Alliant Energy Executive Joins Capstone Turbine Board.

Business Editors

CHATSWORTH, Calif.--(BUSINESS WIRE)--April 18, 2002

Eliot G. Protsch, President of Alliant Energy-Interstate Power and Light and Executive Vice-President, Energy Delivery at Alliant Energy Corporation (www.alliantenergy.com) (NYSE:LNT), has been named to the board of directors of Capstone Turbine Corporation (www.microturbine.com) (Nasdaq:CPST).

Protsch's more than 20-year career in the energy industry spans executive positions at Alliant Energy and at Wisconsin Power and Light, with which Alliant Energy merged. Alliant Energy, a Capstone Turbine pre-IPO investor, is also an energy service provider customer of Capstone MicroTurbine systems.

"Capstone is the one corporate entity in the distributed generation sector that offers products proven clean, reliable and economically beneficial to a diverse range of business and public facilities," Protsch said. "I have been a proponent of Capstone MicroTurbines for several years, and look forward to this opportunity to aid in guiding the company to higher levels of success."

Currently, Protsch serves on the boards of directors of the Iowa Utilities Association, Nuclear Management Company (www.nmcco.com) and Cargill/Alliant LLC (www.alliantenergyresources.com/cargill.htm). Since 1995, Protsch has been a member of the Research Advisory Committee of the Electric Power Research Institute (www.epri.com), and served as its chairman from 2000 to 2001. He also previously served on the boards of American Transmission Company and Heartland Environmental.

"We are pleased and fortunate that Mr. Protsch has joined our board. He brings a wealth of experience from both the regulated and the unregulated electric utility industry," said Dr. Ake Almgren, President and CEO of Capstone Turbine. "Mr. Protsch has personally led efforts to modernize regulation of the electrical distribution infrastructure, as well as initiatives for renewable energy. This expertise is particularly relevant to the markets we serve and the business environments in which we operate."

About Alliant Energy

Headquartered in Madison, Wisconsin, Alliant Energy (www.alliantenergy.com) (NYSE:LNT) markets competitively priced energy and other products and services to more than 1.2 million industrial, commercial and residential customers in the Midwest as well as nearly a million others through operations and investments throughout the United States, Australia, Brazil, China, Mexico and New Zealand. Areas of expertise include energy planning and procurement, energy trading, rail and barge transportation, affordable housing, environmental consulting, mass marketing and international operations.

About Capstone Turbine

Southern California based Capstone Turbine Corporation (www.microturbine.com) (Nasdaq:CPST) is the world's leading producer of very-low-emission microturbine systems. In 1998, Capstone was the first to offer commercial power products utilizing microturbine technology, the result of more than ten years of focused research. Capstone Turbine has sold and shipped more than 2,000 commercial production Capstone MicroTurbine systems to customers worldwide. These award-winning systems have logged more than 1.5 million hours (170 years) of operation serving, among others, the following applications:

-- Hybrid electric vehicles (HEVs): onboard generation

-- Resource recovery: converting oilfield, landfill and sewage waste gases into
electricity

-- Micro-cogeneration: combined heat/power/chilling/drying solutions

-- The 9s market: power security, quality and reliability

This press release may contain "forward-looking statements," as that term is used in the federal securities laws, about Capstone's business, such as the expectation of higher levels of success in the marketplace. These forward-looking statements are subject to numerous assumptions, risks and uncertainties that may cause Capstone's actual results to be materially different from any future results expressed or implied in such statements. These risk factors are identified, among other places, under "Business Risks" in Capstone's most recent 10-K SEC filing. Capstone cautions you not to place undue reliance on these statements, which speak only as of the date of this release. Capstone undertakes no obligation to release any revisions to such statements to reflect events or circumstances after the date of this release or to reflect the occurrence of unanticipated events.

"Capstone Turbine Corp" is a registered trademark of Capstone Turbine Corporation. All other trademarks mentioned in this press release are the property of their respective owners.