You can have a cleaner fleet tomorrow. So goes the marketing push for biodiesel, an alternative fuel that promises emissions reductions, local economic benefit, national security rewards and few additional costs beyond the price differential for traditional diesel fuel.
A growing number of school districts is filling up on that promise.
In New Jersey, Medford Township Public Schools has switched half of its fleet from petroleum diesel to an 80/20 blend of petroleum diesel and vegetable oil (B20).
The biodiesel program, part of a U.S. Department of Energy (DOE) demonstration, kicked off in 1997 when the incremental cost was $1.05 per gallon. Seven years later, 22 of the 44 buses are still running on the stuff, at only 20 cents more per gallon than conventional diesel, according to Joe Biluck, Medford’s director of operations and technology.
Biluck says Medford’s experiment with biodiesel was prompted by a desire to prove two points: that the fleet could run on an alternative fuel without adverse effects and that biodiesel would lead to a significant reduction in emissions. Biluck says his buses are running smoothly, with noticeably less noxious fumes.
Not just an illusion
But there’s more than just anecdotal evidence. The Environmental Protection Agency (EPA) found decreases of 10 percent in carbon monoxide, 10 percent in total hydrocarbon emissions, 15 percent in particulate matter and 20 percent in sulfates for diesel engines running on B20.
Says Janet Cohen, team leader for the EPA’s Clean School Bus USA program, “I think everybody is motivated to reduce exposure to diesel exhaust.”
In Michigan, Mike Thompson, transportation supervisor for Ithaca Public Schools, has noticed less smoke from his fleet, a less powerful stench in his power washer and a marked improvement in one driver’s serious asthma since he began running his 30-bus fleet and maintenance vehicles on B20 last April. The dramatic effect on drivers is an often unheralded, but substantial, positive of moving to alternative fuels.
“Drivers are the ones who are out there first thing in the morning, starting up and doing pretrips,” says Pauline Gervais, director of transportation for the Denver-area Adams Twelve Five Star Schools. Especially in colder climates, biodiesel has the potential to reduce the drivers’ exposure to unhealthful emissions of an idling petroleum diesel engine.
There are other green reasons to pursue biodiesel. Its higher flashpoint makes it safer to handle and the percentage of biodiesel that is not petroleum-based is biodegradable and a renewable resource. While most biodiesel is derived from soybean oil, it can be made of any vegetable oil, including recycled cooking oil. School buses in Clark and Washoe counties, the two largest in Nevada, are fueled by used cooking oil from casinos and fast-food restaurants.
Easy to climb aboard
While biodiesel is not the only alternative fuel that offers similar environmental advantages, fans like Biluck say the ease of implementation sets it apart.
“There’s no additional tanks, facility upgrades or dedicated vehicles,” Biluck says. “You can use it on one or two vehicles to get comfortable with it and then expand ... it’s a win-win for both the municipality and the residents of the community and state.”
A seamless transition is what sold a consortium of 12 Denver-area school districts represented by the Regional Air Quality Council (RAQC) on biodiesel. The group received $400,000 of $5 million in available grant money from the EPA’s Clean School Bus USA program. They plan to use it to install diesel catalyst mufflers and to cover the incremental cost of moving to B20.
“We do have access to compressed natural gas and propane, but there’s a cost incurred making that switch,” says Gervais, a participant in the grant program. “With biodiesel, if you have a bus making a long trip, it can just pull up to a gas station and fill up with diesel.”
Differential can vary widely
The cost of biodiesel is in the fuel. Incremental differences are anywhere from 10 to 24 cents a gallon. Jenna Higgins, a spokeswoman for