THIS FORTY-SIXTH SUPPLEMENTAL INDENTURE , dated as of February 1, 2009, is between OGLETHORPE POWER CORPORATION (AN ELECTRIC MEMBERSHIP CORPORATION) , formerly known as Oglethorpe Power Corporation (An Electric Membership Generation & Transmission Corporation), an electric membership corporation organized and existing under the laws of the State of Georgia, as Grantor (the “Company”), and U.S. BANK NATIONAL ASSOCIATION , a national banking association, as successor to SunTrust Bank, formerly known as SunTrust Bank, Atlanta, as trustee (in such capacity, the “Trustee”).

WHEREAS, the Company has heretofore executed and delivered to the Trustee an Indenture, dated as of March 1, 1997 (the “Original Indenture”), for the purpose of securing its Existing Obligations and providing for the authentication and delivery of Additional Obligations by the Trustee from time to time under the Original Indenture (capitalized terms used herein and not otherwise defined shall have the meanings assigned to them in the Original Indenture);

WHEREAS, the Company has heretofore executed and delivered to the Trustee forty-five Supplemental Indentures (the Original Indenture, as heretofore, hereby and hereafter supplemented and modified, the “Indenture”), and the Original Indenture and the forty-five Supplemental Indentures have been recorded as set forth on Schedule 1 ;

WHEREAS, the Board of Directors of the Company has authorized a new series of Additional Obligations to be designated the First Mortgage Bonds, Series 2009 A, due March 15, 2019 in the principal amount of Three Hundred and Fifty Million Dollars ($350,000,000) (the “Series 2009 A Bonds”);

WHEREAS, the Company will enter into that certain Registration Rights Agreement with the Initial Purchasers (as defined therein) dated as of February 10, 2009 (the “Registration Rights Agreement”) requiring that the Company register the Series 2009 A Bonds under the Securities Act of 1933 (the “Securities Act”) with the Securities and Exchange Commission (the “SEC”);

WHEREAS, the Company has complied or will comply with all provisions required to issue Additional Obligations provided for in the Original Indenture;

WHEREAS, the Company desires to execute and deliver this Forty-Sixth Supplemental Indenture, in accordance with the provisions of the Original Indenture, for the purpose of providing for the creation and designation of the Series 2009 A Bonds as Additional Obligations and specifying the form and provisions thereof;

WHEREAS, Section 12.1 of the Original Indenture provides that, without the consent of the Holders of any of the Obligations, the Company, when authorized by a Board Resolution, and the Trustee may enter into Supplemental Indentures for the purposes and subject to the conditions set forth in said Section 12.1, including to create additional series of Obligations under the Indenture and to make provisions for such additional series of Obligations; and

WHEREAS, all acts and proceedings required by law and by the Articles of Incorporation and Bylaws of the Company necessary to secure under the Indenture the payment

of the principal of and interest and premium, if any, on the Series 2009 A Bonds, to make the Series 2009 A Bonds to be issued hereunder, when executed by the Company, authenticated and delivered by the Trustee and duly issued, the valid, binding and legal obligation of the Company, and to constitute the Indenture a valid and binding lien for the security of the Series 2009 A Bonds, in accordance with its terms, have been done and taken; and the execution and delivery of this Forty-Sixth Supplemental Indenture has been in all respects duly authorized by the Company;

NOW, THEREFORE, THIS FORTY-SIXTH SUPPLEMENTAL INDENTURE WITNESSES , that, to secure the payment of the principal of and interest and premium, if any, on the Outstanding Secured Obligations, including, when authenticated and delivered, the Series 2009 A Bonds, to confirm the lien of the Indenture upon the Trust Estate, including property purchased, constructed or otherwise acquired by the Company since the date of execution of the Original Indenture, to secure performance of the covenants therein and herein contained, to declare the terms and conditions on which the Series 2009 A Bonds are secured, and in consideration of the premises thereof and hereof, the Company by these presents does grant, bargain, sell, alienate, remise, release, convey, assign, transfer, mortgage, hypothecate, pledge, set over and confirm to the Trustee, and its successors and assigns in the trust created thereby and hereby, in trust, all property, rights, privileges and franchises (other than Excepted Property or Excludable Property) of the Company, whether now owned or hereafter acquired, of the character described in the Granting Clauses of the Original Indenture, wherever located, including all such property, rights, privileges and franchises acquired since the date of execution of the Original Indenture, subject to all exceptions, reservations and matters of the character referred to in the Indenture, and does grant a security interest therein for the purposes expressed herein and in the Original Indenture subject in all cases to Sections 5.2 and 11.2 B of the Original Indenture and to the rights of the Company under the Original Indenture, including the rights set forth in Article V thereof; but expressly excepting and excluding from the lien and operation of the Indenture all properties of the character specifically excepted as “Excepted Property” or “Excludable Property” in the Original Indenture to the extent contemplated thereby.

PROVIDED, HOWEVER , that if, upon the occurrence of an Event of Default, the Trustee, or any separate trustee or co-trustee appointed under Section 9.14 of the Original Indenture or any receiver appointed pursuant to statutory provision or order of court, shall have entered into possession of all or substantially all of the Trust Estate, all the Excepted Property described or referred to in Paragraphs A through H, inclusive, of “Excepted Property” in the Original Indenture then owned or thereafter acquired by the Company, shall immediately, and, in the case of any Excepted Property described or referred to in Paragraphs I, J, L, N and P of “Excepted Property” in the Original Indenture (excluding the property described in Section 2 of Exhibit B in the Original Indenture), upon demand of the Trustee or such other trustee or receiver, become subject to the lien of the Indenture to the extent permitted by law, and the Trustee or such other trustee or receiver may, to the extent permitted by law, at the same time likewise take possession thereof, and whenever all Events of Default shall have been cured and the possession of all or substantially all of the Trust Estate shall have been restored to the Company, such Excepted Property shall again be excepted and excluded from the lien of the Indenture to the extent and otherwise as hereinabove set forth and as set forth in the Indenture.

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The Company may, however, pursuant to the Granting Clause Third of the Original Indenture, subject to the lien of the Indenture any Excepted Property or Excludable Property, whereupon the same shall cease to be Excepted Property or Excludable Property.

TO HAVE AND TO HOLD all such property, rights, privileges and franchises hereby and hereafter (by a Supplemental Indenture or otherwise) granted, bargained, sold, alienated, remised, released, conveyed, assigned, transferred, mortgaged, hypothecated, pledged, set over or confirmed as aforesaid, or intended, agreed or covenanted so to be, together with all the tenements, hereditaments and appurtenances thereto appertaining (said properties, rights, privileges and franchises, including any cash and securities hereafter deposited or required to be deposited with the Trustee (other than any such cash which is specifically stated in the Indenture not to be deemed part of the Trust Estate) being part of the Trust Estate), unto the Trustee, and its successors and assigns in the trust herein created by the Indenture, forever.

SUBJECT, HOWEVER , to (i) Permitted Exceptions and (ii) to the extent permitted by Section 13.6 of the Original Indenture as to property hereafter acquired (a) any duly recorded or perfected prior mortgage or other lien that may exist thereon at the date of the acquisition thereof by the Company and (b) purchase money mortgages, other purchase money liens, chattel mortgages, conditional sales agreements or other title retention agreements created by the Company at the time of acquisition thereof.

BUT IN TRUST, NEVERTHELESS , with power of sale, for the equal and proportionate benefit and security of the Holders from time to time of all the Outstanding Secured Obligations without any priority of any such Obligation over any other such Obligation and for the enforcement of the payment of such Obligations in accordance with their terms.

UPON CONDITION that, until the happening of an Event of  Default and subject to the provisions of Article V of the Original Indenture, and not in limitation of the rights elsewhere provided in the Original Indenture, including the rights set forth in Article V of the Original Indenture, the Company shall be permitted to (i) possess and use the Trust Estate, except cash, securities, Designated Qualifying Securities and other personal property deposited, or required to be deposited, with the Trustee, (ii) explore for, mine, extract, separate and dispose of coal, ore, gas, oil and other minerals, and harvest standing timber, and (iii) receive and use the rents, issues, profits, revenues and other income, products and proceeds of the Trust Estate.

THE INDENTURE, INCLUDING THIS FORTY-SIXTH SUPPLEMENTAL INDENTURE, is intended to operate and is to be construed as a deed passing title to the Trust Estate and is made under the provisions of the laws of the State of Georgia relating to deeds to secure debt, and not as a mortgage or deed of trust, and is given to secure the Outstanding Secured Obligations.  Should the indebtedness secured by the Indenture be paid according to the tenor and effect thereof when the same shall become due and payable and should the Company perform all covenants contained in the Indenture in a timely manner, then the Indenture shall be canceled and surrendered.

AND IT IS HEREBY COVENANTED AND DECLARED that the Series 2009 A Bonds are to be authenticated and delivered and the Trust Estate is to be held and applied by the Trustee, subject to the covenants, conditions and trusts set forth herein and in the Indenture, and

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the Company does hereby covenant and agree to and with the Trustee, for the equal and proportionate benefit of all Holders of the Outstanding Secured Obligations, as follows:

ARTICLE I

DEFINITIONS

Section 1.1                                    Definitions .

All words and phrases defined in Article I of the Original Indenture shall have the same meaning in this Forty-Sixth Supplemental Indenture, except as otherwise appears herein, in this Article I or unless the context clearly requires otherwise.  In addition, the following terms have the following meaning in this Forty-Sixth Supplemental Indenture unless the context clearly requires otherwise.

“ Closing Date ” means February 19, 2009.

 “ Interest Payment Date ” means March 15 and September 15 of each year, commencing on September 15, 2009.

“ Record Date ” means the 1st day (whether or not a Business Day) of the calendar month of such Interest Payment Date.

“ Securities Depository ” means The Depository Trust Company and its successors and assigns or any other securities depository selected by the Company which agrees to follow the procedures required to be followed by such securities depository in connection with the Series 2009 A Bonds.

ARTICLE II

THE SERIES 2009 A BONDS AND
CERTAIN PROVISIONS RELATING THERETO

Section 2.1                                    Terms of the Series 2009 A Bonds .

There shall be established a series of Additional Obligations known as and entitled the “First Mortgage Bonds, Series 2009 A” (the “Series 2009 A Bonds”).

The aggregate principal amount of the Series 2009 A Bonds which may be authenticated and delivered and Outstanding at any one time is limited to Three Hundred and Fifty Million Dollars ($350,000,000).  The Series 2009 A Bonds shall consist of bonds in an aggregate principal amount of $350,000,000, due March 15, 2019.

Pursuant the Registration Rights Agreement, the Company will register the Series 2009 A Bonds under the Securities Act with the SEC.  For the purposes of this paragraph and Exhibit A, the Series 2009 A Bonds issued on the Closing Date shall be referred to as the “Initial Series 2009 A Bonds” and the Series 2009 A Bonds issued pursuant to the Exchange Offer (as hereinafter defined) shall be referred to as the “Exchange Series 2009 A Bonds.”  The

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Registration Rights Agreement requires the Company to register the Initial Series 2009 A Bonds (i) by exchanging the Initial Series 2009 A Bonds for Exchange Series 2009 A Bonds through an exchange offer (the “Exchange Offer”) and/or (ii) by filing a Shelf Registration Statement.  For all purposes under this Forty-Sixth Supplemental Indenture, each series of Initial Series 2009 A Bonds and the related Exchange Series 2009 A Bonds shall be treated as a single series of Series 2009 A Bonds.

The Series 2009 A Bonds shall bear interest from their date of issuance, payable semi-annually on March 15 and September 15 of each year, commencing on September 15, 2009.  The Series 2009 A Bonds shall bear interest at the annual rate of 6.10%; provided, however, that if (i) the Company fails to file a registration statement under the Securities Act of 1933, as amended, registering the Series 2009 A Bonds (the “Exchange Offer Registration Statement”) under the Securities Act in connection with the Exchange Offer with the SEC on or prior to the 90th day after the Closing Date, (ii) the Exchange Offer Registration Statement has not been declared effective by the SEC on or before the 180th day after the Closing Date, (iii) the Exchange Offer has not been completed within 60 days after the initial effective date of the Exchange Offer Registration Statement, (iv) if a Shelf Registration Statement (as defined in the Registration Rights Agreement) is required to be filed as a result of a Shelf Registration Event (as defined in the Registration Rights Agreement) but is not filed with the SEC on or prior to the 30th day after the date of such Shelf Registration Event, or (v) if a Shelf Registration Statement is required to be filed as a result of a Shelf Registration Event but is not declared effective by the SEC on or prior to the 60th day after the date of such Shelf Registration Event (each such event referred to in clauses (i) through (v), a “Registration Default” and each period during which a Registration Default has occurred and is continuing, a “Registration Default Period”), then additional interest on the Series 2009 A Bonds will accrue (in addition to the stated interest on the Series 2009 A Bonds) at a rate of 1.00% per annum (“Special Interest”) on the principal amount of the Series 2009 A Bonds, from the date of the occurrence of any Registration Default until such Registration Default is remedied; provided, however, no Registration Default Period shall continue beyond the first anniversary of the Closing Date.  The amount of Special Interest shall not increase because more than one Registration Default has occurred and is continuing.

If the Exchange Offer Registration Statement or the Shelf Registration Statement, if required, has become effective and thereafter either ceases to be effective or the Prospectus (as defined in the Registration Rights Agreement) contained therein ceases to be usable at any time during the period when the Exchange Offer Registration Statement is being used by Requesting Participating Broker-Dealers (as defined in the Registration Rights Agreement) or during the Shelf Effectiveness Period (as defined in the Registration Rights Agreement), respectively, and such failure to remain effective or usable exists for more than 30 days (whether or not consecutive) prior to, in the case of the Exchange Offer Registration Statement being used by a Requesting Participating Broker-Dealer, the 180th day after the Exchange Date (as defined in the Registration Rights Agreement) or, in the case of the Shelf Offer Registration Statement, the first anniversary of the Closing Date, then the interest rate on the Registrable Securities will be increased by the Special Interest amount commencing on the 31st day in such period and ending (i) the date that the Exchange Offer Registration Statement or the Shelf Registration Statement, as applicable, has again become effective, (ii) the date the Prospectus relating thereto, as applicable, again becomes usable, or (iii) in the case of the Exchange Offer Registration Statement being used by a Requesting Participating Broker-Dealer, on the 180th day after the

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Exchange Date or, in the case of the Shelf Registration Statement, on the first anniversary of the Closing Date.

The Series 2009 A Bonds shall be issued as fully registered global bonds without coupons and in denominations of $1,000 or any integral multiple thereof.  The Series 2009 A Bonds (i) shall be initially registered in the name of J.P. Morgan Securities Inc., as representative of the Initial Purchasers (as defined in the Registration Rights Agreement) (the “Representative”) and (ii) upon the transfer of the Series 2009 A Bonds by the Representative to Cede & Co., as nominee of the Securities Depository, shall be registered in the name of Cede & Co., as nominee of the Securities Depository, pursuant to the Securities Depository’s Book-Entry System.  When the Series 2009 A Bonds are held in the Book-Entry System, purchases of beneficial interests in the Series 2009 A Bonds shall be made in book-entry form, without certificates.  If at any time the Book-Entry System is discontinued for the Series 2009 A Bonds, the Series 2009 A Bonds shall be exchangeable for other fully registered certificated Series 2009 A Bonds of like tenor and of an equal aggregate principal amount, in authorized denominations.  The Trustee may impose a charge sufficient to reimburse the Company or the Trustee for any tax, fee or other governmental charge required to be paid with respect to such exchange or any transfer of a Series 2009 A Bond.&nbs