Rate Matters (Tables)

12 Months Ended

Dec. 31, 2017

Public Utilities, General Disclosures [Abstract]

NSP-Minnesota 2016 Rate Case Final Order [Table Text Block]

(Millions of Dollars, incremental)	2016		2017		2018		2019		Total
Revenues	$	75	$	55	$	—	$	50	$	180
NSP-Minnesota’s sales true-up	60		—		—		—		60
Total rate impact	$	135	$	55	$	—	$	50	$	240

Colorado 2017 Multi-Year Electric Rate Case [Table Text Block]

Revenue Request (Millions of Dollars)	2018		2019		2020		2021		Total
Revenue request	$	74	$	75	$	60	$	36	$	245
CACJA revenue conversion to base rates (a)	90		—		—		—		90
TCA revenue conversion to base rates (a)	43		—		—		—		43
Total (b)	$	207	$	75	$	60	$	36	$	378
Expected year-end rate base (billions of dollars) (b)	$	6.8	$	7.1	$	7.3	$	7.4

^(a)  The roll-in of the TCA and CACJA rider revenues into base rates will not have an impact on customer bills or revenue as these costs are already being recovered through a rider. Transmission investments for 2019-2021 will be recovered through the TCA rider.

^(b)  This base rate request does not include the impacts of the RESA and ECA for the Rush Creek wind investments or the proposed CEP.

Colorado 2017 Multi-Year Gas Rate Case [Table Text Block]

Revenue Request (Millions of Dollars)	2018		2019		2020		Total
Revenue request	$	63	$	33	$	43	$	139
PSIA revenue conversion to base rates (a)	—		94		—		94
Total	$	63	$	127	$	43	$	233
Expected year-end rate base (billions of dollars) (b)	$	1.5	$	2.3	$	2.4

^(a) The roll-in of PSIA rider revenue into base rates will not have an impact on customer bills or revenue as these costs are already being recovered through the rider. The recovery of incremental PSIA related investments in 2019 and 2020 are included in the base rate request.

^(b)   The additional rate base in 2019 predominantly reflects the roll-in of capital associated with the PSIA rider.

Texas 2017 Rate Case [Table Text Block]

The following table summarizes SPS’ rate increase request:

Revenue Request (Millions of Dollars)
Incremental revenue request	$	69
TCRF revenue conversion to base rates (a)	(14		)
Net revenue increase request	$	55

^(a)  The roll-in of the TCRF rider revenue into base rates will not have an impact on customer bills or revenue as these costs are already being recovered through the rider. SPS can request another TCRF rider after the conclusion of this rate case to recover transmission investments subsequent to June 30, 2017.