A bus equipped with a ThunderVolt hybrid gasoline-electric drive system from ISE Corp. has successfully completed a 15,000-mile durability and safety test conducted by the Federal Transit Administration.
The drive system employs BOOSTCAP ultracapacitor cells from Maxwell Technologies to store electrical energy generated by the bus’s braking system and reuse the energy to assist in acceleration, thus improving fuel economy. Transit agencies in Long Beach and Elk Grove, California, have ordered 44 ThunderVolt-powered buses.
The ThunderVolt system in the bus that completed the FTA test consists of a Ford Triton V10 gasoline engine, Siemens ELFA electric motors, motor controllers and generators, and a ThunderPack II ultracapacitor-based energy storage system with 288 Maxwell BOOSTCAP ultracapacitors.
ISE president David Mazaika said the ThunderVolt system is the only commercially available gasoline-electric hybrid drive system certified to meet the California Air Resources Board's strict emissions standards.