Hybrid school buses hit the road; Iowa State researchers test their performance

AMES, Iowa -- 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."

The two school districts will show off two of the country's first hybrid school buses during short ceremonies on Thursday, Jan. 24:

  • The Nevada event will be at 9 a.m. at the school district's bus garage at 157 11th St. South.
  • The Sigourney event will be at 2 p.m. at the school district's bus garage at 807 N. Main St.
The Sigourney school district's hybrid bus.

The Sigourney Community School District's hybrid bus is running two rural routes a day. Photo by Dennis Kroeger.

The events will feature short remarks by the districts' superintendents, Jim Walker in Nevada and Todd Abrahamson in Sigourney. People can also look over the buses built by the IC Corp. and equipped with an Enova Systems Inc. hybrid electric drive train. Short bus rides will also be offered. The events are free and open to the public.

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 (CTRE) 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 Energy Center's participation in the bus project, along with all the other national sponsors, proved a force that moved manufacturers to develop the first generation of hybrid electric school bus," said Floyd Barwig, the director of the Iowa Energy Center. "We look forward to having CTRE analyze the energy and environmental performance of the buses so we can pass that information along to other schools in Iowa."

The hybrid 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."