Hybrid Buses have been a successful application of Hybrid Technology. After all, buses tend to operate on routes where there is plenty of stop and go - perfect for a hybrid system. The Orion VII Hybrid has been in use by NYCTransit and other operators for about 5 years now. All those buses use inexpensive, reliable, but heavy lead acid batteries - 4,000 pounds of lead acid batteries mounted on the roof. That is equivalent to a bus with a Buick permanently mounted on its roof. The weight itself tends to reduce fuel economy, not improve it. Even so, operators of these vehicles report economy improvements over 30 percent or so. Very worthwhile in a vehicle that is supposed to last 12 years and accumulate 500,000 plus miles.
The supplier of the hybrid system - BAE Systems - has announced a change for 2008 production: Lithion ion battery packs from our friends at A123Systems. Estimates are they will add another 10 to 15 percent improvement in fuel economy bringing total fuel economy saving to 40 percent relative to a conventional bus on the same route. Forty percent savings is like getting 10 years of operation out of 6 years of fuel. Part of that saving must come from the reduced empty weight of the bus.
Hybrid technology is sorting itself out. It has proved itself in light duty and heavy duty vehicles. Now, as experience is gained, different niche markets are being identified for hybridization. One is delivery trucks. Another is refuse trucks. Still another is the military. As the automatic transmission generally replaced the manual, the hybrid may replace the automatic. If it does, it will be in the next decade or so. Let's all watch and see.
[Source: Popular Mechanics]