SUMMARY OF PRINCIPAL ACCOUNTING POLICIES (Convertible Senior Notes, Revenue Recognition, Deferred Project Revenue, Cost of Revenues, Warranty Costs and Government Grants) (Narrative) (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Revenue recognition [Line Items] | |||
| Amortization of deferred convertible notes issuance costs and premium | $ 0 | $ 32,935 | $ 764,527 |
| Other Assets, Noncurrent | $ 3,425,098 | 3,250,754 | |
| Percenatge of Total Selling Price of Power Projects | 50.00% | ||
| Revenue from Grants | $ 4,184,724 | 1,708,163 | $ 1,534,297 |
| Deferred project revenue | |||
| Deferred project revenue | 0 | 32,242,995 | |
| Solar power projects [Member] | |||
| Deferred project revenue | |||
| Deferred project revenue | $ 20,791,918 | $ 32,242,995 | |