Property, plant and equipment and construction in progress (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 145,171,425	$ 139,782,227
Less accumulated depreciation	89,288,904	87,252,682
Property, Plant and Equipment, Net, Total	55,882,521	52,529,545
Construction in progress	495,471	3,705,681
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	6,488,400	6,488,400
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	26,044,551	23,280,880
Plant And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	66,000,977	64,532,994
Distribution Systems [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	39,546,175	39,544,395
Office furniture, fixtures and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,338,760	3,109,546
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,433,561	2,525,576
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	306,545	287,980
Lab equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 12,456	$ 12,456