AMENDMENT AND WAIVER

Exhibit 10.4

AMENDMENT AND WAIVER

AMENDMENT AND WAIVER, dated as of January 10, 2007 (this “ Amendment ”), to and under that certain Credit Agreement, dated as of December 2, 2005 (as heretofore amended, supplemented or otherwise modified, the “ Credit Agreement ”), among SunPower Corporation (the “ Borrower ”), the several lenders from time to time parties to the Credit Agreement (the “ Lenders ”), and Credit Suisse, Cayman Islands Branch, as administrative agent for the Lenders (in such capacity, the “ Administrative Agent ”).

W I T N E S S E T H :

WHEREAS, the Borrower, the Lenders, and the Administrative Agent are parties to the Credit Agreement;

WHEREAS, the Borrower has entered into that certain Agreement and Plan of Merger, dated as of November 15, 2006 (as amended by (i) that certain First Amendment to Agreement and Plan of Merger, dated as of December 21, 2006 and (ii) that certain side letter agreement dated as of January 10, 2007), by and among Borrower, Pluto Acquisition Company LLC (to be renamed PowerLight LLC in connection with the Merger described below) (the “ Merger Sub ”), PowerLight Corporation (the “ Target ”) and Thomas L. Dinwoodie, as shareholders’ representative (the “ Merger Agreement ”), pursuant to which the Target merged into the Merger Sub with the Merger Sub continuing as the surviving company (the “ Merger ”);

WHEREAS, Merger Sub is a wholly owned subsidiary of the Borrower and a Group Member under the Credit Agreement;

WHEREAS, Merger Sub is party to that certain Loan Agreement, dated as of January 10, 2007, among the Target and Union Bank of California, N.A. (the “ Union Bank Loan Agreement ”) providing for extensions of credit in an aggregate amount not to exceed $10,000,000 and which shall terminate on April 30, 2007 (the “ Union Bank Termination Date ”);

WHEREAS, the Borrower has requested that the Lenders agree to waive compliance, with certain requirements of the Credit Agreement;

WHEREAS, the Borrower intends to issue convertible debt securities in an amount not to exceed $200,000,000 with terms reasonably satisfactory to the Administrative Agent (the “ Convertible Debt ”);

WHEREAS, in connection with the issuance of the Convertible Debt, the Borrower has requested that the Lenders agree to amend the Credit Agreement to permit the incurrence of the Convertible Debt by the Borrower; and

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WHEREAS, the Required Lenders and Administrative Agent have agreed to amend the Credit Agreement and grant the waivers as provided herein upon the terms and subject to the conditions set forth herein;

NOW, THEREFORE, in consideration of the premises and the mutual agreements contained herein, and for other valuable consideration the receipt of which is hereby acknowledged, the Borrower, the Lenders, and the Administrative Agent agree as follows:

SECTION 1. DEFINITIONS. Unless otherwise defined herein, capitalized terms are used herein as defined in the Credit Agreement.

SECTION 2. WAIVER.

2.1      The Lenders hereby waive the compliance with the provisions of the following Subsections of the Credit Agreement as they relate to the Merger and Merger Agreement: Subsection 7.3 (Fundamental Changes), Subsection 7.6 (Investments) and Subsection 7.12 (Lines of Business).

2.2      The Lenders hereby waive the compliance with the provisions of the following Subsections of the Credit Agreement with respect to the Union Bank Loan Agreement, until the Union Bank Termination Date, solely as such Subsections relate to the Target and its subsidiaries (and subsequent to the Merger, Merger Sub and its subsidiaries) (collectively, the “ Powerlight Group ”): Subsection 4.8 (Ownership of Property; Liens), Subsection 6.8 (Additional Collateral, etc.), Subsection 7.1 (Indebtedness), Subsection 7.2 (Liens), Subsection 7.4 (Disposition of Property), Subsection 7.5 (Restricted Payments), Subsection 7.7 (Transactions with Affiliates), Subsection 7.10 (Negative Pledge Clauses) and Subsection 7.11 (Clauses Restricting Subsidiary Distributions).

2.3      Until the Union Bank Termination Date, the Lenders hereby agree that:

(a)      no member of the Powerlight Group shall (i) be deemed a Subsidiary Guarantor or be required to become a party to the Guaranty and Collateral Agreement or any other Security Document, or (ii) be required to pledge, or grant a security interest in, any of its property; and

(b)      notwithstanding Section 7.6 of the Credit Agreement, the Borrower may make Investments in the Powerlight Group in an amount not to exceed $15,000,000 in additi