Revenues

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Revenues

Revenue is classified by the type of goods/services rendered and market/customer type. SPS’ operating revenues consisted of the following:

	Year Ended Dec. 31
(Millions of Dollars)	2023		2022		2021
Major revenue types
Revenue from contracts with customers:
Residential	$	442	$	445	$	375
C&I (a)	1,094		1,102		842
Other	58		51		38
Total retail	1,594		1,598		1,255
Wholesale	223		407		873
Transmission	296		296		287
Other	—		10		6
Total revenue from contracts with customers	2,113		2,311		2,421
Alternative revenue and other	39		115		44
Total revenues	$	2,152	$	2,426	$	2,465