Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Total revenues	$ 7,183,121	$ 5,630,130	$ 21,755,712	$ 16,544,014
Total cost of sales	4,999,555	3,149,216	13,888,613	9,408,288
Gross profit	2,183,566	2,480,914	7,867,099	7,135,726
Operating expenses:
General and administrative	3,411,762	2,681,558	9,431,073	8,428,119
Selling	572,869	442,812	1,682,085	1,377,758
Research and development	297,926	233,809	859,318	734,994
(Gain) loss on disposition of assets	1,713	(4,042)	1,433	(8,070)
Total operating expenses	4,284,270	3,354,137	11,973,909	10,532,801
Loss from operations	(2,100,704)	(873,223)	(4,106,810)	(3,397,075)
Other income (expense), net
Other income (expense), net	81,925	(18,453)	61,302	(15,305)
Interest expense	(41,113)	(23,003)	(111,592)	(59,542)
Unrealized gain (loss) on investment securities	(56,246)	18,749	(74,995)	0
Total other income (expense), net	(15,434)	(22,707)	(125,285)	(74,847)
Loss before provision for state income taxes	(2,116,138)	(895,930)	(4,232,095)	(3,471,922)
Provision for state income taxes	2,928	0	20,615	22,100
Consolidated net loss	(2,119,066)	(895,930)	(4,252,710)	(3,494,022)
(Income) loss attributable to the non-controlling interest	(11,881)	(34,478)	(2,264)	(80,149)
Loss attributable to Tecogen Inc.	$ (2,130,947)	$ (930,408)	$ (4,254,974)	$ (3,574,171)
Earnings Per Share [Abstract]
Net loss per share - basic (in USD per share)	$ (0.07)	$ (0.04)	$ (0.16)	$ (0.14)
Weighted average shares outstanding - basic (in shares)	28,817,040	24,850,261	26,354,875	24,850,261
Net loss per share - diluted (in usd per share)	$ (0.07)	$ (0.04)	$ (0.16)	$ (0.14)
Weighted average shares outstanding - diluted (in shares)	28,817,040	24,850,261	26,354,875	24,850,261
Products
Total revenues	$ 2,983,795	$ 1,391,016	$ 8,672,927	$ 3,002,087
Total cost of sales	1,885,377	797,209	5,605,282	2,018,734
Services
Total revenues	3,943,510	3,850,551	12,153,700	11,991,378
Total cost of sales	2,946,438	2,139,042	7,675,073	6,423,114
Energy Service [Member]
Total revenues	255,816	388,563	929,085	1,550,549
Total cost of sales	$ 167,740	$ 212,965	$ 608,258	$ 966,440

TECOGEN INC. 10-Q