3.	Selected Balance Sheet Data

(Thousands of Dollars)	Sept. 30, 2011			Dec. 31, 2010
Accounts receivable, net
Accounts receivable	$	324,614		$	329,523
Less allowance for bad debts		(23,852	)		(24,054	)
	$	300,762		$	305,469
Inventories
Materials and supplies	$	52,903		$	51,615
Fuel		87,809			67,187
Natural gas		120,909			104,256
	$	261,621		$	223,058
Property, plant and equipment, net
Electric plant	$	9,336,137		$	9,003,103
Natural gas plant		2,373,634			2,284,212
Common and other property		756,210			757,059
Plant to be retired (a)		182,487			236,606
Construction work in progress		265,202			231,636
Total property, plant and equipment		12,913,670			12,512,616
Less accumulated depreciation		(3,507,830	)		(3,312,060	)
	$	9,405,840		$	9,200,556

(a)

In 2009, in accordance with the Colorado Public Utilities Commission (CPUC's) approval of PSCo's 2007 Colorado resource plan and subsequent rate case decisions, PSCo agreed to early retire its Cameo Units 1 and 2, Arapahoe Units 3 and 4 and Zuni Units 1 and 2 facilities. In 2010, in response to the Clean Air Clean Jobs Act (CACJA), the CPUC approved the early retirement of Cherokee Units 1, 2 and 3, Arapahoe Unit 3 and Valmont Unit 5 between 2011 and 2017. Amounts are presented net of accumulated depreciation.