Sunpower (SPWRQ) 10-K 2005 FY Annual report

EXHIBIT 32.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND

CHIEF FINANCIAL OFFICER PURSUANT TO

18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the annual report of SunPower Corporation (the “Company”) on Form 10-K for the period ending December 31, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”). We, Thomas H. Werner, Chief Executive Officer and Emmanuel T. Hernandez, Chief Financial Officer, of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of our knowledge and belief:

(1) the Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) the information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

Dated: March 22, 2006

/S/    THOMAS H. WERNER        

Thomas H. Werner

Chief Executive Officer

(Principal Executive Officer)

/S/    EMMANUEL T. HERNANDEZ        

Emmanuel T. Hernandez

Chief Financial Officer

(Principal Financial and Accounting Officer)