PROPERTY, PLANT AND EQUIPMENT, NET
 12 Months Ended
Dec. 31, 2017
PROPERTY, PLANT AND EQUIPMENT, NET [Abstract]  
PROPERTY, PLANT AND EQUIPMENT, NET
7. PROPERTY, PLANT AND EQUIPMENT, NET
 
Property, plant and equipment, net, comprise:
 
 
 
At December 31,
 
 
 
2016
 
2017
 
Buildings
 
$
282,000
 
$
282,000
 
Plant and machinery
 
 
4,873
 
 
1,097,710
 
Motor vehicles
 
 
-
 
 
50,971
 
Office equipment
 
 
50,170
 
 
39,247
 
Power stations
 
 
23,170,604
 
 
125,753,462
 
 
 
 
 
 
 
 
 
Less: Accumulated depreciation
 
 
(3,354,205)
 
 
(8,388,858)
 
 
 
 
20,153,442
 
 
118,834,532
 
Construction in progress
 
 
5,147
 
 
35,824,545
 
Property, plant and equipment, net
 
$
20,158,589
 
$
154,659,077
 
 
Construction in progress mainly represents new solar power projects for self-electricity generation in China.
 
The carrying amount of the power stations of $23.2 million as of December 31, 2016 was reclassified from project assets to property plant and equipment at the point it no longer met the held for sale criteria. All these power stations were self-constructed for electricity generation purpose.
 
Depreciation expense for the years ended December 31, 2015, 2016 and 2017 was $3,548,898, $2,400,522 and $4,475,823, respectively.