Phasing in electric cars and trucks is a widely recognized benchmark in any plan to cut greenhouse gas emissions. Now there’s a new stop being proposed on Maine’s long, ambitious climate-change journey – battery-powered school buses.

A bill in the Legislature this winter will ask the Department of Education to help transition Maine’s fleet of 3,000 school buses to all-electric by 2040. The process would start this year, with the department setting aside money for e-buses as part of its ongoing vehicle addition and replacement program for school districts.

School buses may not be top of mind in climate change-fighting priorities. But transportation is the single largest source of Maine’s greenhouse gas pollution, accounting for more than half its total emissions. And school buses are the largest means of public transportation, logging 30 million miles and burning 5 million gallons of diesel fuel each year in Maine, according to state estimates.

For those reasons, school buses present unique opportunities. But helping big yellow to go green presents special challenges.

E-buses are cleaner, especially if the power to charge them comes from a grid heavily supplied from renewable sources. Maine checks off that box. And because electric motors have  fewer parts, maintenance is cheaper. Thomas Built Buses, an industry leader, estimates an electric school bus can save $4,400 a year in maintenance and $2,000 in fuel, compared to diesel.

With their large arrays of lithium-ion batteries, the school buses also can become energy storage units when they’re not in service. Emerging vehicle-to-grid technology offers the potential for e-buses feeding power to the grid during periods of high demand, a new revenue source for school districts. That’s happening in New York and California, and is set to start in Virginia.

But just like cars, e-buses are more expensive than their internal-combustion peers – $300,000 or so compared with less than $150,000. Range is an issue, too. Today’s batteries can power a school bus for roughly 100 to 130 miles.

Cold weather and long rural routes – common factors in Maine – could reduce that range. And then there’s the cost of installing charging stations, and training staff to drive and maintain something different.

But funding has just come through to finance the first school e-bus in Maine.

In a competition for money available from the Volkswagen settlement, in which the carmaker agreed to pay $14.7 billion nationally toward pollution mitigation to settle an emissions-cheating scandal, Mount Desert Island High School won $280,000 to offset most of the cost of a new electric bus.

The award reflects the fact that many school district transportation heads say they’d be interested in e-buses, according to an education department survey sent out last year. Disregarding price, the survey asked, would your district welcome the opportunity to get an e-bus? Fifty-three managers said they would. Fifteen said no.

The survey was encouraging to Sen. Eloise Vitelli, D-Arrowsic, the bill’s lead sponsor.

Vitelli supports Gov. Janet Mills’ goals to reduce Maine’s greenhouse gas emissions by 45 percent in 10 years and 80 percent by 2050. After becoming aware of an e-bus program in Massachusetts, she sought to create some incentives in Maine.

“Given where Maine is with climate change,” Vitelli said, “school buses would be a good thing to add to the mix.”

Vitelli’s bill builds on the current process of the state’s school bus purchase program. It accepts applications from districts for financial help with replacing old buses or adding new ones.

The department gives out $9 million a year and in the last fiscal year received 217 requests and approved 89 buses. Among the criteria is vehicle age and mileage. For instance, a typical school bus needs to be at least 10 years old and have 125,000 miles on it to qualify for replacement.

Vitelli’s bill envisions changes in existing criteria to add electric buses, as well as setting aside “some percentage of existing resources” for districts to buy e-buses and charging stations.

“Over the life of an electric bus, the savings are there,” she said. “It’s funding the upfront cost that’s the problem.”

SOME STATES DRIVING AHEAD

One solution could be to start small, with a pilot program.  That’s set to happen this year in Vermont.

Applications are in for a two-year demonstration project that will involve two school districts and one transit agency, according to Energy News Network. The pilot would tap money from Vermont’s share of the Volkswagen settlement. Noting that school district budgets are always tight, a consultant running the program, the Vermont Energy Investment Corp., said utility programs or some source of outside revenue is needed to bring the new technology to schools.

In Virginia, some of that money is coming from a regional power utility. Richmond-based Dominion Energy is partnering with Virginia school districts this year to replace 50 diesel buses with e-buses. It then plans to add 200 e-buses a year for the next five years. It will provide charging stations at no cost.

Dominion cites several benefits. For schools, operations and maintenance costs will drop by 60 percent, it says. For the planet, replacing 1,050 buses over five years will reduce carbon dioxide emissions by 810 million pounds, equal to taking 78,000 cars off the road.

For Dominion, the buses can be a new electricity source for balancing intermittent renewables and backstopping power outages. The company estimates the batteries in 1,050 buses can store enough energy to run 10,000 homes.

‘RIGHT DECISION, RIGHT TIME’

Until now, phasing in alternative-fuel school buses in Maine has primarily meant propane and compressed natural gas. School districts that include Sanford, Madison and Farmington have bought propane-powered buses, which have lower emissions than diesel-powered buses and are less costly to operate.

The propane buses made by Blue Bird, a major producer, emit 90 percent less smog-forming nitrogen oxides than their diesel counterparts, according to the Maine Department of Environmental Protection. The final round of Volkswagen settlement money also helped pay for 16 propane buses for Maine schools, plus another nine that were approved for funding last year.

This slow transition to alternative fuels suggest that, accounting for tight funding and the lifespan of school buses, it would take many years to move Maine’s fleet to e-buses. That may not be a bad thing, because evolving battery technology is leading to lower costs and greater range for electric vehicles in general.

Topper West, Falmouth’s transportation director, has expressed interest in e-buses to augment his 25-vehicle diesel fleet. Falmouth has an ongoing commitment to backing out of oil. Its schools are heated with a wood chip boiler, and the high school recently installed two new charging stations for electric cars.  

“This seems like it may be the next thing to come down the pike,” West said about e-buses.

But West said a pilot program is a good idea, because he also has some concerns. E-buses would work for morning and afternoon runs, but what about after-school sports trips? He’d need so-called “level 3” fast-charging stations, which are more expensive but can top up a bus in three hours.

In Portland, similar issues may push e-buses further down the road. The school’s 39 buses transport 2,300 students daily and log 400,000 miles a year. In addition to regular runs, they’re in service for field trips and summer school.

Eric Wood, the city’s transportation director, said he has been phasing in buses powered by gasoline or compressed natural gas as an alternative to diesel. Wood expects e-buses to be a comprehensive solution at some point, but isn’t sure that time has come.

“We’re open to pursuing those opportunities, but we want to make the right decision at the right time,” he said.

Now is the right time at Mount Desert Island High School. The school recently installed a large solar electric project. It’s part of an effort, organized around the A Climate To Thrive resident initiative, to make Bar Harbor and surrounding communities energy independent by 2030.

Butch Bracy, the school’s facilities manager, said he’s not concerned about the added cost of a charging station, because the solar panels will help offset the expense. The school now has six diesel buses, but Bracy said a couple of shorter routes will be a good match for the e-bus.

“I would think that if we have good luck with our first electric bus, we would consider getting another one in the future,” he said.