EXHIBIT 32.1

                            CERTIFICATION 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 combined annual report of Sierra Pacific Resources,
Nevada Power Company and Sierra Pacific Power Company (the "Companies") on Form
10-K for the period ended December 31, 2005 as filed with the Securities and
Exchange Commission on the date hereof, I, Walter M. Higgins, III, Chief
Executive Officer of the Companies, certify, pursuant to 18 U.S.C. Section 1350,
as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

      1.    the combined annual report fully complies with the requirements of
            section 13(a) or 15(d) of the Securities Exchange Act of 1934, as
            amended; and

      2.    the information contained in the combined annual report fairly
            presents, in all material respects, the financial condition and
            results of operations of the Companies.

/s/ Walter  M. Higgins, III
- -----------------------------------------
    Walter M. Higgins, III
    Chief Executive Officer
    March 6, 2006

This Certification accompanies this Report pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002 and shall not, except to the extent required by the
Sarbanes-Oxley Act of 2002, be deemed filed by the Company for purposes of
Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise
subject to the liability of that section. Such certification will not be deemed
to be incorporated by reference into any filing under the Securities Act or the
Exchange Act, except to the extent the Companies specifically incorporate it by
reference.

A signed original of this written statement required by Section 906 has been
provided to the Companies and will be retained by the Companies and furnished to
the Securities and Exchange Commission or its staff upon request.