EX-4.01





 Exhibit 4.01 

SUPPLEMENTAL TRUST INDENTURE 

FROM 
 NORTHERN STATES POWER
COMPANY 
 (A WISCONSIN CORPORATION) 

TO 
 U.S. BANK NATIONAL
ASSOCIATION 
 TRUSTEE 
 DATED
AS OF 
 MAY 18, 2020 

SUPPLEMENTAL TO TRUST INDENTURE 

DATED APRIL 1, 1947 
 AND 

SUPPLEMENTAL AND RESTATED 
 TRUST
INDENTURE 
 DATED MARCH 1, 1991 












 TABLE OF CONTENTS 

 

							
	 	  	 	  	Page	 
	PARTIES	  		  	 	1	 
			
	RECITALS	  		  	 	1	 
			
	ARTICLE I 	  	SPECIFIC SUBJECTION OF ADDITIONAL PROPERTY TO THE LIEN OF THE INDENTURE	  	 	8	 
			
	 Section 1.01
	  	Grant of Certain Property, Including Personal Property to Comply with the Uniform Commercial Code, Subject to Permitted Encumbrances Contained in the Indenture	  	 	8	 
			
	ARTICLE II 	  	FORM AND EXECUTION OF SERIES DUE MAY 1, 2051	  	 	9	 
			
	 Section 2.01
	  	Series Due May 1, 2051	  	 	9	 
			
	 Section 2.02
	  	Redemption of Bonds	  	 	10	 
			
	 Section 2.03
	  	Surrender	  	 	11	 
			
	 Section 2.04
	  	Taxes and Governmental Charges	  	 	11	 
			
	 Section 2.05
	  	Book-Entry System	  	 	11	 
			
	ARTICLE III 	  	APPOINTMENT OF AUTHENTICATING AGENT	  	 	14	 
			
	 Section 3.01
	  	Appointment of Agent or Agents for Bonds of Series due May 1, 2051	  	 	14	 
			
	 Section 3.02
	  	Concerning the Agent	  	 	14	 
			
	 Section 3.03
	  	Form of Alternate Certificate of Authentication	  	 	15	 
			
	 Section 3.04
	  	Limit on Location and Number of Agents	  	 	15	 
			
	ARTICLE IV 	  	FINANCING STATEMENT TO COMPLY WITH THE UNIFORM COMMERCIAL CODE	  	 	16	 
			
	 Section 4.01
	  	Names and Addresses of Debtor and Securing Party	  	 	16	 
			
	 Section 4.02
	  	Property Subject to Lien	  	 	16	 
			
	 Section 4.03
	  	Maturity Dates and Principal Amounts of Obligations Secured	  	 	16	 
			
	 Section 4.04
	  	Financing Statement Adopted for all First Mortgage Bonds Listed in Section 4.03	  	 	16	 
			
	 Section 4.05
	  	Recording Data for the Indenture	  	 	17	 
			
	 Section 4.06
	  	Mortgage Bonds	  	 	17	 


  
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 TABLE OF CONTENTS 

(continued) 
  


							
	 	  	 	  	Page	 
			
	 ARTICLE V 
	  	 MISCELLANEOUS
	  	 	17	 
			
	 Section 5.01
	  	Recitals of Fact, Except as Stated, are Statements of the Company	  	 	17	 
			
	 Section 5.02
	  	Supplemental Trust Indenture to be Construed as Part of the Indenture	  	 	18	 
			
	 Section 5.03
	  	Trust Indenture Act and Severability	  	 	18	 
			
	 Section 5.04
	  	Indenture	  	 	18	 
			
	 Section 5.05
	  	References to Either Party in Supplemental Trust Indenture Include Successors or Assigns	  	 	18	 
			
	 Section 5.06
	  	Counterparts and Headings	  	 	18	 

 Schedule A – Properties 

  
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 Supplemental Trust Indenture, made effective as of the 18th day of May, 2020, by and between NORTHERN STATES POWER COMPANY, a corporation duly organized and existing under and by virtue of the laws of the State of Wisconsin, having its principal office in
the City of Eau Claire, Wisconsin (the “Company”), party of the first part, and U.S. BANK NATIONAL ASSOCIATION, a national banking association organized and existing under and by virtue of the laws of the United States of America, having
its principal office in the City of St. Paul, Minnesota, as successor trustee (the “Trustee”), party of the second part; 

WITNESSETH: 

WHEREAS, the Company, has heretofore executed and delivered to the Trustee its Trust Indenture, made as of April 1, 1947
(the “1947 Indenture”), whereby the Company granted, bargained, sold, warranted, released, conveyed, assigned, transferred, mortgaged, pledged, set over and confirmed to the Trustee, and to its respective successors in trust, all property,
real, personal and mixed then owned or thereafter acquired or to be acquired by the Company (except as therein excepted from the lien thereof) and subject to the rights reserved by the Company in and by the provisions of the 1947 Indenture, to be
held by said Trustee in trust in accordance with the provisions of the 1947 Indenture for the equal pro rata benefit and security of all and every of the bonds issued and to be issued thereunder in accordance with the provisions thereof; and 

WHEREAS, the Indenture (as defined below) provides that bonds may be issued thereunder in one or more series, each series to
have such distinctive designation as the Board of Directors of the Company may select for such series; and 
 WHEREAS, the
Company heretofore has executed and delivered to the Trustee the following additional Supplemental Trust Indentures which, in addition to conveying, assigning, transferring, mortgaging, pledging, setting over and confirming to the Trustee, and its
respective successors in said trust, additional property acquired by it subsequent to the preparation of the next preceding Supplemental Trust Indenture and adding to the covenants, conditions and agreements of the Indenture certain additional
covenants, conditions and agreements to be observed by the Company, created the following series of First Mortgage Bonds: 













			
	 Date of Supplemental

Trust Indenture
	  	 Designation of Series

		
	March 1, 1949	  	Series due March 1, 1979 (retired)
	June 1, 1957	  	Series due June 1, 1987 (retired)
	August 1, 1964	  	Series due August 1, 1994 (redeemed)
	December 1, 1969	  	Series due December 1, 1999 (redeemed)
	September 1, 1973	  	Series due October 1, 2003 (redeemed)
	February 1, 1982	  	Pollution Control Series A (redeemed)
	March 1, 1982	  	Series due March 1, 2012 (redeemed)
	June 1, 1986	  	Series due July 1, 2016 (redeemed)
	March 1, 1988	  	Series due March 1, 2018 (redeemed)
	April 1, 1991	  	Series due April 1, 2021 (redeemed)
	March 1, 1993	  	Series due March 1, 2023 (redeemed)
	October 1, 1993	  	Series due October 1, 2003 (retired)
	December 1, 1996	  	Series due December 1, 2026 (redeemed)
	September 1, 2003	  	Series A due October 1, 2018, and Series B due October 1, 2018 (redeemed)
	September 1, 2008	  	Series due September 1, 2038
	October 1, 2012	  	Series due October 1, 2042
	June 1, 2014	  	Series due June 15, 2024
	November 1, 2017	  	Series due December 1, 2047
	September 1, 2018	  	Series due September 1, 2048

 WHEREAS, the 1947 Indenture and all of the foregoing Supplemental Trust Indentures are referred
to herein collectively as the “Original Indenture”; and 
 WHEREAS, the Company heretofore has executed and
delivered to the Trustee a Supplemental and Restated Trust Indenture, dated March 1, 1991 (the “Restated Indenture”), which, in addition to conveying, assigning, transferring, mortgaging, pledging, setting over and confirming to the
Trustee, and its respective successors in said trust, additional property acquired by it subsequent to the preparation of the next preceding Supplemental Trust Indenture, amended and restated the Original Indenture (except for those Supplemental
Trust Indentures executed after March 1, 1991); and 
 WHEREAS, the Restated Indenture became effective and operative on
October 1, 1993; and 
 WHEREAS, the Original Indenture, the Restated Indenture and all trust indentures supplemental
thereto are referred to herein collectively as the “Indenture” and certain capitalized terms defined in Section 1.03 of the Restated Indenture are used with the same meanings herein; and 

  
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 WHEREAS, the Company is desirous of providing for the creation under the
Indenture of a new series of First Mortgage Bonds, said new series of bonds to be designated “First Mortgage Bonds, Series due May 1, 2051” the bonds of said series to be issued as registered bonds without coupons in denominations of
a multiple of $2,000 and integral multiples of $1,000 in excess thereof, and the bonds of said series to be substantially in the following form: 

(Form of Bonds of Series due May 1, 2051) 

NORTHERN STATES POWER COMPANY 

(Incorporated under the laws of the State of Wisconsin) 

First Mortgage Bond 
 Series due
May 1, 2051 
 CUSIP 665789 BB8 
  

			
	 No. _______________
	  	$________________

 [Unless this certificate is presented by an authorized representative of The Depository Trust Company, a New
York corporation, to the Company or its agent for registration of transfer, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized representative of The
Depository Trust Company (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of The Depository Trust Company), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR
TO ANY PERSON IS WRONGFUL since the registered owner hereof, Cede & Co., has an interest herein.]* 

EXCEPT UNDER THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE, THIS GLOBAL BOND MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE
DEPOSITORY OR BY A NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY, ANOTHER NOMINEE OF THE DEPOSITORY, A SUCCESSOR OF THE DEPOSITORY OR A NOMINEE OF SUCH SUCCESSOR.* 

NORTHERN STATES POWER COMPANY, a corporation organized and existing under and by virtue of the laws of the State of Wisconsin (the
“Company”), for value received, hereby promises to pay to _________ or its registered assigns, at the office of the Trustee in St. Paul, Minnesota, the sum of _________ Dollars in lawful money of the United States of America, on the 1st day of May 2051, and to pay interest hereon from the date hereof at the rate of 3.05 percent per annum, in like money, until the principal hereof becomes due and payable; said interest being
payable to the person entitled to such interest at the office of U.S. Bank National Association in St. Paul, Minnesota on the 1st day of May and on the 1st day of November in each year, commencing November 1, 2020; provided that at the option of the Company payment of interest may be made by wire transfer to the person entitled thereto if such
person has provided proper wire transfer instructions or by check mailed to the address of such person as such address shall appear in the Bond Register maintained by the Trustee; provided further that as long as there is no existing default in the
payment of interest and except for the payment of defaulted interest, the interest payable on any May 1 or November 1 will be paid to the person in whose name this bond was registered at the close of business on the record date (the
April 15 prior to such May 1 or October 15 prior to such November 1 (whether or not a business day)). If any interest payment date or date on which the principal of this bond is required to be paid is not a 

 

	* 	 This legend to be included if the bonds are issued as a global bond in book-entry form.




  
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business day, then payment of principal, premium or interest need not be made on such date but may be made on the next succeeding business day with the same force and effect as if made on such
interest payment date or date on which the principal of this bond is required to be paid and, in the case of timely payment thereof, no interest shall accrue for the period from and after such interest payment date or the date on which the principal
of this bond is required to be paid. The term “business day” shall mean any day other than a Saturday or Sunday or a day on which the offices of the Trustee in the City of St. Paul, Minnesota are closed pursuant to authorization of
law. 
 This bond is one of a duly authorized issue of bonds of the Company, known as its First Mortgage Bonds, of the series and
designation indicated on the face hereof, which issue of bonds consists, or may consist, of several series of varying denominations, dates and tenor, all issued and to be issued under and equally secured (except insofar as a sinking fund, or similar
fund, established in accordance with the provisions of the Indenture may afford additional security for the bonds of any specific series) by a Trust Indenture dated April 1, 1947 (the “1947 Indenture”), as supplemented by 19
supplemental trust indentures (collectively, the “Supplemental Trust Indentures”), a Supplemental and Restated Trust Indenture dated March 1, 1991 (the “Restated Indenture”) and a new supplemental trust indenture for the
bonds of this series (the “Supplemental Trust Indenture”), all of which instruments are herein collectively called the “Indenture,” executed by the Company to U.S. Bank National Association, as successor trustee (the
“Trustee”). The Restated Indenture amends and restates the 1947 Indenture and certain of the Supplemental Trust Indentures and became effective and operative on October 1, 1993. Certain capitalized terms defined in the Indenture are
used with the same meanings herein. Reference is made to the Indenture for a complete description of its terms. Reference hereby is made to the Indenture for a description of the property mortgaged and pledged, the nature and extent of the security,
the rights of the registered holders of the bonds as to such security and the terms and conditions upon which the bonds may be issued under the Indenture and are secured. The principal hereof may be declared or may become due on the conditions, in
the manner and at the time set forth in the Indenture upon the happening of a Completed Default as provided in the Indenture. 
 With the
consent of the Company and to the extent permitted by and as provided in the Indenture, the rights and obligations of the Company and of the registered holders of the bonds and the terms and provisions of the Indenture and of any instruments
supplemental thereto may be modified or altered by the affirmative vote of the registered holders of at least 66 2/3% in principal amount of the bonds then outstanding under the Indenture and any instruments supplemental thereto (excluding bonds
disqualified from voting by reason of the interest of the Company or of certain related persons therein as provided in the Indenture); provided that without the consent of all registered holders of all bonds affected no such modification or
alteration shall permit the extension of the maturity of the principal of any bond or the reduction in the rate of interest hereon or any other modification in the terms of payment of such principal or interest. 

The Company and the Trustee may deem and treat the person in whose name this bond is registered as the absolute owner hereof for the purpose
of receiving payment of or on account of the principal hereof and interest hereon and for all other purposes and shall not be affected by any notice to the contrary. 

  
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 At any time prior to November 1, 2050 (which is the date that is six months prior to
the maturity of the bonds of this series (the “Par Call Date”)), the Company may redeem, in whole or in part, the bonds of this series, on any date upon not less than 30 days’ previous notice to be given in the manner and with the
effect provided in Section 10.02 of the Indenture, at a redemption price equal to the greater of (i) 100% of the principal amount of such bonds of this series being redeemed and (ii) the sum of the present values of the remaining scheduled
payments of principal and interest on the bonds of this series being redeemed that would be due if such bonds matured on the Par Call Date (excluding the portion of any such accrued and unpaid interest to but excluding the date fixed for
redemption), discounted to but excluding the date fixed for redemption on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the
Treasury Rate (as defined below) plus 30 basis points plus, in each case, accrued and unpaid interest thereon to but excluding the date fixed for redemption. 

At any time on or after the Par Call Date, the Company may redeem, in whole or in part, the bonds of this series, at 100% of the principal
amount being redeemed plus accrued and unpaid interest thereon to but excluding the date fixed for redemption. 
 “Comparable Treasury
Issue” means the U.S. Treasury security selected by an Independent Investment Banker as having a maturity comparable to the remaining term of the bonds being redeemed (assuming, for this purpose, that the bonds of this series matured on the Par
Call Date) that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of the bonds being redeemed. 

“Comparable Treasury Price” means with respect to any redemption date of the bonds of this series (1) the average of the
Reference Treasury Dealer Quotations for such date fixed for redemption, after excluding the highest and lowest of such Reference Treasury Dealer Quotations for such date fixed for redemption, or (2) if the Independent Investment Banker obtains
fewer than four of such Reference Treasury Dealer Quotations for the date fixed for redemption, the average of all of such Reference Treasury Dealer Quotations for the date fixed for redemption. 

“Independent Investment Banker” means one of the Reference Treasury Dealers or their respective successors or, if such firms or
their respective successors are unwilling or unable to select the Comparable Treasury Issue, an independent investment banking institution of national standing appointed by the Company. 

“Primary Treasury Dealer” means any primary U.S. Government securities dealer in the United States. 

“Reference Treasury Dealer” means (1) Mizuho Securities USA LLC, or its affiliates or successors, provided, however, that if
any of the foregoing ceases to be a Primary Treasury Dealer, the Company will appoint another Primary Treasury Dealer as a substitute and (2) any other Primary Treasury Dealers selected by the Company after consultation with an Independent
Investment Banker. 

  
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 “Reference Treasury Dealer Quotations” means, for any Reference Treasury Dealer
and any date fixed for redemption, the average, as determined by an Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to an
Independent Investment Banker by the Reference Treasury Dealer at 5:00 p.m., Eastern time, on the third business day preceding the date fixed for redemption. 

“Treasury Rate” means, with respect to any date fixed for redemption, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such date fixed for redemption. The Treasury Rate
will be calculated on the third business day preceding the date fixed for redemption. 
 This bond is transferable as prescribed in the
Indenture by the registered holder hereof in person, or by his duly authorized attorney, at the office of the Trustee in St. Paul, Minnesota, or elsewhere if authorized by the Company, upon surrender and cancellation of this bond, and thereupon a
new bond or bonds of the same series and of a like aggregate principal amount will be issued to the transferee in exchange therefor as provided in the Indenture, upon payment of taxes or other governmental charges, if any, that may be imposed in
relation thereto. 
 Bonds of this series are interchangeable as to denominations in the manner and upon the conditions prescribed in the
Indenture. 
 No charge shall be made by the Company for any exchange or transfer of bonds of this series, other than for taxes or other
governmental charges, if any, that may be imposed in relation thereto. 
 The Company shall not be required to issue, transfer or exchange
any bond of this series during a period of 15 days immediately preceding any selection of bonds of this series to be redeemed. The Company shall not be required to transfer or exchange any bond of this series called or being called for redemption in
its entirety or to transfer or exchange the called portion of a bond of this series which has been called for partial redemption. 
 No
recourse shall be had for the payment of the principal of or any premium or the interest on this bond, or any part thereof, or of any claim based hereon or in respect hereof or of said Indenture, against any incorporator, or any past, present or
future shareholder, officer or director of the Company or of any predecessor or successor corporation, either directly or through the Company, or through any such predecessor or successor corporation, or through any receiver or a trustee in
bankruptcy, whether by virtue of any constitution, statute or rule of law or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof,
expressly waived and released, as more fully provided in the Indenture. 
 This bond shall not be valid or become obligatory for any purpose
unless and until the certificate of authentication hereon shall have been signed by or on behalf of U.S. Bank National Association, as successor Trustee under the Indenture, or its successor thereunder. 

  
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 IN WITNESS WHEREOF, NORTHERN STATES POWER COMPANY has caused this bond to be signed in its
name by its President or a Vice President and its corporate seal, or a facsimile thereof, to be hereto affixed and attested by its Secretary or an Assistant Secretary. 
  

									
	Dated: ____________	 		 	NORTHERN STATES POWER COMPANY
					
	Attest:	 	[Form-Not for Signature]	 		 	By:	 	[Form-Not for Signature]
		 		 		 		 	[Vice] President

 (Form of Trustee’s Certificate) 

This bond is one of the bonds of the series designated thereon, described in the within-mentioned
Indenture. 
  

			
	U.S. BANK NATIONAL ASSOCIATION, as Trustee
		
	By:	 	[Form-Not for Signature]
		 	Authorized Officer


 and 

WHEREAS, the Company is desirous of conveying, assigning, transferring, mortgaging, pledging, setting over and confirming to
the Trustee and to its respective successors in trust, additional property that was not expressly described in the Original Indenture, in the Restated Indenture or in any previous Supplemental Trust Indenture; and 

WHEREAS, the Indenture provides in substance that the Company and the Trustee may enter into indentures supplemental thereto
for the purposes, among others, of creating and setting forth the terms of any new series of bonds and of conveying, assigning, transferring, mortgaging, pledging, setting over and confirming to the Trustee additional property of the Company, and
for any other purpose not inconsistent with the terms of the Indenture; and 
 WHEREAS, the execution and delivery of this
Supplemental Trust Indenture have been duly authorized by a resolution adopted by the Board of Directors or a Committee of the Board of Directors of the Company; and 

WHEREAS, the Trustee has duly determined to execute this Supplemental Trust Indenture and to be bound, insofar as it may
lawfully do so, by the provisions hereof; 
 NOW, THEREFORE, Northern States Power Company, in consideration
of the premises and of one dollar duly paid to it by the Trustee at or before the ensealing and delivery of these presents, the receipt of which is hereby acknowledged, and other good and valuable considerations, does hereby covenant and agree to
and with U.S. Bank National Association, as Trustee, and its successors in the trust under the Indenture for the benefit of the registered holders of the bonds, or any of them, issued or to be issued thereunder, as follows: 

  
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 ARTICLE I 

SPECIFIC SUBJECTION OF ADDITIONAL PROPERTY 

TO THE LIEN OF THE INDENTURE 

SECTION 1.01. The Company, in order to better secure the payment, of both the principal and interest, of all bonds of the Company at any
time outstanding under the Indenture according to their tenor and effect and the performance of and compliance with the covenants and conditions contained in the Indenture, has granted, bargained, sold, warranted, released, conveyed, assigned,
transferred, mortgaged, pledged, set over and confirmed, and by these presents does grant, bargain, sell, warrant, release, convey, assign, transfer, mortgage, pledge, set over and confirm, unto U.S. Bank National Association, as Trustee, and to its
respective successors in said trust forever, subject to the rights reserved by the Company in and by the provisions of the Indenture, all of the property described and mentioned or enumerated in the schedule annexed hereto and marked Schedule A,
reference to said schedule being made hereby with the same force and effect as if the same were incorporated herein at length; together with all and singular the tenements, hereditaments and appurtenances belonging and in any way appertaining to the
aforesaid property or any part thereof with the reversion and reversions, remainder and remainders, tolls, rents and revenues, issues, income, products and profits thereof; 

Also, in order to subject the personal property and chattels of the Company to the Lien of the Indenture and in conformity with the provisions
of the Uniform Commercial Code, all fossil, nuclear, hydro and other electric generating plants, including buildings and other structures, turbines, generators, boilers, reactors, nuclear fuel, other boiler plant equipment, condensing equipment and
all other generating equipment; substations; electric transmission and distribution systems, including structures, poles, towers, fixtures, conduits, insulators, wires, cables, transformers, services and meters; steam heating mains and equipment;
gas transmission and distribution systems, including structures, storage facilities, mains, compressor stations, purifier stations, pressure holders, governors, services and meters; office, shop and other buildings and structures, furniture and
equipment; apparatus and equipment of all other kinds and descriptions; all municipal and other franchises, all leaseholds, licenses, permits, privileges and patent rights, parts or parcels of such real property; all as now owned or hereafter
acquired by the Company pursuant to the provisions of the Indenture; 
 All the estate, right, title and interest and claim whatsoever, at
law as well as in equity, that the Company now has or hereafter may acquire in and to the aforesaid property and franchises and every part and parcel thereof; excluding, however, (1) all shares of stock, bonds, notes, evidences of indebtedness
and other securities other than such as may be or are required to be deposited from time to time with the Trustee in accordance with the provisions of the Indenture; (2) cash on hand and in banks other than such as may be or is required to be
deposited from time to time with the Trustee in accordance with the provisions of the Indenture; (3) contracts, claims, bills and accounts receivable and choses in action other than such as may be or are required to be assigned to the Trustee
in accordance with the provisions of the Indenture; (4) motor vehicles; (5) any stock of goods, wares and merchandise, equipment and supplies acquired for the purpose of sale or lease in the usual course of business or for the purpose of
consumption in the operation, construction or repair of any of the properties of the Company; and (6) the properties described in Schedule B annexed to the 1947 Indenture; 

  
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 To have and to hold all said property, real, personal and mixed, mortgaged, pledged or
conveyed by the Company as aforesaid, or intended so to be, to the Trustee and its successors and assigns forever, subject, however, to Permitted Encumbrances and to the further reservations, covenants, conditions, uses and trusts set forth
in the Indenture; in trust nevertheless for the same purposes and upon the same conditions as are set forth in the Indenture. 
 ARTICLE II

 FORM AND EXECUTION OF SERIES DUE MAY 1, 2051 

SECTION 2.01. There is hereby created, for issuance under the Indenture, a series of bonds designated Series due May 1, 2051, each
of which shall bear the descriptive title “First Mortgage Bonds, Series due May 1, 2051,” (such bonds, the “Series 2051 Bonds”) and the form thereof shall contain suitable provisions with respect to the matters specified in
this Section 2.01. The bonds of said series shall be substantially of the tenor and purport hereinbefore recited. The bonds of said series shall initially be authenticated and delivered in the aggregate principal amount of $100,000,000. The
bonds of said series may be reopened and additional bonds of said series may be issued in excess of the amount initially authenticated and delivered, provided that such additional bonds of said series will contain the same terms (including the
maturity date and interest payment terms) as the other bonds of said series, except for the price to the public, the issue date and, if applicable, the first interest accrual and payment dates. Any such additional bonds of said series, together with
the bonds of said series initially authenticated, shall constitute a single series for purposes of the Indenture and shall be limited to an aggregate principal amount of $750,000,000. The bonds of said series shall mature on May 1, 2051, and
shall be issued as registered bonds without coupons in denominations of a multiple of $2,000 and integral multiples of $1,000 in excess thereof. The bonds of said series shall bear interest at the rate of 3.05% per annum payable semi-annually on
May 1 and November 1 of each year commencing November 1, 2020, and the principal shall be payable at the office of the Trustee in St. Paul, Minnesota, in lawful money of the United States of America, and the interest shall be payable
in like money to the person entitled to such interest at said office of the Trustee in St. Paul, Minnesota, provided that at the option of the Company payment of interest may be made by wire transfer to the person entitled thereto if such person has
provided proper wire transfer instructions or by check mailed to the address of such person as such address shall appear in the Bond Register maintained by the Trustee. Interest on the Series 2051 Bonds shall be calculated on the basis of a 360-day year consisting of twelve 30-day months. If any interest payment date or date on which the principal of the Series 2051 Bonds is required to be paid is not a business
day, then payment of principal, premium or interest need not be made on such date but may be made on the next succeeding business day with the same force and effect as if made on such interest payment date or date on which the principal of the
Series 2051 Bonds is required to be paid and, in the case of timely payment thereof, no interest shall accrue for the period from and after such interest payment date or the date on which the principal of the Series 2051 Bonds is required to be
paid. The Series 2051 Bonds shall be dated as of the date of authentication thereof by the Trustee. 
 As long as there is no existing
default in the payment of interest on the Series 2051 Bonds, the person in whose name any Series 2051 Bond is registered at the close of business on any Regular Record Date with respect to any interest payment date shall be entitled to receive the
interest payable on such interest payment date notwithstanding any transfer or exchange of such Series 2051 Bond subsequent to the Regular Record Date and on or prior to such interest payment date. Defaulted Interest shall be paid by the Company as
provided in Section 2.03 of the Indenture. 

  
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 The term “Regular Record Date” as used herein with respect to any interest payment
date (May 1 or November 1) shall mean the April 15 prior to such May 1 or October 15 prior to such November 1 (whether or not a business day). The term “business day” as used in this Section 2.01 shall mean any day
other than a Saturday or Sunday or a day on which the offices of the Trustee in the City of St. Paul, Minnesota are closed pursuant to authorization of law. 

SECTION 2.02. At any time prior to November 1, 2050 (which is the date that is six months prior to the maturity of the Series 2051
Bonds (the “Par Call Date”)), the Company may redeem, in whole or in part, the Series 2051 Bonds, on any date upon not less than 30 days’ previous notice to be given in the manner and with the effect provided in Section 10.02 of
the Indenture, at a redemption price equal to the greater of (i) 100% of the principal amount of such Series 2051 Bonds being redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest on the
Series 2051 Bonds being redeemed that would be due if such Bonds matured on the Par Call Date (excluding the portion of any such accrued and unpaid interest to but excluding the date fixed for redemption), discounted to but excluding the date fixed
for redemption on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate (as defined below) plus 30 basis points, plus, in
each case, accrued and unpaid interest thereon to but excluding the date fixed for redemption. At any time on or after the Par Call Date, the Company may redeem, in whole or in part, the Series 2051 Bonds at 100% of the principal amount being
redeemed plus accrued and unpaid interest thereon to but excluding the date fixed for redemption. 
 “Comparable Treasury Issue”
means the U.S. Treasury security selected by an Independent Investment Banker as having a maturity comparable to the remaining term of the bonds being redeemed (assuming, for this purpose, that the Series 2051 Bonds matured on the Par Call Date)
that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of the Series 2051 Bonds being redeemed. 

“Comparable Treasury Price” means with respect to any redemption date of the Series 2051 Bonds (1) the average of the Reference
Treasury Dealer Quotations for such date fixed for redemption, after excluding the highest and lowest of such Reference Treasury Dealer Quotations for such date fixed for redemption, or (2) if the Independent Investment Banker obtains fewer
than four of such Reference Treasury Dealer Quotations for the date fixed for redemption, the average of all of such Reference Treasury Dealer Quotations for the date fixed for redemption. 

“Independent Investment Banker” means one of the Reference Treasury Dealers or their respective successors or, if such firms or
their respective successors are unwilling or unable to select the Comparable Treasury Issue, an independent investment banking institution of national standing appointed by the Company. 

  
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 “Primary Treasury Dealer” means any primary U.S. Government securities dealer in
the United States. 
 “Reference Treasury Dealer” means (1) Mizuho Securities USA LLC, or its affiliates or successors,
provided, however, that if any of the foregoing ceases to be a Primary Treasury Dealer, the Company will appoint another Primary Treasury Dealer as a substitute and (2) any other Primary Treasury Dealers selected by the Company after
consultation with an Independent Investment Banker. 
 “Reference Treasury Dealer Quotations” means, for any Reference Treasury
Dealer and any date fixed for redemption, the average, as determined by an Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in
writing to an Independent Investment Banker by the Reference Treasury Dealer at 5:00 p.m., Eastern time, on the third business day preceding the date fixed for redemption. 

“Treasury Rate” means, with respect to any date fixed for redemption, the rate per annum equal to the semi-annual equivalent yield
to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such date fixed for redemption. The Treasury Rate
will be calculated on the third business day preceding the date fixed for redemption. 
 The Series 2051 Bonds are not subject to a sinking
fund. 
 The redemption prices of the Series 2051 Bonds need not be specified in any temporary bond of said series if an appropriate
reference be made in said temporary bond to the provision of this Section 2.02. 
 SECTION 2.03. The registered owner of any
Series 2051 Bond or Bonds at his, her or its option may surrender the same at the office of the Trustee in St. Paul, Minnesota, or elsewhere if authorized by the Company, for cancellation, in exchange for other bonds of the said series of the same
aggregate principal amount, bearing interest as provided in Section 2.01 hereof thereupon, and upon receipt of any payment required under the provisions of Section 2.04 hereof, the Company shall execute and deliver to the Trustee and the
Trustee shall authenticate and deliver such other registered bonds to such registered holder at its office or at any other place specified as aforesaid. 

SECTION 2.04. No charge shall be made by the Company for any exchange or transfer of the Series 2051 Bonds other than for taxes or other
governmental charges, if any, that may be imposed in relation thereto. 
 SECTION 2.05. (a) Except as provided in subsections
(c) and (g) of this Section 2.05, the registered holder of all of the Series 2051 Bonds shall be The Depository Trust Company (“DTC”) and such Series 2051 Bonds shall be registered in the name of Cede & Co., as nominee
for DTC. Payment of principal of, premium, if any, and interest on any Series 2051 Bonds registered in the name of Cede & Co. shall be made by transfer of New York Federal or equivalent immediately available funds with respect to the Series
2051 Bonds to the account of Cede & Co. on each such payment date for the Series 2051 Bonds at the address indicated for Cede & Co. in the Bond Register kept by the Trustee. 

  
 11 













 (b) The Series 2051 Bonds shall be initially issued in the form of one or more separate
single authenticated fully registered certificates in the aggregate principal amount of the Series 2051 Bonds. Upon initial issuance, the ownership of such Series 2051 Bonds shall be registered in the Bond Register kept by the Trustee in the name of
Cede & Co., as nominee of DTC. The Trustee and the Company may treat DTC (or its nominee) as the sole and exclusive registered holder of the Series 2051 Bonds registered in its name for the purposes of payment of the principal of, premium,
if any, and interest on the Series 2051 Bonds and of giving any notice permitted or required to be given to registered holders under the Indenture, except as provided in Subsection 2.05(g) below; and neither the Trustee nor the Company shall be
affected by any notice to the contrary. Neither the Trustee nor the Company shall have any responsibility or obligation to any of DTC’s participants (each a “Participant”), any person claiming a beneficial ownership in the Series 2051
Bonds under or through DTC or any Participant (each a “Beneficial Owner”), or any other person that is not shown on the Bond Register maintained by the Trustee as being a registered holder, with respect to (1) the accuracy of any
records maintained by DTC or any Participant; (2) the payment of DTC or any Participant of any amount in respect of the principal of, premium, if any, or interest on the Series 2051 Bonds; (3) the delivery by DTC or any Participant of any
notice to any Beneficial Owner which is permitted or required to be given to registered holders under the Indenture of the Series 2051 Bonds; (4) the selection of the Beneficial Owners to receive payment in the event of any partial redemption
of the Series 2051 Bonds; or (5) any consent given or other action taken by DTC as bondholder. The Trustee shall pay all principal of, premium, if any, and interest on the Series 2051 Bonds registered in the name of Cede & Co. only to
or “upon the order of” (as that term is used in the Uniform Commercial Code as adopted in Wisconsin and New York) DTC, and all such payments shall be valid and effective to fully satisfy and discharge the Company’s obligations with
respect to the principal of, premium, if any, and interest on such Series 2051 Bonds to the extent of the sum or sums so paid. Except as otherwise provided in Subsections 2.05(c) and (g) below, no person other than DTC shall receive
authenticated bond certificates evidencing the obligation of the Company to make payments of principal of, premium, if any, and interest on the Series 2051 Bonds. Upon delivery by DTC to the Trustee of written notice to the effect that DTC has
determined to substitute a new nominee in place of Cede & Co., and subject to the provisions of the Indenture with respect to transfers of bonds, the word “Cede & Co.” in this Supplemental Trust Indenture shall refer to
such new nominee of DTC. 
 (c) If the Company in its discretion determines that it is in the best interest of the Beneficial Owners that
they be able to obtain bond certificates for the Series 2051 Bonds or there shall have occurred and be continuing a Completed Default with respect to the Series 2051 Bonds, the Company may notify DTC and the Trustee, whereupon DTC will notify the
Participants of the availability through DTC of bond certificates. In such event, the Trustee shall issue, transfer and exchange bond certificates as requested by DTC in appropriate amounts pursuant to Article II of the Indenture and
Section 2.03 of this Supplemental Trust Indenture. The Company shall pay all costs in connection with the production of bond certificates if the Company makes such a determination under this Subsection 2.05(c). DTC may determine to discontinue
providing its services with respect to the Series 2051 Bonds at any time by giving written notice to the Company and the Trustee and discharging its responsibilities with respect 

  
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thereto under applicable law. Under such circumstances (if there is no successor book-entry depository), the Company and the Trustee shall be obligated (at the sole cost and expense of the
Company) to deliver bond certificates as described in this Supplemental Trust Indenture. If bond certificates are issued, the provisions of the Indenture shall apply to, among other things, the transfer and exchange of such certificates and the
method of payment of principal of, premium, if any, and interest on such certificates. Whenever DTC requests the Company and the Trustee to do so, the Company will direct the Trustee (at the sole cost and expense of the Company) to cooperate with
DTC in taking appropriate action after reasonable notice (1) to make available one or more separate certificates evidencing the Series 2051 Bonds to any Participant or (2) to arrange for another book-entry depository to maintain custody of
certificates evidencing the Series 2051 Bonds registered in the name of such depository or its nominee. Any successor book-entry depository must be a clearing agency registered with the Securities and Exchange Commission pursuant to Section 17A
of the Securities Exchange Act of 1934, as amended, and must enter into an agreement with the Company and the Trustee agreeing to act as the depository and clearing agency for the Series 2051 Bonds (except as provided in Subsection 2.05(g) below).
After such agreement has become effective, DTC shall present the Series 2051 Bonds for registration of transfer in accordance with Section 2.11 of the Indenture, and the Trustee shall register them in the name of the successor book-entry
depository or its nominee and all references thereafter to DTC shall be to such successor book-entry depository. If a successor book-entry depository has not accepted such position before the effective date of DTC’s termination of its services,
the book-entry system shall automatically terminate and may not be reinstated without the consent of all registered holders of the Series 2051 Bonds. 

(d) Notwithstanding any other provision of this Supplemental Trust Indenture to the contrary, so long as any Series 2051 Bonds are registered
in the name of Cede & Co., as nominee of DTC, all payments with respect to the principal of, premium, if any, and interest on such Series 2051 Bonds and all notices with respect to such Series 2051 Bonds shall be made and given,
respectively, to DTC as provided in the blanket representation letter among DTC, the Company and the Trustee. The Trustee is hereby authorized and directed to comply with all terms of the representation letter. 

(e) In connection with any notice or other communication to be provided pursuant to the Indenture for the Series 2051 Bonds by the Company or
the Trustee with respect to any consent or other action to be taken by the registered holders of the Series 2051 Bonds, the Company or the Trustee, as the case may be, shall seek to establish a record date to the extent permitted by the Indenture
for such consent or other action and give DTC notice of such record date not less than fifteen (15) calendar days in advance of such record date to the extent possible. Such notice to DTC shall be given only when DTC is the sole registered
holder. 
 (f) NEITHER THE COMPANY NOR THE TRUSTEE WILL HAVE ANY RESPONSIBILITY OR OBLIGATIONS TO THE PARTICIPANTS OR THE BENEFICIAL OWNERS
WITH RESPECT TO (1) THE ACCURACY OF ANY RECORDS MAINTAINED BY DTC OR ANY PARTICIPANT; (2) THE PAYMENT BY DTC OR ANY PARTICIPANT OF ANY AMOUNT DUE TO ANY BENEFICIAL OWNER IN RESPECT OF THE PRINCIPAL OF, PREMIUM, IF ANY, OR INTEREST ON THE
SERIES 2051 BONDS; (3) THE DELIVERY BY DTC OR ANY PARTICIPANT OF ANY NOTICE TO ANY BENEFICIAL OWNER WHICH IS REQUIRED OR PERMITTED UNDER THE TERMS OF 

  
 13 













 THE INDENTURE TO BE GIVEN TO REGISTERED HOLDERS; (4) THE SELECTION OF THE BENEFICIAL OWNERS TO RECEIVE
PAYMENT IN THE EVENT OF ANY PARTIAL REDEMPTION OF THE SERIES 2051 BONDS; OR (5) ANY CONSENT GIVEN OR OTHER ACTION TAKEN BY DTC AS A REGISTERED HOLDER. 

SO LONG AS CEDE & CO. IS THE REGISTERED HOLDER OF THE SERIES 2051 BONDS AS NOMINEE OF DTC, REFERENCES HEREIN TO REGISTERED HOLDERS OF
THE SERIES 2051 BONDS SHALL MEAN CEDE & CO. AND SHALL NOT MEAN THE BENEFICIAL OWNERS OF THE SERIES 2051 BONDS NOR THE PARTICIPANTS. 

(g) The Company, in its sole discretion, may terminate the services of DTC with respect to the Series 2051 Bonds if the Company determines
that: (i) DTC (x) is unable to discharge its responsibilities with respect to the Series 2051 Bonds or (y) at any time ceases to be a clearing agency registered under the Securities Exchange Act of 1934, as amended; or (ii) there
shall have occurred and be continuing a Completed Default with respect to the Series 2051 Bonds. The Company, in its sole discretion, may terminate the services of DTC with respect to the Series 2051 Bonds if the Company determines that a
continuation of the requirement that all of the outstanding Series 2051 Bonds be registered with the registration books kept by the Trustee in the name of Cede & Co., as nominee of DTC, is not in the best interest of the Beneficial Owners
of the Series 2051 Bonds. After such event and if no substitute book-entry depository is appointed by the Company, bond certificates will be delivered as described in the Indenture. 

(h) Upon the termination of the services of DTC with respect to the Series 2051 Bonds pursuant to subsections (c) or (g) of this
Section 2.05 after which no substitute book-entry depository is appointed, the Series 2051 Bonds shall be registered in whatever name or names registered holders transferring or exchanging the Series 2051 Bonds shall designate in accordance
with the provisions of the Indenture. 
 ARTICLE III 

APPOINTMENT OF AUTHENTICATING AGENT 

SECTION 3.01. The Trustee shall, if requested in writing to do so by the Company, promptly appoint an agent or agents of the Trustee who
shall have authority to authenticate registered Series 2051 Bonds in the name and on behalf of the Trustee. Such appointment by the Trustee shall be evidenced by a certificate of a vice-president of the Trustee delivered to the Company prior to the
effectiveness of such appointment. 
 SECTION 3.02. (a) Any such authenticating agent shall be acceptable to the Company and at
all times shall be a corporation which is organized and doing business under the laws of the United States or of any State, is authorized under such laws to act as authenticating agent, has a combined capital and surplus of at least $10,000,000 and
is subject to supervision or examination by federal or state authority. If such corporation publishes reports of condition at least annually, pursuant to law or to the requirements of the aforesaid supervising or examining authority, then for the
purposes of this Section 3.02, the combined capital and surplus of such corporation shall be deemed to be its combined capital and surplus as set forth in its most recent report of condition so published. 

  
 14 













 (b) Any corporation into which any authenticating agent may lawfully be merged or converted
or with which it may be consolidated, or any corporation resulting from any merger, conversion or consolidation to which any authenticating agent shall be a party, or any corporation succeeding to the corporate agency business of any authenticating
agent, shall continue to be the authenticating agent without the execution or filing of any paper or any further act on the part of the Trustee or the authenticating agent. 

(c) Any authenticating agent at any time may resign by giving written notice of resignation to the Trustee and to the Company. The Trustee may
at any time, and upon written request of the Company to the Trustee shall, terminate the agency of any authenticating agent by giving written notice of termination to such authenticating agent and to the Company. Upon receiving such a notice of
resignation or upon such a termination, or in case at any time any authenticating agent shall cease to be eligible in accordance with the provisions of this Section 3.02, the Trustee, unless otherwise requested in writing by the Company,
promptly shall appoint a successor authenticating agent, which shall be acceptable to the Company. Any successor authenticating agent upon acceptance of its appointment hereunder shall become vested with all the rights, powers, duties and
responsibilities of its predecessor hereunder, with like effect as if originally named. No successor authenticating agent shall be appointed unless eligible under the provisions of this Section 3.02. 

(d) The Trustee agrees to pay to any authenticating agent, appointed in accordance with the provisions of this Section 3.02, reasonable
compensation for its services, and the Trustee shall be entitled to be reimbursed for such payments. 
 SECTION 3.03. If an appointment
is made pursuant to this Article III, the registered Series 2051 Bonds shall have endorsed thereon, in addition to the Trustee’s Certificate, an alternate Trustee’s Certificate in the following form: 

This bond is one of the bonds of the Series designated thereon, described in the within-mentioned Indenture. 

 

			
	U.S. BANK NATIONAL ASSOCIATION, as Trustee
		
	By:	 	[Form-Not for Signature]
		 	Authenticating Agent
		
	By:	 	[Form-Not for Signature]
		 	Authorized Officer


 SECTION 3.04. No provision of this Article III shall require the Trustee to have at any time more
than one such authenticating agent for any one State or to appoint any such authenticating agent in the State in which the Trustee has its principal place of business. 

  
 15 













 ARTICLE IV 

FINANCING STATEMENT TO COMPLY WITH 

THE UNIFORM COMMERCIAL CODE 

SECTION 4.01. The name and address of the debtor and secured party are set forth below: 

 

			
	Debtor:	  	 Northern States Power Company
 c/o Dawn Schultz,
Siting & Land Rights 
Xcel Energy
 PO Box 8
 Eau
Claire, WI 54702-0008

		
	Secured Party:	  	 U.S. Bank National Association, as Trustee
 c/o
U.S. Bank Global Corporate Trust Services
 60 Livingston Avenue,
EP-MN-WS3C
 St. Paul, Minnesota 55107


 NOTE: Northern States Power Company, the debtor above named, is “a transmitting utility” under the
Uniform Commercial Code as adopted in Wisconsin and Michigan. 
 SECTION 4.02. Reference to Article I hereof is made for a description
of the property of the debtor covered by this Financing Statement with the same force and effect as if incorporated in this Section 4.02 at length. 

SECTION 4.03. The maturity dates and respective principal amounts of obligations of the debtor secured and presently to be secured by the
Indenture, reference to all of which for the terms and conditions thereof is hereby made with the same force and effect as if incorporated herein at length, are as follows: 
  

					
	 First Mortgage Bonds
	  	Principal Amount	 
	 Series due September 1, 2038
	  	$	200,000,000	 
	 Series due October 1, 2042
	  	$	100,000,000	 
	 Series due June 15, 2024
	  	$	200,000,000	 
	 Series due December 1, 2047
	  	$	100,000,000	 
	 Series due September 1, 2048
	  	$	200,000,000	 
	 Series due May 1, 2051
	  	$	100,000,000	 

 SECTION 4.04. This Financing Statement is hereby adopted for all of the First Mortgage Bonds of the
Series mentioned above secured by said Indenture. 

  
 16 













 SECTION 4.05. The 1947 Indenture, the Restated Indenture and the Supplemental Trust
Indentures, as set forth below, have been filed or recorded in each and every office in the States of Wisconsin and Michigan designated by law for the filing or recording thereof in respect of all property of the Company subject thereto: 

 

			
		
	 Original Indenture 
Dated April 1, 1947
	  	 Supplemental Trust Indenture 
Dated March 1, 1949

		
	 Supplemental Trust Indenture 
Dated June 1, 1957
	  	 Supplemental Trust Indenture 
Dated August 1, 1964

		
	 Supplemental Trust Indenture 
Dated December 1, 1969
	  	 Supplemental Trust Indenture 
Dated September 1, 1973

		
	 Supplemental Trust Indenture 
Dated February 1, 1982
	  	 Supplemental Trust Indenture 
Dated March 1, 1982

		
	 Supplemental Trust Indenture 
Dated June 1, 1986
	  	 Supplemental Trust Indenture 
Dated March 1, 1988

		
	 Supplemental and Restated Trust Indenture 
Dated March 1, 1991
	  	 Supplemental Trust Indenture 
Dated April 1, 1991

		
	 Supplemental Trust Indenture 
Dated March 1, 1993
	  	 Supplemental Trust Indenture 
Dated October 1, 1993

		
	 Supplemental Trust Indenture 
Dated December 1, 1996
	  	 Supplemental Trust Indenture 
Dated September 1, 2003

		
	 Supplemental Trust Indenture 
Dated September 1, 2008
	  	 Supplemental Trust Indenture 
Dated October 1, 2012

		
	 Supplemental Trust Indenture
Dated June 1, 2014
	  	 Supplemental Trust Indenture 
Dated November 1, 2017

		
	 Supplemental Trust Indenture 
Dated September 1, 2018
	  	

 SECTION 4.06. The property covered by this Financing Statement also shall secure additional series of
First Mortgage Bonds of the debtor that may be issued from time to time in the future in accordance with the provisions of the Indenture. 

ARTICLE V 
 MISCELLANEOUS

 SECTION 5.01. The recitals of fact herein, except the recital that the Trustee has duly determined to execute this Supplemental
Trust Indenture and be bound, insofar as it may lawfully so do, by the provisions hereof and in the bonds shall be taken as statements of the Company and shall not be construed as made by the Trustee. The Trustee makes no representations as to the
value of any of the property subjected to the Lien of the Indenture, or any part thereof, or as to the title of the Company thereto, or as to the security afforded thereby and hereby, or as to the validity of this Supplemental Trust Indenture or of
the bonds issued under the Indenture by virtue hereof (except the Trustee’s certificate), and the Trustee shall incur no responsibility in respect of such matters. 

  
 17 













 SECTION 5.02. This Supplemental Trust Indenture shall be construed in connection with
and as a part of the Indenture. 
 SECTION 5.03. (a) If any provision of this Supplemental Trust Indenture limits, qualifies or
conflicts with another provision of the Indenture required to be included in indentures qualified under the Trust Indenture Act of 1939, as amended (as enacted prior to the date of this Supplemental Trust Indenture) by any of the provisions of
Sections 310 to 317, inclusive, of the said Act, such required provisions shall control. 
 (b) In case any one or more of the provisions
contained in this Supplemental Trust Indenture or in the bonds issued hereunder shall be invalid, illegal or unenforceable in any respect, the validity, legality and enforceability of the remaining provisions contained herein and therein shall not
in any way be affected, impaired, prejudiced or disturbed thereby. 
 SECTION 5.04. Wherever in this Supplemental Trust Indenture the
word “Indenture” is used without the prefix “1947,” “Original,” “Restated” or “Supplemental,” such word was used intentionally to include in its meaning the 1947 Indenture, as amended and restated by
the Restated Indenture, and all indentures supplemental thereto. 
 SECTION 5.05. Wherever in this Supplemental Trust Indenture either
of the parties hereto is named or referred to, this shall be deemed to include the successors or assigns of such party, and all the covenants and agreements in this Supplemental Trust Indenture contained by or on behalf of the Company or by or on
behalf of the Trustee shall bind and inure to the benefit of the respective successors and assigns of such parties, whether so expressed or not. 

SECTION 5.06. (a) This Supplemental Trust Indenture may be executed simultaneously in several counterparts, and all said
counterparts executed and delivered, each as an original, shall constitute but one and the same instrument. 
 (b) The Table of Contents and
the descriptive headings of the several Articles of this Supplemental Trust Indenture were formulated, used and inserted in this Supplemental Trust Indenture for convenience only and shall not be deemed to affect the meaning or construction of any
of the provisions hereof. 

  
 18 













 IN WITNESS WHEREOF, NORTHERN STATES POWER COMPANY, a Wisconsin corporation, party of the
first part, has caused its corporate name to be hereunto affixed, and this Supplemental Trust Indenture, to be signed by its President or a Vice President, and attested by an authorized officer, for and in its behalf, and U.S. BANK NATIONAL
ASSOCIATION, a national banking association duly organized and existing under and by virtue of the laws of the United States of America, as Trustee, party of the second part, to evidence its acceptance of the trust hereby created, has caused this
Supplemental Trust Indenture to be signed by its President or a Vice President, and attested by an authorized officer, for and in its behalf, all done this 10th day of May, 2020. 

 

	
	NORTHERN STATES POWER COMPANY
	
	/s/ Sarah W. Soong
	By: Sarah W. Soong
	Its: Vice President and Treasurer


  

	
	Attest:
	
	/s/ Wendy B. Mahling
	By: Wendy B. Mahling
	Its: Vice President, Corporate Secretary

 [Signature page to Supplemental Trust Indenture] 












 
	
	U.S. BANK NATIONAL ASSOCIATION, as Trustee
	
	/s/ Joshua A. Hahn
	By: Joshua A. Hahn
	Its: Vice President


  

	
	Attest:
	
	/s/ Donnie Hurrelbrink
	By: Donnie Hurrelbrink
	Its: Vice President

 [Signature page to Supplemental Trust Indenture] 













							
	STATE OF MINNESOTA	 	)	 		  	
		 	)	 	SS.:	  	
	COUNTY OF SCOTT	 	)	 		  	

 On this the 10th day of May, 2020, before me, Kristin
Lynn Westlund, a Notary Public, the undersigned officer, personally appeared Sarah W. Soong and Wendy B. Mahling, who acknowledged themselves to be the Vice President and Treasurer and the Vice President, Corporate Secretary, respectively, of
Northern States Power Company, a Wisconsin corporation, and that they, as such Vice President and Treasurer and Vice President, Corporate Secretary, respectively, being authorized to do so, executed the foregoing instrument for the purposes therein
contained, by signing the name of the corporation by themselves as Sarah W. Soong and Wendy B. Mahling, respectively. 
 IN
WITNESS WHEREOF, I hereunto set my hand and official seal. 
  

	
	
	/s/ Kristin Lynn Westlund
	Kristin Lynn Westlund
	Notary Public In and For County of Scott
	State of Minnesota
	My commission expires: January 31, 2021

 (NOTARY SEAL) 

[Notary page to Supplemental Trust Indenture] 













							
	STATE OF MINNESOTA	 	)	 		  	
		 	)	 	SS.:	  	
	County of Ramsey	 	)	 		  	

 On this the 6th day of May, 2020, before me, Judy A.
Galberth, notary public, the undersigned officer, personally appeared Joshua A. Hahn and Donnie Hurrelbrink, who acknowledged themselves to each be a Vice President of U.S. Bank National Association, a national banking association, and that they, as
such Vice Presidents, being authorized to do so, executed the foregoing instrument for the purposes therein contained, by signing the name of the corporation by themselves as Vice President and Vice President, respectively. 

IN WITNESS WHEREOF, I hereunto set my hand and official seal. 

 

	
	
	/s/ Judy Ann Galberth
	Judy Ann Galberth
	Notary Public In and For County of Ramsey
	State of Minnesota
	My commission expires: January 31, 2021

 (NOTARY SEAL) 

[Notary page to Supplemental Trust Indenture] 












 SCHEDULE A 

The property referred to in the granting clause in the foregoing Supplemental Trust Indenture from Northern States Power Company to U.S. Bank National
Association, as Trustee, dated May 18, 2020 includes parts or parcels of real property and other property hereinafter more specifically described. Such description, however, is not intended to limit or impair the scope or intention of the
general description contained in the granting clauses or elsewhere herein or in the Indenture. 
 I. PROPERTIES IN THE STATE OF WISCONSIN

  

	1.	 The following described real property, situated, lying and being in the County of Barron, to wit:



 Pine Street Substation 

Parcel 1: Lot 4 of Certified Survey Map No. 4975, recorded in Volume 34 of Certified Survey Maps, on Page 96, as Document No. 697736,
being located in the Northwest Quarter of the Southeast Quarter of Section 31, also located in Certified Survey Map No. 4906, Volume 34, Page 27, as Document No. 691237, all in Section 31, Township 34 North, Range 14 West, (in
the Village of Turtle Lake), Barron County, Wisconsin 
 Parcel 2: Outlot 1 of Certified Survey Map No. 4906, recorded in Volume 34,
Page 27, as Document No. 691237, being located in the Northwest Quarter of the Southeast Quarter of Section 31, Township 34 North, Range 14 West, (in the Village of Turtle Lake), Barron County, Wisconsin. 

The Parcel Identification Numbers are
186-8047-18-000 and
186-8047-18-020. 
  

	2.	 The following described real property, situated, lying and being in the County of Bayfield, to wit:



 Cable Substation Additional Land 

Part of Lot One (1), Block Ten (10) of Assessor’s Plat No. 2 of Village (now Town) of Cable, located in Section Eighteen (18),
Township Forty-three (43) North, Range Seven (7) West, Village (now Town) of Cable, Bayfield County, Wisconsin, described as follows: Commencing at the Southwest corner of Lot 1, Block 10 of Assessor’s Plat No. 2 of Village (now
Town) of Cable and being the North right-of-way line of County Trunk Highway M, thence along the South line of Lot 1, Block 10 of Assessor’s Plat No. 2 of
Village (now Town ) of Cable and the North right-of-way line of County Trunk Highway M, North 82° 49’ 26” East, a distance of 346.00 feet to the Southwest
corner of Lot 2, Block 10 of Assessor’s Plat No. 2 of Village (now Town) of Cable; thence North 07° 10’ 34” West along the Westerly line of Lot 2, Block 10 of Assessor’s Plat No. 2 of Village (now Town) of Cable, a
distance of 100.00 feet to the Point of Beginning; thence continuing North 07° 10’ 34” West, a distance of 50.00 feet; thence North 82° 49’ 26” East, a distance of 215.25 feet; thence South 07° 10’ 34” East,
a distance of 150.00 feet to the North right-of-way line 

  
 A-1 













 
of County Trunk Highway M; thence South 82° 49’ 26” West along the North right-of-way line of County
Trunk Highway M, a distance of 115.25 feet to the Southeast corner of Lot 2, Block 10 of Assessor’s Plat No. 2 of Village (now Town) of Cable; thence North 07° 10’ 34” West along the Easterly line of Lot 2, Block 10 of
Assessor’s Plat No. 2 of the Village (now Town) of Cable, a distance of 100.00 feet to the Northeast corner of Lot 2, Block 10 of Assessor’s Plat No. 2 of Village (now Town) of Cable; thence South 82° 49’ 26” West
along the Northerly line of Lot 2, Block 10 of Assessor’s Plat No. 2 of the Village (now Town) of Cable, a distance of 100.00 feet to the Point of Beginning. 

The Parcel Identification Number is part of 04-012-2-43-07-18-2 00-116-06500.

  

	3.	 The following described real property, situated, lying and being in the County of Chippewa, to wit:



 Bateman Substation 

Lot 1 of Certified Survey Map Number 4846, recorded February 26, 2018 in Volume 22 of Certified Survey Maps, Pages 261-262 as Document Number 875983; being a part of the Southeast Quarter of the Southwest Quarter (SE 1⁄4 SW 1⁄4) Section 5, Township 28 North, Range 7 West, Town of Lafayette, Chippewa County, Wisconsin. 

The Parcel Identification Number is 22807-0534-74846001. 
  

	4.	 The following described real property, situated, lying and being in the County of Dunn, to wit:



 Wakanda Substation 

Lot 2 of Certified Survey Map #3009 as recorded in Volume 13 of Certified Survey Maps on Page 169 as Document #514942; being a part of Lots 2
and 3, Wilson Square Subdivision, City of Menomonie, Dunn County, Wisconsin. 
 The Parcel Identification Number is 17251-2-281314-310-0006. 

 

	5.	 The following described real property, situated, lying and being in the County of Polk, to wit:



 Luck Substation Additional Land 

A parcel of land in the North Half of the Southeast Quarter of the Northwest Quarter (N1/2 SE1/4 NW1/4) of Section 28, Township 36 North,
Range 17 West, more particularly described as follows: Beginning at a point 14 rods North of the Northwestern corner of Lot 1, Block 11, Second Addition to Lawson City, in the Village of Luck, Polk County, Wisconsin, thence running North 6 rods,
thence at right angles East 6 rods, thence at right angles South 6 rods, thence at right angles West 6 rods to the place of beginning. 

  
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 The Parcel Identification Number is 146-00485-0002

 II. TRANSMISSION LINES OF THE COMPANY 

IN THE STATE OF WISCONSIN 
 The electric
transmission lines of the Company, including towers, poles, pole lines, wire switch racks, switchboards, insulators, and other appliances and equipment, and all other property forming a part thereof or appertaining thereto, and all service lines
extending therefrom; together with all rights for or relating to the construction, maintenance of operation thereof, through, over, under, or upon any private property of public street or highways within as well as without the corporate limits of
any municipal corporation, and particularly the following described lines, to wit: 
 Line 3405 

Dunn County 
 Sections 16,
21 and 22, Township 28 North, Range 12 West 
 Line 3430 

Polk County 

Section 28, Township 36 North, Range 17 West 

Line 3470 
 Sawyer County

 Section 22, Township 41 North, Range 9 West 

Line 3474 
 Rusk County 

Section 31, Township 35 North, Range 6 West 

Line 3477 
 Price County

 Sections 11, 14, 22, 23, 26, 27 and 35, Township 34 North, Range 1 East 

Taylor County 
 Sections
2, 3, 10, 15, 22, 27 and 34, Township 33 North, Range 1 East 
 Section 35, Township 34 North, Range 1 East 

Line 3488 
 Rusk County 

Section 31, Township 35 North, Range 6 West 

Line 3511 
 Rusk County 


  
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 Section 31, Township 35 North, Range 6 West 

II. TRANSMISSION LINES OF THE COMPANY 

IN THE STATE OF MICHIGAN 
 The electric
transmission lines of the Company, including towers, poles, pole lines, wire switch racks, switchboards, insulators, and other appliances and equipment, and all other property forming a part thereof or appertaining thereto, and all service lines
extending therefrom; together with all rights for or relating to the construction, maintenance of operation thereof, through, over, under, or upon any private property or public street or highways within as well as without the corporate limits of
any municipal corporation, and particularly the following described lines, to wit: 
 Line 3352 

Gogebic County 

Section 9, Township 46 North, Range 43 West 

Line 3316 
 Gogebic County

 Section 27, Township 47 North, Range 47 West 

  
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 COMPANY’S RECEIPT FOR COPY 

The undersigned, Northern States Power Company, a Wisconsin corporation, the Company described in the foregoing instrument, hereby acknowledges
that it has this day received from U.S. Bank National Association the Supplemental Trust Indenture described therein, a full, true, complete, and correct copy of said instrument with signatures and acknowledgments thereon shown. Dated this 10th day of May, 2020. 
  

	
	NORTHERN STATES POWER COMPANY
	
	/s/ Sarah W. Soong
	By: Sarah W. Soong
	Its: Vice President and Treasurer


  

	
	Attest:
	
	/s/ Wendy B. Mahling
	By: Wendy B. Mahling
	Its: Vice President, Corporate Secretary