Schools consider propane-fueled buses
The largest ground transportation system in the country is gearing up again, and that means confronting the rising cost of fuel. School buses shuttle some 25 million kids on school days, and while most districts have had a summer’s respite from gas prices, those bills will start coming due again soon.
“Even [districts] that budgeted for a significant increase didn’t budget for a 100 percent price increase,” says Mike Martin, executive director of the National Association for Pupil Transportation. Last fall, he says, fuel cost about $1.95 a gallon. By spring, it was $4.05 in places.
So why not switch to a fuel that’s not only cheaper, but greener as well? Some have done so already: The Portland, Ore., school district, for example, received a $600,000 federal tax credit last year for its liquid propane-fueled buses. Propane is cheaper and cleaner than diesel, which powers about 90 percent of the country’s 500,000 school buses.
“I was not a believer in propane,” says Phil Weber, Portland’s director of student transportation. “But I crunched the numbers and propane does pay off.”
Portland has used propane buses since 1983. But making the switch requires up-front investments in infrastructure and bus conversions or purchases.
John Kelly, executive director for transportation and support services at the Richardson, Texas, public schools, says the June fuel bill alone for his maintenance and operations fleet was $30,000. It had averaged just $8,000 a month a few years ago. “That takes a bite out of the budget,”
Mr. Kelly says. Of the school district’s 34,000 students, some 5,000 take the bus.
But by next spring, Richardson students will be riding buses fueled by propane, a move Mr. Kelly hopes will cut fuel costs by 50 percent.
Working with Dallas County Schools, the district considered switching to either biodiesel or propane, but propane is readily available for less than $2 a gallon, Kelly says.
Another incentive for the switch was the fact that the Environmental Protection Agency (EPA) has designated North Texas a “nonattainment” area, meaning that it does not meet federal standards for air quality. Since then, the district has gotten the OK to build a propane fueling station, Kelly says.
Some 130 school districts and other school-bus operators nationwide run more than 2,600 natural gas and propane school buses, according to a 2001 report by the Natural Resources Defense Council. This is admittedly only a small fraction of the 14,000 or so school districts across the nation.
The Northside Independent School District in San Antonio, Texas, currently fuels some 250 of its 700 school buses with propane, and was the first school district to order 16 new Bluebird buses built propane-ready.
About half of Northside’s 85,000 students rode in gasoline-, biodiesel-, or propane-fueled buses last year, costing the district about $2.32 a gallon for gasoline, $2.62 a gallon for “green diesel,” and $1.54 for propane, says Pascual Gonzalez, Northside’s communications director.
It’s the right time for districts to move to propane, says Roy Willis, president of the Propane Education and Research Council (PERC).
“It’s less expensive than gasoline or diesel fuel, and propane has close to 80 percent of the range” of these fuels, Mr. Willis says. Portland’s small propane buses got about six miles per gallon, while its gasoline-powered buses got seven miles per gallon, and diesel, eight.
Government assistance also helps make propane more affordable. A federal tax credit gives districts 50 cents back on every gallon of propane.
And for 2008, Congress appropriated $49.2 million to help reduce emissions from diesel engines, including school buses. That means that federal grants are available to retrofit or establish the infrastructure needed to run a clean-fuel station or purchase a bus that can run on alternative fuels. States like California and Texas lead the way in programs offering to pay much of the cost to retrofit or buy a new bus that can run on alternative fuels.
The economics of propane work better on the West Coast than in the East. According to the April 2008 quarterly Clean Cities Alternative Fuel Price Report by the US Department of Energy, propane on the West Coast was almost $1 per gallon cheaper than gasoline. But Central Atlantic states on average paid 40 cents more per gallon for propane than gasoline.
“These are tough economic times, and I just don’t know if it’s in [districts’] mind-sets to do this,” says Diane Bailey, senior scientist for the Natural Resources Defense Council. “If you’re in a remote area ... it’s just not the cost of fuel but [also] infrastructure.”
Weber says it took Portland about five years to recoup the cost of propane fuel pumps and engine retrofits. A small bus built to run on propane may cost $7,000 to $10,000 more than a regular bus, he says. The price tag for a retrofit is about $6,000.
Some 100 school districts use biodiesel, says Jenna Higgins, communications director for the National Biodiesel Board. Changeover from diesel is quick: Biodiesel can go right into an existing engine, though attention to filters and viscosity is important. It’s more expensive than propane or regular diesel, but “in many respects it’s the least-cost technology,” because retrofits and pumps aren’t an issue, Ms. Higgins says.
Both propane and biodiesel minimize environmental damage. Higgins says emissions for B20 (diesel that contains 20 percent biodiesel) and propane engines are measured differently, but that biodiesel significantly reduces carbon emissions. Her agency’s website lists carbon monoxide exhaust emissions an average of 48 percent lower than such emissions from diesel. Particulate emissions are 47 percent lower for biodiesel than for diesel. Mr. Willis of the Propane Education and Research Council says propane also offers big reductions: 90 percent less nitrous oxide, and up to a 24 percent reduction in other emissions. New propane buses, according to PERC, can reduce particulates in exhaust by 99 percent.
Despite Portland’s success with propane, Weber questions the likelihood of districts switching to alternative fuels if gasoline prices stabilize.
“Every time fuel takes a jump, people get excited [about propane],” he says. “Then, it goes back down and people walk away from it.”
