This blog was written by transportation advocate Sam Little.
Twenty-five million students ride the school bus to school every day. That makes school buses the most-used public transit in the country. But unfortunately, our country’s fleet of school buses runs almost exclusively on diesel. That means school buses are spewing toxic exhaust pollution into the lungs of our young learners. With continued exposure, diesel exhaust causes asthma and high blood pressure, among other health problems over time.
The good news is that there is a better way. Already, the EPA’s Clean School Bus Program (CSBP) will kickstart funding to transition our nation’s dirty, diesel school bus fleet to clean, zero-emission electric school buses
PIRG has written extensively about the benefits of this technology for protecting students’ health, and we are actively supporting the CSBP funding electric buses. However, a common concern has cropped up from both sides of the political spectrum. The question is: “Do electric school buses simply push pollution from one place (tailpipes) to another (power plants)?”
This question can come from those skeptical of electrification. They insinuate that electric buses are moving the pollution away from the end-users but exacerbating it elsewhere, whether up the supply chain or at the power plant.
America’s power grids vary wildly in how clean they are. Vermont, for example, almost completely relies on renewable clean energy, while some of the South has more coal-burning plants. Electric buses emission savings do depend on the grid they pull from. However, the Union of Concerned Scientists performed a lifecycle analysis and found that electric buses have lower global warming emissions than diesel and natural gas buses everywhere in the country. In total, replacing the country’s diesel-powered transit buses with electric buses could eliminate more than 2 million tons of greenhouse gas emissions each year.
The other side of the conversation is concerned less with the overall climate impacts and more with the local consequences. These advocates worry that fossil fuel pollution will simply get pushed to communities living near the power plants that provide the electricity used to charge the buses – which often tend to be low income communities and communities of color.
It is an understandable concern. Emissions are complicated. They affect us all, but some would bear the brunt of increasing our power plants more than others. So we calculated how much electricity a nationwide fleet of electric school buses would require to estimate what those impacts would be.
We estimate that we would need to increase our power output by 0.3% to accommodate a nationwide fleet of electric school buses.
To calculate this, we multiplied the 480,000 buses in our nationwide fleet by the 12000 VMT per bus per year and 2.17 kWh per mile. This equals 12,499,200 MWh, the power required for a national ESB fleet annually. In 2021, the U.S. generated 4,120,000,000 mWh of total electricity. So 12,499,200 mWh would be a .3% increase in power required. For context, our nation’s grid increased output by 5% in the last 6 years.
However, these communities have every right to be concerned about any technology that will add pollution to their air – even .3% more pollution. This is why the electrification of our school buses must also go hand in hand with the transition to clean, renewable energy. In many ways, this transition is already well underway with 70% of new energy coming from solar and wind in 2021.
Electric school buses hitch themselves to this ever-cleaning grid while contributing fewer emissions globally. It would be a shame to watch our grid clean up while continuing to invest in fossil fuel-burning buses that poison our children.
Director, Environment Campaigns, U.S. PIRG Education Fund
Matt oversees PIRG's toxics, transportation and zero waste campaigns and leads PIRG’s climate program to promote a cleaner, healthier future for all Americans. Matt lives in Amherst, Massachusetts, with his wife, two daughters and chihuahua.