Borrowings and Other Financing Instruments Borrowings and Other Financing Instruments (Tables)

12 Months Ended

Dec. 31, 2024

Debt Disclosure [Abstract]

Money Pool

Money pool borrowings:

(Millions of Dollars, Except Interest Rates)	Three Months Ended Dec. 31, 2024		Year Ended
			2024			2023			2022
Borrowing limit	$	150	$	150		$	150		$	150
Amount outstanding at period end	—		—			—			—
Average amount outstanding	—		4			6			25
Maximum amount outstanding	—		54			43			81
Weighted average interest rate, computed on a daily basis	N/A		5.34		%	4.98		%	1.10		%
Weighted average interest rate at period end	N/A		N/A			N/A			N/A

Commercial Paper

Commercial paper outstanding:

(Millions of Dollars, Except Interest Rates)	Three Months Ended Dec. 31, 2024			Year Ended Dec. 31
				2024			2023			2022
Borrowing limit	$	150		$	150		$	150		$	150
Amount outstanding at period end	35			35			60			47
Average amount outstanding	3			11			15			18
Maximum amount outstanding	35			99			93			123
Weighted average interest rate, computed on a daily basis	4.59		%	5.42		%	4.85		%	1.03		%
Weighted average interest rate at end of period	4.59			4.59			5.50			4.55

Schedule of Debt To Total Capitalization Ratio

Debt-to-Total Capitalization Ratio (a)				Amount Facility May Be Increased (millions of dollars)	Additional Periods for Which a One-Year Extension May Be Requested (b)
2024		2023
47.1	%	48.2	%	N/A	1

(a)The credit facility has a financial covenant requiring that the debt-to-total capitalization ratio be less than or equal to 65%.

(b)All extension requests are subject to majority bank group approval.

Credit Facilities

NSP-Wisconsin had the following committed credit facility available as of Dec. 31, 2024 (in millions of dollars):

Credit Facility (a)		Drawn (b)		Available
$	150	$	35	$	115

(a)This credit facility matures in September 2027.

(b)Includes outstanding commercial paper.

^[1],[2]

Schedule of Long-Term Debt

Long-term debt obligations for NSP-Wisconsin as of Dec. 31 (in millions of dollars):

Financing Instrument	Interest Rate		Maturity Date	2024		2023
First mortgage bonds	3.30	%	June 15, 2024	$	—	$	100
First mortgage bonds	3.30		June 15, 2024	—		100
First mortgage bonds	6.375		Sept. 1, 2038	200		200
First mortgage bonds	3.70		Oct. 1, 2042	100		100
First mortgage bonds	3.75		Dec. 1, 2047	100		100
First mortgage bonds	4.20		Sept. 1, 2048	200		200
First mortgage bonds	3.05		May 1, 2051	100		100
First mortgage bonds	2.82		May 1, 2051	100		100
First mortgage bonds	4.86		Sept. 15, 2052	100		100
First mortgage bonds (a)	5.30		June 15, 2053	125		125
First mortgage bonds (b)	5.65		June 15, 2054	400		—
Unamortized discount				(4)		(3)
Unamortized debt issuance cost				(15)		(11)
Current maturities				—		(200)
Total long-term debt				$	1,406	$	1,011

(a)2023 financing.

(b)2024 financing.

Dividend Payment Restrictions

Equity to Total Capitalization Ratio Required Range (a)			Equity to Total Capitalization Ratio Actual
Low		High	2024
52.5	%	N/A	52.7	%

(a)NSP-Wisconsin cannot pay annual dividends in excess of forecasted levels if its average equity-to-total capitalization ratio falls below the commission authorized level.

Unrestricted Retained Earnings			Total Capitalization			Limit on Total Capitalization
$	12	million	$	2,922	million	N/A

.

[1] This credit facility matures in September 2027.

[2] Includes outstanding commercial paper