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Hybrid School Buses Hit The Road; Researchers Test Their Performance

January 20, 2008
Iowa State University
Two of the first hybrid school buses in the US hit the road this month. The buses use an electric motor at street speeds; their V-8 diesel engines kick in at higher speeds. Researchers will study and evaluate the buses' performance over three years.

You've got to be careful with the accelerator because hybrid school buses like to go.

Dan Taghon, the director of transportation for the Sigourney Community School District in southeast Iowa, said his district's new hybrid bus has been running routes since Jan. 3. And Taghon, who drives the bus on one of the district's six routes, said he likes the 65-passenger machine powered by an electric motor and a V-8 diesel engine.

"It has quite a bit of get up and go," he said. "You push the pedal and it takes right off."

And that's why it takes some practice to get the most out of Iowa's first two hybrid buses, said Rich "Scottie" Scott, the director of transportation for the Nevada Community School District in central Iowa. The hybrid bus there has also been running routes since Jan. 3.

Both districts acquired the hybrid school buses with the help of Iowa State University's Center for Transportation Research and Education.

The buses' electric motors are very responsive to the accelerator, Scott said."Our driver is learning how to operate it," he said. "There's a big learning curve to get all of the efficiency out of it."

Advanced Energy, a nonprofit corporation based in Raleigh, N.C., led the effort to bring the country's first 19 hybrid school buses to school districts in 11 states.

Researchers at Iowa State's Center for Transportation Research and Education worked with Advanced Energy for more than two years to bring the hybrid buses to Iowa. Dennis Kroeger, a transportation research specialist for the center, secured grants that paid for most of the $217,000 cost of each bus. The districts each paid about $70,000, the cost of a conventional bus. The project is also supported by grants of $220,000 from the Iowa Energy Center based at Iowa State; $120,000 from the New York State Energy Research and Development Authority and $83,000 from the Iowa Department of Natural Resources and the School Administrators of Iowa. The grant money also pays for a three-year study of the buses' performance.

The buses feature electric drive trains that can move the buses at street speeds; their diesel engines take over at higher speeds. They also have technology that captures some of the energy of braking and uses that to help recharge their own batteries.

Kroeger said researches will soon hook the buses to portable emissions monitors. They'll also download information from the engines' computers. They'll use the data to evaluate the buses' performance, fuel efficiency and emissions.

And the hybrids should do a lot better than standard buses. Kroeger said fuel efficiency could jump 40 percent to 50 percent, from six miles per gallon for a standard bus up to 10 or 11 miles per gallon for the hybrids.

Taghon, the director of transportation for the Sigourney district, said last week he still hadn't had to refuel his district's hybrid bus.

After eight runs, he said the bus still had half to three-quarters of a tank of diesel.

That has Kroeger thinking hybrid technology has a future in school buses.

"This technology is new to school buses," Kroeger said. "But hybrid electric technology isn't brand new. So the development issues have been worked out. We expect these buses will definitely be able to stretch the fuel dollars."

Story Source:

Materials provided by Iowa State University. Note: Content may be edited for style and length.

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Iowa State University. "Hybrid School Buses Hit The Road; Researchers Test Their Performance." ScienceDaily. ScienceDaily, 20 January 2008. <>.
Iowa State University. (2008, January 20). Hybrid School Buses Hit The Road; Researchers Test Their Performance. ScienceDaily. Retrieved April 13, 2024 from
Iowa State University. "Hybrid School Buses Hit The Road; Researchers Test Their Performance." ScienceDaily. (accessed April 13, 2024).

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