The typical school bus stops and starts many times while picking up and letting offstudents. It often spends more time stopped and idling while loading and unloading than driving down the road. Hybrid electric vehicles love lots of starts and stops. That’s why there is so much interest in hybrid electric transit buses, delivery trucks, refuse pickup trucks and taxis. Features like regenerative braking and start-stop operation are key reasons why hybrids save fuel and reduce emissions. Indeed, because of this, hybrids like the Toyota Prius and Ford Escape Hybrid have higher EPA city mpg ratings than highway ratings.
Reducing pollution, especially from diesel engines popularly used in school buses, is of vital importance. There is much evidence that diesel emissions are especially harmful to young children. Fuel saving are also important to schools since fuel costs are a major portion of manyschool district’s budget, and rising.
Hybrid school buses could be just around the corner. The Hybrid Electric School Bus (HESB) project managed by Advanced Energy in North Carolina recently received funding from The State Technologies Advancement Collaborative that could put hybrid electric school buses on U.S. highways in two years. The funding will be used to help purchase 20 hybrid electric school buses that will be put in operation in eleven states around the country to determine theirfeasibility under a variety of operating conditions.
IC Corporation, North America's largest school bus manufacturer, working with hybrid system manufacturer, Enova Systems, Inc., plans to introduce the nation's first hybrid school bus in regular service this spring. As a point of history, in the early 2000s, a consortium comprising of EVermont, NAVC, Solectria Corp. and Bluebird Corp. did convert a Bluebird school bus into a hybrid electric one. Testing showed substantial reduction in fuel usage and emissions compared to a comparable diesel-powered school bus.
School buses are an ideal application for a new type of hybrid, the plug-in hybrid electric vehicle or PHEV. Here the hybrid vehicle is plugged into the electrical grid to recharge the batteries. This reduces the amount of time the internal combustion engine has to run to recharge batteries, thus reducing fuel consumption and emissions. PHEVs can replace mobile emission sources, that is vehicles, with stationary central power plant sources that are already much cleaner and easier to control. School buses recharged overnight reduce ozone and smog because the electric power used is produced at night rather than during the day.
With the large number of school buses in operation in the U.S., there should be a very large market for hybrid school buses. Add the large number of miles driven by school buses, or really the number they are in service, hybrid buses could greatly reduce pollution and use of fossil fuels.