The Capstone MicroTurbineä as a Hybrid Vehicle Energy Source

The 30 kW MicroTurbine developed by Capstone Turbine Corporation is currently being used in commercial service in a hybrid bus in Chattanooga, Tennessee. This program, directed by Capstone, resulted from a joint program with the bus manufacturer, Advanced Vehicle Systems; the bus operator, Chattanooga Area Regional Transportation Authority; and partial funding from CAL-START/ DARPA.

The MicroTurbine has been integrated into a purpose built electric bus used in daily service as part of a fleet of electric buses serving downtown Chattanooga. Over 450 hours and 400 starts have been accumulated. The bus manufacturer and the bus operator are very pleased with the performance, and in particular, the lack of vibration and noise. Riders are unaware of any difference between the hybrid and pure electric buses. The noise level in the bus is only one dbA above the background. The conversion from battery only to hybrid operation has allowed the addition of air-conditioning and provides for increased range. Extended service routes using diesel fueled MicroTurbine hybrid buses are now being considered by CARTA.

A description of the system components, performance and lessons learned and future potential are discussed.