10. Jointly-Owned Facilities

APS shares ownership of some of its generating and transmission facilities with other companies. We are responsible for our share of operating costs, as well as providing our own financing. Our share of operating expenses and utility plant costs related to these facilities is accounted for using proportional consolidation. The following table shows APS’s interests in those jointly-owned facilities recorded on the Consolidated Balance Sheets at December 31, 2012 (dollars in thousands):

	Percent Owned		Plant in Service		Accumulated Depreciation		Construction Work in Progress
Generating facilities:
Palo Verde Units 1 and 3	29.1	%	$	1,717,970	$	1,006,615	$	15,122
Palo Verde Unit 2 (a)	16.8	%	555,132		324,063		4,125
Palo Verde Common	28.0	%(b)	516,950		223,632		83,365
Palo Verde Sale Leaseback		(a)	351,050		222,055		—
Four Corners Units 4 and 5	15.0	%	167,390		36,311		3,040
Four Corners Common	38.4	%(b)	58,810		17,930		1,512
Navajo Generating Station Units 1, 2 and 3	14.0	%	269,792		141,914		2,368
Cholla common facilities (c)	63.3	% (b)	146,571		43,815		1,680
Transmission facilities:
ANPP 500kV System	33.3	%(b)	82,490		31,511		1,607
Navajo Southern System	22.2	%(b)	55,427		15,815		561
Palo Verde — Yuma 500kV System	18.3	%(b)	11,761		4,493		797
Four Corners Switchyards	37.0	%(b)	20,874		6,033		1,466
Phoenix — Mead System	17.1	%(b)	39,772		11,553		—
Palo Verde — Estrella 500kV System	50.0	%(b)	85,643		13,309		4,137
Morgan — Pinnacle Peak System	64.1	%(b)	133,073		3,751		331
Round Valley System	50.0	%(b)	488		261		—

(a) See Note 20.

(b) Weighted-average of interests.

(c) PacifiCorp owns Cholla Unit 4 and APS operates the unit for PacifiCorp. The common facilities at Cholla are jointly-owned.