Joint Ownership of Generation, Transmission and Gas Facilities

12 Months Ended

Dec. 31, 2011

Joint Ownership of Generation, Transmission and Gas Facilities [Abstract]

Joint Ownership of Generation, Transmission and Gas Facilities

6.    Joint Ownership of Generation, Transmission and Gas Facilities

Following are the investments by PSCo in jointly owned generation, transmission and gas facilities and the related ownership percentages as of Dec. 31, 2011:

(Thousands of Dollars)	Plant in Service		Accumulated Depreciation		Construction Work in Progress		Ownership %
Electric Generation:
Hayden Unit 1	$	88,337	$	60,549	$	830		75.5	%
Hayden Unit 2		119,621		55,126		722		37.4
Hayden Common Facilities		34,558		14,155		1		53.1
Craig Units 1 and 2		54,058		33,225		193		9.7
Craig Common Facilities 1, 2 and 3		35,241		15,896		2,863		6.5 - 9.7
Comanche Unit 3		867,976		28,973		1,014		66.7
Comanche Common Facilities		12,628		219		169		82.0
Electric Transmission:
Transmission and other facilities, including substations		150,420		56,654		449	Various
Gas Transportation:
Rifle to Avon		16,278		6,333		-		60.0
Total	$	1,379,117	$	271,130	$	6,241

PSCo has approximately 820 MW of jointly owned generating capacity.  PSCo's share of operating expenses and construction expenditures are included in the applicable utility accounts.  Each of the respective owners is responsible for providing its own financing.