Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, plant and equipment at December 31, 2020 and 2019 consisted of the following:


	Estimated Useful Life (in Years)	2020		2019
Energy systems	10 - 15 years	$	3,526,514	$	4,372,638
Machinery and equipment	5 - 7 years	1,448,024		1,462,208
Furniture and fixtures	5 years	193,698		193,698
Computer software	3 - 5 years	192,865		192,865
Leasehold improvements	*	450,792		450,792
		5,811,893		6,672,201
Less - accumulated depreciation and amortization		(3,528,047)		(3,206,253)
Net property, plant and equipment		$	2,283,846	$	3,465,948

* Lesser of estimated useful life of asset or lease term