For many Americans, propane is that stuff from Home Depot that fuels backyard barbecues. 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 Colorado just signed a 5-year, $30 million contract that includes 122 propane buses.
And 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. “They’re healthier, they’re cleaner burning, they’re much quieter than the diesel option,” said the transportation director. “Right now, it’s projected that over time we’ll see significant savings.” Burning propane reduces greenhouse gas emissions by 22% compared to gasoline-powered buses or 6% compared to diesel.
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, reports The New York Times (May 22, 2015). Most run on ethanol, propane, compressed natural gas and electricity. 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. School districts using the fuel have generally been able to claim a federal alternative fuel tax credit of 50 cents per gallon. The buses, which now represent about 20% of manufacturer Blue Bird’s business, come at a premium — about $103,000, 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.
Classroom discussion questions:
1.Have your students prepare a life cycle analysis, as we present in Supplement 5, comparing the propane vs. diesel options. Gather data from the internet on costs and mileage.
2. What are the advantages of propane over diesel or gas buses?