A Vox article by Rebecca Leber titled “The propane industry’s weird obsession with school buses, explained” has left me struggling to explain some media members’ weird obsession with propane. This obsession seems to be based on a flawed narrative that paints propane-powered school buses as indistinguishable from diesel buses and the propane industry as anti-electrification. Of course, neither of these things is true. So, what’s fueling that narrative? Misleading claims.
Let’s deal with the diesel comparison first. Leber writes that “The US Department of Energy’s National Lab modeled emissions of propane compared to post-2010 diesel buses and found they ‘do not offer significant air quality benefits.’” The 2014 report containing that line is full of sentences, most of which are much more relevant to propane’s benefits. Even the rest of the quoted sentence is instructive: “but replacement of older diesel buses with these propane buses can reduce air pollutant emissions considerably.”
According to the most recent IHS-Polk data, there are 493,089 diesel school buses on U.S. roads today. Over a third of those are older, pre-2010 diesel vehicles. If the goal is to get those buses off the road as quickly as possible and replace them with low- or zero-emission buses, alternative fuels like propane must be part of the solution – it’s simple economics given the relative costs of propane and electric buses.
Leber got it right when she wrote that “The EPA recognizes that propane buses produce some lower emissions, like nitrogen oxides [NOx].” All propane bus engines today are certified to .02 g/hp-hr NOx, which is far below the .035 g/hp-hr limit for EPA and California Air Resources Board (CARB) regulations set to take effect in 2027. Leber doesn’t mention particulate matter emissions here, which are virtually zero with propane engines. NOx and particulate matter are the very health threats that spurred the push to replace older diesel buses in the first place.
And then there’s this puzzling claim: “PERC spent at least $1.2 million from 2018 to 2019 alone on outreach targeting school transportation directors, school board members, and school business officials.” This is news to us. The actual number is much lower, and we’re happy to share real numbers with anyone interested in accuracy.
Another pillar of propane industry criticism, that we are “anti-electrification,” quickly crumbles under the weight of reality. In fact, propane supports fleet electrification through the growing market for propane-powered EV charging.
We readily acknowledge that electric school buses are a clean solution that works in many places. PERC’s messaging around propane school bus adoption addresses the real-world concerns of school transportation officials in areas where electric may not be feasible. Those concerns include unanticipated infrastructure costs, energy costs, charging time, and range. If propane buses can help address those concerns, what’s the harm in saying so? Propane is not a dirty secret; it’s a clean alternative fuel.
Clean school bus advocates should be celebrating propane and electric buses. Why are some disparaging propane? A weird obsession indeed.
The propane industry is obsessed with delivering cost savings and emissions reductions for fleets. We’re obsessed with innovations like ultra-low-carbon renewable propane and the ultra low NOx Cummins B6.7 engine that will deliver some of the lowest greenhouse gas emissions in the medium-duty vehicle market. We’re obsessed with practical steps toward reducing carbon emissions that can be taken today. We’re obsessed with sharing this story in places where propane can make a real difference for children and communities. There’s nothing weird about that.
