Exhibit 99.1

                            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 Annual Report of Active Power, Inc. (the "Company")
on Form 10-K for the period ending December 31, 2002 as filed with the
Securities and Exchange Commission on the date hereof (the "Report"), I, Joseph
F. Pinkerton, III, Chairman of the Board and Chief Executive 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 my knowledge:

(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 results of operations of the Company
      as of the dates and for the periods expressed in the Report.


                                    /s/ Joseph F. Pinkerton, III
                                    ------------------------------------
                                    Joseph F. Pinkerton, III
                                    Chairman of the Board and Chief
                                    Executive Officer
                                    March 7, 2003