Enova Systems has been collaborating with IC Bus for the past couple of years to build a series of plug-in hybrid
school buses for testing purposes. Enova recently had an independent CARB-certified lab conduct dynamometer tests on a pair of PHEV school buses to compare the fuel consumption and emissions against conventional models. Enova's system is designed to be installed downstream of the transmission so that it can be easily adapted to buses and drivetrains from different manufacturers. One 2007 and one 2008 IC Bus Series CE bus with different engines and transmissions were tested on a West Virginia University Suburban
Test Cycle designed to emulate a typical school bus duty cycle. In the tests, the PHEV buses saw a 70 percent reduction in diesel
fuel consumption. Carbon dioxide emissions were cut by 40 percent while soot and NOx were reduced by 30 and 20 percent, respectively. IC Bus has also decided to cut the $200,000+ of the hybrid
buses by $40,000. Currently there are 19 of the Enova equipped buses running in eleven states.