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More Boston school buses should be propane, not electric

Three propane buses can be purchased for every one electric bus, taking more dirty diesel buses off city streets faster.

Safety supervisor Edward Clarke stands near a propane-fueled bus in Boston in 2015.Craig F. Walker

Boston Mayor Michelle Wu recently unveiled a new plan for the city to buy 20 electric school buses for next school year. While that may sound both prudent and a form of climate justice, those public funds would be better spent on propane school buses.

The decision to focus on electric buses is curious, considering all the factors involved. Propane buses are already here. Nearly 400 are in Massachusetts, with over 300 in Boston alone. Another dozen new propane buses will soon begin transporting students thanks to Massachusetts grant funding provided by the US Environmental Protection Agency.

Thus, it would seem the city’s commitment to propane buses is already present. Why? For one, the answer is cost. Three propane buses can be purchased for every one electric bus, taking more dirty diesel buses off city streets faster. In other words, instead of 20 electric buses coming online at the beginning of the next school year, there could be a minimum of 60 propane buses, and probably more.

Propane, a byproduct of natural gas processing which costs up to 50 percent less per gallon than diesel, burns cleaner than any other fuel — conventional or alternative — which dramatically reduces the cost of maintenance, including oil and filters and labor. Plus, a local propane provider can install an onsite refueling station at low or even no cost with signage of a long-term fuel contract. That eliminates the wild fluctuations in diesel costs, exacerbated by the world’s geopolitical situation.


All of those savings can go right back into the classroom. In fact, according to the World LP Gas Association’s 2018 report, “The role of LPG in shaping the energy transition,” if all of the nation’s diesel school buses were converted to clean-operating propane, US school districts could hire more than 23,000 teachers with the fuel and maintenance savings.


Then there are the environmental factors. Just like electric buses, propane buses eliminate the harmful black smoke that comes out of a diesel tailpipe.

According to a West Virginia University study released in 2019, propane school buses dramatically reduce nitrogen oxides by more than 90 percent compared with diesel buses. The EPA says exposure to NOx can exacerbate health problems like asthma, bronchitis, and other respiratory issues. In the developing lungs of school-age children, asthma is particularly problematic because it’s one of the leading causes of absenteeism. Kids should be at school and not at home battling breathing problems caused by dirty air.

The study was completed by WVU’s Center of Alternative Fuels, Engines and Emissions — the same group that exposed the Volkswagen emissions violations in 2015. The school bus study’s results demonstrated that distance-specific NOx emissions measured from a diesel bus were significantly higher than those measured from a propane bus. What’s more, it proved that propane school buses reduce harmful NOx emissions by 93 to 98 percent under real-world driving conditions, including stop-and-go conditions characteristic of school bus operations.

Electricity in Massachusetts is primarily produced by natural gas-fired generators. Battery electric buses don’t eliminate emissions; they simply move those emissions upstream to power plants, which are typically in or near vulnerable communities. At the same time, propane buses take the pressure off our fragile electric grid, and there are no concerns about eventual battery disposal.

At 400 miles, propane buses also have four times longer range than electric buses, helpful especially for after-school activities. And, refueling takes minutes, as opposed to hours for recharging. Propane is also an exclusively domestic fuel — 90 percent is generated here in the United States, with another 7 percent from Canada.


Wu and the city should take a long, hard look at propane school buses because they are the most convenient and cost-effective means to craft the city’s clean future.

Tucker Perkins is president and CEO of the Propane Education & Research Council based in Washington, D.C.