Don't ask Cliff Galante, director of the city's public transit system, for the fuel mileage on one of his big diesel buses. It's not a statistic he figures often because he knows it always produces a discouraging number.
"With big diesel engines like that, you always get less than 10 miles per gallon," Galante said. "They aren't really made for fuel efficiency."
But if work that rural Lawrence resident Karl Birns is conducting becomes successful, transit operators everywhere may have a new answer when asked how many miles they can get to the gallon: As many as you want.
Birns, director of research for the Metropolitan Energy Center in Kansas City, Mo., is among a group of transportation leaders developing a new generation of electric buses.
They're called hybrid-electric plug-ins, which are different than most electric buses on the market and the hybrid cars and trucks available at auto dealerships. Most hybrid vehicles rely on a gasoline or diesel engine to recharge their batteries as they're being used.
A plug-in hybrid, though, theoretically doesn't have to use any petroleum-based fuel. Instead, the vehicle is just plugged into a conventional 110 volt or 220 volt outlet and is recharged overnight.
The vehicles aren't just pie-in-the-sky ideas drawn up on an engineer's chalkboard. A prototype of the bus - the first in the country - is scheduled to arrive from a DaimlerChrysler factory in Germany in the next couple of weeks. It will be put into service in Lawrence's backyard by the Kansas City Area Transportation Authority.
"We're going to put it through the paces and really check it out," Birns said. "But I think this has a lot of potential in the world of transit."
More specifically, the technology may have a future in Lawrence. Birns and the project's partners - which also include the Federal Transit Administration, Electric Power Research Institute and various Kansas University departments that will conduct air-quality testing - are lobbying Congress for an additional $1 million in funding.
If that funding materializes, Birns said it is possible another bus could end up in Lawrence to test how it performs in a less urban environment.
Several city commissioners would love for the community to be a guinea pig.
"Lawrence is the type of community that should be on the cutting edge of something like this," City Commissioner Boog Highberger said. "We should be leaders in this area."
City leaders are particularly interested in new bus technology because the city will be in the bus-buying business during the next several years.
The city's current fleet of 12 fixed-route transit buses have about 220,000 miles on them. Galante said the 5-year-old vehicles are rated for 350,000 miles, and he estimates the city will need to begin replacing the buses in about three years.
That won't be cheap. Heavy-duty diesel buses - the kind that Galante said he most likely would recommend - cost about $320,000 apiece. Medium-duty diesel buses, the kind the city owns now, are in the mid- to upper $200,000 price range.
Some city commissioners are saying they want to make sure that Galante gives a strong look at alternative fuel buses, which can cost 10 percent to 15 percent more than traditional buses but are thought to have lower operating costs.
"At the moment, I can't imagine why we wouldn't want to do this," said City Commissioner David Schauner, though he said the city obviously would need to do more research.
Galante said he has no problem looking at the possibilities.
"We're enthusiastic about it," Galante said. "But ultimately it always comes down to cost and reliability when you are looking at alternative energy."
Some of it may come down to timing as well. The bus that Birns is working on likely wouldn't be available for production before 2010.
There's also much to learn about how the buses will perform in the real world. For example, Birns notes that a plug-in hybrid bus theoretically could run without burning any fossil fuels. But that's not the way it is expected to work in practice.
The prototype bus is equipped with a diesel engine to supplement the power of the electric engine during peak demand. Without the diesel engine, the bus' batteries likely would last only for about 40 miles.
Lawrence leaders, though, will have plenty of other options to consider. There currently are buses that burn propane, natural gas or biodiesel, which is a type of diesel produced from soybeans or corn. The largest movement in the transit industry, however, is the use of traditional hybrid-electric buses that use a diesel engine to recharge their batteries.
According to a 2005 report by the U.S. Department of Transportation, about 60 communities are using the hybrid-electric buses, though some people question whether they are much more fuel efficient than standard diesel buses.
Birns also points out that those buses aren't quite as environmentally friendly as the plug-in hybrid because they still rely on fossil fuels to recharge their batteries.
Of course, the argument could be made that the plug-in hybrid buses rely on coal-burning power plants to produce the electricity they use. But Birns said he still thought the plug-ins would be a better option because the electric industry seems to be moving toward more environmentally friendly ways to produce electricity, such as wind energy.
"I'm really excited about what we're working on," Birns said. "I think it will be big in the transit world, but really I think it is going to be the way of the future for almost all transportation. It is going to be so much more efficient in fuel costs, and that is what everyone is looking for these days."