THE BENEFITS OF DOUBLE LAYER CAPACITOR TECHNOLOGY TO THE HYBRID ELECTRIC TRANSIT BUS (HETB)

A Hybrid Electric Transit Bus (HETB) has been developed by a government, industry and academic cooperative, with the goals of doubling the fuel economy of the city buses currently in service and reducing emissions to one-tenth of EPA standards. This paper describes the design of the HETB, identifies the advantages of double layer capacity energy storage over chemical batteries, compares actual and simulated vehicle performance with both capacitors and batteries, and describes the follow-on work needed to fully develop the capacitor and turbogenerator technologies. The report concludes that double layer capacitor energy storage has significant advantages over the chemical battery technology typically used in hybrid vehicles and that further development efforts are justified.