Second Supplemental Indenture

Exhibit 4.1

DUKE ENERGY CORPORATION

TO

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

Trustee

Second Supplemental Indenture

Dated as of January 26, 2009

$750,000,000 6.30% SENIOR NOTES DUE 2014

TABLE OF CONTENTS ¹

     THIS SECOND SUPPLEMENTAL INDENTURE is made as of the 26th day of January 2009, by and between DUKE ENERGY CORPORATION, a Delaware corporation, having its principal office at 526 South Church Street, Charlotte, North Carolina 28202 (the “Corporation”), and The Bank of New York Mellon Trust Company, N.A. (formerly known as The Bank of New York Trust Company, N.A.), a national banking association, as Trustee (herein called the “Trustee”).

W I T N E S S E T H:

     WHEREAS, the Corporation has heretofore entered into an Indenture, dated as of June 3, 2008 (the “Original Indenture”), with The Bank of New York Mellon Trust Company, N.A., as Trustee;

     WHEREAS, the Original Indenture is incorporated herein by this reference and the Original Indenture, as it may be amended and supplemented to the date hereof, including by this Second Supplemental Indenture, is herein called the “Indenture”;

     WHEREAS, under the Indenture, a new series of Securities may at any time be established in accordance with the provisions of the Indenture and the terms of such series may be described by a supplemental indenture executed by the Corporation and the Trustee;

     WHEREAS, the Corporation hereby proposes to create under the Indenture an additional series of Securities;

     WHEREAS, additional Securities of other series hereafter established, except as may be limited in the Indenture as at the time supplemented and modified, may be issued from time to time pursuant to the Indenture as at the time supplemented and modified; and

     WHEREAS, all conditions necessary to authorize the execution and delivery of this Second Supplemental Indenture and to make it a valid and binding obligation of the Corporation have been done or performed.

     NOW, THEREFORE, in consideration of the agreements and obligations set forth herein and for other good and valuable consideration, the sufficiency of which is hereby acknowledged, the parties hereto hereby agree as follows:

ARTICLE 1

6.30% SENIOR NOTES DUE 2014

     Section 1.01. Establishment . There is hereby established a new series of Securities to be issued under the Indenture, to be designated as the Corporation’s 6.30% Senior Notes due 2014 (the “Notes”).

     There are to be authenticated and delivered $750,000,000 principal amount of the Notes, and no further Notes shall be authenticated and delivered except as provided by Section 304, 305, 306, 906 or 1106 of the Original Indenture and the last paragraph of Section 301 thereof. The Notes shall be issued in fully registered form without coupons.

     The Notes shall be in substantially the form set out in Exhibit A hereto, and the form of the Trustee’s Certificate of Authentication for the Notes shall be in substantially the form set forth in Exhibit B hereto.

     Each Note shall be dated the date of authentication thereof and shall bear interest from the date of original issuance thereof or from the most recent Interest Payment Date to which interest has been paid or duly provided for.

     Section 1.02. Definitions . The following defined terms used in this Article 1 shall, unless the context otherwise requires, have the meanings specified below for purposes of the Notes. Capitalized terms used herein for which no definition is provided herein shall have the meanings set forth in the Original Indenture.

     “Business Day” means any day other than a Saturday or Sunday that is neither a Legal Holiday nor a day on which banking institutions in New York, New York are authorized or required by law, regulation or executive order to close, or a day on which the Corporate Trust Office is closed for business.

     “Interest Payment Date” means each February 1 and August 1 of each year, commencing August 1, 2009.

     “Legal Holiday” means any day that is a legal holiday in New York, New York.

     “Original Issue Date” means January 26, 2009.

     “Regular Record Date” means, with respect to each Interest Payment Date, the close of business on the 15th calendar day prior to such Interest Payment Date (whether or not a Business Day).

     “Stated Maturity” means February 1, 2014.

     Section 1.03. Payment of Principal and Interest . The principal of the Notes shall be due at Stated Maturity (unless earlier redeemed). The unpaid principal amount of the Notes shall bear interest at the rate of 6.30% per annum until paid or duly provided for, such interest to accrue from January 26, 2009 or from the most recent Interest Payment Date to which interest has been paid or duly provided for. Interest shall be paid semi-annually in arrears on each Interest Payment Date to the Person or Persons in whose name the Notes are registered on the Regular Record Date for such Interest Payment Date; provided that interest payable at the Stated Maturity or on a Redemption Date as provided herein shall be paid to the Person to whom principal is payable. Any such interest that is not so punctually paid or duly provided for shall forthwith cease to be payable to the Holders on such Regular Record Date and may either be paid to the Person or Persons in whose name the Notes are registered at the close of business on a Special Record Date for the payment of such defaulted interest to be fixed by the Trustee (“Special Record Date”), notice whereof shall be given to Holders of the Notes not less than ten (10) days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange, if any, on which the Notes may be listed, and upon such notice as may be required by any such exchange, all as more fully provided in the Original Indenture.

     Payments of interest on the Notes shall include interest accrued to but excluding the respective Interest Payment Dates. Interest payments for the Notes shall be computed and paid on the basis of a 360-day year of twelve 30-day months. In the event that any date on which interest is payable on the Notes is not a Business Day, then payment of the interest payable on such date shall be made on the next succeeding day that is a Business Day (and without any interest or payment in respect of any such delay) with the same force and effect as if made on the date the payment was originally payable.

     Payment of principal of, premium, if any, and interest on the Notes shall be made in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts. Payments of principal of, premium, if any, and interest on Notes represented by a Global Security shall be made by wire transfer of immediately available funds to the Holder of such Global Security, provided that, in the case of payments of principal and premium, if any, such Global Security is first surrendered to the Paying Agent. If any of the Notes are no longer represented by a Global Security, (i) payments of principal, premium, if any, and interest due at the Stated Maturity or earlier redemption of such Notes shall be made at the office of the Paying Agent upon surrender of such Notes to the Paying Agent and (ii) payments of interest shall be made, at the option of the Corporation, subject to such surrender where applicable, (A) by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register or (B) by wire transfer at such place and to such account at a banking institution in the United States as may be designated in writing to the Trustee at least sixteen (16) days prior to the date for payment by the Person entitled thereto.

     Section 1.04. Denominations . The Notes shall be issued in denominations of $2,000 or any integral multiple of $1,000 in excess thereof.

     Section 1.05. Global Securities . The Notes shall initially be issued in the form of one or more Global Securities registered in the name of the Depositary (which initially shall be The Depository Trust Company) or its nominee. Except under the limited circumstances described below, Notes represented by such Global Security or Global Securities shall not be exchangeable for, and shall not otherwise be issuable as, Notes in definitive form. The Global Securities described in this Article 1 may not be transferred except by the Depositary to a nominee of the Depositary or by a nominee of the Depositary to the Depositary or another nominee of the Depositary or to a successor Depositary or its nominee.

     A Global Security shall be exchangeable for Notes registered in the names of persons other than the Depositary or its nominee only if (i) the Depositary notifies the Corporation that it is unwilling or unable to continue as a Depositary for such Global Security and no successor Depositary shall have been appointed by the Corporation within 90 days of receipt by the Corporation of such notification, or if at any time the Depositary ceases to be a clearing agency registered under the Exchange Act at a time when the Depositary is required to be so registered to act as such Depositary and no successor Depositary shall have been appointed by the Corporation within 90 days after it becomes aware of such cessation, (ii) an Event of Default has occurred and is continuing with respect to the Notes and beneficial owners of a majority in aggregate principal amount of the Notes represented by Global Securities advise the Depositary to cease acting as Depositary, or (iii) the Corporation in its sole discretion, and subject to the procedures of the Depositary, determines that such Global Security shall be so exchangeable.

Any Global Security that is exchangeable pursuant to the preceding sentence shall be exchangeable for Notes registered in such names as the Depositary shall direct.

     Section 1.06. Redemption . The Notes shall be redeemable, in whole or from time to time in part, at the option of the Corporation on any date (a “Redemption Date”), at a Redemption Price equal to the greater of (i) 100% of the principal amount of the Notes to be redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest thereon (exclusive of interest accrued to such Redemption Date) discounted to such Redemption Date on a semiannual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 50 basis points, plus, in either case, accrued and unpaid interest on the principal amount being redeemed to such Redemption Date.

     “Treasury Rate” means, with respect to any Redemption Date, the rate per annum equal to the semiannual equivalent yield to maturity or interpolated maturity (on a day count basis) of the Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such Redemption Date. The Treasury Rate shall be calculated on the third Business Day preceding the Redemption Date.

     “Comparable Treasury Issue” means the United States Treasury security selected by the Quotation Agent as having an actual or interpolated maturity comparable to the remaining term of the Notes to be redeemed 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 such Notes.

     “Quotation Agent” means a Reference Treasury Dealer appointed by the Corporation.

     “Comparable Treasury Price” means, with respect to any Redemption Date, (1) the average of the Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and lowest such Reference Treasury Dealer Quotations, or (2) if fewer than four such Reference Treasury Dealer Quotations are obtained, the average of all such Reference Treasury Dealer Quotations.

     “Reference Treasury Dealer” means each of Banc of America Securities LLC, J.P. Morgan Securities Inc. and Morgan Stanley & Co. Incorporated, plus two other financial institutions appointed by the Corporation at the time of any redemption or their respective affiliates which are primary U.S. Government securities dealers in the United States (a “Primary Treasury Dealer”), and their respective successors; provided , however , that if any of the foregoing or their affiliates or successors shall cease to be a Primary Treasury Dealer, the Corporation will substitute therefor another Primary Treasury Dealer.

     “Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Quotation Agent, 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 the Quotation Agent by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.