Regulatory Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2023

Regulatory Assets and Liabilities Disclosure [Abstract]

Components of regulatory assets:


(Millions of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2023				Dec. 31, 2022
Regulatory Assets			Current		Noncurrent		Current		Noncurrent
Pension and retiree medical obligations	9	Various	2		62		2		61
Environmental remediation costs	1, 10	Various	$	13	$	48	$	13	$	63
Recoverable deferred taxes on AFUDC		Plant lives	—		26		—		20
State commission adjustments		Plant lives	1		22		1		22
Net AROs (a)	1, 10	Various	—		21		—		18
Deferred natural gas and electric energy/fuel costs	7	Less than one year	1		—		23		—
Other		Various	7		6		5		9
Total regulatory assets			$	24	$	185	$	44	$	193

(a)Includes amounts recorded for future recovery of AROs, less amounts recovered through NSP-Wisconsin’s share of nuclear decommissioning accruals and gains from decommissioning investments.

Regulatory Liabilities

Components of regulatory liabilities:


(Millions of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2023				Dec. 31, 2022
Regulatory Liabilities			Current		Noncurrent		Current		Noncurrent
Plant removal costs	1, 10	Various	$	—	$	251	$	—	$	223
Deferred income tax adjustments and TCJA refunds (a)	7	Various	—		140		—		144
DOE Settlement		One to two years	4		6		12		3
Deferred natural gas and electric energy/fuel costs		Less than one year	28		—		5		—
Other		Various	10		10		4		13
Total regulatory liabilities			$	42	$	407	$	21	$	383

(a)Includes the revaluation of recoverable/regulated plant accumulated deferred income taxes and revaluation impact of non-plant accumulated deferred income taxes due to the TCJA.

^[1]

[1]	Includes the revaluation of recoverable/regulated plant accumulated deferred income taxes and revaluation impact of non-plant accumulated deferred income taxes due to the TCJA.