Quarterly report pursuant to Section 13 or 15(d)

Intangible Assets and Liabilities Other Than Goodwill -Amounts related to intangible assets (Details)

Intangible Assets and Liabilities Other Than Goodwill -Amounts related to intangible assets (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 2,441,872	$ 2,578,564
Less - accumulated amortization	(1,009,113)	(984,783)
Intangible assets, net	1,432,759	1,593,781
Unfavorable contract liability	4,689,025	4,689,025
Less - accumulated amortization	(2,264,046)	(2,154,207)
Unfavorable contract liability, net	2,424,979	2,534,818
Product Certifications
Finite-Lived Intangible Assets [Line Items]
Intangible assets	726,159	726,159
Less - accumulated amortization	(413,468)	(399,906)
Intangible assets, net	312,691	326,253
Patents
Finite-Lived Intangible Assets [Line Items]
Intangible assets	880,416	1,017,108
Less - accumulated amortization	(210,501)	(206,499)
Intangible assets, net	669,915	810,609
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets	240,000	240,000
Less - accumulated amortization	(112,000)	(108,000)
Intangible assets, net	128,000	132,000
Favorable contract asset
Finite-Lived Intangible Assets [Line Items]
Intangible assets	274,858	274,858
Less - accumulated amortization	(265,742)	(263,901)
Intangible assets, net	9,116	10,957
TTcogen Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets	29,607	29,607
Less - accumulated amortization	(7,402)	(6,477)
Intangible assets, net	22,205	23,130
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	0	0
Intangible assets, net	$ 263,936	$ 263,936