Annual report pursuant to Section 13 and 15(d)

Bank Loans (Details)

v3.21.2
Bank Loans (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Property, Plant and Equipment [Line Items]      
Weighted average interest rate for short-term bank loans 5.30% 6.50% 5.50%
Weighted average interest rate for long-term bank loans 4.40% 5.40% 5.20%
Interest expense $ 14,909,159 $ 6,700,421 $ 1,800,121
Construction-in-Progress [Member]      
Property, Plant and Equipment [Line Items]      
Interest costs capitalized $ 1,476,240 $ 334,851 $ 589,147