PROPERTY, PLANT AND EQUIPMENT, NET
12 Months Ended
Dec. 31, 2022
PROPERTY, PLANT AND EQUIPMENT, NET  
PROPERTY, PLANT AND EQUIPMENT, NET

7. PROPERTY, PLANT AND EQUIPMENT, NET

Property, plant and equipment, net:

At December 31,

    

2021

    

2022

Land

$

282,000

$

275,000

Plant and machinery

 

858,948

 

781,324

Motor vehicles

 

65,473

 

94,654

Office equipment

 

252,150

 

381,118

Power stations(1)

 

138,533,441

 

191,011,142

 

 

Less: Accumulated depreciation

 

(19,181,277)

 

(25,438,066)

 

120,810,735

 

167,105,172

Construction in progress

 

4,835,751

 

3,372,189

Property, plant and equipment, net

$

125,646,486

$

170,477,361

(1)All power stations were self-constructed, except for Project Branston that the Company acquired on September 30, 2022 with an original cost of $42,793,499 (as discussed in Note 3).

Construction in progress mainly represents solar power projects which are under development for self-electricity generation in China.

Depreciation expense for the years ended December 31, 2020, 2021 and 2022 was $7,342,327, $6,794,404 and $6,817,331, respectively.