In 2006, Southern California’s SunLine Transit Agency began demonstrating and testing a prototype hybrid fuel cell bus developed by UTC Power, ISE Corporation, and Van Hool. During the first two years of the demonstration, the bus accumulated nearly 45,000 miles and 3,500 hours of operation.

In April 2008, UTC Power installed the newest version of the fuel cell power system in the bus at SunLine, aiming to operate it for another two years. SunLine plans to operate the bus at least 8 hours per day, 7 days per week. Additional operation time is being considered, depending on reliability and durability of the batteries that make up the energy storage system.

The U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) is working with SunLine to evaluate this bus to help determine the status of hydrogen and fuel cell systems and associated hydrogen infrastructure in transit applications. To provide a baseline, NREL collects performance data and compares the results to those for buses that use a conventional technology, such as a combustion engine. Results are published at regular intervals and are available on NREL’s Web site.

SunLine has been serving passengers in and around Palm Springs for more than 30 years.