More than 90% of vehicle-owning households in the United States would see a reduction in the percentage of income they spend on transportation energy if they switched to electric vehicles, research finds.

And more than 90% of households that replace gas-powered vehicles with EVs would also reduce the amount of climate-warming greenhouse gases they generate, the findings show.

However, more than half of the lowest-income US households (an estimated 8.3 million households) would continue to experience high transportation energy burdens, defined in this study as spending more than 4% of household income on filling the tank or charging up.

“Our results confirm the potential for widespread benefits from EV adoption,” says corresponding author of the study Joshua Newell, an urban geographer at the University of Michigan Center for Sustainable Systems, part of the School for Environment and Sustainability.

“However, EV ownership in the US has thus far been dominated by households with higher incomes and education levels, leaving the most vulnerable populations behind. Policy interventions are needed to increase EV accessibility so that all Americans can benefit from the EV transition.”

The new study appears in the journal Environmental Research Letters. It is the first study to consider the spatial variation of both EV energy costs and greenhouse gas emissions across the country.

It’s also the first study to examine EV energy costs through the lens of distributive justice by calculating the EV energy burden (percentage of income spent on EV charging) for the entire United States. Distributive justice concerns the fair distribution of benefits and burdens.

EVs currently account for about 1% of the cars, SUVs, and pickups on American roads. If all those vehicles were replaced with new EVs, the transportation energy burdens and associated greenhouse gas emissions would vary widely from place to place, according to the new study.

Reductions in both transportation energy burden and GHG emissions would be especially pronounced on the West Coast and in parts of the Northeast, due largely to cleaner energy grids and lower electricity prices.

Households in some locations could reduce their annual transportation-energy costs by $600 or more, and cut their annual carbon footprint by more than 4.1 metric tons of carbon dioxide equivalents, by buying a new EV.

But lower-income households in other parts of the country wouldn’t fare as well, Newell says.

Very high EV transportation energy burdens, ranging from 10% to 64%, would persist for the lowest-income households and would be concentrated in the Midwest and in the two states with the highest electricity prices: Hawaii and Alaska.

Of US households, 8% (an estimated 9.6 million) would see low savings in both transportation energy burden and greenhouse gas emissions by choosing an EV. “Both low” households are scattered across the country, with about half of them in Midwest states.

Read the full article about electric vehicles by JIm Erickson at Futurity .