Schools Turn to Propane Buses as Stricter Emissions Standards Loom

Source: By  DIANE CARDWELL, New York Times • Posted: Friday, May 22, 2015

MACON, Ga. — For many Americans, propane is that stuff from the home improvement store that fuels backyard barbecues and patio dinners. But in a growing number of cities across the country, it is what gets children to school.

Of the top 25 school bus markets, 19 have propane-fueled vehicles in their fleets, including New York, Chicago, Houston, Los Angeles, Miami, Philadelphia and Phoenix. Boston just bought 86 of the alternative-fuel buses for the fall, while in the Mesa County Valley district in Grand Junction, Colo., administrators recently signed a five-year, $30 million contract that includes 122 propane buses.

And here, about an hour and a half southeast of Atlanta, Bibb County school administrators are so happy with the 33 buses they started running last year that they have ordered 20 more.

With tougher emissions standards looming and the constant pressure to save money, propane has become increasingly attractive as an alternative to traditional fossil fuels for some vehicles. Burning propane reduces greenhouse gas emissions by 22 percent compared to gasoline-powered buses or 6 percent compared to diesel, according to the Propane Education and Research Council, an industry-funded group.

Sales of new diesel buses, which run cleaner and safer than older models, their proponents say, outstrip those using propane. But it is one among many alternatives that vehicle fleets are finding to traditional gasoline and diesel fuels.

The number of alternative fuel fleet vehicles on the road has steadily increased in the last decades, reaching nearly 1.2 million in 2011 from 247,000 in 1995, according to the Department of Energy. Most run on ethanol, propane, compressed natural gas and electricity.

Other fuels are increasingly in the mix, including liquefied natural gas for long-haul trucking and biomethane, derived from decomposing organic waste. This month, for instance, United Parcel Service announced an agreement to buy such renewable natural gas from Clean Energy Fuels, a company backed by T. Boone Pickens, for its alternative fuel and advanced technology fleet. Over all, the company has more than 2,500 vehicles that run on alternative fuels.

In Blue Bird, a leading manufacturer based in Fort Valley, about 35 minutes southwest of here, said that the annual demand for its propane buses — often distinguished by a green bird logo in place of the traditional black — had increased to thousands from hundreds since 2011, said Phil Horlock, Blue Bird’s chief executive.


Students in Macon, Ga. Propane buses cost about $15,000 more than diesel, but are cheaper to operate and maintain. CreditGrant Blankenship for The New York Times 

“Everyone wants to show their school district, their parents in the school district, ‘Hey, I’ve got a green fuel here — we’re doing great things for the environment,’ ” he said. Nationwide, there are 480,000 school buses, the American School Bus Council estimates.

The fuel, a byproduct of oil refining and natural gas processing, is abundant and less expensive than diesel, running about $1 less per gallon equivalent in Bibb County, for instance. School districts using the fuel have generally been able to claim a federal alternative fuel tax credit of 50 cents per gallon.

Proponents of the fuel’s use say that although it is highly flammable, it is less so than other petroleum products used in transportation. It ignites only when the propane-air mix contains 2.2 to 9.6 percent propane vapor — considered a narrow range — and at a temperature of at least 940 degrees, much higher than gasoline’s ignition point of 430 to 500 degrees, according to the propane council.

The buses, which now represent about 20 percent of Blue Bird’s business, come at a premium — about $103,000 for the buses on the way, Mr. Jackson said, roughly $15,000 more than a diesel model — but they are cheaper to operate and maintain, requiring less oil and fewer filters than conventional vehicles.

Although companies running other types of vehicle fleets — delivery vans, city buses, long-haul trucks — are likely to continue migrating toward compressed or liquid natural gas for similar economic and regulatory compliance reasons, propane has other potential applications, said Roy Willis, chief executive of the propane council.

Esther Muhammad in her school bus. Bus drivers say that students riding in the quieter buses tend to be quieter, too. “When I had to use a spare bus and it was loud, they’re loud,” she said. CreditKevin Liles for The New York Times 

For instance, the fuel is becoming popular for use in smaller motorized equipment like lawn mowers, especially at golf courses near residences because the lower noise allows work to start earlier.

With the school buses, that relative quiet may offer a different benefit, administrators and operators say: It helps make the children, and the ride, more orderly and easier to manage. On the diesel buses, said Cami Hamlin, the assistant principal at Springdale Elementary School, the children often yell, which can be distracting or it difficult for the driver to spot problems.

“They’re not trying to be trouble — they’re just trying to talk to their friends,” she said, adding that this year she had not had to discipline any children for disruptions on the propane buses. “Riding the bus to school or even going on a field trip, you can actually have a conversation. Kids can actually talk to their friends and hear without being a safety hazard to the bus drivers.”

Esther D. Muhammad, a driver, said that she, too, had noticed the difference among her charges.

“When I had to use a spare bus and it was loud, they’re loud,” she said.

Even some of the riders say the buses are quieter — though they are hardly rolling libraries.

“It’s kind of noisy sometimes because of all the people talking,” said Tyler Otero, 9, who used to ride a diesel bus. “It was louder last year, but it’s still loud.”