SOUTHWESTERN PUBLIC SERVICE CO, 10-Q filed on 10/27/2022
Quarterly Report
v3.22.2.2
Cover Page - shares
 9 Months Ended
Sep. 30, 2022
Oct. 27, 2022
Cover [Abstract]    
Entity Registrant Name SOUTHWESTERN PUBLIC SERVICE CO  
Entity Central Index Key 0000092521  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2022  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2022  
Document Transition Report false  
Entity Tax Identification Number 75-0575400  
Entity Incorporation, State or Country Code NM  
Entity Address, Address Line One 790 South Buchanan Street  
Entity Address, City or Town Amarillo  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 79101  
City Area Code (303)  
Local Phone Number 571-7511  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   100
Entity File Number 001-03789  
v3.22.2.2
STATEMENTS OF INCOME (UNAUDITED) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Operating revenues        
Operating revenues $ 741 $ 575 $ 1,876 $ 2,007
Operating expenses        
Electric fuel and purchased power 362 250 881 1,195
Operating and maintenance expenses 79 66 238 208
Demand side management expenses 7 5 18 13
Depreciation and amortization 89 71 299 227
Taxes (other than income taxes) 26 20 84 59
Total operating expenses 563 412 1,520 1,702
Operating income 178 163 356 305
Other (expense) income, net (3) 0 (2) 1
Allowance for funds used during construction — equity 1 1 2 3
Interest charges and financing costs        
Interest charges — includes other financing costs of $1, $1, $3 and $3, respectively 33 28 108 87
Allowance for funds used during construction — debt 0 0 (1) (1)
Total interest charges and financing costs 33 28 107 86
Income before income taxes 143 136 249 223
Income tax expense (benefit) 5 2 (34) (37)
Net income $ 138 $ 134 $ 283 $ 260
v3.22.2.2
STATEMENTS OF INCOME (UNAUDITED) (Parenthetical) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Interest charges and financing costs        
Debt Related Commitment Fees and Debt Issuance Costs $ 1 $ 1 $ 3 $ 3
v3.22.2.2
STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Operating activities    
Net income $ 283 $ 260
Adjustments to reconcile net income to cash provided by operating activities:    
Depreciation and amortization 302 229
Deferred income taxes 21 (31)
Allowance for equity funds used during construction (2) (3)
Provision for bad debts 6 6
Changes in operating assets and liabilities:    
Accounts receivable (69) (66)
Accrued unbilled revenues 28 20
Inventories (14) (14)
Prepayments and other (5) 21
Accounts payable 49 6
Net regulatory assets and liabilities (73) (113)
Other current liabilities 30 19
Pension and other employee benefit obligations 1 (16)
Other, net (2) (2)
Net cash provided by operating activities 499 276
Investing activities    
Utility capital/construction expenditures (405) (446)
Investments in utility money pool arrangement 133 83
Repayments from utility money pool arrangement 113 83
Net cash used in investing activities (425) (446)
Financing activities    
Repayments of short-term borrowings, net (137) (232)
Proceeds from issuance of long-term debt, net 196 247
Borrowings under utility money pool arrangement 262 539
Repayments under utility money pool arrangement (353) (439)
Capital contributions from parent 210 304
Dividends paid to parent (250) (254)
Net cash (used in) provided by financing activities (72) 165
Net change in cash, cash equivalents and restricted cash 2 (5)
Cash, cash equivalents and restricted cash at beginning of period 1 6
Cash, cash equivalents and restricted cash at end of period 3 1
Supplemental disclosure of cash flow information:    
Cash paid for interest (net of amounts capitalized) (94) (75)
Cash received for income taxes, net 45 19
Supplemental disclosure of non-cash investing and financing transactions:    
Accrued property, plant and equipment additions 40 39
Inventory transfers to property, plant and equipment 8 6
Allowance for equity funds used during construction 2 3
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents $ 3 $ 1
v3.22.2.2
BALANCE SHEETS (UNAUDITED) - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Current assets    
Cash and cash equivalents $ 3 $ 1
Accounts receivable, net 171 115
Accounts receivable from affiliates 15 9
Investments in money pool arrangements 20 0
Accrued unbilled revenues 153 125
Inventories 58 51
Regulatory assets 274 193
Derivative instruments 237 30
Prepaid taxes 13 3
Prepayments and other 67 21
Total current assets 1,011 548
Property, plant and equipment, net 8,006 7,838
Other assets    
Regulatory assets 352 380
Derivative instruments 4 6
Operating lease right-of-use assets 441 463
Other 31 27
Total other assets 828 876
Total assets 9,845 9,262
Current liabilities    
Short-term debt 0 137
Borrowings under utility money pool arrangement 0 91
Accounts payable 216 172
Accounts payable to affiliates 24 16
Regulatory liabilities 262 54
Taxes accrued 61 47
Accrued interest 41 30
Dividends payable to parent 69 58
Derivative instruments 4 4
Operating lease liabilities 31 30
Other 81 24
Total current liabilities 789 663
Deferred credits and other liabilities    
Deferred income taxes 738 702
Regulatory liabilities 723 709
Asset retirement obligations 120 116
Derivative instruments 3 6
Pension and employee benefit obligations 7 8
Operating lease liabilities 411 434
Other 9 8
Total deferred credits and other liabilities 2,011 1,983
Capitalization    
Long-term debt 3,210 3,013
Common stock — 200 shares authorized of $1.00 par value; 100 shares outstanding at September 30, 2022 and Dec. 31, 2021, respectively 0 0
Additional paid in capital 3,301 3,091
Retained earnings 535 513
Accumulated other comprehensive loss (1) (1)
Total common stockholder's equity 3,835 3,603
Total liabilities and equity $ 9,845 $ 9,262
v3.22.2.2
BALANCE SHEETS (UNAUDITED) (Parenthetical) - $ / shares
Sep. 30, 2022
Dec. 31, 2021
Statement of Financial Position [Abstract]    
Common Stock, Shares Authorized 200 200
Common Stock, Par or Stated Value Per Share $ 1.00 $ 1.00
Common Stock, Shares, Outstanding 100 100
v3.22.2.2
CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($)
$ in Millions
Total
Common Stock
Additional Paid In Capital
Retained Earnings
Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2020   100      
Beginning balance at Dec. 31, 2020 $ 3,298 $ 0 $ 2,790 $ 509 $ (1)
Increase (Decrease) in Stockholders' Equity          
Net income 260     260  
Dividends declared to parent (253)     (253)  
Contributions of capital by parent 301   301    
Ending balance (in shares) at Sep. 30, 2021   100      
Ending balance at Sep. 30, 2021 3,606 $ 0 3,091 516 (1)
Beginning balance (in shares) at Jun. 30, 2021   100      
Beginning balance at Jun. 30, 2021 3,597 $ 0 3,094 504 (1)
Increase (Decrease) in Stockholders' Equity          
Net income 134     134  
Dividends declared to parent (122)     (122)  
Contributions of capital by parent (3)   (3)    
Ending balance (in shares) at Sep. 30, 2021   100      
Ending balance at Sep. 30, 2021 $ 3,606 $ 0 3,091 516 (1)
Beginning balance (in shares) at Dec. 31, 2021 100 100      
Beginning balance at Dec. 31, 2021 $ 3,603 $ 0 3,091 513 (1)
Increase (Decrease) in Stockholders' Equity          
Net income 283     283  
Dividends declared to parent (261)     (261)  
Contributions of capital by parent $ 210   210    
Ending balance (in shares) at Sep. 30, 2022 100 100      
Ending balance at Sep. 30, 2022 $ 3,835 $ 0 3,301 535 (1)
Beginning balance (in shares) at Jun. 30, 2022   100      
Beginning balance at Jun. 30, 2022 3,847 $ 0 3,301 547 (1)
Increase (Decrease) in Stockholders' Equity          
Net income 138     138  
Dividends declared to parent $ (150)     (150)  
Ending balance (in shares) at Sep. 30, 2022 100 100      
Ending balance at Sep. 30, 2022 $ 3,835 $ 0 $ 3,301 $ 535 $ (1)
v3.22.2.2
Legal
$ in Millions
Sep. 30, 2022
USD ($)
Settled Litigation  
Loss Contingencies [Line Items]  
Loss Contingency Accrual $ 50
v3.22.2.2
Management's Opinion
 9 Months Ended
Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Management's Opinion
In the opinion of management, the accompanying unaudited financial statements contain all adjustments necessary to present fairly, in accordance with GAAP, the financial position of SPS as of Sept. 30, 2022 and Dec. 31, 2021; the results of SPS’ operations, including the components of net income and changes in stockholder’s equity for the three and nine months ended Sept. 30, 2022 and 2021; and SPS’ cash flows for the nine months ended Sept. 30, 2022 and 2021.
All adjustments are of a normal, recurring nature, except as otherwise disclosed. Management has also evaluated the impact of events occurring after Sept. 30, 2022 up to the date of issuance of these financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. The Dec. 31, 2021 balance sheet information has been derived from the audited 2021 financial statements included in the SPS Annual Report on Form 10-K for the year ended Dec. 31, 2021.
Notes to the financial statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP on an annual basis have been condensed or omitted pursuant to such rules and regulations. For further information, refer to the financial statements and notes thereto included in the SPS Annual Report on Form 10-K for the year ended Dec. 31, 2021, filed with the SEC on Feb. 23, 2022.
Due to the seasonality of SPS’ electric sales, interim results are not necessarily an appropriate base from which to project annual results.
v3.22.2.2
Summary of Significant Accounting Policies
 9 Months Ended
Sep. 30, 2022
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies The significant accounting policies set forth in Note 1 to the financial statements in the SPS Annual Report on Form 10-K for the year ended Dec. 31, 2021 appropriately represent, in all material respects, the current status of accounting policies and are incorporated herein by reference.
v3.22.2.2
Accounting Pronouncements
 9 Months Ended
Sep. 30, 2022
Accounting Standards Update and Change in Accounting Principle [Abstract]  
Accounting Pronouncements As of Sept. 30, 2022, there was no material impact from the recent adoption of new accounting pronouncements, nor expected material impact from recently issued accounting pronouncements yet to be adopted, on SPS’ financial statements.
v3.22.2.2
Selected Balance Sheet Data
 9 Months Ended
Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]  
Selected Balance Sheet Data
(Millions of Dollars)Sept. 30, 2022Dec. 31, 2021
Accounts receivable, net
Accounts receivable$184 $127 
Less allowance for bad debts(13)(12)
Accounts receivable, net$171 $115 
(Millions of Dollars)Sept. 30, 2022Dec. 31, 2021
Inventories
Materials and supplies$38 $29 
Fuel20 22 
Total inventories$58 $51 
(Millions of Dollars)Sept. 30, 2022Dec. 31, 2021
Property, plant and equipment, net
Electric plant$9,947 $9,639 
Plant to be retired (a)
270 299 
CWIP230 171 
Total property, plant and equipment10,447 10,109 
Less accumulated depreciation(2,441)(2,271)
Property, plant and equipment, net$8,006 $7,838 
v3.22.2.2
Borrowings and Other Financing Instruments
 9 Months Ended
Sep. 30, 2022
Debt Disclosure [Abstract]  
Borrowings and Other Financing Instruments
Short-Term Borrowings
SPS meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility and the money pool.
Money Pool — Xcel Energy Inc. and its utility subsidiaries have established a money pool arrangement that allows for short-term investments in and borrowings between the utility subsidiaries. Xcel Energy Inc. may make investments in the utility subsidiaries at market-based interest rates; however, the money pool arrangement does not allow the utility subsidiaries to make investments in Xcel Energy Inc.
Money pool borrowings for SPS:
(Amounts in Millions, Except Interest Rates)Three Months Ended Sept. 30, 2022Year Ended Dec. 31, 2021
Borrowing limit$100 $100 
Amount outstanding at period end— 91 
Average amount outstanding— 51 
Maximum amount outstanding4 100 
Weighted average interest rate, computed on a daily basis2.27 %0.05 %
Weighted average interest rate at period endN/A0.05 
Commercial Paper — Commercial paper outstanding for SPS:
(Amounts in Millions, Except Interest Rates)Three Months Ended Sept. 30, 2022Year Ended Dec. 31, 2021
Borrowing limit$500 $500 
Amount outstanding at period end— 137 
Average amount outstanding— 63 
Maximum amount outstanding— 342 
Weighted average interest rate, computed on a daily basisN/A0.21 %
Weighted average interest rate at period endN/A0.26 
Letters of Credit — SPS uses letters of credit, generally with terms of one year, to provide financial guarantees for certain obligations. At both Sept. 30, 2022 and Dec. 31, 2021, there were $2 million of letters of credit outstanding under the credit facility. Amounts approximate their fair value and are subject to fees.
Revolving Credit Facility — In order to issue its commercial paper, SPS must have a revolving credit facility in place at least equal to the amount of its commercial paper borrowing limit and cannot issue commercial paper exceeding available capacity under this credit facility. The credit facility provides short-term financing in the form of notes payable to banks, letters of credit and back-up support for commercial paper borrowings.
In September 2022, SPS entered into an amended five-year credit agreement with a syndicate of banks, with substantially the same terms and conditions as the prior credit agreements. The maturity was extended from June 2024 to September 2027.
SPS has the right to request an extension of the revolving credit facility termination date for two additional one-year periods. All extension requests are subject to majority bank group approval.
As of Sept. 30, 2022, SPS had the following committed revolving credit facility available (in millions of dollars):
Credit Facility (a)
Drawn (b)
Available
$500 $2 $498 
(a)Expires in September 2027.
(b)Includes outstanding letters of credit.
All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. SPS had no direct advances on the credit facility outstanding as of Sept. 30, 2022 and Dec. 31, 2021.
Long-Term Borrowings
During the nine months ended Sept. 30, 2022, SPS issued $200 million of 5.15% first mortgage bonds due June 1, 2052.
v3.22.2.2
Revenues
 9 Months Ended
Sep. 30, 2022
Revenue from Contract with Customer [Abstract]  
Revenue
Revenue is classified by the type of goods/services rendered and market/customer type. SPS’ operating revenues consisted of the following:
Three Months Ended Sept. 30
(Millions of Dollars)20222021
Major revenue types
Revenue from contracts with customers:
Residential$159 $126 
Commercial and Industrial325 241 
Other17 11 
Total retail501 378 
Wholesale149 109 
Transmission80 75 
Other— 2 
Total revenue from contracts with customers730 564 
Alternative revenue and other11 11 
Total revenues$741 $575 
Nine Months Ended Sept. 30
(Millions of Dollars)20222021
Major revenue types
Revenue from contracts with customers:
Residential$356 $302 
Commercial and Industrial811 631 
Other38 30 
Total retail1,205 963 
Wholesale327 785 
Transmission226 218 
Other6 6 
Total revenue from contracts with customers1,764 1,972 
Alternative revenue and other112 35 
Total revenues$1,876 $2,007 
v3.22.2.2
Income Taxes
 9 Months Ended
Sep. 30, 2022
Income Tax Disclosure [Abstract]  
Income Taxes
6. Income Taxes
Reconciliation between the statutory rate and ETR:
Nine Months Ended Sept. 30
20222021
Federal statutory rate21.0 %21.0 %
State tax (net of federal tax effect)2.3 2.5 
Decreases:
Wind PTCs (a)
(31.8)(32.9)
Plant regulatory differences (b)
(3.7)(4.9)
Amortization of excess nonplant deferred taxes(0.9)(1.1)
Other (net)(0.6)(1.2)
Effective income tax rate(13.7)%(16.6)%
(a)Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income.
(b)Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.
v3.22.2.2
Fair Value of Financial Assets and Liabilities
 9 Months Ended
Sep. 30, 2022
Fair Value Disclosures [Abstract]  
Fair Value of Financial Assets and Liabilities
Fair Value Measurements
Accounting guidance for fair value measurements and disclosures provides a single definition of fair value and requires disclosures about assets and liabilities measured at fair value. A hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value is established by this guidance.
•Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. The types of assets and liabilities included in Level 1 are highly liquid and actively traded instruments with quoted prices.
•Level 2 — Pricing inputs are other than quoted prices in active markets, but are either directly or indirectly observable as of the reporting date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts or priced with models using highly observable inputs.
•Level 3 — Significant inputs to pricing have little or no observability as of the reporting date. The types of assets and liabilities included in Level 3 are those valued with models requiring significant management judgment or estimation.
Specific valuation methods include:
Cash equivalents — The fair values of cash equivalents are generally based on cost plus accrued interest; money market funds are measured using quoted net asset value.
Interest rate derivatives — The fair values of interest rate derivatives are based on broker quotes that utilize current market interest rate forecasts.
Commodity derivatives — Methods used to measure the fair value of commodity derivative forwards and options utilize forward prices and volatilities, as well as pricing adjustments for specific delivery locations and are generally assigned a Level 2 classification. When contractual settlements relate to inactive delivery locations or extend to periods beyond those readily observable on active exchanges or quoted by brokers, the significance of the use of less observable inputs on a valuation is evaluated and may result in Level 3 classification.
Electric commodity derivatives held by SPS include transmission congestion instruments, generally referred to as FTRs. FTRs purchased from a RTO are financial instruments that entitle or obligate the holder to monthly revenues or charges based on transmission congestion across a given transmission path.
The values of these instruments are derived from, and designed to offset, the costs of transmission congestion. In addition to overall transmission load, congestion is also influenced by the operating schedules of power plants and the consumption of electricity pertinent to a given transmission path. Unplanned plant outages, scheduled plant maintenance, changes in the relative costs of fuels used in generation, weather and overall changes in demand for electricity can each impact the operating schedules of the power plants on the transmission grid and the value of these instruments. FTRs are recognized at fair value and adjusted each period prior to settlement. Given the limited observability of certain variables underlying the reported auction values of FTRs, these fair value measurements have been assigned a Level 3.
If costs of electric transmission congestion increase or decrease for a given path, the value of that particular instrument will likewise increase or decrease.
Derivative Instruments Fair Value Measurements
SPS enters into derivative instruments, including forward contracts, for trading purposes and to manage risk in connection with changes in interest rates and electric utility commodity prices.
Interest Rate Derivatives — SPS may enter into various instruments that effectively fix the interest payments on certain floating rate debt obligations or effectively fix the yield or price on a specified benchmark interest rate for an anticipated debt issuance for a specific period. These derivative instruments are generally designated as cash flow hedges for accounting purposes.
As of Sept. 30, 2022, accumulated other comprehensive loss related to interest rate derivatives included immaterial net losses expected to be reclassified into earnings during the next 12 months as the related hedged interest rate transactions impact earnings. As of Sept. 30, 2022, SPS had no unsettled interest rate derivatives.
Wholesale and Commodity Trading Risk — SPS conducts various wholesale and commodity trading activities, including the purchase and sale of electric capacity, energy and energy-related instruments, including derivatives. SPS is allowed to conduct these activities within guidelines and limitations as approved by its risk management committee, comprised of management personnel not directly involved in the activities governed by this policy. Sharing of any margins is determined through state regulatory proceedings as well as the operation of the FERC approved joint operating agreement.
Commodity Derivatives — SPS enters into derivative instruments to manage variability of future cash flows from changes in commodity prices in its electric utility operations. This could include the purchase or sale of energy or energy-related products and FTRs.
Amounts in Millions (a)
Sept. 30, 2022Dec. 31, 2021
Megawatt hours of electricity12 8 
(a)Amounts are not reflective of net positions in the underlying commodities.
Consideration of Credit Risk and Concentrations — SPS continuously monitors the creditworthiness of counterparties to its interest rate derivatives and commodity derivative contracts, prior to settlement, and assesses each counterparty’s ability to perform on the transactions set forth in the contracts. Impact of credit risk was immaterial to the fair value of unsettled commodity derivatives presented in the balance sheets.
SPS’ most significant concentrations of credit risk with particular entities or industries are contracts with counterparties to its wholesale, trading and non-trading commodity activities.
At Sept. 30, 2022, two of the eight most significant counterparties for these activities, comprising $9 million, or 27%, of this credit exposure, had investment grade credit ratings from S&P Global Ratings, Moody’s Investor Services or Fitch Ratings. Five of the eight most significant counterparties, comprising $25 million, or 72%, of this credit exposure, were not rated by external ratings agencies, but based on SPS’ internal analysis, had credit quality consistent with investment grade. One of these significant counterparties, comprising an immaterial amount of this credit exposure, had credit quality less than investment grade, based on internal analysis. All eight of these significant counterparties are municipal or cooperative electric entities, RTOs or other utilities.
Impact of Derivative Activities on Income — Changes in the fair value of FTRs resulting in pre-tax net losses of $13 million and gains of $80 million for the three and nine months ended Sept. 30, 2022, respectively, were recognized as regulatory assets or liabilities. Changes in the fair value of FTRs resulting in pre-tax net gains of $5 million and $15 million for the three and nine months ended Sept. 30, 2021, respectively, were recognized as regulatory assets or liabilities. The classification as a regulatory asset or liability is based on expected recovery of FTR settlements through fuel and purchased energy cost recovery mechanisms.
FTR settlement losses of $8 million and gains of $26 million for the three and nine months ended Sept. 30, 2022, respectively, were recorded to electric fuel and purchased power. FTR settlement losses of $4 million and gains of $13 million for the three and nine months ended Sept. 30, 2021, respectively, were recorded to electric fuel and purchased power. These derivative settlement gains and losses are shared with electric customers through fuel and purchased energy cost-recovery mechanisms and reclassified out of income as regulatory assets or liabilities, as appropriate.
All FTR settlements are shared with customers and do not have a material impact on net income. Presented amounts reflect changes in fair value between auction and settlement dates, but exclude the original auction fair value.
SPS had immaterial derivative instruments designated as fair value hedges during the three and nine months ended Sept. 30, 2022 and 2021.
Recurring Fair Value Measurements — SPS’ derivative assets and liabilities measured at fair value on a recurring basis were as follows:
Sept. 30, 2022Dec. 31, 2021
Fair ValueFair Value Total
Netting (a)
TotalFair ValueFair Value Total
Netting (a)
Total
(Millions of Dollars)Level 1Level 2Level 3Level 1Level 2Level 3
Current derivative assets
Other derivative instruments:
Electric commodity (b)
$— $— $234 $234 $— $234 $— $— $27 $27 $— $27 
Total current derivative assets$— $— $234 $234 $— 234 $— $— $27 $27 $— 27 
PPAs (c)
3 3 
Current derivative instruments$237 $30 
Noncurrent derivative assets
PPAs (c)
$4 $6 
Noncurrent derivative instruments$4 $6 
Current derivative liabilities
PPAs (c)
$4 $4 
Current derivative instruments$4 $4 
Noncurrent derivative liabilities
PPAs (c)
$3 $6 
Noncurrent derivative instruments$3 $6 
(a)SPS nets derivative instruments and related collateral on its balance sheets when supported by a legally enforceable master netting agreement. At Sept. 30, 2022 and Dec. 31, 2021, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.
(b)Amounts relate to FTR instruments administered by SPP (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, fair values for FTRs are offset/deferred as a regulatory asset or liability and do not have a material impact on net income.
(c)During 2006, SPS qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.
Changes in Level 3 commodity derivatives for the three and nine months ended Sept. 30, 2022 and 2021:
Three Months Ended Sept. 30
(Millions of Dollars)20222021
Balance at July 1$284 $41 
Purchases/Issuances (a)
4 2 
Settlements (a)
(22)(18)
Net transactions recorded during the period:
Net (losses) gains recognized as regulatory assets and liabilities (a)
(32)12 
Balance at Sept. 30$234 $37 
Nine Months Ended Sept. 30
(Millions of Dollars)20222021
Balance at Jan. 1$27 $7 
Purchases/Issuances (a)
241 11 
Settlements (a)
(116)(39)
Net transactions recorded during the period:
Net gains recognized as regulatory assets and liabilities (a)
82 58 
Balance at Sept. 30$234 $37 
(a)Relates primarily to FTR instruments administered by SPP (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income.
SPS recognizes transfers between levels as of the beginning of each period. There were no transfers of amounts between levels for derivative instruments for the three and nine months ended Sept. 30, 2022 and 2021.
Fair Value of Long-Term Debt
Other financial instruments for which the carrying amount did not equal fair value:
Sept. 30, 2022Dec. 31, 2021
(Millions of Dollars)Carrying AmountFair ValueCarrying AmountFair Value
Long-term debt$3,210 $2,656 $3,013 $3,454 
Fair value of SPS’ long-term debt is estimated based on recent trades and observable spreads from benchmark interest rates for similar securities. Fair value estimates are based on information available to management as of Sept. 30, 2022 and Dec. 31, 2021 and given the observability of the inputs, fair values presented for long-term debt were assigned as Level 2.
v3.22.2.2
Benefit Plans and Other Postretirement Benefits
 9 Months Ended
Sep. 30, 2022
Retirement Benefits [Abstract]  
Benefit Plans and Other Postretirement Benefits
Components of Net Periodic Benefit Cost (Credit)
Three Months Ended Sept. 30
2022202120222021
(Millions of Dollars)Pension BenefitsPostretirement Health
Care Benefits
Service cost$2 $3 $— $— 
Interest cost (a)
4 3 — — 
Expected return on plan assets (a)
(8)(7)— — 
Amortization of net loss (gain) (a)
3 4 (1)— 
Settlement charge (b)
2 — — — 
Net periodic benefit cost$3 $3 $(1)$— 
Effects of regulation(1)(1)— — 
Net benefit cost recognized for financial reporting$2 $2 $(1)$— 
Nine Months Ended Sept. 30
2022202120222021
(Millions of Dollars)Pension BenefitsPostretirement Health
Care Benefits
Service cost$7 $8 $— $— 
Interest cost (a)
12 11 1 — 
Expected return on plan assets (a)
(23)(22)(1)(1)
Amortization of net loss (gain) (a)
8 11 (1)— 
Settlement charge (b)
2 — — — 
Net periodic benefit cost$6 $8 $(1)$(1)
Effects of regulation(1)— — — 
Net benefit cost recognized for financial reporting$5 $8 $(1)$(1)
(a)The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the statements of income or capitalized on the balance sheets as a regulatory asset.
(b)A settlement charge is required when the amount of all lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In the third quarter as a result of lump-sum distributions during the 2022 plan year, SPS recorded a pension settlement charge of $2 million, the majority of which was not recognized in earnings due to the effects of regulation.
In January 2022, contributions of $50 million were made across four of Xcel Energy’s pension plans, none of which was attributable to SPS. Xcel Energy does not expect additional pension contributions during 2022.
v3.22.2.2
Commitments and Contingencies
 9 Months Ended
Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies
The following includes commitments, contingencies and unresolved contingencies that are material to SPS’ financial position.
Legal
SPS is involved in various litigation matters in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. Management maintains accruals for losses probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including but not limited to when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories.
In such cases, there is considerable uncertainty regarding the timing or ultimate resolution, including a possible eventual loss. For current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, would have a material effect on SPS’ financial statements. Legal fees are generally expensed as incurred.
Other Litigation — In 2019, SPS and Xcel Energy Services, Inc. were served with a lawsuit related to a traffic accident that resulted in two fatalities in New Mexico. A loss contingency of approximately $50 million was recorded as of Sept. 30, 2022 within Other current liabilities. In July 2022, a confidential settlement was reached. No impact to earnings has or is expected to occur, as the amounts are expected to be reimbursed by SPS’ insurers. An offsetting asset has been recorded to reflect the reimbursement within Prepayments and other current assets.
Rate Matters and Other
SPS is involved in various regulatory proceedings arising in the ordinary course of business. Until resolution, typically in the form of a rate order, uncertainties may exist regarding the ultimate rate treatment for certain activities and transactions. Amounts have been recognized for probable and reasonably estimable losses that may result. Unless otherwise disclosed, any reasonably possible range of loss in excess of any recognized amount is not expected to have a material effect on the financial statements.
SPP OATT Upgrade Costs — Costs of transmission upgrades may be recovered from other SPP customers whose transmission service depends on capacity enabled by the upgrade under the SPP OATT. SPP had not been charging its customers for these upgrades, even though the SPP OATT had allowed SPP to do so since 2008. In 2016, the FERC granted SPP’s request to recover these previously unbilled charges and SPP subsequently billed SPS approximately $13 million.
In July 2018, SPS’ appeal to the D.C. Circuit over the FERC rulings granting SPP the right to recover previously unbilled charges was remanded to the FERC. In February 2019, the FERC reversed its 2016 decision and ordered SPP to refund charges retroactively collected from its transmission customers, including SPS, related to periods before September 2015. In March 2020, SPP and Oklahoma Gas & Electric separately filed petitions for review of the FERC’s orders at the D.C. Circuit. In August 2021, the D.C. Circuit issued a decision denying these appeals and upholding the FERC’s orders. Refunds received by SPS are expected to be given back to SPS customers through future rates.
In October 2017, SPS filed a separate related complaint asserting SPP assessed upgrade charges to SPS in violation of the SPP OATT. In March 2018, the FERC issued an order denying the SPS complaint. SPS filed a request for rehearing in April 2018. The FERC issued a tolling order granting a rehearing for further consideration in May 2018. If SPS’ complaint results in additional charges or refunds, SPS will seek to recover or refund the amount through future SPS customer rates. In October 2020, SPS filed a petition for review of the FERC’s March 2018 order and May 2018 tolling order at the D.C. Circuit. In February 2022, FERC issued an order rejecting SPS’ request for hearing. SPS has appealed that order. That appeal has been combined with SPS’ prior appeal.
Contract Termination — SPS and LP&L have a 25-year, 170 MW partial requirements contract. In May 2021, SPS and LP&L finalized a settlement which would terminate the contract upon LP&L’s move from the SPP to the Electric Reliability Council of Texas (expected in 2023). The settlement agreement requires LP&L to pay SPS $78 million, to the benefit of SPS’ remaining customers. LP&L would remain obligated to pay for SPP transmission charges associated with LP&L’s load in SPP. The agreement is subject to approval by the PUCT and FERC. Approval steps are in process, but approval timing from the PUCT is uncertain.
Environmental
Manufactured Gas Plant, Landfill and Disposal Sites
SPS is remediating a former disposal site. SPS has recognized its best estimate of costs/liabilities from final resolution of these issues, however, the outcome and timing are unknown. In addition, there may be insurance recovery and/or recovery from other potentially responsible parties, offsetting a portion of costs incurred.
Leases
SPS evaluates contracts that may contain leases, including PPAs and arrangements for the use of office space and other facilities, vehicles and equipment. A contract contains a lease if it conveys the exclusive right to control the use of a specific asset.
Components of lease expense:
Three Months Ended Sept. 30
(Millions of Dollars)20222021
Operating leases
PPA capacity payments$13 $13 
Other operating leases (a)
1 — 
Total operating lease expense (b)
$14 $13 
(a)Includes immaterial short-term lease expense for 2022 and 2021.
(b)PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.
Nine Months Ended Sept. 30
(Millions of Dollars)20222021
Operating leases
PPA capacity payments$39 $40 
Other operating leases (a)
4 2 
Total operating lease expense (b)
$43 $42 
(a)Includes short-term lease expense of $1 million for 2022 and 2021, respectively.
(b)PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.
Commitments under operating leases as of Sept. 30, 2022:
(Millions of Dollars)PPA Operating LeasesOther Operating LeasesTotal Operating Leases
Total minimum obligation$508 $54 $562 
Interest component of obligation(106)(14)(120)
Present value of minimum obligation$402 $40 442 
Less current portion(31)
Noncurrent operating lease liabilities$411 
Variable Interest Entities
Under certain PPAs, SPS purchases power from IPPs for which SPS is required to reimburse fuel costs, or to participate in tolling arrangements under which SPS procures the natural gas required to produce the energy that they purchase. These specific PPAs create a variable interest in the IPP.
SPS had approximately 1,197 MW of capacity under long-term PPAs at both Sept. 30, 2022 and Dec. 31, 2021 with entities that have been determined to be variable interest entities. SPS concluded that these entities are not required to be consolidated in its financial statements because it does not have the power to direct the activities that most significantly impact the entities’ economic performance. The PPAs have expiration dates through 2041.
v3.22.2.2
Selected Balance Sheet Data (Tables)
 9 Months Ended
Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]  
Accounts Receivable, Net
(Millions of Dollars)Sept. 30, 2022Dec. 31, 2021
Accounts receivable, net
Accounts receivable$184 $127 
Less allowance for bad debts(13)(12)
Accounts receivable, net$171 $115 
Inventories
(Millions of Dollars)Sept. 30, 2022Dec. 31, 2021
Inventories
Materials and supplies$38 $29 
Fuel20 22 
Total inventories$58 $51 
Property, Plant and Equipment, Net
(Millions of Dollars)Sept. 30, 2022Dec. 31, 2021
Property, plant and equipment, net
Electric plant$9,947 $9,639 
Plant to be retired (a)
270 299 
CWIP230 171 
Total property, plant and equipment10,447 10,109 
Less accumulated depreciation(2,441)(2,271)
Property, plant and equipment, net$8,006 $7,838 
v3.22.2.2
Borrowings and Other Financing Instruments (Tables)
 9 Months Ended
Sep. 30, 2022
Borrowings and Other Financing Instruments [Abstract]  
Credit Facilities
As of Sept. 30, 2022, SPS had the following committed revolving credit facility available (in millions of dollars):
Credit Facility (a)
Drawn (b)
Available
$500 $2 $498 
(a)Expires in September 2027.
(b)Includes outstanding letters of credit.
Money Pool  
Borrowings and Other Financing Instruments [Abstract]  
Short-Term Borrowings
Money pool borrowings for SPS:
(Amounts in Millions, Except Interest Rates)Three Months Ended Sept. 30, 2022Year Ended Dec. 31, 2021
Borrowing limit$100 $100 
Amount outstanding at period end— 91 
Average amount outstanding— 51 
Maximum amount outstanding4 100 
Weighted average interest rate, computed on a daily basis2.27 %0.05 %
Weighted average interest rate at period endN/A0.05 
Commercial Paper  
Borrowings and Other Financing Instruments [Abstract]  
Short-Term Borrowings Commercial paper outstanding for SPS:
(Amounts in Millions, Except Interest Rates)Three Months Ended Sept. 30, 2022Year Ended Dec. 31, 2021
Borrowing limit$500 $500 
Amount outstanding at period end— 137 
Average amount outstanding— 63 
Maximum amount outstanding— 342 
Weighted average interest rate, computed on a daily basisN/A0.21 %
Weighted average interest rate at period endN/A0.26 
v3.22.2.2
Revenues (Tables)
 9 Months Ended
Sep. 30, 2022
Revenue from Contract with Customer [Abstract]  
Disaggregation of Revenue SPS’ operating revenues consisted of the following:
Three Months Ended Sept. 30
(Millions of Dollars)20222021
Major revenue types
Revenue from contracts with customers:
Residential$159 $126 
Commercial and Industrial325 241 
Other17 11 
Total retail501 378 
Wholesale149 109 
Transmission80 75 
Other— 2 
Total revenue from contracts with customers730 564 
Alternative revenue and other11 11 
Total revenues$741 $575 
Nine Months Ended Sept. 30
(Millions of Dollars)20222021
Major revenue types
Revenue from contracts with customers:
Residential$356 $302 
Commercial and Industrial811 631 
Other38 30 
Total retail1,205 963 
Wholesale327 785 
Transmission226 218 
Other6 6 
Total revenue from contracts with customers1,764 1,972 
Alternative revenue and other112 35 
Total revenues$1,876 $2,007 
v3.22.2.2
Income Taxes (Tables)
 9 Months Ended
Sep. 30, 2022
Income Tax Disclosure [Abstract]  
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Reconciliation between the statutory rate and ETR:
Nine Months Ended Sept. 30
20222021
Federal statutory rate21.0 %21.0 %
State tax (net of federal tax effect)2.3 2.5 
Decreases:
Wind PTCs (a)
(31.8)(32.9)
Plant regulatory differences (b)
(3.7)(4.9)
Amortization of excess nonplant deferred taxes(0.9)(1.1)
Other (net)(0.6)(1.2)
Effective income tax rate(13.7)%(16.6)%
(a)Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income.
(b)Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.
v3.22.2.2
Fair Value of Financial Assets and Liabilities (Tables)
 9 Months Ended
Sep. 30, 2022
Fair Value Disclosures [Abstract]  
Gross Notional Amounts of Commodity FTRs
Amounts in Millions (a)
Sept. 30, 2022Dec. 31, 2021
Megawatt hours of electricity12 8 
(a)Amounts are not reflective of net positions in the underlying commodities.
Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis by Hierarchy Level
Recurring Fair Value Measurements — SPS’ derivative assets and liabilities measured at fair value on a recurring basis were as follows:
Sept. 30, 2022Dec. 31, 2021
Fair ValueFair Value Total
Netting (a)
TotalFair ValueFair Value Total
Netting (a)
Total
(Millions of Dollars)Level 1Level 2Level 3Level 1Level 2Level 3
Current derivative assets
Other derivative instruments:
Electric commodity (b)
$— $— $234 $234 $— $234 $— $— $27 $27 $— $27 
Total current derivative assets$— $— $234 $234 $— 234 $— $— $27 $27 $— 27 
PPAs (c)
3 3 
Current derivative instruments$237 $30 
Noncurrent derivative assets
PPAs (c)
$4 $6 
Noncurrent derivative instruments$4 $6 
Current derivative liabilities
PPAs (c)
$4 $4 
Current derivative instruments$4 $4 
Noncurrent derivative liabilities
PPAs (c)
$3 $6 
Noncurrent derivative instruments$3 $6 
(a)SPS nets derivative instruments and related collateral on its balance sheets when supported by a legally enforceable master netting agreement. At Sept. 30, 2022 and Dec. 31, 2021, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.
(b)Amounts relate to FTR instruments administered by SPP (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, fair values for FTRs are offset/deferred as a regulatory asset or liability and do not have a material impact on net income.
(c)During 2006, SPS qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.
Changes in Level 3 Commodity Derivatives
Changes in Level 3 commodity derivatives for the three and nine months ended Sept. 30, 2022 and 2021:
Three Months Ended Sept. 30
(Millions of Dollars)20222021
Balance at July 1$284 $41 
Purchases/Issuances (a)
4 2 
Settlements (a)
(22)(18)
Net transactions recorded during the period:
Net (losses) gains recognized as regulatory assets and liabilities (a)
(32)12 
Balance at Sept. 30$234 $37 
Nine Months Ended Sept. 30
(Millions of Dollars)20222021
Balance at Jan. 1$27 $7 
Purchases/Issuances (a)
241 11 
Settlements (a)
(116)(39)
Net transactions recorded during the period:
Net gains recognized as regulatory assets and liabilities (a)
82 58 
Balance at Sept. 30$234 $37 
(a)Relates primarily to FTR instruments administered by SPP (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income.
Carrying Amount and Fair Value of Long-term Debt
Other financial instruments for which the carrying amount did not equal fair value:
Sept. 30, 2022Dec. 31, 2021
(Millions of Dollars)Carrying AmountFair ValueCarrying AmountFair Value
Long-term debt$3,210 $2,656 $3,013 $3,454 
v3.22.2.2
Benefit Plans and Other Postretirement Benefits (Tables)
 9 Months Ended
Sep. 30, 2022
Retirement Benefits [Abstract]  
Components of Net Periodic Benefit Cost (Credit)
Components of Net Periodic Benefit Cost (Credit)
Three Months Ended Sept. 30
2022202120222021
(Millions of Dollars)Pension BenefitsPostretirement Health
Care Benefits
Service cost$2 $3 $— $— 
Interest cost (a)
4 3 — — 
Expected return on plan assets (a)
(8)(7)— — 
Amortization of net loss (gain) (a)
3 4 (1)— 
Settlement charge (b)
2 — — — 
Net periodic benefit cost$3 $3 $(1)$— 
Effects of regulation(1)(1)— — 
Net benefit cost recognized for financial reporting$2 $2 $(1)$— 
Nine Months Ended Sept. 30
2022202120222021
(Millions of Dollars)Pension BenefitsPostretirement Health
Care Benefits
Service cost$7 $8 $— $— 
Interest cost (a)
12 11 1 — 
Expected return on plan assets (a)
(23)(22)(1)(1)
Amortization of net loss (gain) (a)
8 11 (1)— 
Settlement charge (b)
2 — — — 
Net periodic benefit cost$6 $8 $(1)$(1)
Effects of regulation(1)— — — 
Net benefit cost recognized for financial reporting$5 $8 $(1)$(1)
(a)The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the statements of income or capitalized on the balance sheets as a regulatory asset.
(b)A settlement charge is required when the amount of all lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In the third quarter as a result of lump-sum distributions during the 2022 plan year, SPS recorded a pension settlement charge of $2 million, the majority of which was not recognized in earnings due to the effects of regulation.
v3.22.2.2
Commitments and Contingencies (Tables)
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]    
Lease, Cost
Components of lease expense:
Three Months Ended Sept. 30
(Millions of Dollars)20222021
Operating leases
PPA capacity payments$13 $13 
Other operating leases (a)
1 — 
Total operating lease expense (b)
$14 $13 
(a)Includes immaterial short-term lease expense for 2022 and 2021.
(b)PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.
Nine Months Ended Sept. 30
(Millions of Dollars)20222021
Operating leases
PPA capacity payments$39 $40 
Other operating leases (a)
4 2 
Total operating lease expense (b)
$43 $42 
(a)Includes short-term lease expense of $1 million for 2022 and 2021, respectively.
(b)PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power. 		 
Lessee, Operating Lease, Liability, Maturity  
Commitments under operating leases as of Sept. 30, 2022:
(Millions of Dollars)PPA Operating LeasesOther Operating LeasesTotal Operating Leases
Total minimum obligation$508 $54 $562 
Interest component of obligation(106)(14)(120)
Present value of minimum obligation$402 $40 442 
Less current portion(31)
Noncurrent operating lease liabilities$411 
v3.22.2.2
Selected Balance Sheet Data Accounts Receivable, Net (Details) - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Accounts receivable, net    
Accounts receivable $ 184 $ 127
Less allowance for bad debts (13) (12)
Accounts receivable, net $ 171 $ 115
v3.22.2.2
Selected Balance Sheet Data Selected Balance Sheet Data Inventories (Details) - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Inventories $ 58 $ 51
Inventory, Net 58 51
Materials and supplies    
Inventories 38 29
Fuel    
Inventories $ 20 $ 22
v3.22.2.2
Selected Balance Sheet Data Balance Sheet Related Disclosures, Property, Plant and Equipment, Net (Details) - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Public Utility, Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 10,447 $ 10,109
Accumulated depreciation (2,441) (2,271)
Property, plant and equipment, net 8,006 7,838
Electric plant    
Public Utility, Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 9,947 9,639
Plant to be Retired    
Public Utility, Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross [1] 270 299
Construction work in progress    
Public Utility, Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 230 $ 171
[1] Amounts include Tolk and conversion of Harrington to natural gas and are reported net of accumulated depreciation.
v3.22.2.2
Borrowings and Other Financing Instruments - Money Pool (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Sep. 30, 2022
Dec. 31, 2021
Short-term Debt [Line Items]    
Short-term debt $ 0 $ 137
Money Pool    
Short-term Debt [Line Items]    
Borrowing limit 100 100
Short-term debt 0 91
Average amount outstanding 0 51
Maximum amount outstanding $ 4 $ 100
Weighted average interest rate, computed on a daily basis 2.27% 0.05%
Weighted average interest rate at period end   0.05%
Commercial Paper    
Short-term Debt [Line Items]    
Borrowing limit $ 500 $ 500
Short-term debt 0 137
Average amount outstanding 0 63
Maximum amount outstanding $ 0 $ 342
Weighted average interest rate, computed on a daily basis   0.21%
Weighted average interest rate at period end   0.26%
v3.22.2.2
Borrowings and Other Financing Instruments - Commercial Paper (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Sep. 30, 2022
Dec. 31, 2021
Short-term Debt [Line Items]    
Short-term debt $ 0 $ 137
Commercial Paper    
Short-term Debt [Line Items]    
Borrowing limit 500 500
Short-term debt 0 137
Average amount outstanding 0 63
Maximum amount outstanding $ 0 $ 342
Weighted average interest rate, computed on a daily basis   0.21%
Weighted average interest rate at period end   0.26%
v3.22.2.2
Borrowings and Other Financing Instruments - Letters of Credit (Details) - USD ($)
 9 Months Ended
Sep. 30, 2022
Dec. 31, 2021
Line of Credit Facility [Line Items]    
Short-term debt $ 0 $ 137,000,000
Letter of Credit    
Line of Credit Facility [Line Items]    
Short-term debt $ 2,000,000 2,000,000
Debt Instrument, Term 1 year  
Revolving Credit Facility [Member]    
Line of Credit Facility [Line Items]    
Direct advances on the credit facility outstanding $ 0 $ 0
v3.22.2.2
Borrowings and Other Financing Instruments - Credit Facility (Details)
 9 Months Ended
Sep. 30, 2022
USD ($)
Plan
Dec. 31, 2021
USD ($)
Line of Credit Facility [Line Items]    
Number of extension you can request | Plan 2  
Credit Facility    
Line of Credit Facility [Line Items]    
Credit Facility [1] $ 500,000,000  
Outstanding [2] 2,000,000  
Available 498,000,000  
Direct advances on the credit facility outstanding $ 0 $ 0
[1] Expires in September 2027
[2] Includes outstanding letters of credit.
v3.22.2.2
Borrowings and Other Financing Instruments - Long-Term Borrowings (Details) - Series Due June 1, 2052 - Bonds [Member]
Sep. 30, 2022
USD ($)
Debt Instrument [Line Items]  
Debt Instrument, Face Amount $ 200,000,000
Debt Instrument, Interest Rate, Stated Percentage 5.15%
v3.22.2.2
Borrowings and Other Financing Instruments - Narrative (Details) - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Debt Disclosure [Abstract]    
Short-term debt $ 0 $ 137
v3.22.2.2
Revenues (Details) - Regulated Electric - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers $ 730 $ 564 $ 1,764 $ 1,972
Total revenues        
Disaggregation of Revenue [Line Items]        
Total revenues 741 575 1,876 2,007
Retail        
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers 501 378 1,205 963
Retail | Residential        
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers 159 126 356 302
Retail | C&I        
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers 325 241 811 631
Retail | Other        
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers 17 11 38 30
Wholesale        
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers 149 109 327 785
Transmission        
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers 80 75 226 218
Other        
Disaggregation of Revenue [Line Items]        
Revenue from contracts with customers 0 2 6 6
Alternative and Other        
Disaggregation of Revenue [Line Items]        
Alternative revenue and other $ 11 $ 11 $ 112 $ 35
v3.22.2.2
Income Taxes (Details)
 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Income Tax Disclosure [Abstract]    
Federal statutory rate, percent 21.00% 21.00%
State tax (net of federal tax effect), percent 2.30% 2.50%
Wind PTCs, percent [1] (31.80%) (32.90%)
Plant regulatory differences, percent [2] (3.70%) (4.90%)
Other tax credits, percent (0.90%) (1.10%)
Other (net), percent (0.60%) (1.20%)
Effective income tax rate, percent (13.70%) (16.60%)
[1] Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income.
[2] Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.
v3.22.2.2
Fair Value of Financial Assets and Liabilities - Commodity Derivatives (Details) - MWh
MWh in Millions
Sep. 30, 2022
Dec. 31, 2021
Electric Commodity [Member]    
Derivative [Line Items]    
Mwh of electricity [1] 12 8
[1] Amounts are not reflective of net positions in the underlying commodities.
v3.22.2.2
Fair Value of Financial Assets and Liabilities - Consideration of Credit Risk Concentrations (Details) - Credit Concentration Risk
$ in Millions
Sep. 30, 2022
USD ($)
Counterparty
Derivative [Line Items]  
Significant counterparties 8
Municipal or cooperative electric entities or other utilities  
Derivative [Line Items]  
Significant counterparties 8
External credit rating, investment grade  
Derivative [Line Items]  
Significant counterparties 2
Credit exposure | $ $ 9
Credit exposure, percentage 27.00%
Internal investment grade  
Derivative [Line Items]  
Significant counterparties 5
Credit exposure | $ $ 25
Credit exposure, percentage 72.00%
External Credit Rating, Non Investment Grade [Member]  
Derivative [Line Items]  
Significant counterparties 1
v3.22.2.2
Fair Value of Financial Assets and Liabilities - Impact of Derivative Activities on Income and Accumulated Other Comprehensive Loss (Details) - Other Derivative Instruments - Electric Commodity - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]        
Changes in fair value of FTRs pre-tax gains $ 13 $ 5 $ 80 $ 15
FTR settlement gains $ 8 $ 4 $ 26 $ (13)
v3.22.2.2
Fair Value of Financial Assets and Liabilities - Recurring Fair Value Measurements (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Dec. 31, 2021
Derivatives, Fair Value          
Reclaim Cash Collateral $ 0   $ 0   $ 0
Return Cash Collateral 0   0   0
Commodity Contract [Member]          
Changes in Level 3 Commodity Derivatives          
Balance at beginning of period 284 $ 41 27 $ 7  
Purchases [1] 4 2 241 11  
Settlements [1] (22) (18) (116) (39)  
Net gains recognized as regulatory assets and liabilities [1] (32) 12 82 58  
Balance at end of period 234 37 234 37  
Transfers Level 3, Net 0 $ 0 0 $ 0  
Other Current Assets          
Derivatives, Fair Value          
Derivative asset, net 237   237   30
Other Noncurrent Assets          
Derivatives, Fair Value          
Derivative asset, net 4   4   6
Other Current Liabilities          
Derivatives, Fair Value          
Derivative liability, net 4   4   4
Other Noncurrent Liabilities          
Derivatives, Fair Value          
Derivative liability, net 3   3   6
Fair Value Measured on a Recurring Basis | Other Current Assets          
Derivatives, Fair Value          
Derivative asset, gross 234   234   27
Asset, netting [2] 0   0   0
Derivative asset, net 234   234   27
Fair Value Measured on a Recurring Basis | Other Current Assets | Level 1          
Derivatives, Fair Value          
Derivative asset, gross 0   0   0
Fair Value Measured on a Recurring Basis | Other Current Assets | Level 2          
Derivatives, Fair Value          
Derivative asset, gross 0   0   0
Fair Value Measured on a Recurring Basis | Other Current Assets | Level 3          
Derivatives, Fair Value          
Derivative asset, gross 234   234   27
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Electric Commodity          
Derivatives, Fair Value          
Derivative asset, gross [3] 234   234   27
Asset, netting [2],[3] 0   0   0
Derivative asset, net [3] 234   234   27
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 1 | Electric Commodity          
Derivatives, Fair Value          
Derivative asset, gross [3] 0   0   0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 2 | Electric Commodity          
Derivatives, Fair Value          
Derivative asset, gross [3] 0   0   0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 3 | Electric Commodity          
Derivatives, Fair Value          
Derivative asset, gross [3] 234   234   27
Fair Value, Measurements, Nonrecurring | Other Current Assets | PPAs          
Derivatives, Fair Value          
Derivative asset, net [4] 3   3   3
Fair Value, Measurements, Nonrecurring | Other Noncurrent Assets | PPAs          
Derivatives, Fair Value          
Derivative asset, net [4] 4   4   6
Fair Value, Measurements, Nonrecurring | Other Current Liabilities | PPAs          
Derivatives, Fair Value          
Derivative liability, net 4 [4]   4 [4]   4
Fair Value, Measurements, Nonrecurring | Other Noncurrent Liabilities | PPAs          
Derivatives, Fair Value          
Derivative liability, net $ 3 [4]   $ 3 [4]   $ 6
[1] Relates primarily to FTR instruments administered by SPP (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income.
[2] SPS nets derivative instruments and related collateral on its balance sheets when supported by a legally enforceable master netting agreement. At Sept. 30, 2022 and Dec. 31, 2021, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.
[3] Amounts relate to FTR instruments administered by SPP (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, fair values for FTRs are offset/deferred as a regulatory asset or liability and do not have a material impact on net income.
[4] During 2006, SPS qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.
v3.22.2.2
Fair Value of Financial Assets and Liabilities - Fair Value of Long-Term Debt (Details) - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term Debt, Carrying Amount $ 3,210 $ 3,013
Level 2    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term Debt, Fair Value $ 2,656 $ 3,454
v3.22.2.2
Benefit Plans and Other Postretirement Benefits (Details)
$ in Millions
 1 Months Ended 3 Months Ended 9 Months Ended
Jan. 31, 2022
USD ($)
Plan
Sep. 30, 2022
USD ($)
Sep. 30, 2021
USD ($)
Sep. 30, 2022
USD ($)
Sep. 30, 2021
USD ($)
Pension Plan [Member]          
Components of Net Periodic Benefit Cost (Credit) [Abstract]          
Service cost   $ 2 $ 3 $ 7 $ 8
Interest cost (a) [1]   4 3 12 11
Expected return on plan assets (a) [1]   (8) (7) (23) (22)
Amortization of net loss (gain) (a) [1]   3 4 8 11
Net periodic benefit cost (credit)   3 3 6 8
Contributions to pension plans $ 0        
Effects of regulation   (1) (1) (1) 0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)   2 2 5 8
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement   2 [2] 0 2 [2] 0
Pension Plan [Member] | Xcel Energy Inc.          
Components of Net Periodic Benefit Cost (Credit) [Abstract]          
Contributions to pension plans $ 50        
Number of pension plans to which contributions were made | Plan 4        
Other Postretirement Benefits Plan [Member]          
Components of Net Periodic Benefit Cost (Credit) [Abstract]          
Service cost   0 0 0 0
Interest cost (a)   0 0 1 [1] 0
Expected return on plan assets (a)   0 0 (1) [1] (1) [1]
Amortization of net loss (gain) (a)   (1) [1] 0 (1) [1] 0
Net periodic benefit cost (credit)   (1) 0 (1) (1)
Effects of regulation   0 0 0 0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)   (1) 0 (1) (1)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement   $ 0 $ 0 $ 0 $ 0
[1] The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the statements of income or capitalized on the balance sheets as a regulatory asset.
[2] A settlement charge is required when the amount of all lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In the third quarter as a result of lump-sum distributions during the 2022 plan year, SPS recorded a pension settlement charge of $2 million, the majority of which was not recognized in earnings due to the effects of regulation.
v3.22.2.2
Commitments and Contingencies - SPP OATT Upgrade Costs (Details)
$ in Millions
 6 Months Ended
Jun. 30, 2019
USD ($)
Southwest Power Pool (SPP) | SPP Open Access Transmission Tariff Upgrade Costs  
Public Utilities, General Disclosures [Line Items]  
Charges For Transmission Service Upgrades $ 13
v3.22.2.2
Contract Termination (Details)
$ in Millions
 9 Months Ended
Sep. 30, 2022
USD ($)
MW
Commitments and Contingencies Disclosure [Abstract]  
Megawatts, Lubbock Power and Light contract | MW 170
Lubbock Power and Light contract length 25 years
Settlement Agreement Payment, Lubbock Power and Light Contract | $ $ 78
v3.22.2.2
Leases (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Dec. 31, 2021
Lessee, Lease, Description [Line Items]          
Operating Lease, Cost $ 14 [1] $ 13 [1] $ 43 [2] $ 42 [2]  
Lessee, Operating Lease, Liability, to be Paid 562   562    
Lessee, Operating Lease, Liability, Undiscounted Excess Amount (120)   (120)    
Operating Lease, Liability 442   442    
Operating Lease, Liability, Current (31)   (31)   $ (30)
Operating lease liabilities 411   411   $ 434
Short-term Lease, Cost     1 1  
PPAs          
Lessee, Lease, Description [Line Items]          
Operating Lease, Cost 13 13 39 40  
Lessee, Operating Lease, Liability, to be Paid 508   508    
Lessee, Operating Lease, Liability, Undiscounted Excess Amount (106)   (106)    
Operating Lease, Liability 402   402    
Property, Plant and Equipment, Other Types          
Lessee, Lease, Description [Line Items]          
Operating Lease, Cost 1 [3] $ 0 [3] 4 [4] $ 2 [4]  
Lessee, Operating Lease, Liability, to be Paid 54   54    
Lessee, Operating Lease, Liability, Undiscounted Excess Amount (14)   (14)    
Operating Lease, Liability $ 40   $ 40    
[1] PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.
[2] PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.
[3] Includes immaterial short-term lease expense for 2022 and 2021.
[4] Includes short-term lease expense of $1 million for 2022 and 2021, respectively.
v3.22.2.2
Commitments and Contingencies - Variable Interest Entities (Details) - MW
Sep. 30, 2022
Dec. 31, 2021
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]    
Purchased Power Agreements [Abstract]    
Generating capacity (in MW) 1,197 1,197
v3.22.2.2
Other Comprehensive Income (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Income Tax Expense (Benefit) $ 5 $ 2 $ (34) $ (37)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Accumulated other comprehensive loss at beginning of period     3,603  
Accumulated other comprehensive loss at end of period $ 3,835   $ 3,835