Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2022

Property, plant and equipment at December 31, 2022 and 2021 consisted of the following:


	Estimated Useful Life (in Years)	2022		2021
Energy systems	10 - 15 years	$	2,810,232	$	3,556,488
Machinery and equipment	5 - 7 years	1,624,885		1,463,153
Furniture and fixtures	5 years	196,007		193,698
Computer software	3 - 5 years	192,865		192,865
Leasehold improvements	*	466,789		466,789
		5,290,778		5,872,993
Less - accumulated depreciation and amortization		(3,883,058)		(4,090,049)
Net property, plant and equipment		$	1,407,720	$	1,782,944

* Lesser of estimated useful life of asset or lease term