Annual report pursuant to Section 13 and 15(d)

Cover

v3.22.0.1
Cover - USD ($)
 12 Months Ended
Dec. 31, 2021
Mar. 09, 2022
Jun. 30, 2021
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2021    
Current Fiscal Year End Date --12-31    
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 466-6400    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Emerging Growth Company false    
Entity Small Business true    
ICFR Auditor Attestation Flag false    
Entity Shell Company false    
Entity Public Float     $ 28,812,496
Entity Common Stock, Shares Outstanding   24,850,261  
Documents Incorporated by Reference Certain information required for Part III of this Annual Report on Form 10-K is incorporated by reference to Tecogen Inc.'s definitive proxy statement for its 2022 Annual Meeting of Stockholders which will be filed with the Securities and Exchange Commission ("SEC") pursuant to Regulation 14A under the Securities Act of 1934, as amended, within 120 days following its fiscal year ended December 31, 2021.    
Entity Central Index Key 0001537435    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false