Jointly-Owned Facilities

12 Months Ended

Dec. 31, 2024

Jointly Owned Utility Plant, Net Ownership Amount [Abstract]

Jointly-Owned Facilities

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 which are included in the corresponding operating expenses on our Consolidated Statements of Income. We are also responsible for 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, 2024 (dollars in thousands):

	Percent Owned			Plant in Service		Accumulated Depreciation		Construction Work in Progress
Generating facilities:
Palo Verde Units 1 and 3	29.1	%		$	2,010,346	$	1,081,321	$	20,694
Palo Verde Unit 2 (a)	16.8	%		709,414		397,235		9,076
Palo Verde Common	28.0	%	(b)	898,401		366,027		47,962
Palo Verde Sale Leaseback			(a)	351,050		268,494		—
Four Corners Generating Station	63.0	%		1,848,412		705,667		56,226
Cholla Common Facilities (c)	50.5	%		301,035		231,170		1,743
Transmission facilities:
Arizona Nuclear Power Project 500kV System	33.3	%	(b)	134,713		60,174		7,174
Navajo Southern System	24.7	%	(b)	88,528		38,797		626
Palo Verde — Yuma 500kV System	25.5	%	(b)	24,260		8,120		142
Four Corners Switchyards	58.0	%	(b)	84,367		23,886		309
Phoenix — Mead System	17.1	%	(b)	39,788		21,173		330
Palo Verde — Rudd 500kV System	50.0	%		95,785		34,254		1,808
Morgan — Pinnacle Peak System	63.2	%	(b)	117,500		29,013		287
Round Valley System	50.0	%		548		213		—
Palo Verde — Morgan System	87.5	%	(b)	266,547		46,327		208
Hassayampa — North Gila System	80.0	%		154,330		27,739		—
Cholla 500kV Switchyard	85.7	%		8,454		2,859		35
Saguaro 500kV Switchyard	60.0	%		29,850		15,768		101
Kyrene — Knox System	50.0	%		578		349		—
Agua Fria Switchyard	10.0	%		—		—		82

(a)See Note 17.

(b)Weighted-average of interests.

(c)PacifiCorp owns Cholla Unit 4 (see Note 3 for additional information), and APS operated the unit for PacifiCorp.  Cholla Unit 4 was retired on December 24, 2020. The common facilities at Cholla are jointly-owned.