PROPERTY, PLANT AND EQUIPMENT, NET

12 Months Ended

Dec. 31, 2015

PROPERTY, PLANT AND EQUIPMENT, NET [Abstract]

PROPERTY, PLANT AND EQUIPMENT, NET

13. PROPERTY, PLANT AND EQUIPMENT, NET

Property, plant and equipment and related accumulated depreciation are as follows:

	As of December 31,
	2014			2015
	RMB			RMB
Buildings		674,404,784			843,434,719
Machinery and equipment		3,587,003,598			4,109,490,563
Motor vehicles		31,996,742			34,708,696
Furniture, fixture and office equipment		70,296,117			92,267,645
		4,363,701,241			5,079,901,623
Less: Accumulated depreciation		(1,354,103,750	)		(1,732,792,756	)
Less: Impairment		(37,759,828	)		(35,281,427	)
Subtotal		2,971,837,663			3,311,827,440
Construction in progress		129,957,509			459,628,038
Property, plant and equipment, net		3,101,795,172			3,771,455,478

Depreciation expenses were RMB328,311,127 , RMB348,022,445 and RMB393,162,784 for the years ended December 31, 2013, 2014 and 2015, respectively.

Construction in progress primarily represents the construction of new production line. Costs incurred in the construction are capitalized and transferred to property and equipment upon completion, at which time depreciation commences.

In the years ended December 31, 2013, 2014 and 2015, the Group recorded impairment of RMB3,573,248, RMB6,217,151 and nil related to the retirement of certain equipment in the wafer and cell production line that had become obsolete.

As of December 31, 2015, certain property, plant and equipment with net book value amounting of RMB2,063,567,296 are pledged as collateral for the Group's borrowings (Note 20).