 Fair value at December 31, 2021 $ 74,995 Unrealized gains 37,497 Fair value at June 30, 2022 $ 112,492

Commitments and contingencies

Commitments and contingencies	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and Contingencies     On November 23, 2022, we were served with a suit filed against us on August 24, 2022 in the Ontario Superior Court of Justice by The Corporation of the Town of Milton, Milton Energy Generation Solutions Inc. and Milton Hydro Distribution Inc (the "Plaintiffs"), all of whom are municipal corporations incorporated in the Province of Ontario. The plaintiffs sued for damages in the amount of CDN $1,000,000, pre-judgment and post-judgment interest, legal fees, and any further relief the court may deem, alleging breach of contract, breach of warranty, negligent misrepresentations and nuisance. Plaintiffs allege that on or about July 10, 2022, a Tecogen cogenerator installed by us at the plaintiffs facility caught fire, causing damage to the cogenerator and the plaintiff's facility. We have filed a response denying liability and are being represented by Canadian counsel. For the year ended December 31, 2022, we reserved $150,000 for anticipated damages which may not be covered by our insurance.

Segments

Segments	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Segments	Segments As of June 30, 2023, we were organized into three (3) operating segments through which senior management evaluates our business. These segments, as described in more detail in Note 1, are organized around the products and services provided to customers and represent our reportable segments. The following table presents information by reportable segment for the three and six months ended June 30, 2023 and 2022: Products Services Energy Production Corporate, other and elimination (1) Total Three Months Ended June 30, 2023 Revenue - external customers $ 2,445,631 $ 3,952,971 $ 350,156 $ — $ 6,748,758 Intersegment revenue — 66,143 — (66,143) — Total revenue $ 2,445,631 $ 4,019,114 $ 350,156 $ (66,143) $ 6,748,758 Gross profit $ 827,175 $ 1,877,102 $ 130,149 $ — $ 2,834,426 Identifiable assets $ 9,955,171 $ 13,051,494 $ 3,284,542 $ 3,508,978 $ 29,800,185 Six Months Ended June 30, 2023 Revenue - external customers $ 4,155,767 $ 7,089,144 $ 883,665 $ — $ 12,128,576 Intersegment revenue — 154,357 — (154,357) — Total revenue $ 4,155,767 $ 7,243,501 $ 883,665 $ (154,357) $ 12,128,576 Gross profit $ 1,324,743 $ 3,275,673 $ 325,919 $ — $ 4,926,335 Identifiable assets $ 9,955,171 $ 13,051,494 $ 3,284,542 $ 3,508,978 $ 29,800,185 Three Months Ended June 30, 2022 Revenue - external customers $ 3,010,115 $ 3,050,191 $ 354,287 $ — $ 6,414,593 Intersegment revenue — 62,415 — (62,415) — Total revenue $ 3,010,115 $ 3,112,606 $ 354,287 $ (62,415) $ 6,414,593 Gross profit $ 994,649 $ 1,576,605 $ 132,195 $ — $ 2,703,449 Identifiable assets $ 11,237,886 $ 9,799,483 $ 3,855,043 $ 5,441,312 $ 30,333,724 Six Months Ended June 30, 2022 Revenue - external customers $ 6,949,596 $ 5,967,471 $ 935,849 $ — $ 13,852,916 Intersegment revenue — 157,669 — (157,669) — Total revenue $ 6,949,596 $ 6,125,140 $ 935,849 $ (157,669) $ 13,852,916 Gross profit $ 2,289,375 $ 3,127,133 $ 377,730 $ — $ 5,794,238 Identifiable assets $ 11,237,886 $ 9,799,483 $ 3,855,043 $ 5,441,312 $ 30,333,724 (1) Corporate, intersegment revenue, other and elimination includes various corporate assets.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events     We have evaluated subsequent events through the date of this filing and determined that no material subsequent events occurred that would require recognition in the consolidated financial statements or disclosure in the notes thereto.

Aegis Contract and Related Asse

Aegis Contract and Related Asset Acquisition	6 Months Ended
	Jun. 30, 2023
Business Combination and Asset Acquisition [Abstract]
Aegis Contract and Related Asset Acquisition	Aegis Contract and Related Asset Acquisition On March 15, 2023, we entered into an agreement ("Agreement") with Aegis Energy Services, LLC (“Aegis”) pursuant to which Aegis agreed to assign to us and we agreed to assume certain Aegis maintenance agreements, we agreed to purchase certain assets from Aegis, and related matters (“Acquisition”). On April 1, 2023, the Acquisition closed. Under the Agreement, we agreed to acquire from Aegis and assume Aegis’ rights and obligations arising on or after April 1, 2023, under maintenance agreements pursuant to which Aegis provided maintenance services to third parties for approximately 200 cogeneration systems and we agreed to acquire from Aegis certain vehicles and inventory used by Aegis in connection with the performance of its maintenance services. At closing, we acquired eight (8) Aegis vehicles for consideration consisting of $170,000 in cash. Also, we issued credits against outstanding accounts receivable due from Aegis in the amount of $300,000 for the acquisition of inventory that Aegis used to provide maintenance services. At closing, we hired eight (8) Aegis employees who, following the closing, have agreed to continue to provide maintenance services relating to the cogeneration systems covered by the maintenance agreements assumed pursuant to the Agreement. Following the closing and for a period of up to seven (7) years, we have agreed to pay Aegis a percentage of the revenue collected for maintenance services provided pursuant to the maintenance agreements acquired from Aegis. Further, prior to December 31, 2023, we have the right to acquire and assume additional Aegis’ maintenance agreements for cogeneration systems on substantially similar terms and conditions. The Agreement contained certain indemnification provisions and agreements on the part of Aegis and for each party to cooperate with each other and provide certain transitional assistance. We acquired the Aegis maintenance agreements to expand our Service portfolio and to benefit from the long-term contract revenue stream generated by these agreements. We have determined that the assignment and assumption of the Aegis maintenance agreements, in combination with the related asset acquisition and the retention of the former Aegis employees, constitutes a business and should be accounted for as a business combination under the acquisition method. As of the acquisition date, we recognized, separately from goodwill, the identifiable assets acquired and the liabilities assumed, at fair value. We have included the financial results of the Aegis maintenance agreements in our consolidated financial statements from April 1, 2023, the closing or acquisition date. The following table summarizes the consideration paid for the Aegis acquisition and the fair value of assets acquired and contract-related liabilities assumed as the acquisition date: Consideration Paid: Cash $ 170,000 Accounts receivable credit issued 300,000 Account payable 111,178 Contingent consideration 1,442,462 Total fair value of consideration transferred 2,023,639 Identifiable assets acquired and liabilities assumed: Assets acquired Property, plant and equipment 170,000 Inventory 411,178 Identifiable intangible asset - customer contracts 1,591,327 2,172,505 Acquired contract-related liabilities assumed Deferred maintenance reserve (871,856) (871,856) Net identifiable assets acquired 1,300,649 Excess of cost over fair value of net assets acquired (Goodwill) $ 722,991 The amounts recognized for inventory, identifiable intangible assets, contingent consideration and deferred maintenance reserves are provisional pending completion of the necessary valuations and analysis. ASC 805 establishes a measurement period to provide companies with a reasonable amount of time to obtain the information necessary to identify and measure various items in a business combination and cannot extend beyond one year from the acquisition date. The fair value of the contingent consideration was estimated using the income approach. The excess cash flow was discounted to present value using an appropriate rate of return to estimate the market value of the customer identifiable intangible asset and the risks associated with the future revenue forecasts due to potential changes in customer energy requirements or changes in the economic viability of these CHP sites which depend on the spread between natural gas fuel and electricity prices, all of which are not within our control. Key assumptions to value the customer identifiable intangible asset included a discount rate of 15%, anticipated existing contract run out and forecasted revenue. On the date of acquisition, the fair value of the contingent consideration and the deferred maintenance reserve were calculated using a weighted average cost of capital of 12%, discounting the future cash flows to present value and are subsequently remeasured to fair value at each reporting date until the contingencies are resolved. The contingent consideration is payable within forty-five (45) days following the end of each calendar quarter through the earlier of the expiration or termination of the relevant maintenance agreements, or the seventh (7th) anniversary of the acquisition date. The consideration is equal to the product of the revenues collected in a calendar quarter multiplied by an applicable percentage. The agreement stipulates quarterly aggregate revenue targets and an applicable percentage, and provides for a higher applicable percentage if revenues exceed the target revenues. The applicable percentage ranges from 5% to 10% over the agreement term. The deferred maintenance reserve represents costs, which are expected to be incurred over a three-year period from the date of acquisition, to repair customer equipment that had not been properly maintained prior to our acquisition of the maintenance service agreements. Revenues and gross profit since the acquisition date were $628,813 and $411,106, respectively, for the three months ended June 30, 2023 and are included in our Services segment. The purchase price of the acquisition was allocated to the tangible and intangible assets acquired and liabilities assumed and recognized at their fair value based on widely accepted valuation techniques in accordance with ASC 820, "Fair Value Measurement," as of the acquisition date. The process for estimating fair value requires the use of significant assumptions and estimates of future cash flows and developing appropriate discount rates. The excess of the purchase price over fair value of the net identified assets acquired and liabilities assumed was recorded as goodwill. Goodwill is primarily attributable to the going concern element of the Aegis business, including its assembled workforce and the long-term nature of the customer maintenance agreements, as well as anticipated cost synergies due primarily to the elimination of administrative overhead. Goodwill resulting from the Aegis acquisition is not expected to be deductible for income tax purposes. Acquisition-related costs which consisted on recurring internal resources were deminimus and such costs were expensed as incurred (ASC805-50-30-1). The following table summarizes the contract-related liabilities assumed as of: June 30, 2023 December 31, 2022 Acquisition liabilities, current Contingent consideration $ 164,357 $ — Deferred maintenance reserve 484,884 — 649,241 — Acquisition liabilities, long-term Contingent consideration 1,278,105 — Deferred maintenance reserve 365,462 — $ 1,643,567 $ —

Description of business and b_2

Description of business and basis of presentation (Policies)	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 8 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation have been included. Operating results for the six months ended June 30, 2023 are not necessarily indicative of the results that may be expected for the year ending December 31, 2023. The condensed consolidated balance sheet at December 31, 2022 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. For further information, refer to the consolidated financial statements and footnotes thereto included in Tecogen's Annual Report on Form 10-K for the year ended December 31, 2022. The accompanying unaudited condensed consolidated financial statements include our accounts and the accounts of entities in which we have a controlling financial interest. Those entities include our wholly-owned subsidiaries American DG Energy Inc., Tecogen CHP Solutions, Inc., and a joint venture, American DG New York, LLC, in which American DG Energy Inc. holds a 51% interest. Investments in partnerships and companies in which we do not have a controlling financial interest but where we have significant influence are accounted for under the equity method. Any intercompany transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates    The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates
Income Taxes	Income Taxes The provisions for income taxes in the accompanying unaudited consolidated statements of operations differ from that which would be expected by applying the federal statutory tax rate primarily due to losses for which no benefit is recognized.

Loss Per Common Share (Tables)

Loss Per Common Share (Tables)	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Income (Loss) Per Common Share, Basic and Diluted	Basic and diluted loss per share for the three and six months ended June 30, 2023 and 2022, respectively, were as follows: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Numerator: Net loss available to stockholders $ (780,110) $ (856,218) $ (2,270,139) $ (766,809) Denominator: Weighted average shares outstanding - Basic 24,850,261 24,850,261 24,850,261 24,850,261 Effect of dilutive securities: Stock options — — — — Weighted average shares outstanding - Diluted 24,850,261 24,850,261 24,850,261 24,850,261 Basic loss per share $ (0.03) $ (0.03) $ (0.09) $ (0.03) Diluted loss per share $ (0.03) $ (0.03) $ (0.09) $ (0.03) Anti-dilutive shares underlying stock options outstanding 1,831,851 925,396 1,831,851 925,396

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jun. 30, 2023
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories at June 30, 2023 and December 31, 2022 consisted of the following: June 30, 2023 December 31, 2022 Raw materials, net $ 9,895,804 $ 9,001,491 Work-in-process 1,001,676 498,139 Finished goods 1,130,045 983,099 Total inventories, net $ 12,027,525 $ 10,482,729

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment	Property, plant and equipment at June 30, 2023 and December 31, 2022 consisted of the following: Estimated Useful June 30, 2023 December 31, 2022 Energy systems 1 - 15 years $ 2,810,232 $ 2,810,232 Machinery and equipment 5 - 7 years 1,766,945 1,624,885 Furniture and fixtures 5 years 198,170 196,007 Computer software 3 - 5 years 192,865 192,865 Leasehold improvements * 466,789 466,789 5,435,001 5,290,778 Less - accumulated depreciation and amortization (4,082,683) (3,883,058) $ 1,352,318 $ 1,407,720 * Lesser of estimated useful life of asset or lease term

Intangible Assets and Liabili_2

Intangible Assets and Liabilities Other Than Goodwill (Tables)	6 Months Ended
	Jun. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	As of June 30, 2023 and December 31, 2022 we had the following amounts related to intangible assets and liabilities other than goodwill: June 30, 2023 December 31, 2022 Intangible assets Cost Accumulated Amortization Total Cost Accumulated Amortization Total Product certifications $ 777,465 $ (618,749) $ 158,716 $ 777,465 $ (584,863) $ 192,602 Patents 888,910 (452,914) 435,996 888,910 (405,140) 483,770 Developed technology 240,000 (164,000) 76,000 240,000 (156,000) 84,000 Trademarks 26,896 — 26,896 26,896 — 26,896 In Process R&D 263,936 (84,837) 179,099 263,936 (65,984) 197,952 Favorable contract asset 384,465 (374,287) 10,178 384,465 (372,091) 12,374 Customer contract 1,591,327 (56,833) 1,534,494 — — — $ 4,172,999 $ (1,751,620) $ 2,421,379 $ 2,581,672 $ (1,584,078) $ 997,594 Intangible liability Unfavorable contract liability $ 2,618,168 $ (1,913,807) $ 704,361 $ 2,618,168 $ (1,797,951) $ 820,217
Schedule of Future Amortization Expense	Aggregate future amortization over the next five years and thereafter as of June 30, 2023 is estimated to be as follows: Non-contract Related Intangibles Contract Related Intangibles Total Year 1 $ 183,504 $ 13,774 $ 197,278 Year 2 179,922 95,572 275,494 Year 3 176,029 143,370 319,399 Year 4 172,418 165,490 337,908 Year 5 100,048 174,871 274,919 Thereafter 48,068 237,056 285,124 Total $ 859,989 830,133 $ 1,690,122

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2023
Leases [Abstract]
Supplemental Information Related to Leases	Supplemental information related to leases for the six months ended June 30, 2023 was as follows: Six Months Ended June 30, 2023 2022 Cash paid for amounts included in the measurement of operating lease liabilities $ 371,264 $ 365,509 Right-of-use assets obtained in exchange for operating lease liabilities $ — $ — Weighted-average remaining lease term - operating leases 3.70 years 3.70 years Weighted-average discount rate - operating leases 6 % 6 %
Future Minimum Lease Commitments	Future minimum lease commitments under non-cancellable operating leases as of June 30, 2023 were as follows: Operating Leases Year 1 $ 550,785 Year 2 132,569 Year 3 121,565 Year 4 76,818 Year 5 53,422 Thereafter 144,100 Total lease payments 1,079,259 Less: imputed interest 106,076 Total $ 973,183
Assets and Liabilities, Lessee	Supplemental information related to operating leases as of June 30, 2023 and December 31, 2022 was as follows: June 30, 2023 December 31, 2022 Operating leases Right-of-use assets $ 920,690 $ 1,245,549 Operating lease liability, current $ 513,811 $ 687,589 Operating lease liability, long-term 459,372 623,452 Total operating lease liability $ 973,183 $ 1,311,041

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2023
Tecogen
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Stock Option Activity	Stock option activity for the six months ended June 30, 2023 was as follows: Common Stock Options Number of Exercise Weighted Weighted Aggregate Outstanding, December 31, 2022 3,204,297 $0.71-$10.33 $ 1.61 7.30 years $ 882,074 Granted 125,000 $1.10 $ 1.11 Exercised — Canceled and forfeited (42,000) $1.10-$3.20 $ 2.98 Outstanding, June 30, 2023 3,287,297 $0.71-$10.33 $ 1.57 7.00 years $ 406,845 Exercisable, June 30, 2023 1,788,972 $ 2.06 $ 206,145 Vested and expected to vest, June 30, 2023 3,062,548 $ 1.61 $ 376,740

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables present the asset reported in "other assets" in the consolidated balance sheet measured at its fair value on a recurring basis as of June 30, 2023 and 2022 by level within the fair value hierarchy. June 30, 2023 Quoted prices in active markets for identical assets Significant other observable inputs Significant unobservable inputs Unrealized Description Total Level 1 Level 2 Level 3 Gains Recurring fair value measurements Marketable equity securities EuroSite Power Inc. $ 131,241 $ — $ 131,241 $ — $ 37,497 Total recurring fair value measurements $ 131,241 $ — $ 131,241 $ — $ 37,497 June 30, 2022 Quoted prices in active markets for identical assets Significant other observable inputs Significant unobservable inputs Unrealized Description Total Level 1 Level 2 Level 3 Gains Recurring fair value measurements Marketable equity securities EuroSite Power Inc. $ 112,492 $ — $ 112,492 $ — $ 37,497 Total recurring fair value measurements $ 112,492 $ — $ 112,492 $ — $ 37,497
Schedule of Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	The following table summarizes changes in Level 2 assets which are comprised of marketable equity securities for the six months ended June 30, 2023 and 2022: Fair value at December 31, 2022 $ 93,744 Unrealized gains 37,497 Fair value at June 30, 2023 $ 131,241 Fair value at December 31, 2021 $ 74,995 Unrealized gains 37,497 Fair value at June 30, 2022 $ 112,492

Segments (Tables)

Segments (Tables)	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The following table presents information by reportable segment for the three and six months ended June 30, 2023 and 2022: Products Services Energy Production Corporate, other and elimination (1) Total Three Months Ended June 30, 2023 Revenue - external customers $ 2,445,631 $ 3,952,971 $ 350,156 $ — $ 6,748,758 Intersegment revenue — 66,143 — (66,143) — Total revenue $ 2,445,631 $ 4,019,114 $ 350,156 $ (66,143) $ 6,748,758 Gross profit $ 827,175 $ 1,877,102 $ 130,149 $ — $ 2,834,426 Identifiable assets $ 9,955,171 $ 13,051,494 $ 3,284,542 $ 3,508,978 $ 29,800,185 Six Months Ended June 30, 2023 Revenue - external customers $ 4,155,767 $ 7,089,144 $ 883,665 $ — $ 12,128,576 Intersegment revenue — 154,357 — (154,357) — Total revenue $ 4,155,767 $ 7,243,501 $ 883,665 $ (154,357) $ 12,128,576 Gross profit $ 1,324,743 $ 3,275,673 $ 325,919 $ — $ 4,926,335 Identifiable assets $ 9,955,171 $ 13,051,494 $ 3,284,542 $ 3,508,978 $ 29,800,185 Three Months Ended June 30, 2022 Revenue - external customers $ 3,010,115 $ 3,050,191 $ 354,287 $ — $ 6,414,593 Intersegment revenue — 62,415 — (62,415) — Total revenue $ 3,010,115 $ 3,112,606 $ 354,287 $ (62,415) $ 6,414,593 Gross profit $ 994,649 $ 1,576,605 $ 132,195 $ — $ 2,703,449 Identifiable assets $ 11,237,886 $ 9,799,483 $ 3,855,043 $ 5,441,312 $ 30,333,724 Six Months Ended June 30, 2022 Revenue - external customers $ 6,949,596 $ 5,967,471 $ 935,849 $ — $ 13,852,916 Intersegment revenue — 157,669 — (157,669) — Total revenue $ 6,949,596 $ 6,125,140 $ 935,849 $ (157,669) $ 13,852,916 Gross profit $ 2,289,375 $ 3,127,133 $ 377,730 $ — $ 5,794,238 Identifiable assets $ 11,237,886 $ 9,799,483 $ 3,855,043 $ 5,441,312 $ 30,333,724 (1) Corporate, intersegment revenue, other and elimination includes various corporate assets.

Aegis Contract and Related As_2

Aegis Contract and Related Asset Acquisition (Tables)	6 Months Ended
	Jun. 30, 2023
Business Combination and Asset Acquisition [Abstract]
Asset Acquisition	The following table summarizes the consideration paid for the Aegis acquisition and the fair value of assets acquired and contract-related liabilities assumed as the acquisition date: Consideration Paid: Cash $ 170,000 Accounts receivable credit issued 300,000 Account payable 111,178 Contingent consideration 1,442,462 Total fair value of consideration transferred 2,023,639 Identifiable assets acquired and liabilities assumed: Assets acquired Property, plant and equipment 170,000 Inventory 411,178 Identifiable intangible asset - customer contracts 1,591,327 2,172,505 Acquired contract-related liabilities assumed Deferred maintenance reserve (871,856) (871,856) Net identifiable assets acquired 1,300,649 Excess of cost over fair value of net assets acquired (Goodwill) $ 722,991 The following table summarizes the contract-related liabilities assumed as of: June 30, 2023 December 31, 2022 Acquisition liabilities, current Contingent consideration $ 164,357 $ — Deferred maintenance reserve 484,884 — 649,241 — Acquisition liabilities, long-term Contingent consideration 1,278,105 — Deferred maintenance reserve 365,462 — $ 1,643,567 $ —

Description of business and b_3

Description of business and basis of presentation - Additional Information (Details)					3 Months Ended		6 Months Ended
	Mar. 15, 2023 USD ($)	Jan. 12, 2023 USD ($)	Apr. 14, 2022 USD ($)	May 18, 2017	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2023 USD ($) segment	Dec. 31, 2022 USD ($)
Business Acquisition [Line Items]
Ownerhsip interest in American DG New York, LLC (percent)							51%
Number of business segments | segment							3
Employee Retention Credit						$ 713,269
Accrued interest received					$ 1,275	$ 15,775
Employee retention credit receivable							$ 46,148	$ 713,269
Aegis Energy Services, LLC
Business Acquisition [Line Items]
Total fair value of consideration transferred	$ 2,023,639	$ 667,121	$ 564,027		$ 562,752
Accounts receivable credit issued	300,000
Cash	$ 170,000
American DG Energy, Inc.
Business Acquisition [Line Items]
Ownership interest (percent)				100%

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenue	$ 6,748,758	$ 6,414,593	$ 12,128,576	$ 13,852,916
Products
Disaggregation of Revenue [Line Items]
Total revenue	2,445,631	3,010,115	4,155,767	6,949,596
Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	3,952,971	3,050,191	7,089,144	5,947,362
Energy production
Disaggregation of Revenue [Line Items]
Total revenue	350,156	354,287	883,665	935,849
Installation services
Disaggregation of Revenue [Line Items]
Total revenue				20,109
Products
Disaggregation of Revenue [Line Items]
Total revenue	2,445,631	3,010,115	4,155,767	6,949,596
Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	4,019,114	3,112,606	7,243,501	6,125,140
Energy production
Disaggregation of Revenue [Line Items]
Total revenue	350,156	354,287	883,665	935,849
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	6,748,758	6,414,593	12,128,576	13,852,916
Operating Segments | Products
Disaggregation of Revenue [Line Items]
Total revenue	2,445,631	3,010,115	4,155,767	6,949,596
Operating Segments | Products | Products
Disaggregation of Revenue [Line Items]
Total revenue	2,445,631	3,010,115	4,155,767	6,949,596
Operating Segments | Products | Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | Products | Energy production
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | Products | Installation services
Disaggregation of Revenue [Line Items]
Total revenue				0
Operating Segments | Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	3,952,971	3,050,191	7,089,144	5,967,471
Operating Segments | Maintenance services | Products
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | Maintenance services | Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	3,952,971	3,050,191	7,089,144	5,947,362
Operating Segments | Maintenance services | Energy production
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | Maintenance services | Installation services
Disaggregation of Revenue [Line Items]
Total revenue				20,109
Operating Segments | Energy production
Disaggregation of Revenue [Line Items]
Total revenue	350,156	354,287	883,665	935,849
Operating Segments | Energy production | Products
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | Energy production | Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Operating Segments | Energy production | Energy production
Disaggregation of Revenue [Line Items]
Total revenue	$ 350,156	$ 354,287	$ 883,665	935,849
Operating Segments | Energy production | Installation services
Disaggregation of Revenue [Line Items]
Total revenue				$ 0

Revenue - Additional Informatio

Revenue - Additional Information (Details)	6 Months Ended
	Jun. 30, 2023 USD ($)
Revenue Recognition [Abstract]
Revenue billed this period that had been recognized in previous periods	$ 16,428
Deferred revenue recognized	648,435
Remaining performance obligations	$ 2,200,000
Performance obligation revenue expected to be recognized over the next 24 months (percent)	98.90%
Performance obligation revenue to be recognized in first 12 months (percent)	93.10%
Performance obligation revenue to be recognized over the subsequent 12 months (percent)	5.80%

Loss Per Common Share - Schedul

Loss Per Common Share - Schedule of Income (Loss) Per Common Share, Basic and Diluted (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net loss available to stockholders	$ (780,110)	$ (856,218)	$ (2,270,139)	$ (766,809)
Weighted average shares outstanding - basic	24,850,261	24,850,261	24,850,261	24,850,261
Effect of dilutive securities:
Weighted average shares outstanding - Diluted	24,850,261	24,850,261	24,850,261	24,850,261
Net income (loss) per share - basic (in USD per share)	$ (0.03)	$ (0.03)	$ (0.09)	$ (0.03)
Net income (loss) per share - diluted (in usd per share)	$ (0.03)	$ (0.03)	$ (0.09)	$ (0.03)
Stock Options
Effect of dilutive securities:
Stock options	0	0	0	0
Anti-dilutive shares underlying stock options outstanding	1,831,851	925,396	1,831,851	925,396

Inventory (Details)

Inventory (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials, net	$ 9,895,804	$ 9,001,491
Work-in-process	1,001,676	498,139
Finished goods	1,130,045	983,099
Inventories, net	$ 12,027,525	$ 10,482,729

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Property and Equipment (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,435,001	$ 5,290,778
Less - accumulated depreciation and amortization	(4,082,683)	(3,883,058)
Property and equipment, net, before construction in progress	1,352,318	1,407,720
Energy systems
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,810,232	2,810,232
Energy systems | Minimum
Property, Plant and Equipment [Line Items]
Useful life - years	1 year
Energy systems | Maximum
Property, Plant and Equipment [Line Items]
Useful life - years	15 years
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,766,945	1,624,885
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life - years	5 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life - years	7 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 198,170	196,007
Useful life - years	5 years
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 192,865	192,865
Computer software | Minimum
Property, Plant and Equipment [Line Items]
Useful life - years	3 years
Computer software | Maximum
Property, Plant and Equipment [Line Items]
Useful life - years	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 466,789	$ 466,789

Property, Plant and Equipment_2

Property, Plant and Equipment - Depreciation (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 161,701	$ 123,818	$ 279,193	$ 250,610

Intangible Assets and Liabili_3

Intangible Assets and Liabilities Other Than Goodwill -Amounts related to intangible assets (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 4,172,999	$ 2,581,672
Less - accumulated amortization	(1,751,620)	(1,584,078)
Intangible assets, net	2,421,379	997,594
Unfavorable contract liability	2,618,168	2,618,168
Less - accumulated amortization	(1,913,807)	(1,797,951)
Unfavorable contract liability, net	704,361	820,217
Product Certifications
Finite-Lived Intangible Assets [Line Items]
Intangible assets	777,465	777,465
Less - accumulated amortization	(618,749)	(584,863)
Intangible assets, net	158,716	192,602
Patents
Finite-Lived Intangible Assets [Line Items]
Intangible assets	888,910	888,910
Less - accumulated amortization	(452,914)	(405,140)
Intangible assets, net	435,996	483,770
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets	240,000	240,000
Less - accumulated amortization	(164,000)	(156,000)
Intangible assets, net	76,000	84,000
Favorable contract asset
Finite-Lived Intangible Assets [Line Items]
Intangible assets	384,465	384,465
Less - accumulated amortization	(374,287)	(372,091)
Intangible assets, net	10,178	12,374
TTcogen Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets	1,591,327	0
Less - accumulated amortization	(56,833)	0
Intangible assets, net	1,534,494	0
Trademarks
Finite-Lived Intangible Assets [Line Items]
Intangible assets	26,896	26,896
Less - accumulated amortization	0	0
Intangible assets, net	26,896	26,896
In Process R&D
Finite-Lived Intangible Assets [Line Items]
Intangible assets	263,936	263,936
Less - accumulated amortization	(84,837)	(65,984)
Intangible assets, net	$ 179,099	$ 197,952

Intangible Assets and Liabili_4

Intangible Assets and Liabilities Other Than Goodwill (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 117,833	$ 50,469	$ 167,194	$ 100,491
Net credit to cost of sales for amortization of contract related intangible assets and liabilities	$ 54,575	$ 62,857	115,508	133,383
Gain on termination of unfavorable contract liability			$ 0	$ (71,375)

Intangible Assets and Liabili_5

Intangible Assets and Liabilities Other Than Goodwill - Future Amortization of Customer Contracts (Details) - USD ($)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Non-contract Related Intangibles [Abstract]
Total	$ 2,421,379		$ 997,594
Contract-related Intangibles [Abstract]
Gain on termination of unfavorable contract liability	0	$ 71,375
Contract Asset and Liability
Non-contract Related Intangibles [Abstract]
Year 4	337,908
Year 5	274,919
Contract-related Intangibles [Abstract]
Year 1	197,278
Year 2	275,494
Year 3	319,399
Thereafter	285,124
Total	1,690,122
Non-contract Related Intangible Assets | Contract Asset and Liability
Non-contract Related Intangibles [Abstract]
Year 1	183,504
Year 2	179,922
Year 3	176,029
Year 4	172,418
Year 5	100,048
Thereafter	48,068
Total	859,989
Customer Contracts | Contract Asset and Liability
Contract-related Intangibles [Abstract]
Year 1	13,774
Year 2	95,572
Year 3	143,370
Year 4	165,490
Year 5	174,871
Thereafter	237,056
Total	$ 830,133

Sale of Energy Producing Asse_2

Sale of Energy Producing Assets and Goodwill Impairment (Details)	3 Months Ended
	Mar. 31, 2021 USD ($) site sale	Jun. 30, 2023 USD ($)
Discontinued Operations and Disposal Groups [Abstract]
Number of sales of energy producing assets | sale	2
Number of energy producing sites sold | site	8
Consideration received	$ 7,000,000
Obligation under energy production contracts		$ 22,229

Leases (Details)

Leases (Details)		3 Months Ended		6 Months Ended
	Jan. 01, 2024 USD ($)	Jun. 30, 2023 USD ($) ft²	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) ft²	Jun. 30, 2022 USD ($)	Mar. 31, 2023 ft²
Lessee, Lease, Description [Line Items]
Lease cost		$ 216,841	$ 210,155	$ 406,556	$ 407,074
Cash paid for amounts included in the measurement of operating lease liabilities				371,264	365,509
Right-of-use assets obtained in exchange for operating lease liabilities				$ 0	$ 0
Weighted-average remaining lease term - operating leases		3 years 8 months 12 days	3 years 8 months 12 days	3 years 8 months 12 days	3 years 8 months 12 days
Weighted-average discount rate - operating leases (percent)		6%	6%	6%	6%
Square feet of lease | ft²		43,000		43,000		26,412
Rent expense				$ 44,254
Lease term		5 years		5 years
Forecast
Lessee, Lease, Description [Line Items]
Lease cost	$ 38,200
Rent expense	$ 24,800
Minimum
Lessee, Lease, Description [Line Items]
Lease improvement costs				$ 1,000,000
Maximum
Lessee, Lease, Description [Line Items]
Lease improvement costs				$ 1,250,000

Leases - Assets and Liabilities

Leases - Assets and Liabilities, Lessee (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Leases [Abstract]
Right of use assets	$ 920,690	$ 1,245,549
Operating Lease, Liability, Current	513,811	687,589
Operating Lease, Liability, Noncurrent	459,372	623,452
Total	$ 973,183	$ 1,311,041
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Lease obligations, current	Lease obligations, current
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Lease obligations, net of current portion	Lease obligations, net of current portion

Leases - Future Minimum Lease C

Leases - Future Minimum Lease Commitments (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Leases [Abstract]
Year 1	$ 550,785
Year 2	132,569
Year 3	121,565
Year 4	76,818
Year 5	53,422
Thereafter	144,100
Total lease payments	1,079,259
Less: imputed interest	106,076
Total	$ 973,183	$ 1,311,041

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 09, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Noncash Expense	$ 28,589	$ 89,893	$ 105,937	$ 185,600
Fair value of options			$ 62,500
Weighted average grant date fair value (in dollars per share)			$ 0.50
Share-based Payment Arrangement, Nonemployee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price (dollars per share)	$ 1.10		$ 1.10
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized, amount	$ 455,445		$ 455,445
Compensation cost not yet recognized, period for recognition			2 years 11 months 26 days
Nonqualified Options | Share-based Payment Arrangement, Nonemployee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)			125,000
2022 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares remaining available for future issuance	3,475,000		3,475,000
2022 Stock Incentive Plan | Nonqualified Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance					3,800,000
Tecogen
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)			125,000
Tecogen | Amended Plan | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance	3,838,750		3,838,750
Number of shares remaining available for future issuance	188,393		188,393

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock Option Activity (Details) - Tecogen - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2021	Jun. 30, 2023	Dec. 31, 2022
Stock Options Outstanding [Roll Forward]
Beginning (shares)	3,204,297		3,204,297
Granted (shares)			125,000
Exercised (shares)			0
Canceled and forfeited (shares)			(42,000)
Ending (shares)			3,287,297
Exercisable (shares)			1,788,972
Vested and expected to vest (shares)			3,062,548
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Outstanding, Minimum (per share)	$ 0.71		$ 0.71
Exercise Price Per Share, Outstanding, Maximum (dollars per share)	10.33		10.33
Weighted Average Exercise Price [Roll Forward]
Beginning (usd per share)	$ 1.61		1.61
Granted (usd per share)			1.11
Canceled and forfeited (usd per share)			2.98
Ending (usd per share)			1.57
Exercisable (usd per share)			2.06
Vested and expected to vest (usd per share)			$ 1.61
Weighted Average Remaining Life		7 years 3 months 18 days	7 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, Aggregate Intrinsic Value			$ 406,845	$ 882,074
Exercisable, Aggregate Intrinsic Value			206,145
Vested and expected to vest, Aggregate Intrinsic Value			$ 376,740
Minimum
Exercise Price Per Share [Abstract]
Exercise price per share, Granted (dollars per share)			$ 1.10

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value on a Recurring Basis (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain (loss) on investment securities	$ 37,497	$ 0	$ 37,497	$ 37,497
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain (loss) on investment securities			37,497	37,497
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale equity securities	131,241	112,492	131,241	112,492	$ 93,744	$ 74,995
Unrealized gain (loss)			37,497	37,497
Assets, Fair Value Disclosure	131,241	112,492	131,241	112,492
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	131,241	112,492	131,241	112,492
Eurosite Power, Inc. | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain (loss) on investment securities			37,497	37,497
Eurosite Power, Inc. | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale equity securities	0	0	0	0
Eurosite Power, Inc. | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale equity securities	131,241	112,492	131,241	112,492
Eurosite Power, Inc. | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale equity securities	0	0	0	0
Eurosite Power, Inc. | Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale equity securities	$ 131,241	$ 112,492	$ 131,241	$ 112,492

Fair Value Measurements - Chang

Fair Value Measurements - Change in Level 2 Assets (Details) - Fair Value, Measurements, Recurring - Level 2 - USD ($)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, beginning	$ 93,744	$ 74,995
Unrealized gain (loss)	37,497	37,497
Fair value, ending	131,241	112,492
Eurosite Power, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, ending	$ 131,241	$ 112,492

Commitments and Contingencies (

Commitments and Contingencies (Details)	Nov. 23, 2022 CAD ($)	Dec. 31, 2022 USD ($)
Loss Contingencies [Line Items]
Damages sought	$ 1,000,000
Guarantee liability		$ 150,000

Segments (Details)

Segments (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) segment	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of operating divisions | segment			3
Revenue	$ 6,748,758	$ 6,414,593	$ 12,128,576	$ 13,852,916
Gross profit	2,834,426	2,703,449	4,926,335	5,794,238
Assets	29,800,185	30,333,724	29,800,185	30,333,724	$ 28,252,857
Products
Segment Reporting Information [Line Items]
Revenue	2,445,631	3,010,115	4,155,767	6,949,596
Gross profit	827,175	994,649	1,324,743	2,289,375
Assets	9,955,171	11,237,886	9,955,171	11,237,886
Maintenance services
Segment Reporting Information [Line Items]
Revenue	4,019,114	3,112,606	7,243,501	6,125,140
Gross profit	1,877,102	1,576,605	3,275,673	3,127,133
Assets	13,051,494	9,799,483	13,051,494	9,799,483
Energy production
Segment Reporting Information [Line Items]
Revenue	350,156	354,287	883,665	935,849
Gross profit	130,149	132,195	325,919	377,730
Assets	3,284,542	3,855,043	3,284,542	3,855,043
Corporate, other and elimination
Segment Reporting Information [Line Items]
Revenue	(66,143)	(62,415)	(154,357)	(157,669)
Gross profit	0	0	0	0
Assets	3,508,978	5,441,312	3,508,978	5,441,312
Operating Segments
Segment Reporting Information [Line Items]
Revenue	6,748,758	6,414,593	12,128,576	13,852,916
Operating Segments | Products
Segment Reporting Information [Line Items]
Revenue	2,445,631	3,010,115	4,155,767	6,949,596
Operating Segments | Maintenance services
Segment Reporting Information [Line Items]
Revenue	3,952,971	3,050,191	7,089,144	5,967,471
Operating Segments | Energy production
Segment Reporting Information [Line Items]
Revenue	350,156	354,287	883,665	935,849
Operating Segments | Corporate, other and elimination
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Intersegment Eliminations | Products
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Intersegment Eliminations | Maintenance services
Segment Reporting Information [Line Items]
Revenue	66,143	62,415	154,357	157,669
Intersegment Eliminations | Energy production
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Intersegment Eliminations | Corporate, other and elimination
Segment Reporting Information [Line Items]
Revenue	$ (66,143)	$ (62,415)	$ (154,357)	$ (157,669)

Aegis Contract and Related As_3

Aegis Contract and Related Asset Acquisition (Details) - Aegis Energy Services, LLC				3 Months Ended
	Mar. 15, 2023 USD ($) employee vehicle	Jan. 12, 2023 USD ($)	Apr. 14, 2022 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2021 USD ($)
Asset Acquisition [Line Items]
Assets acquired | vehicle	8
Employees acquired | employee	8
Cash	$ 170,000
Accounts receivable credit issued	300,000
Account payable	111,178
Contingent consideration	1,442,462
Total fair value of consideration transferred	2,023,639	$ 667,121	$ 564,027		$ 562,752
Property, plant and equipment	170,000
Inventory	411,178
Identifiable intangible asset - customer contracts	1,591,327
Assets acquired	2,172,505
Deferred maintenance reserve	(871,856)
Liabilities assumed	(871,856)
Net identifiable assets acquired	1,300,649
Goodwill	722,991
Total revenues				$ 628,813
Net income (loss)				$ 411,106
Contingent consideration	164,357
Deferred maintenance reserve	484,884
Liabilities assumed, current	649,241
Contingent consideration	1,278,105
Deferred maintenance reserve	365,462
Liabilities assumed, noncurrent	$ 1,643,567
Measurement Input, Discount Rate
Asset Acquisition [Line Items]
Intangible Assets, Measurement Input	15%
Measurement Input, WACC
Asset Acquisition [Line Items]
Intangible Assets, Measurement Input	12%