There are nearly half a million school buses in the US and a new study, published yesterday, puts a price on the benefits of replacing the old diesel variety with electric ones.
The report finds that replacing a seven year-old diesel school bus with electric would result in $84,200 in health and climate benefits, increasing to $247,600 if the bus dates from 2005 or earlier in a large metropolitan area.
Claiming to be the first study to specifically quantify the health and climate benefits of replacing diesel school buses with electric ones, the researchers believe their findings should encourage an acceleration of the transition to clean school vehicles.
Senior author Kari Nadeau, John Rock Professor of Climate and Population Studies and chair of the Department of Environmental Health, said: ‘Research on air pollution and climate change should strive to quantify health benefits,. Our findings can inform policymakers that greenhouse gas emissions and air pollution are reduced by implementing solutions like electric vehicle use. Our data offer strong evidence that accelerating the ongoing transition to electric school buses will benefit individual, public, and planetary health.’
The researchers compared the amounts of CO2 emitted from diesel school bus tailpipes and from electric school buses’ electricity generation and battery production. To assess the buses’ health impacts, the researchers compared how their respective emissions contribute to PM2.5.
The study found that an electric bus emitted 181 fewer tonnes of carbon dioxide than its diesel counterpart, amounting to $40,400 worth of climate benefits. Meanwhile, each electric school bus was associated with $43,800 in health savings, from less air pollution and reduced rates of mortality and childhood asthma.
The study also found that electric school buses’ health benefits vary depending on location and the age of the diesel bus being replaced. Large metropolitan areas – those with a population of more than one million – would derive the greatest health benefits from electrifying their fleets of school buses, given the larger number of people whose air quality is improved.
The researchers calculated that, in a large city, replacing a 2005 diesel school bus with an electric bus would achieve $207,200 in health benefits per bus.
One of the reasons that local, state, and federal officials are slow to replace their diesel bus fleets is the expense and the researchers hope that their work may highlight the financial benefits of electrifying the fleets sooner.
Nadeau said: ‘In a dense urban setting where old diesel buses still comprise most school bus fleets, the savings incurred from electrifying these buses outweigh the costs of replacement. Not to mention how the tangible benefits of electric school buses can improve lives—especially for racial minorities and those living in low-income communities who are disproportionately impacted by the everyday health risks of air pollution.’
Nadeau and her co-authors noted that the study did not tackle one important question: how electric school buses impact children’s exposure to in-cabin air pollution while riding the bus. They suggest that additional research into this topic is needed.
The full paper can be read here.