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, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 2,483,661	$ 3,754,762
Less - accumulated amortization	(910,262)	(860,772)
Intangible assets, net	1,573,399	2,893,990
Unfavorable contract liability	4,689,025	8,341,922
Less - accumulated amortization	(1,818,686)	(876,972)
Unfavorable contract liability, net	2,870,339	7,464,950
Product Certifications
Finite-Lived Intangible Assets [Line Items]
Intangible assets	726,159	726,159
Less - accumulated amortization	(359,221)	(345,658)
Intangible assets, net	366,938	380,501
Patents
Finite-Lived Intangible Assets [Line Items]
Intangible assets	923,849	910,569
Less - accumulated amortization	(193,524)	(188,239)
Intangible assets, net	730,325	722,330
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets	240,000	240,000
Less - accumulated amortization	(96,000)	(92,000)
Intangible assets, net	144,000	148,000
Favorable contract asset
Finite-Lived Intangible Assets [Line Items]
Intangible assets	274,858	1,561,739
Less - accumulated amortization	(257,817)	(232,099)
Intangible assets, net	17,041	1,329,640
TTcogen Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets	29,607	0
Less - accumulated amortization	(925)	0
Intangible assets, net	28,682	0
Trademarks
Finite-Lived Intangible Assets [Line Items]
Intangible assets	25,252	22,752
Less - accumulated amortization	0	0
Intangible assets, net	25,252	22,752
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