Have you ever cringed as noxious fumes belched towards you out of a car, bus or truck? Engineers have already glimpsed an auto-exhaust-free future in the form of vehicles powered by fuel cells; alas, they are still many years away from having fuel cells
ready for mass production.
Hybrid engines . . . those that combine two or more power sources . . . are however already among us, reducing our gasoline consumption, protecting the environment both locally and globally and reducing our dependence on foreign oil.
Several hybrid automobiles are already available on the American market; the Honda Civic Hybrid, the Honda Insight and the Toyota Prius all have received much press and favorable notices for their performance, driving comfort and fuel conservation.
Not yet widely available and used in the United States, unfortunately, are hybrid vans, such as the Mercedes-Benz Sprinter. Increased public awareness of this technology will hopefully lead to increased pressure for its widespread employment in this country. When a hybrid vehicle operates in a center city, near a hospital or convention center or other congested area, it can move on electric power alone, completely eliminating polluting exhaust fumes. Whether you live on New York’s Fifth Avenue or Main Street, U.S.A., the desirability of cleaner air is self-evident.
The Mercedes-Benz Sprinter, a commercial vehicle, features a four-cylinder diesel engine in combination with an electric engine. That electric engine is integrated into the powertrain between the transmission and the clutch, and gets its energy from a drive battery beneath the vehicle floor; the battery therefore does not take up valuable cargo space. The driver can switch between diesel, electric, and combined diesel-electric drives at the push of a button. When in hybrid mode, the vehicle uses a computer to decide which percentage of its energy should come from the diesel and electric sources.
Remarkably, such a hybrid motor can recoup part of the energy it consumes. How does it accomplish such a feat? Whenever being braked or going downhill, the wheels drive the electric motor via the transmission, and the electric motor thus turns into a generator which recharges its own battery with the electricity it produces.
The Mercedes-Benz Sprinter is already in use in various European countries, whose citizens are enjoying the ecological benefits which its hybrid engine guarantees; beyond the absence of repugnant exhaust fumes near pedestrian areas, these hybrid engines also operate with less production of noise.
Some other countries have already produced hybrid commercial vehicles. In the 2004 Tokyo Auto Show, Daihatsu showed its Hijet Cargo Hybrid, with a fuel-use efficiency 30% better than that of a standard combustion engine and corresponding emissions reductions.
In the United States, the ISE corporation has developed hybrid commercial busses, now used in several municipalities in California, one of which, the Thunderbolt, reduces particulate matter in emissions to zero. That is important because particulate matter in engine emissions are a known carcinogen. All of ISE’s commercial hybrid busses reduce fuel consumption from between 50% to 100% Unhappily, conventional diesel engines are still in use for 86% of the nation’s 76,000 active transit busses. Beyond the cancer menace presented by particulate matter are the nitrogen oxide emissions of diesel engines which dramatically worsen asthma, particularly among children and the elderly.
The Environmental and Energy Study Institute issued in October of
2004 citations for four districts in the United States which have made significant efforts to improve the environmentally-friendly aspects of their local bus fleets; Oakland, California, the Durham Public Schools in North Carolina, the Jordan School District in Salt Lake City, Knoxville Area Transit, King County Metro Transit in Seattle and the State of Maine.
Given the development of hybrid engine technology and the availability of commercial vehicles which employ it, combined with the obvious benefits of its use, don’t you wonder why such busses are not the only ones being used in the United States today?
In 1998, federal legislation was enacted which established the Clean Fuels Formula “Clean Bus” grant program, but the program was never funded, expired in 2003 and requires reauthorization. If it seems preposterous to you that the program was never funded and has not been reauthorized since it expired, perhaps you will be motivated to write letters to our legislators urging action, as just a little lung cancer goes quite a long way.