FORM OF SUPPLEMENTAL TRUST INDENTURE

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Exhibit 4(a)(4)

FORM OF
SUPPLEMENTAL TRUST INDENTURE

FROM

NORTHERN STATES POWER COMPANY
(A MINNESOTA CORPORATION)

TO

BNY MIDWEST TRUST COMPANY

DATED [                        ], [            ]

SUPPLEMENTAL TO TRUST INDENTURE
DATED FEBRUARY 1, 1937

AND

SUPPLEMENTAL AND RESTATED
TRUST INDENTURE

DATED MAY 1, 1988

TABLE OF CONTENTS

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TABLE OF CONTENTS
(continued)

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        Supplemental Trust Indenture , made effective as of the [    ] day of [            ], [        ], by and between NORTHERN STATES POWER COMPANY (formerly Northern Power Corporation), a corporation duly organized and existing under and by virtue of the laws of the State of Minnesota, having its principal office in the City of Minneapolis, Minnesota (the "Company"), party of the first part, and BNY MIDWEST TRUST COMPANY, a corporation duly organized and existing under and by virtue of the laws of the State of Illinois, having its principal office in the City of Chicago, Illinois (as successor Trustee to Harris Trust and Savings Bank), as trustee (the "Trustee"), party of the second part;

WITNESSETH:

        WHEREAS, a predecessor in interest to the Company, Xcel Energy Inc. (formerly Northern States Power Company), a corporation duly organized and existing under and by virtue of the laws of the State of Minnesota (the "Predecessor Company") has heretofore executed and delivered to the Trustee its Trust Indenture (the "1937 Indenture"), made as of February 1, 1937, whereby the Predecessor 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 Predecessor Company (except as therein excepted from the lien thereof) and subject to the rights reserved by the Predecessor Company in and by the provisions of the 1937 Indenture, to be held by said Trustee in trust in accordance with the provisions of the 1937 Indenture for the equal pro rata benefit and security of all and each of the bonds issued and to be issued thereunder in accordance with the provisions thereof; and

        WHEREAS, the Predecessor Company heretofore has executed and delivered to the Trustee a Supplemental Trust Indenture, made as of June 1, 1942, whereby the Predecessor Company conveyed, assigned, transferred, mortgaged, pledged, set over and confirmed to the Trustee, and its respective successors in said trust, additional property acquired by it subsequent to the date of the 1937 Indenture; and

        WHEREAS, the Predecessor 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 1937 Indenture certain additional covenants, conditions and agreements to be observed by the Predecessor Company, created the following series of First Mortgage Bonds:

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        WHEREAS, on August 18, 2000, New Centuries Energies, Inc. was merged with and into the Predecessor Company and the Predecessor Company changed its corporate name from Northern States Power Company to Xcel Energy Inc.; and

        WHEREAS, pursuant to an Assignment and Assumption Agreement dated as of August 18, 2000 between the Predecessor Company and the Company, substantially all the assets of the Predecessor Company (other than the stock of the Predecessor Company's subsidiaries) were conveyed to, and substantially all the liabilities of the Predecessor Company, including liabilities created under the Indenture, were assumed by, the Company (the "Assignment"); and

        WHEREAS, pursuant to the Supplemental Trust Indenture dated as of August 1, 2000 among the Predecessor Company, the Company and Harris Trust and Savings Bank, as trustee, the requirements and conditions precedent set forth in the Original Indenture and the Restated Indenture (each as hereinafter defined) with respect to the Assignment were satisfied; 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 (or, as the case may be, the Predecessor Company) subsequent to the preparation of the next preceding Supplemental Trust Indenture and adding to the covenants, conditions and agreements of the 1937 Indenture certain additional covenants, conditions, and agreements to be observed by the Company, created the following series of First Mortgage Bonds:

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        WHEREAS, the 1937 Indenture and all of the foregoing Supplemental Trust Indentures are referred to herein collectively as the "Original Indenture"; and

        WHEREAS, the Predecessor Company heretofore has executed and delivered to the Trustee a Supplemental and Restated Trust Indenture, dated May 1, 1988 (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 May 1, 1988); and

        WHEREAS, the Restated Indenture will become effective and operative when all bonds of each series issued under the Original Indenture prior to May 1, 1988, shall have been retired through payment or redemption (including those bonds "deemed to be paid" within the meaning of that term as used in Article XVII of the 1937 Indenture) or when, subject to certain exceptions, the holders of the requisite principal amount of such bonds shall have consented to the amendments contained in the Restated Indenture (such date being herein called the "Effective Date"); and

        WHEREAS, in accordance with the terms of the Restated Indenture, because all bonds of each series issued under the Original Indenture prior to May 1, 1988 have been retired through payment or redemption, the Company desires to have the Restated Indenture become effective and operative on the date this Supplemental Trust Indenture is first recorded and filed in such manner and to such extent as is required by law; and

        WHEREAS, the Effective Date will be [                        ]; and

        WHEREAS, the Original Indenture, the Restated Indenture and all trust indentures supplemental thereto are referred to herein collectively as the "Indenture"; and

        WHEREAS, pursuant to the Agreement of Resignation, Appointment and Acceptance dated as of May 1, 2002 among the Company, BNY Midwest Trust Company, as successor trustee, and Harris Trust and Savings Bank, the Trustee accepted the rights, powers, duties and obligations of the trustee under the Indenture effective as of May 9, 2002; and

        WHEREAS, the Indenture 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 is desirous of providing for the creation of a new series of First Mortgage Bonds, said new series of bonds to be designated "First Mortgage Bonds, Series due [                        ]" the bonds of such series to be issued as registered bonds without coupons in denominations of a multiple of $1,000, and the bonds of such series to be substantially in the form and of the tenor following [with the redemption prices inserted therein in conformity with the provisions of Section 2.02 hereof,] to-wit:

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(Form of Bonds of Series due [        ])
NORTHERN STATES POWER COMPANY

(Incorporated under the laws of the State of Minnesota)
First Mortgage Bond
Series due [                        ]

        [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.]*

        NORTHERN STATES POWER COMPANY, a corporation organized and existing under the laws of the State of Minnesota (the "Company"), for value received, hereby promises to pay to [                        ] or its registered assigns, at the office of the Trustee, in Chicago, Illinois, or, at the option of the registered owner, at the agency of the Company in the Borough of Manhattan, City and State of New York, an amount equal to [                        ] Dollars in lawful money of the United States of America, on the [            ] day of [            ], [            ],and to pay interest hereon from the date hereof at the rate of [            ] percent per annum, in like money, until the Company's obligation with respect to the payment of such principal sum shall be discharged; said interest being payable at the option of the person entitled to such interest either at the office of the Trustee, in Chicago, Illinois, or at the agency of the Company in the Borough of Manhattan, City and State of New York, on the [            ] day of [            ] and on the [            ] day of [            ] in each year provided 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 [                        ] or [                        ] will be paid to the person in whose name this bond was registered at the close of business on the record date (the [                        ] prior to such [                        ] or the [                        ] prior to such [                        ] (whether or not a business day)).

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

        This bond is one of a duly authorized issue of bonds of the Company, 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

*

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

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series) by a Trust Indenture dated February 1, 1937 (the "1937 Indenture"), as supplemented by 54 supplemental trust indentures (collectively, the "Supplemental Indentures"), a Supplemental and Restated Trust Indenture dated May 1, 1988 (the "Restated Indenture") and a new supplemental trust indenture for the bonds of this series (this "Supplemental Trust Indenture"), executed by the Company to BNY MIDWEST TRUST COMPANY (as successor trustee to Harris Trust and Savings Bank), as trustee (the "Trustee"). The 1937 Indenture, as supplemented by the Supplemental Indentures, the Restated Indenture and this Supplemental Trust Indenture, is referred to herein as the "Indenture". The Restated Indenture amends and restates the 1937 Indenture and certain of the Supplemental Indentures and became effective and operative on [                        ]. 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 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 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 holders of the bonds and the terms and provisions of the Indenture and of any instruments supplemental thereto may be modified or altered by affirmative vote of the 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 challenged and disqualified from voting by reason of the Company's interest therein as provided in the Indenture); provided that without the consent of all 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 thereon 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 and for all other purposes and shall not be affected by any notice to the contrary.

        [At the option of the Company, and upon not less than 30 days' notice prior to the date fixed for redemption, in the manner and with the effect provided in the Indenture, any or all of the bonds of this Series due [            ] may be redeemed, [other than for the Sinking Fund provided for bonds of this series,] by the Company on any date by the payment of

[REDEMPTION TERMS ARE TO BE INSERTED FOR EACH BOND
IN CONFORMITY WITH THE PROVISIONS OF SECTION 2.02]]

        [Bonds of this series are not redeemable prior to maturity, for any reason, and are not subject to a sinking fund.]

        This bond is transferable as prescribed in the Indenture by the registered owner hereof in person, or by his duly authorized attorney, at the office of the Trustee in Chicago, Illinois, or at the option of the owner at the agency of the Company in the Borough of Manhattan, City and State of New York, 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

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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.

        No recourse shall be had for the payment of the principal of 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 BNY Midwest Trust Company (as successor trustee to Harris Trust and Savings Bank), as 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 executed 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.

(Form of Trustee's Certificate)

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

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 acquired by it subsequent to the date of the preparation of the Supplemental Trust Indenture dated as of August 1, 2003; 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 particulars of any new series of bonds and of providing the terms and conditions of the issue of the bonds of any series not expressly provided for in the Indenture 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 of the Company;

        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 BNY Midwest Trust Company (as successor trustee to Harris Trust and Savings Bank), as Trustee, and its successors in the trust

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under the Indenture for the benefit of those who hold or shall hold the bonds, or any of them, issued or to be issued thereunder, as follows:

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, to the 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 a 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 to conform with the provisions of the Uniform Commercial Code, all fossil, nuclear, hydro and other electric generating plants, including buildings and other structures, turbines, generators, exciters, 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; telephone plant and related distribution systems; trucks and trailers; office, shop and other buildings and structures, furniture and equipment; apparatus and equipment of all other kinds and descriptions; materials and supplies; all municipal and other franchises, leaseholds, licenses, permits, privileges, patents and patent rights; all shares of stock, bonds, evidences of indebtedness, contracts, claims, accounts receivable, choses in action and other intangibles, all books of account and other corporate records;

        Excluding, however, all merchandise and appliances heretofore or hereafter acquired for the purpose of sale to customers and others;

        All the estate, right, title, interest and claim, whatsoever, at law as well as in equity, which the Company now has or hereafter may acquire in and to the aforesaid property and every part and parcel thereof subject, however, to the right of the Company, upon the occurrence and continuation of a Completed Default as defined in the Indenture, to retain in its possession all shares of stock, notes, evidences of indebtedness, other securities and cash not expressly required by the provisions hereof to be deposited with the Trustee, to retain in its possession all contracts,

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bills and accounts receivable, motor cars, any stock of goods, wares and merchandise, equipment or supplies acquired for the purpose of consumption in the operation, construction or repair of any of the properties of the Company, and to sell, exchange, pledge, hypothecate or otherwise dispose of any or all of such property so retained in its possession, free from the lien of the Indenture, without permission or hindrance on the part of the Trustee, or any of the bondholders. No person in any dealings with the Company in respect of any such property shall be charged with any notice or knowledge of any such Completed Default under the Indenture while the Company is in possession of such property. Nothing contained herein or in the Indenture shall be deemed or construed to require the deposit with, or delivery to, the Trustee of any of such property, except such as is specifically required to be deposited with the Trustee by some express provision of the Indenture;

        To have and to hold all said property, real, personal and mixed, granted, bargained, sold, warranted, released, conveyed, assigned, transferred, mortgaged, pledged, set over or confirmed 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 [            ]

        SECTION 2.01.    There is hereby created, for issuance under the Indenture, a series of bonds designated Series due [            ], each of which shall bear the descriptive title "First Mortgage Bonds, Series due [            ]," and the form thereof shall contain suitable provisions with respect to the matters hereafter specified in this Section. The bonds of the Series due [            ] may forthwith be executed by the Company substantially in the form set forth in the recitals, including the relevant provisions as indicated therein, and delivered to the Trustee for authentication and delivery by the Trustee in accordance with the provisions of the Indenture and this Supplemental Indenture. The aggregate principal amount of the bonds of the Series due [            ] outstanding at any time shall not exceed $[            ]. The bonds of the Series due [            ] shall mature on [            ], and shall be issued as registered bonds without coupons in denominations of $1,000. The bonds of the Series due [            ] shall bear interest at a rate of [            ]% per annum on the principal amount thereof payable semi-annually on [            ] and [            ] of each year, and the principal shall be payable at the office of the Trustee in Chica