When you hear the term “EV,” you probably think of a car, but it is a big umbrella. E-bikes and scooters fall under the category as well, and so do buses. Public transit is already a fairly green choice. Given the large size of bus battery packs and their pre-existing efficiency for mass transportation, does switching buses to electric appreciably lower emissions? Is it worth the work and cost of adding commercial charging infrastructure?

Electrified buses are cleaning up urban transit

One of our first stops in answering these questions is the Joint Office of Energy and Transportation. This is a very specialized government group that actively supports the electrification of public transit, offering resources and technical assistance to local agencies.

They tell us that over the lifetime of a single battery electric bus, total greenhouse gas emissions are estimated to be 1,192 short tons versus 2,112 short tons in its diesel equivalent. That is more than 40% difference and that is a compelling argument for electric buses purely on climate impact.

The Joint Office of Energy and Transportation pointed us to the AFLEET online tool, which estimates everything concerning transit emission scenarios. For example, one all-electric transit bus operating in the District of Columbia has a fuel economy estimated at 11.2 miles per diesel gallon equivalent (MPDGE), while a diesel transit bus is estimated at 4.4 miles per gallon (MPG). Because in terms of emissions, getting almost twice the mileage is pretty darn good.

And let’s not talk only about greenhouse gases; there are local emissions too. From the station to the street, the public transit rider is subjected to all sorts of particulates. The American Lung Association said that we can decrease incidences of pediatric asthma attacks and infant deaths through the reduction of direct emissions from transportation.

Cumulatively, adoption of zero-emission vehicles could yield $978 billion in public health benefits, sparing 89,300 from premature deaths, 2.2 million asthma attacks, and 10.7 million lost workdays. This benefit would be equitable, as low-income people tend to travel by bus.

Related: Plug-in Hybrid Electric Vehicles: 7 Things You Need to Know

By conveniently centralizing DC fast chargers in maintenance-friendly bus depots, electrified buses get their chargers sometimes relatively akin to consumer vehicles. Nonetheless, much more charging points are to be installed out within service areas to be able to have electric buses run consistently up time, where programming of bus routes also needs modifications for such.

Public transit is the first step in electrifying buses, as school buses actually move greater volumes of people every day. More than 25 million kids in the U.S. ride a school bus every day. Set schedules with big breaks in between provides predictability for school bus charging and grid demand. Bus batteries are so big that their potential contribution in vehicle-to-grid energy on this timetable is promising.

Through schemes like that provided by Zum in Oakland, school buses can help power homes during peak evening hours when the grid is under the most strain. These buses can even start paying back their up-front cost through net metering, whereby schools earn credit on their electrical bills by feeding power back into the grid when it’s needed most. As we look for success stories, it’s hard to ignore China.

Quote-“They have about half a million EV buses on the road now. That suggests we could be doing more in this space. I would not be surprised if China is 80% of the world’s electric bus fleet,” says Knittel. Christopher Knittel is from the Center for Energy and Environmental Policy Research at MIT. He is an economist who has spent considerable time looking at costs, challenges, and opportunities surrounding transit electrification.

Indeed, he is spot on when it comes to China’s reality. Validated by the last tally in 2022, China’s pure electric buses were about 455,500, accounting for 64.8% of the global share at the time. In comparison, the U.S. was in possession of slightly more than 6,000 battery electric buses in 2023.

The most notable area is Shenzhen. This tech hub is at the border of Hong Kong, where many of our gadgets were built. Seven years ago, local talent applied themselves to making electric all of their 16,000 buses. Since then, they have made their entire taxi fleet electric, showing that it can be done, but government support is crucial.

Bumps in the road

Why haven’t we flipped the switch already and electrified America’s bus fleets?

This is because we need to wait for the gas-guzzlers to retire. Municipalities have spent good money on the buses they have, and with tight budgets, it makes no financial sense to retire them while they are still functional. According to 2021 statistics, nearly 22% of the entire American bus fleet is eligible for retirement, which isn’t a huge number to start with.

Even then, once diesel buses have been retired, the electric alternative costs more than three times the cost of fossil fuel buses; it’s a bitter pill to swallow, even with savings in fuel and maintenance costs in the long run. It would take $8.5 billion to replace the 22% of bus fleet as at 2021 and another $2.0 to $3.1 billion to replace the three to four thousand buses retiring each year until 2035. On the flipside, Chicago’s transit authority estimates that they would save about $25 millions in annual costs if the fleet were entirely converted.

Climate affects performance as well. Batteries aren’t happy either at higher temperatures, which demands more energy to cool. That extra energy can rob anywhere from 25% of range, depending on conditions. One rollout in Albuquerque was delayed due to the inability of the buses to heat, among other issues, and the city has proceeded to expand their electrified fleet. Indianapolis had to add additional wireless charging stations to compensate for reduced range due to cold weather.

Related: What Is the price of charging an electric car?

What next?

Answering a question on how to improve electrified fleets’ adoption in the U.S, Knittel pinned his hopes on policy changes.

“I would love to see more federal guidance on this. We can leave it up to municipalities. We can leave it up to the states. We can leave it up to school districts. But there is potentially a lot of economies of scale here. Unless we have market coordination across states and cities, we just are not going to have access to the cheapest and best technologies.”

New York has passed a mandate that school transportation is to be converted to electric buses. California has similar legislation that will see public transit completely switch to electric as of 2040. Such new tax credit incentives in the Inflation Reduction Act will be among federal-level incentives for commercial EVs and charging infrastructure, plus about $1.5 billion direct electrification funding being provided. Such funding will take time to be felt. It’s a good start, but there’s still a long road to travel yet.