Exhibit (a)(1)(viii)


                FORM OF E-MAIL REMINDER ABOUT EXPIRATION OF OFFER


      This is a reminder that if you wish to exchange any of your eligible
options pursuant to our Offer to Exchange Certain Outstanding Options for New
Options dated June 25, 2003 (the "Offer"), you must submit your properly
completed Election Form via fax or hand delivery (e-mail is not sufficient) for
receipt by 5:00 p.m., Pacific Time, on July 24, 2003 (the "Expiration Date") to:

            Capstone Turbine Corporation
            Attention: Debbie Bernard
            21211 Nordhoff Street
            Chatsworth, California 91311
            Phone: (818) 734-5431
            Fax:   (818) 734-5381

      This is a firm deadline. If your Election Form is received after this
time, it will not be accepted. We urge you to respond early to avoid any last
minute problems.

      If you have already submitted an Election Form, your election to exchange
your options may be withdrawn or changed at any time prior to the Expiration
Date. To withdraw your election, you must submit a Notice to Withdraw from the
Offer prior to the Expiration Date per the procedures set forth in the Offer. To
change your election, you must submit a new Election Form prior to the
Expiration Date per the procedures set forth in the Offer.