Tecogen (TGEN) 10-Q 12 May 22 2022 Q1 Quarterly report Financial data

Cover

Cover	3 Months Ended
	Mar. 31, 2022shares
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
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	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Current assets:
Cash and cash equivalents	$ 5,460,870	$ 3,614,463
Accounts receivable, net	7,631,611	8,482,286
Unbilled revenue	2,906,931	3,258,189
Employee retention credit	1,276,021	1,276,021
Inventories, net	7,756,737	7,764,989
Prepaid and other current assets	576,787	578,801
Total current assets	25,608,957	24,974,749
Property, plant and equipment, net	1,705,974	1,782,944
Right of use assets	1,716,737	1,869,210
Intangible assets, net	1,140,925	1,181,023
Goodwill	2,406,156	2,406,156
Other assets	185,222	148,140
TOTAL ASSETS	32,763,971	32,362,222	$ 31,600,210
Current liabilities:
Accounts payable	4,402,772	3,508,354
Accrued expenses	2,478,523	2,343,728
Deferred revenue	1,446,048	1,957,752
Lease obligations, current	653,176	641,002
Unfavorable contract liability, current	295,065		330,032
Total current liabilities	9,275,584	8,780,868
Long-term liabilities:
Deferred revenue, net of current portion	215,931	208,456
Lease obligations, net of current portion	1,147,982	1,315,275
Unfavorable contract liability, net of current portion	816,690	929,474
Total liabilities	11,456,187	11,234,073
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	57,112,566	57,016,859
Accumulated deficit	(35,744,212)	(35,833,621)
Total Tecogen Inc. stockholders’ equity	21,393,204	21,208,088
Non-controlling interest	(85,420)	(79,939)
Total stockholders’ equity	21,307,784	21,128,149	$ 19,066,746
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 32,763,971	$ 32,362,222
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	Mar. 31, 2022	Dec. 31, 2021
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
	Mar. 31, 2022	Mar. 31, 2021
Total revenues	$ 7,438,323	$ 6,057,161
Total cost of sales	4,347,535	3,105,953
Gross profit	3,090,788	2,951,208
Operating expenses
General and administrative	2,473,903	2,453,853
Selling	501,091	510,203
Research and development	140,135	126,150
Gain on disposition of assets	(33,945)	0
Gain on termination of unfavorable contract liability	(71,375)	0
Total operating expenses	3,009,809	3,090,206
Income (loss) from operations	80,979	(138,998)
Other income (expense)
Other income (expense), net	(14,150)	(1,203)
Interest expense	(828)	(4,640)
Gain on extinguishment of debt	0	1,887,859
Gain on sale of investment securities	0	6,046
Unrealized gain (loss) on investment securities	37,497	37,497
Total other income (expense), net	22,519	1,925,559
Income before provision for state income taxes	103,498	1,786,561
Provision for state income taxes	3,930	8,058
Consolidated net income	99,568	1,778,503
Income attributable to the non-controlling interest	(10,159)	(11,796)
Net income attributable to Tecogen Inc.	$ 89,409	$ 1,766,707
Earnings Per Share [Abstract]
Net income (loss) per share - basic (in USD per share)	$ 0	$ 0.07
Net income (loss) per share - diluted (in usd per share)	$ 0	$ 0.07
Weighted average shares outstanding - basic	24,850,261	24,850,261
Weighted average shares outstanding - diluted	25,028,616	25,122,271
Products
Total revenues	$ 3,939,481	$ 2,122,722
Total cost of sales	2,644,756	1,174,287
Services
Total revenues	2,917,280	3,281,144
Total cost of sales	1,366,752	1,537,603
Energy production
Total revenues	581,562	653,295
Total cost of sales	$ 336,027	$ 394,063

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, 2020		24,850,261
Beginning balance at Dec. 31, 2020	$ 17,242,484	$ 24,850	$ 56,814,428	$ (39,529,621)	$ (42,323)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	39,085		39,085
Distributions to Noncontrolling interests	(18,176)				18,176
Net income	(11,796)			(1,766,707)
Net income (loss)	1,778,503				11,796
Ending balance (shares) at Mar. 31, 2021		24,850,261
Ending balance at Mar. 31, 2021	19,066,746	$ 24,850	56,853,513	(37,762,914)	(48,703)
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	95,707		95,707
Distributions to Noncontrolling interests	(15,640)				(15,640)
Net income	(10,159)			(89,409)
Net income (loss)	99,568				10,159
Ending balance (shares) at Mar. 31, 2022		24,850,261
Ending balance at Mar. 31, 2022	$ 21,307,784	$ 24,850	$ 57,112,566	$ (35,744,212)	$ (85,420)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Consolidated net loss	$ 99,568	$ 1,778,503
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization, net	107,061	124,066
Gain on extinguishment of debt	0	(1,887,859)
Stock-based compensation	95,707	39,085
Gain on disposition of assets	(33,945)	0
Debt Securities, Available-for-sale, Realized Gain	0	(6,046)
Unrealized gain on investment securities	(37,497)	(37,497)
Gain on termination of unfavorable contract liability	(71,375)	0
Impairment of intangible asset	0	7,400
Changes in operating assets and liabilities
Accounts receivable	850,674	638,643
Unbilled revenue	351,259	122,814
Inventory	8,252	326,655
Prepaid expenses and other current assets	2,014	17,307
Other assets	152,888	(583,419)
Increase (decrease) in:
Accounts payable	894,418	(799,615)
Accrued expenses and other current liabilities	134,795	153,225
Deferred revenue	(504,229)	(97,937)
Other liabilities	(155,119)	574,447
Net cash provided by operating activities	1,894,471	369,772
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(80,873)	(16,098)
Proceeds from the sale of investment securities	0	11,637
Purchases of intangible assets	(16,220)	(5,682)
Proceeds from the sale of investment securities	64,669	0
Distributions to non-controlling interest	(15,640)	(18,176)
Net cash used in investing activities	(48,064)	(28,319)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from note payable	0	1,874,269
Net cash provided by financing activities	0	1,874,269
Change in cash and cash equivalents	1,846,407	2,215,722
Cash and cash equivalents, beginning of the period	3,614,463	1,490,219
Cash and cash equivalents, end of the period	5,460,870	3,705,941
Non-cash investing and financing activities:
Cash paid for interest	413	0
Cash paid for taxes	$ 3,930	$ 8,058

Description of business and bas

Description of business and basis of presentation	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Description of business and basis of presentation	Description of Business and Basis of Presentation Description of Business Tecogen Inc., or we, our or us, produces commercial and industrial engine-driven, combined heat and power (CHP) products that reduce energy costs, decrease greenhouse gas emissions and alleviate congestion on the national power grid. Our products supply electric power or mechanical power for cooling, while heat from the engine is recovered and purposefully used at a facility. We also install, own, operate and maintain complete energy systems and other complementary systems at customer sites and sell electricity, hot water, heat and cooling energy under long-term contracts at prices guaranteed to the customer to be below conventional utility rates. The majority of our customers are located in regions with the highest utility rates, typically California, the Midwest and the Northeast. 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, the Company acquired 100% of the outstanding common stock of American DG Energy Inc., formerly a related entity, in a stock-for-stock merger. 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 three months ended March 31, 2022 are not necessarily indicative of the results that may be expected for the year ending December 31, 2022. The condensed consolidated balance sheet at December 31, 2021 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, 2021. 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. Section 2301(c)(2)(B) of the CARES Act permits an employer to use an alternative quarter to calculate gross receipts and the employer may determine if the decline in gross receipt tests is met for a calendar quarter in 2021 by comparing its gross receipts for the immediately preceding calendar quarter with those for the corresponding calendar quarter in 2019. Accordingly, for the first quarter of 2021, we elected to use our gross receipts for the fourth calendar quarter of 2020 compared to our gross receipts for the fourth calendar quarter of 2019. 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 that were applied to the Paycheck Protection Loan Second Draw, were eligible for the ERC. Wages used towards PPP loan forgiveness cannot be used as qualified wages for purposes of the ERC Accounting Standards Codification 105, "Generally Accepted Accounting Principles," describes the decision-making framework when no guidance exists in US GAAP for a particular transaction. Specifically, ASC 105-10-05-2 instructs companies to look for guidance for a similar transaction within US GAAP and apply that guidance by analogy. As such, forms of government assistance, such as the ERC, provided to business entities would not be within the scope of ASC 958, but it may be applied by analogy under ASC 105-10-05-2. We accounted for the Employee Retention Credit as a government grant in accordance with Accounting Standards Update 2013-06, Not-for-Profit Entities (Topic 958) ("ASU 2013-06") by analogy under ASC 105-10-05-2. Under this standard, government grants are recognized when the conditions on which they depend are substantially met. The conditions for recognition of the ERC include, but are not limited to: • An entity has been adversely affected by the COVID-19 pandemic • We have not used qualifying payroll for both the Paycheck Protection Program and the ERC • We incurred payroll costs to retain employees • The process for filing for the credit is an administrative task and not a barrier to receiving the credits

Revenue

Revenue	3 Months Ended
	Mar. 31, 2022
Revenue Recognition [Abstract]
Revenue	Revenue Revenue is recognized when performance obligations under the terms of a contract with our customer are satisfied; generally this occurs with the transfer of control of our products, services and energy production. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods or providing services or energy to customers. Shipping and handling fees billed to customers in a sales transaction are recorded in revenue and shipping and handling costs incurred are recorded in cost of sales. We have elected to exclude from revenue any value-added sales and other taxes which we collect concurrent with revenue-producing activities. These accounting policy elections are consistent with the manner in which we historically recorded shipping and handling fees and value-added taxes. Incremental costs incurred by us to obtain a contract with a customer are negligible, if any, and are expensed ratably in proportion to the related revenue recognized. Disaggregated Revenue In general, our business segmentation is aligned according to the nature and economic characteristics of our products and customer relationships and provides meaningful disaggregation of each business segment's results of operations. The following table further disaggregates our revenue by major source by segment for the three months ended March 31, 2022 and 2021. Three Months Ended March 31, 2022 Products and Services Energy Production Total Products $ 3,939,481 $ — $ 3,939,481 Installation services 20,109 — 20,109 Maintenance services 2,897,171 — 2,897,171 Energy production — 581,562 581,562 Total revenue $ 6,856,761 $ 581,562 $ 7,438,323 Three Months Ended March 31, 2021 Products and Services Energy Production Total Products $ 2,122,722 $ — $ 2,122,722 Installation services 517,696 — 517,696 Maintenance services 2,763,448 — 2,763,448 Energy production — 653,295 653,295 Total revenue $ 5,403,866 $ 653,295 $ 6,057,161 Product and Services Segment Products. Our Product revenues include cogeneration systems that supply electricity and hot water, chillers that provide air-conditioning and hot water and engineered accessories, which consist of ancillary products and parts necessary to install a cogeneration unit including integration into the customers’ existing electrical and mechanical systems. We refer to the package of engineered accessories and engineering and design services necessary for the customers' installation of a cogeneration unit as light installation services. We transfer control and generally recognize a sale when we ship a product from our manufacturing facility at which point the customer takes ownership of the product. Payment terms on product sales are generally 30 days. We recognize revenue in certain circumstances before delivery to the customer has occurred (commonly referred to as bill and hold transactions). We recognize revenue related to such transactions once, among other things, the customer has made a written fixed commitment to purchase the product(s) under normal billing and credit terms, the customer has requested the product(s) be held for future delivery as scheduled and designated by them, risk of ownership has been assumed by the customer, and the product(s) are tagged as sold and segregated for storage awaiting further direction from the customer. Due to the infrequent nature and duration of bill and hold arrangements, the value associated with custodial storage services is deemed immaterial in the context of the contract and in total, and accordingly, none of the transaction price is allocated to such service. Depending on the product and terms of the arrangement, we may defer the recognition of a portion of the transaction price received because we have to satisfy a future obligation (e.g., product start-up service). Amounts allocated to product start-up services are recognized as revenue when the start-up service has been completed. We use an observable selling price to determine standalone selling prices where available and either a combination of an adjusted market assessment approach, an expected cost plus a margin approach, and/or a residual approach to determine the standalone selling prices for separate performance obligations as a basis for allocating contract consideration when an observable selling price is not available. Amounts received but not recognized pending completion of performance are recognized as contract liabilities and are recorded as deferred revenue along with deposits by customers. Installation Services. We provide installation services typically including all necessary engineering and design, labor, subcontract labor and service to install a cogeneration unit including integration into the customers’ existing electrical and mechanical systems. Under complete turnkey installation service contracts revenue is recognized over time using the percentage-of-completion method determined on a cost to cost basis. Our performance obligation under such contracts is satisfied progressively over time as enhancements are made to customer owned and controlled properties. We measure progress towards satisfaction of the performance obligation based on an cost-based input method which we believe appropriately measures and is the most accurate depiction of the transfer of products and services to the customer under these contracts. When the financial metrics of a contract indicate a loss, our policy is to record the entire expected loss as soon as it is known. Contract costs and profit recognized to date under the percentage-of-completion method in excess of billings are recognized as contract assets and are recorded as unbilled revenue. Billings in excess of contract costs and profit are recognized as contract liabilities and are recorded as deferred revenue. Generally billings under complete turnkey installation contracts are made when contractually determined milestones of progress have been achieved, with payment terms generally being 30 days. Maintenance Services. Maintenance services are provided under either long-term maintenance contracts or time and material maintenance contracts. Revenue under time and material maintenance contracts is recognized when the maintenance service is completed. Revenue under long-term maintenance contracts is recognized either ratably over the term of the contract where the contract price is fixed or when the periodic maintenance activities are completed where the invoiced cost to the customer is based on run hours or kilowatts produced in a given period. We use an output method to measure progress towards completion of our performance obligation which results in the recognition of revenue on the basis of a direct measurement of the value to the customer of the services transferred to date relative to the remaining services promised under the contract. We use the practical expedient at ASC 606-10-55-18 of recognizing revenue in an amount equal to the amount we have the right to invoice the customer under the contract. Payment terms for maintenance services are generally 30 days. Energy Production Segment Energy Production. Revenue from energy contracts is recognized when electricity, heat, hot and/or chilled water is produced by our owned on-site cogeneration systems. Each month we invoice the customer and recognize revenue for the various forms of energy delivered, based on actual meter readings which capture the quantity of the various forms of energy delivered in a given month, under a contractually defined formula which takes into account the current month's cost of energy from the local power utility. As the various forms of energy delivered by us under energy production contracts are simultaneously delivered and consumed by the customer, our performance obligation under these contracts is considered to be satisfied over time. We use an output method to measure progress towards completion of our performance obligation which results in the recognition of revenue on the basis of a direct measurement of the value to the customer of the services transferred to date relative to the remaining services promised under the contract. We use the practical expedient at ASC 606-10-55-18 of recognizing revenue in an amount equal to the amount that we have the right to invoice the customer under the contract. Payment terms on invoices under these contracts are generally 30 days. Contract Balances The timing of revenue recognition, billings and cash collections result in billed accounts receivable, unbilled revenue (contract assets) and deferred revenue, consisting of customer deposits and billings in excess of revenue recognized (contract liabilities) on the condensed consolidated balance sheets. We did not recognize any revenue during the three months ended March 31, 2022 that was included in unbilled revenue at the end of the period. Approximately $1,064,545 was billed in this period that had been recognized as revenue in previous periods. Revenue recognized during the three ended months March 31, 2022 that was included in deferred revenue at the beginning of the period was approximately $434,571. Remaining Performance Obligations Remaining performance obligations related to ASC 606 represent the aggregate transaction price allocated to performance obligations with an original contract term of greater than one year, excluding certain maintenance contracts and all energy production contracts where a direct measurement of the value to the customer is used as a method of measuring progress towards completion of our performance obligation. Exclusion of these remaining performance obligations is due in part to the inability to quantify values based on unknown future levels of delivery and in some cases rates used to invoice customers. Remaining performance obligations therefore consist of unsatisfied or partially satisfied performance obligations related to fixed price maintenance contracts and installation contracts. As of March 31, 2022, the aggregate amount of the transaction price allocated to remaining performance obligations was approximately $2.2 million. We expect to recognize revenue of approximately 92.9% of the remaining performance obligations over the next 24 months, 90.4% recognized in the first 12 months and 2.5% recognized over the subsequent 12 months, and the remainder recognized thereafter.

Income (Loss) Per Common Share

Income (Loss) Per Common Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Income (Loss) Per Common Share	Income Per Common Share Basic and diluted income per share for the three months ended March 31, 2022 and 2021, respectively, were as follows: Three Months Ended March 31, 2022 March 31, 2021 Numerator: Net income available to stockholders $ 89,409 $ 1,766,707 Denominator: Weighted average shares outstanding - Basic 24,850,261 24,850,261 Effect of dilutive securities: Stock options 178,355 272,010 Weighted average shares outstanding - Diluted 25,028,616 25,122,271 Basic income per share $ 0.00 $ 0.07 Diluted income per share $ 0.00 $ 0.07 Anti-dilutive shares underlying stock options outstanding 928,271 777,296

Inventories, net

Inventories, net	3 Months Ended
	Mar. 31, 2022
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net Inventories at March 31, 2022 and December 31, 2021 consisted of the following: March 31, 2022 December 31, 2021 Raw materials $ 7,211,826 $ 7,072,991 Less: reserves (381,000) (381,000) Raw materials, net $ 6,830,826 $ 6,691,991 Work-in-process 402,715 549,802 Finished goods 523,196 523,196 Total inventories, net $ 7,756,737 $ 7,764,989

Property, Plant and Equipment,

Property, Plant and Equipment, net	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, net	Property, Plant and Equipment, net Property, plant and equipment at March 31, 2022 and December 31, 2021 consisted of the following: Estimated Useful March 31, 2022 December 31, 2021 Energy systems 1 - 15 years $ 3,478,824 $ 3,556,488 Machinery and equipment 5 - 7 years 1,506,919 1,463,153 Furniture and fixtures 5 years 196,007 193,698 Computer software 3 - 5 years 192,865 192,865 Leasehold improvements * 466,789 466,789 5,841,404 5,872,993 Less - accumulated depreciation and amortization (4,135,430) (4,090,049) $ 1,705,974 $ 1,782,944 * Lesser of estimated useful life of asset or lease term

Intangible Assets and Liabiliti

Intangible Assets and Liabilities Other Than Goodwill	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Liabilities Other Than Goodwill	Intangible Assets and Liabilities Other Than Goodwill As of March 31, 2022 and December 31, 2021 we had the following amounts related to intangible assets and liabilities other than goodwill: March 31, 2022 December 31, 2021 Intangible assets Cost Accumulated Amortization Total Cost Accumulated Amortization Total Product certifications $ 777,465 $ (546,094) $ 231,371 $ 765,850 $ (532,676) $ 233,174 Patents 875,626 (337,696) 537,930 871,021 (314,997) 556,024 Developed technology 240,000 (144,000) 96,000 240,000 (140,000) 100,000 Trademarks 26,896 — 26,896 26,896 — 26,896 In Process R&D 263,936 (37,705) 226,231 263,936 (28,279) 235,657 Favorable contract asset 384,465 (361,968) 22,497 384,465 (355,193) 29,272 $ 2,568,388 $ (1,427,463) $ 1,140,925 $ 2,552,168 $ (1,371,145) $ 1,181,023 Intangible liability Unfavorable contract liability $ 2,903,419 $ (1,791,664) $ 1,111,755 $ 3,056,655 $ (1,797,149) $ 1,259,506 The aggregate amortization expense related to intangible assets and liabilities exclusive of contract related intangibles for the three months ended March 31, 2022 and 2021 was $50,795 and $42,890. The net credit to cost of sales related to the amortization of the contract related intangible asset and liability for the three months ended March 31, 2022 and 2021 was $70,526 and $79,053, respectively Favorable/Unfavorable Contract Assets and Liabilities 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. 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 March 31, 2022 is estimated to be as follows: Non-contract Related Intangibles Contract Related Intangibles Total Year 1 $ 199,518 $ (288,741) $ (89,223) Year 2 195,929 (239,891) (43,962) Year 3 179,372 (147,725) 31,647 Year 4 175,602 (114,043) 61,559 Year 5 170,801 (79,359) 91,442 Thereafter 185,113 (234,302) (49,189) Total $ 1,106,335 (1,104,061) $ 2,274 We recognized a gain on termination of unfavorable contract liability of $71,375 in three months ended March 31, 2022 due to the closing of certain energy production sites.

Sale of Energy Producing Assets

Sale of Energy Producing Assets and Goodwill Impairment	3 Months Ended
	Mar. 31, 2022
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 March 31, 2022 we do not expect to make any material payments under the guarantee. At March 31, 2022, our obligation under the energy production contracts was $3,911. 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	3 Months Ended
	Mar. 31, 2022
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 months ended March 31, 2022 and 2021 was $196,979 and and $195,273, respectively. Supplemental information related to leases for the three months ended March 31, 2022 was as follows: Three Months Ended March 31, 2022 March 31, 2021 Cash paid for amounts included in the measurement of operating lease liabilities $ 181,661 $ 171,502 Right-of-use assets obtained in exchange for operating lease liabilities $ — $ 721,429 Weighted-average remaining lease term - operating leases 3.80 years 4.50 years Weighted-average discount rate - operating leases 6 % 6 % Supplemental information related to operating leases as of March 31, 2022 and December 31, 2021 was as follows: March 31, 2022 December 31, 2021 Operating leases Right-of-use assets $ 1,716,737 $ 1,869,210 Operating lease liability, current $ 653,176 $ 641,002 Operating lease liability, long-term 1,147,982 1,315,275 Total operating lease liability $ 1,801,158 $ 1,956,277 Future minimum lease commitments under non-cancellable operating leases as of March 31, 2022 were as follows: Operating Leases Year 1 $ 552,222 Year 2 745,244 Year 3 299,248 Year 4 108,785 Year 5 102,978 Thereafter 228,150 Total lease payments 2,036,627 Less: imputed interest 235,469 Total $ 1,801,158

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2022
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 March 31, 2022, 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 domestic relations order. 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 March 31, 2022 was 42,643. During the three months ended March 31, 2022, we granted nonqualified options to purchase an aggregate of 726,650 shares of common stock at $1.10 per share to certain officers and employees. These options have a vesting schedule of two years and expire in ten years. The fair value of the options issued in 2022 was $304,550. The weighted-average grant date fair value of stock options granted during 2022 was $0.42 per share. 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. 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 adoption of the 2022 Plan is subject to approval by our shareholders. As of March 31, 2022, there have been no grants issued under the 2022 Plan. Stock option activity for the three months ended March 31, 2022 was as follows: Common Stock Options Number of Exercise Weighted Weighted Aggregate Outstanding, December 31, 2021 2,386,842 $0.71-$10.33 $ 1.81 7.56 years $ 731,744 Granted 726,650 $1.10-$1.13 $ 1.10 Exercised — Canceled and forfeited (4,525) $1.10-$4.50 $ 1.63 Outstanding, March 31 2022 3,108,967 $0.71-$10.33 $ 1.64 7.90 years $ 1,751,592 Exercisable, March 31, 2022 731,592 $ 3.52 $ 139,485 Vested and expected to vest, March 31, 2022 2,752,361 $ 1.72 $ 1,509,777 Consolidated stock-based compensation expense for the three months ended March 31, 2022 and 2021 was $95,707 and $39,085, respectively. No tax benefit was recognized related to the stock-based compensation recorded during the period.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
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 presents the asset reported in "other assets" in the consolidated balance sheet measured at its fair value on a recurring basis as of March 31, 2022 and 2021 by level within the fair value hierarchy. March 31, 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 March 31, 2021 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. $ 149,990 $ — $ 149,990 $ — $ 37,497 Total recurring fair value measurements $ 149,990 $ — $ 149,990 $ — $ 37,497 We utilize a Level 2 category fair value measurement to value its 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 three months ended March 31, 2022 and 2021: Fair value at December 31, 2021 $ 74,995 Unrealized gains 37,497 Fair value at March 31, 2022 $ 112,492 Fair value at December 31, 2020 $ 118,084 Sale of 93,187 shares (5,591) Unrealized gains 37,497 Fair value at March 31, 2021 $ 149,990

Notes Payable (Notes)

Notes Payable (Notes)	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Notes Payable	Notes Payable Paycheck Protection Program Loan On April 17, 2020, we obtained an unsecured loan through Webster Bank, N.A. in the amount of $1,874,200 in connection with the Paycheck Protection Program pursuant to the Coronavirus Aid, Relief, and Economic Security Act, as amended ("CARES Act”) administered by the United States Small Business Administration ("SBA"). On January 19, 2021, we received a letter dated January 12, 2021 from Webster Bank, NA confirming that the Paycheck Protection Program Loan issued to us pursuant to the CARES Act, in the original principal amount of $1,874,200 together with accrued interest of $13,659 was forgiven in full as of January 11, 2021. We have accounted for the loan forgiveness of $1,887,859 as debt extinguishment in accordance with Accounting Standards Update 2020-09, Debt (Topic 470) ("ASU 2020-09") and reported as a separate component of other income (expense), net in the condensed consolidated statements of operations for the three months ended March 31, 2021. The loan forgiveness is nontaxable for both state and federal purposes and has been treated accordingly in our condensed consolidated financial statements. Paycheck Protection Program Second Draw Loan On February 5, 2021, we obtained a Paycheck Protection Program Second Draw unsecured loan through Webster Bank, N.A. in the amount of $1,874,269 pursuant to the CARES Act. On September 20, 2021, we received a letter dated September 13, 2021 from Webster Bank, NA confirming that the Paycheck Protection Program Second Draw Loan issued to us pursuant to the CARES Act, in the original principal amount of $1,874,269 together with accrued interest of $11,386 was forgiven in full as of September 8, 2021. We have accounted for the loan forgiveness of $1,885,655 as debt extinguishment in accordance with Accounting Standards Update 2020-09, Debt (Topic 470) ("ASU 2020-09") and reported as a separate component of other income (expense), net in the condensed consolidated statements of operations for the three months ended March 31, 2021. The loan forgiveness is nontaxable for both state and federal purposes and has been treated accordingly in our condensed consolidated financial statements.

Commitments and contingencies

Commitments and contingencies	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and Contingencies     We guaranteed certain obligations of a former subsidiary of ADGE, EuroSite Power Inc. These guarantees include a payment performance guarantee in respect of collateralized equipment financing loans, with a remaining principal amount outstanding subject to the guarantee. In October 2021, the loan was paid in full. We have no further obligation to Eurosite Power Inc. under this guarantee.

Segments

Segments	3 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Segments	Segments As of March 31, 2022, we were organized into three 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 months ended March 31, 2022 and 2021: Products and Services Energy Production Corporate, other and elimination (1) Total Three months ended March 31, 2022 Revenue - external customers $ 6,856,761 $ 581,562 $ — $ 7,438,323 Intersegment revenue 95,253 — (95,253) — Total revenue $ 6,952,014 $ 581,562 $ (95,253) $ 7,438,323 Gross profit $ 2,845,253 $ 245,535 $ — $ 3,090,788 Identifiable assets $ 28,785,826 $ 3,978,145 $ — $ 32,763,971 Three months ended March 31, 2021 Revenue - external customers $ 5,403,866 $ 653,295 $ — $ 6,057,161 Intersegment revenue 131,516 — (131,516) — Total revenue $ 5,535,382 $ 653,295 $ (131,516) $ 6,057,161 Gross profit $ 2,691,976 $ 259,232 $ — $ 2,951,208 Identifiable assets $ 26,997,887 $ 4,602,323 $ — $ 31,600,210

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2022
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.

Description of business and b_2

Description of business and basis of presentation (Policies)	3 Months Ended
	Mar. 31, 2022
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 three months ended March 31, 2022 are not necessarily indicative of the results that may be expected for the year ending December 31, 2022. The condensed consolidated balance sheet at December 31, 2021 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, 2021. 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 EstimatesThe 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.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2022
Revenue Recognition [Abstract]
Disaggregation of Revenue	The following table further disaggregates our revenue by major source by segment for the three months ended March 31, 2022 and 2021. Three Months Ended March 31, 2022 Products and Services Energy Production Total Products $ 3,939,481 $ — $ 3,939,481 Installation services 20,109 — 20,109 Maintenance services 2,897,171 — 2,897,171 Energy production — 581,562 581,562 Total revenue $ 6,856,761 $ 581,562 $ 7,438,323 Three Months Ended March 31, 2021 Products and Services Energy Production Total Products $ 2,122,722 $ — $ 2,122,722 Installation services 517,696 — 517,696 Maintenance services 2,763,448 — 2,763,448 Energy production — 653,295 653,295 Total revenue $ 5,403,866 $ 653,295 $ 6,057,161

Loss Per Common Share (Tables)

Loss Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of Income (Loss) Per Common Share, Basic and Diluted	Basic and diluted income per share for the three months ended March 31, 2022 and 2021, respectively, were as follows: Three Months Ended March 31, 2022 March 31, 2021 Numerator: Net income available to stockholders $ 89,409 $ 1,766,707 Denominator: Weighted average shares outstanding - Basic 24,850,261 24,850,261 Effect of dilutive securities: Stock options 178,355 272,010 Weighted average shares outstanding - Diluted 25,028,616 25,122,271 Basic income per share $ 0.00 $ 0.07 Diluted income per share $ 0.00 $ 0.07 Anti-dilutive shares underlying stock options outstanding 928,271 777,296

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2022
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories at March 31, 2022 and December 31, 2021 consisted of the following: March 31, 2022 December 31, 2021 Raw materials $ 7,211,826 $ 7,072,991 Less: reserves (381,000) (381,000) Raw materials, net $ 6,830,826 $ 6,691,991 Work-in-process 402,715 549,802 Finished goods 523,196 523,196 Total inventories, net $ 7,756,737 $ 7,764,989

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment	Property, plant and equipment at March 31, 2022 and December 31, 2021 consisted of the following: Estimated Useful March 31, 2022 December 31, 2021 Energy systems 1 - 15 years $ 3,478,824 $ 3,556,488 Machinery and equipment 5 - 7 years 1,506,919 1,463,153 Furniture and fixtures 5 years 196,007 193,698 Computer software 3 - 5 years 192,865 192,865 Leasehold improvements * 466,789 466,789 5,841,404 5,872,993 Less - accumulated depreciation and amortization (4,135,430) (4,090,049) $ 1,705,974 $ 1,782,944 * Lesser of estimated useful life of asset or lease term

Intangible Assets and Liabili_2

Intangible Assets and Liabilities Other Than Goodwill (Tables)	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	As of March 31, 2022 and December 31, 2021 we had the following amounts related to intangible assets and liabilities other than goodwill: March 31, 2022 December 31, 2021 Intangible assets Cost Accumulated Amortization Total Cost Accumulated Amortization Total Product certifications $ 777,465 $ (546,094) $ 231,371 $ 765,850 $ (532,676) $ 233,174 Patents 875,626 (337,696) 537,930 871,021 (314,997) 556,024 Developed technology 240,000 (144,000) 96,000 240,000 (140,000) 100,000 Trademarks 26,896 — 26,896 26,896 — 26,896 In Process R&D 263,936 (37,705) 226,231 263,936 (28,279) 235,657 Favorable contract asset 384,465 (361,968) 22,497 384,465 (355,193) 29,272 $ 2,568,388 $ (1,427,463) $ 1,140,925 $ 2,552,168 $ (1,371,145) $ 1,181,023 Intangible liability Unfavorable contract liability $ 2,903,419 $ (1,791,664) $ 1,111,755 $ 3,056,655 $ (1,797,149) $ 1,259,506
Schedule of Future Amortization Expense	Aggregate future amortization over the next five years and thereafter as of March 31, 2022 is estimated to be as follows: Non-contract Related Intangibles Contract Related Intangibles Total Year 1 $ 199,518 $ (288,741) $ (89,223) Year 2 195,929 (239,891) (43,962) Year 3 179,372 (147,725) 31,647 Year 4 175,602 (114,043) 61,559 Year 5 170,801 (79,359) 91,442 Thereafter 185,113 (234,302) (49,189) Total $ 1,106,335 (1,104,061) $ 2,274 We recognized a gain on termination of unfavorable contract liability of $71,375 in three months ended March 31, 2022 due to the closing of certain energy production sites.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Supplemental Information Related to Leases	Supplemental information related to leases for the three months ended March 31, 2022 was as follows: Three Months Ended March 31, 2022 March 31, 2021 Cash paid for amounts included in the measurement of operating lease liabilities $ 181,661 $ 171,502 Right-of-use assets obtained in exchange for operating lease liabilities $ — $ 721,429 Weighted-average remaining lease term - operating leases 3.80 years 4.50 years Weighted-average discount rate - operating leases 6 % 6 %
Future Minimum Lease Commitments	Future minimum lease commitments under non-cancellable operating leases as of March 31, 2022 were as follows: Operating Leases Year 1 $ 552,222 Year 2 745,244 Year 3 299,248 Year 4 108,785 Year 5 102,978 Thereafter 228,150 Total lease payments 2,036,627 Less: imputed interest 235,469 Total $ 1,801,158
Assets and Liabilities, Lessee	Supplemental information related to operating leases as of March 31, 2022 and December 31, 2021 was as follows: March 31, 2022 December 31, 2021 Operating leases Right-of-use assets $ 1,716,737 $ 1,869,210 Operating lease liability, current $ 653,176 $ 641,002 Operating lease liability, long-term 1,147,982 1,315,275 Total operating lease liability $ 1,801,158 $ 1,956,277

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Tecogen
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Stock Option Activity	Stock option activity for the three months ended March 31, 2022 was as follows: Common Stock Options Number of Exercise Weighted Weighted Aggregate Outstanding, December 31, 2021 2,386,842 $0.71-$10.33 $ 1.81 7.56 years $ 731,744 Granted 726,650 $1.10-$1.13 $ 1.10 Exercised — Canceled and forfeited (4,525) $1.10-$4.50 $ 1.63 Outstanding, March 31 2022 3,108,967 $0.71-$10.33 $ 1.64 7.90 years $ 1,751,592 Exercisable, March 31, 2022 731,592 $ 3.52 $ 139,485 Vested and expected to vest, March 31, 2022 2,752,361 $ 1.72 $ 1,509,777

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables presents the asset reported in "other assets" in the consolidated balance sheet measured at its fair value on a recurring basis as of March 31, 2022 and 2021 by level within the fair value hierarchy. March 31, 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 March 31, 2021 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. $ 149,990 $ — $ 149,990 $ — $ 37,497 Total recurring fair value measurements $ 149,990 $ — $ 149,990 $ — $ 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 three months ended March 31, 2022 and 2021: Fair value at December 31, 2021 $ 74,995 Unrealized gains 37,497 Fair value at March 31, 2022 $ 112,492 Fair value at December 31, 2020 $ 118,084 Sale of 93,187 shares (5,591) Unrealized gains 37,497 Fair value at March 31, 2021 $ 149,990

Segments (Tables)

Segments (Tables)	3 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The following table presents information by reportable segment for the three months ended March 31, 2022 and 2021: Products and Services Energy Production Corporate, other and elimination (1) Total Three months ended March 31, 2022 Revenue - external customers $ 6,856,761 $ 581,562 $ — $ 7,438,323 Intersegment revenue 95,253 — (95,253) — Total revenue $ 6,952,014 $ 581,562 $ (95,253) $ 7,438,323 Gross profit $ 2,845,253 $ 245,535 $ — $ 3,090,788 Identifiable assets $ 28,785,826 $ 3,978,145 $ — $ 32,763,971 Three months ended March 31, 2021 Revenue - external customers $ 5,403,866 $ 653,295 $ — $ 6,057,161 Intersegment revenue 131,516 — (131,516) — Total revenue $ 5,535,382 $ 653,295 $ (131,516) $ 6,057,161 Gross profit $ 2,691,976 $ 259,232 $ — $ 2,951,208 Identifiable assets $ 26,997,887 $ 4,602,323 $ — $ 31,600,210

Description of business and b_3

Description of business and basis of presentation - Additional Information (Details)	May 18, 2017	Mar. 31, 2022USD ($)segment	Mar. 31, 2020	Dec. 31, 2020employee
Business Acquisition [Line Items]
Ownerhsip interest in American DG New York, LLC (percent)		51.00%
Number of business segments | segment		3
Decrease in gross receipts in quarter (percent)			20.00%
Average number of employees | employee				100
Gain on extinguishment of debt | $		$ 1,276,021
American DG Energy, Inc.
Business Acquisition [Line Items]
Ownership interest (percent)	100.00%

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 7,438,323	$ 6,057,161
Products
Disaggregation of Revenue [Line Items]
Total revenue	3,939,481	2,122,722
Installation services
Disaggregation of Revenue [Line Items]
Total revenue	20,109	517,696
Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	2,897,171	2,763,448
Energy production
Disaggregation of Revenue [Line Items]
Total revenue	581,562	653,295
Products and Services
Disaggregation of Revenue [Line Items]
Total revenue	6,952,014	5,535,382
Energy Production
Disaggregation of Revenue [Line Items]
Total revenue	581,562	653,295
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	7,438,323	6,057,161
Operating Segments | Products and Services
Disaggregation of Revenue [Line Items]
Total revenue	6,856,761	5,403,866
Operating Segments | Products and Services | Products
Disaggregation of Revenue [Line Items]
Total revenue	3,939,481
Operating Segments | Products and Services | Installation services
Disaggregation of Revenue [Line Items]
Total revenue	20,109	517,696
Operating Segments | Products and Services | Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	2,897,171	2,763,448
Operating Segments | Products and Services | Energy production
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | Energy Production
Disaggregation of Revenue [Line Items]
Total revenue	581,562	653,295
Operating Segments | Energy Production | Products
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | Energy Production | Installation services
Disaggregation of Revenue [Line Items]
Total revenue	0	0
Operating Segments | Energy Production | Maintenance services
Disaggregation of Revenue [Line Items]
Total revenue	0	$ 0
Operating Segments | Energy Production | Energy production
Disaggregation of Revenue [Line Items]
Total revenue	$ 581,562

Revenue - Additional Informatio

Revenue - Additional Information (Details)	3 Months Ended
	Mar. 31, 2022USD ($)
Revenue Recognition [Abstract]
Payment term on product sales	30 days
Payment term on contractually determined milestones	30 days
Payment term on energy production contract invoices	30 days
Revenue billed this period that had been recognized in previous periods	$ 1,064,545
Deferred revenue recognized	434,571
Remaining performance obligations	$ 2,200,000
Performance obligation revenue expected to be recognized over the next 24 months (percent)	92.90%
Performance obligation revenue to be recognized in first 12 months (percent)	90.40%
Performance obligation revenue to be recognized over the subsequent 12 months (percent)	2.50%

Loss Per Common Share - Schedul

Loss Per Common Share - Schedule of Income (Loss) Per Common Share, Basic and Diluted (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income available to stockholders	$ 89,409	$ 1,766,707
Weighted average shares outstanding - basic	24,850,261	24,850,261
Effect of dilutive securities:
Weighted average shares outstanding - Diluted	25,028,616	25,122,271
Net income (loss) per share - basic (in USD per share)	$ 0	$ 0.07
Net income (loss) per share - diluted (in usd per share)	$ 0	$ 0.07
Stock Options
Effect of dilutive securities:
Stock options	178,355	272,010
Anti-dilutive shares underlying stock options outstanding	928,271	777,296

Inventory (Details)

Inventory (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 7,211,826	$ 7,072,991
Less: reserves	(381,000)	(381,000)
Raw materials, net	6,830,826	6,691,991
Work-in-process	402,715	549,802
Finished goods	523,196	523,196
Inventories, net	$ 7,756,737	$ 7,764,989

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Property and Equipment (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,841,404	$ 5,872,993
Less - accumulated depreciation and amortization	(4,135,430)	(4,090,049)
Property and equipment, net, before construction in progress	1,705,974	1,782,944
Energy systems
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,478,824	3,556,488
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	$ 1,506,919	1,463,153
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	$ 196,007	193,698
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
	Mar. 31, 2022	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 126,792	$ 160,556

Intangible Assets and Liabili_3

Intangible Assets and Liabilities Other Than Goodwill -Amounts related to intangible assets (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 2,568,388	$ 2,552,168
Less - accumulated amortization	(1,427,463)	(1,371,145)
Intangible assets, net	1,140,925	1,181,023
Unfavorable contract liability	2,903,419	3,056,655
Less - accumulated amortization	(1,791,664)	(1,797,149)
Unfavorable contract liability, net	1,111,755	1,259,506
Product Certifications
Finite-Lived Intangible Assets [Line Items]
Intangible assets	777,465	765,850
Less - accumulated amortization	(546,094)	(532,676)
Intangible assets, net	231,371	233,174
Patents
Finite-Lived Intangible Assets [Line Items]
Intangible assets	875,626	871,021
Less - accumulated amortization	(337,696)	(314,997)
Intangible assets, net	537,930	556,024
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets	240,000	240,000
Less - accumulated amortization	(144,000)	(140,000)
Intangible assets, net	96,000	100,000
Favorable contract asset
Finite-Lived Intangible Assets [Line Items]
Intangible assets	384,465	384,465
Less - accumulated amortization	(361,968)	(355,193)
Intangible assets, net	22,497	29,272
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	(37,705)	(28,279)
Intangible assets, net	$ 226,231	$ 235,657

Intangible Assets and Liabili_4

Intangible Assets and Liabilities Other Than Goodwill (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 50,795	$ 42,890
Net credit to cost of sales for amortization of contract related intangible assets and liabilities	70,526	79,053
Gain on termination of unfavorable contract liability	$ (71,375)	$ 0

Intangible Assets and Liabili_5

Intangible Assets and Liabilities Other Than Goodwill - Future Amortization of Customer Contracts (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Non-contract Related Intangibles [Abstract]
Total	$ 1,140,925	$ 1,181,023
Contract Asset and Liability
Non-contract Related Intangibles [Abstract]
Year 4	61,559
Year 5	91,442
Contract-related Intangibles [Abstract]
Year 1	(89,223)
Year 2	(43,962)
Year 3	31,647
Thereafter	(49,189)
Total	2,274
Non-contract Related Intangible Assets | Contract Asset and Liability
Non-contract Related Intangibles [Abstract]
Year 1	199,518
Year 2	195,929
Year 3	179,372
Year 4	175,602
Year 5	170,801
Thereafter	185,113
Total	1,106,335
Customer Contracts | Contract Asset and Liability
Contract-related Intangibles [Abstract]
Year 1	(288,741)
Year 2	(239,891)
Year 3	(147,725)
Year 4	(114,043)
Year 5	(79,359)
Thereafter	(234,302)
Total	$ (1,104,061)

Sale of Energy Producing Asse_2

Sale of Energy Producing Assets and Goodwill Impairment (Details) $ in Millions	3 Months Ended
	Dec. 31, 2019USD ($)salesite
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

Leases (Details)

Leases (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Leases [Abstract]
Lease cost	$ 196,979	$ 195,273
Cash paid for amounts included in the measurement of operating lease liabilities	$ 181,661	171,502
Right-of-use assets obtained in exchange for operating lease liabilities		$ 721,429
Weighted-average remaining lease term - operating leases	3 years 9 months 18 days	4 years 6 months
Weighted-average discount rate - operating leases (percent)	6.00%	6.00%

Leases - Assets and Liabilities

Leases - Assets and Liabilities, Lessee (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Right of use assets	$ 1,716,737	$ 1,869,210
Operating Lease, Liability, Current	653,176	641,002
Operating Lease, Liability, Noncurrent	1,147,982	1,315,275
Total	$ 1,801,158	$ 1,956,277
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 ($)	Mar. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Year 1	$ 552,222
Year 2	745,244
Year 3	299,248
Year 4	108,785
Year 5	102,978
Thereafter	228,150
Total lease payments	2,036,627
Less: imputed interest	235,469
Total	$ 1,801,158	$ 1,956,277

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Noncash Expense	$ 95,707	$ 39,085
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized, amount	$ 676,437
Compensation cost not yet recognized, period for recognition	1 year 8 months 26 days
Tecogen
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of options	$ 304,550
Weighted average grant date fair value (in dollars per share)	$ 0.42
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
Number of shares remaining available for future issuance	42,643

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock Option Activity (Details) - Tecogen - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2019
Stock Options Outstanding [Roll Forward]
Beginning (shares)	2,386,842
Granted (shares)	726,650
Exercised (shares)	0
Canceled and forfeited (shares)	(4,525)
Ending (shares)	3,108,967	2,386,842
Exercisable (shares)	731,592
Vested and expected to vest (shares)	2,752,361
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)	1.81
Granted (usd per share)	1.10
Canceled and forfeited (usd per share)	1.63
Ending (usd per share)	1.64	$ 1.81
Exercisable (usd per share)	3.52
Vested and expected to vest (usd per share)	$ 1.72
Weighted Average Remaining Life	7 years 10 months 24 days		7 years 6 months 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, Aggregate Intrinsic Value	$ 1,751,592	$ 731,744
Exercisable, Aggregate Intrinsic Value	139,485
Vested and expected to vest, Aggregate Intrinsic Value	$ 1,509,777
Minimum
Exercise Price Per Share [Abstract]
Exercise price per share, Granted (dollars per share)	$ 1.10
Exercise Price, Canceled and Forfeited (dollars per share)	1.10
Maximum
Exercise Price Per Share [Abstract]
Exercise price per share, Granted (dollars per share)	1.13
Exercise Price, Canceled and Forfeited (dollars per share)	$ 4.50

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value on a Recurring Basis (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
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
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
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale equity securities	112,492	149,990	$ 74,995	$ 118,084
Unrealized gain (loss)	37,497	37,497
Assets, Fair Value Disclosure	112,492	149,990
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
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	112,492	149,990
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
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	112,492	149,990
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
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	$ 112,492	$ 149,990

Fair Value Measurements - Chang

Fair Value Measurements - Change in Level 2 Assets (Details) - Fair Value, Measurements, Recurring - Level 2 - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, beginning	$ 74,995	$ 118,084
Sale of 93,187 shares		(5,591)
Unrealized gain (loss)	37,497	37,497
Fair value, ending	112,492	149,990
Eurosite Power, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, ending	$ 112,492	$ 149,990

Notes Payable (Details)

Notes Payable (Details) - PPP Loan Program - Webster Business Credit Corporation - USD ($)	Sep. 08, 2021	Jan. 11, 2021	Feb. 05, 2021	Apr. 17, 2020
Line of Credit Facility [Line Items]
Notes payable			$ 1,874,269	$ 1,874,200
Principal amount forgiven	$ 1,874,269	$ 1,874,200
Accrued interest forgiven	11,386	13,659
Extinguishment of debt, amount	$ 1,885,655	$ 1,887,859

Segments (Details)

Segments (Details)	3 Months Ended
	Mar. 31, 2022USD ($)segment	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)
Segment Reporting Information [Line Items]
Number of operating divisions | segment	3
Revenue	$ 7,438,323	$ 6,057,161
Gross profit	3,090,788	2,951,208
Assets	32,763,971	31,600,210	$ 32,362,222
Products and Services
Segment Reporting Information [Line Items]
Revenue	6,952,014	5,535,382
Gross profit	2,845,253	2,691,976
Assets	28,785,826	26,997,887
Energy Production
Segment Reporting Information [Line Items]
Revenue	581,562	653,295
Gross profit	245,535	259,232
Assets	3,978,145	4,602,323
Corporate, other and elimination
Segment Reporting Information [Line Items]
Revenue	(95,253)	(131,516)
Gross profit	0	0
Assets	0	0
Operating Segments
Segment Reporting Information [Line Items]
Revenue	7,438,323	6,057,161
Operating Segments | Products and Services
Segment Reporting Information [Line Items]
Revenue	6,856,761	5,403,866
Operating Segments | Energy Production
Segment Reporting Information [Line Items]
Revenue	581,562	653,295
Operating Segments | Corporate, other and elimination
Segment Reporting Information [Line Items]
Revenue	0	0
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	0	0
Intersegment Eliminations | Products and Services
Segment Reporting Information [Line Items]
Revenue	95,253	131,516
Intersegment Eliminations | Energy Production
Segment Reporting Information [Line Items]
Revenue	0	0
Intersegment Eliminations | Corporate, other and elimination
Segment Reporting Information [Line Items]
Revenue	$ (95,253)	$ (131,516)