ThunderPower Hybrid-Electric Fuel Cell Bus Completes Six Month Test Program

Electric Vehicle Product Update from ISE Corporation
Volume III, Issue 1 * 2003.03.01

PALM SPRINGS - On 21 February 2003, the most ambitious demonstration of a fuel cell powered transit bus was successfully completed. An ElDorado National E-Z Rider 30-foot bus, equipped with a new fuel cell based hybrid-electric drive system developed by ISE Research (ISE), completed six months of testing by SunLine Transit Agency in the Palm Springs area. The fuel cell bus is the first vehicle to be developed by ThunderPower LLC, a joint venture created by Thor Industries, Inc. and ISE in 2000 to develop and commercially market fuel cell and hydrogen powered hybrid-electric transit buses.

During the six-month SunLine Transit demonstration program, the ThunderPower fuel cell bus demonstrated the potential for fuel cell buses to achieve unprecedented efficiency and high reliability, as well as elimination of all harmful exhaust emissions. "The ThunderPower bus exceeded all of our expectations," according to Richard Cromwell, General Manager of SunLine

Transit, which operated the fuel cell bus throughout the six-month demonstration. The ThunderPower bus was used in actual revenue service for the last three and a half months of the demonstration program, the only fuel cell powered bus in the world to perform in full operational service, carrying passengers more than 100 miles per day.

In total, the ThunderPower fuel cell bus accumulated nearly 9,000 miles of simulated and actual revenue service between August 2002 and February 2003, far surpassing the mileage achieved in any previous fuel cell bus demonstration. The bus was available for use more than 72% of the time during the test period - a remarkably high level of availability for a first-of-a-kind prototype using such advanced technology. Excluding fuel cell related maintenance, the ThunderPower bus achieved 94% service availability, pointing to the high reliability factor of the integrated battery management and drive system, a ThunderPower exclusive.

The primary source of power for the ThunderPower fuel cell bus is a 60 kilowatt proton exchange membrane (PEM) fuel cell manufactured by UTC Fuel Cells, a division of United Technologies Corp. Electricity produced by the fuel cell is used to drive a pair of Siemens AC induction drive motors, which provide a smooth, quiet ride. The ThunderPower bus is the first bus to mate a fuel cell with a series hybrid-electric drive system, using a deep-cycle battery pack to augment the fuel cell. The availability of battery power enables use of a smaller fuel cell, enhances operating efficiency by recapturing and storing "regenerative" braking energy, and increases vehicle reliability by providing a back-up source of power to the fuel cell.

"The bus really captured the imagination of the public," according to Bill Clapper, who managed the demonstration project for SunLine. Clapper noted that passengers would ride on the fuel cell bus just to "experience the future," and would call to ask when the quiet, clean bus would return when it wasn't in service. In addition to producing zero harmful emissions, the bus achieved up to 11 miles per gasoline-equivalent gallon - more than twice the energy efficiency of similar buses running on the same route using compressed natural gas (see graph below).

The fuel cell, drive motors, batteries, and other hybrid-electric drive components were installed into the bus by ISE engineers and technicians in late 2001, with support from UTC Fuel Cells, Siemens, and ElDorado National. The Siemens "ELFA" motors and motor controllers used in the bus are the most proven hybrid-electric bus components in the world, and are offered by ISE in many other hybrid bus configurations, including hybrid buses using gasoline, diesel, natural gas, and propane. The state-of-the-art hydrogen storage system is manufactured by Quantum.

The ThunderPower fuel cell bus was developed with major investments by Thor Industries and ISE, augmented by funding from the South Coast Air Quality Management District and grants from the U.S. Department of Transportation administered by the Sacramento Municipal Utilities District (SMUD) and WestStart-CALSTART.

For additional information, please contact:

Director of Marketing
ISE Corporation
7345 Mission Gorge Road, Suite K
San Diego, CA 92120
Phone: (619) 287-8785
Fax: (619) 287-8795
www.isecorp.com
marketing@isecorp.com