C Line rapid transit bus
In 2017, Metro Transit received a $1.7 million federal grant to buy eight battery-electric accordion buses for use on the C Line, a rapid bus line that runs from downtown Minneapolis to Brooklyn Center. Credit: Photo by H. Jiahong Pan

In 2021, the Federal Transit Administration awarded a grant to Metro Transit to purchase zero-emission buses from a company that was ambitiously trying to decarbonize heavy-duty transportation vehicles across multiple sectors. 

The company, Proterra, aimed to deliver those buses powered by Proterra batteries to Metro Transit this year. But earlier this year, the agency terminated negotiations with Proterra. Proterra, which also makes chargers for the vehicles they power, subsequently filed for bankruptcy.

Vendor issues are among one of the challenges Metro Transit, as well as other agencies statewide, face as they try to decarbonize their transit fleets. They’ve also encountered problems with operating them in subzero environments, as well as charging them. Though it appears some agencies remain committed to battery-electric vehicles, they are also considering using vehicles powered by other fuel sources.  

The road to zero emissions has not been smooth

Duluth and the Twin Cities have been pioneers in the zero-emission bus transition. In 2015, Duluth received a $6.3 million federal grant for six, ultimately seven, battery-electric buses from Proterra. The buses, delivered in 2018, were the first of their kind to operate in Minnesota. 

Metro Transit followed in 2017 when it received a $1.7 million federal grant to buy eight battery-electric accordion buses from Winnipeg-based New Flyer, as well as associated charging equipment, for use on the C Line, a rapid bus line that runs from downtown Minneapolis to Brooklyn Center on Penn Avenue and Olson Memorial Highway. These buses were the first battery-electric accordion buses to operate in the Upper Midwest. Both the Twin Cities and Duluth have had problems with their battery-electric buses. For one, they can’t go as far as their builders advertised, in part because of the cold weather. Metro Transit’s accordion electric buses were touted to go 150 miles on a single charge. “Using garage chargers alone, electric buses can remain in service for 70 to 75 miles before needing to return to the garage; with on-route chargers, electric buses were scheduled to be in service for up to 90 miles before returning to the garage,” Metro Transit spokesperson Drew Kerr said.

Metro Transit’s battery-electric buses are also less reliable than their diesel-fueled counterparts. A September 2023 presentation to the Met Council’s Transportation Committee showed the battery-electric buses broke down twice as often. The buses were also unable to meet 20% of their scheduled operating miles because they needed battery replacements, which were performed under warranty amid supply chain issues. However, their reliability is better than what it was in 2021, when they were out of service for most of the year because the agency could not charge them at their garage. 

Though the agency has since resolved the charging issues at their garage, they continued to have problems with their on-route chargers installed at Brooklyn Center Transit Center. With their Brooklyn Center charger experiencing over 20 failures so far this year, the agency took them out of service in June. 

Duluth also had “every possible issue” with the chargers for the city’s battery-electric buses, which are proprietary. “They would fail, they would not perform, they would experience malfunctions, glitches. They were extremely problematic right out of the gate,” spokesperson Dave Clark said. Though they were able to replace the chargers, Proterra has yet to reimburse the agency for doing so under warranty terms. As a result, the agency is seeking $1.8 million from Proterra, which includes the amount Duluth paid to replace the faulty chargers as well as to anticipate increases in maintenance costs.

Duluth also had problems with its battery-electric bus fleet. Between April 2019 and February 2020, the fleet averaged 7,717 miles between breakdowns, four times as often compared to their diesel counterparts. (They do not have more current numbers because they do not ordinarily track the distance between breakdowns specifically for their battery-electric bus fleet.) The buses struggled to make it up the city’s storied steep hills and to keep riders warm in the winter. Proterra’s technicians ultimately installed diesel-fired heaters and retooled their buses, incorporating those changes in their most recent model, the ZX5. 

One of those changes includes increased battery capacity, up to 738 kilowatt-hours, so they can handle steep hills and operate longer in subzero temperatures. Metro Transit planned to get eight ZX5 coaches from Proterra when the FTA awarded them a grant in 2021.

But that is no longer in the cards, says Metro Transit, and it’s not because they’ve gone bankrupt. “We were trying to ensure that the contractual agreement that we had in place [with Proterra] addressed some of the early issues that we experienced,” Metro Transit Chief Operating Officer Brian Funk said. “We just simply were not able to come to terms.” 

What’s next?

In August, the Federal Transit Administration awarded Metro Transit a $17.5 million grant to buy 12 battery-electric buses from Livermore, California-based Gillig. It’s unclear when the buses will arrive because the agency and Gillig have not yet agreed to a contract. Meanwhile, the agency is seeking federal approval to use the money originally earmarked to purchase battery-electric buses from Proterra, perhaps to purchase more battery-electric buses from another manufacturer. 

Metro Transit is also buying five more battery-electric accordion buses and associated chargers from New Flyer at $10.8 million. They will be used on nine trips per day on the Gold Line, a bus rapid transit line that will connect St. Paul to Oakdale and Woodbury along I-94 when it opens in 2025.  

Until those buses arrive, Metro Transit is making do with what it has. Since Metro Transit’s December service changes took effect, up to six battery electric buses can operate on the C Line at any one time, but for no more than five hours a day, according to schedule information obtained from the Pantograph app. Before they made the December service changes, up to three battery-electric buses operated on the C Line at any one time for no more than nine hours a day. “We’ve successfully operated electric buses on the C Line without on-route charges before and will continue to do so,” Kerr said.

In the meantime, Metro Transit is also considering vehicles powered by other fuel modes to achieve their zero-emission goals. “We are following hydrogen closely … because of how it addresses the range considerations,” Funk said. One of two hydrogen bus manufacturers in the United States, New Flyer, touts the range of a hydrogen bus is nearly 1.5 times more than that of a battery-electric bus. 

Today’s hydrogen buses, which generate electricity from hydrogen fuel that charges a battery to power the bus, exist mostly in California, Illinois and Ohio. But because Minnesota does not have hydrogen fueling stations, they may have to truck a supply in, perhaps from Illinois. They may also get hybrid buses once again. After years of eschewing hybrid buses because of their maintenance difficulties, instead purchasing clean diesel buses that have a better fuel economy to replace their less fuel-efficient hybrid counterparts, they may once again buy hybrid buses that can operate with their engine turned off for several miles and in certain areas, perhaps in neighborhoods overburdened by pollution as defined by a computer-generated map. Such buses replaced battery-electric buses in Indianapolis and diesel buses in San Francisco and Boston

“We don’t want to rule out [a vehicle that] could be a bridge [to zero emissions]. The battery electrics are still moving forward, we’re gonna continue to acquire them. But they may not be the best use case for everything,” Funk said. “Are we going to get to the point where we have the energy density on board the bus to be able to travel up to 300 miles? That’s something that automobiles have come a long way in the last few years. Time is gonna tell with the buses.”

Since Duluth and Metro Transit rode the electric wave, other agencies joined in on the current. With $5.4 million from two federal grants, Rochester placed into service four battery-electric buses of the exact same make and model as Metro Transit’s on express routes that connect downtown Rochester with park-and-rides on the city’s periphery. The city plans to get 12 more battery-electric buses for a bus rapid transit route connecting downtown Rochester and a park-and-ride on the west end of town. 

Closer to the Twin Cities, Southwest Transit plans to debut the first battery-electric over-the-road coaches to operate in a North American subzero environment sometime early next year. They will buy the buses from Winnipeg-based Motor Coach Industries through a State of Washington contract with a $8.1 million federal grant

What about transit agencies using smaller buses?

Agencies using cutaways — trucks with a bus body grafted into what otherwise would be the cargo bay — have a harder time transitioning their fleet to zero emissions. A zero-emission transition plan prepared by the Met Council in April says only seven different types of such buses exist, and they all have a battery capacity of 100 to 160 kilowatt-hours, compared to up to 700 kilowatt-hours on larger battery-electric buses. 

Considering the range may be even more limited because of cold weather, the transition plan also finds the region’s agencies would have to buy as much as 3.3 times the number of buses they run today on services such as Metro Mobility, Transit Link, and Southwest Prime — an Uber-Lyft-like ride-hail service operating in southeastern Carver County and the city of Eden Prairie — to fully replace their gasoline-powered counterparts. 

To get around limitations in battery capacity, some greater Minnesota transit agencies are turning to propane. In 2018, the White Earth Nation put three propane buses into service. An October 2018 Minnesota Public Transit Association newsletter touted the benefits of propane-fueled buses as having a comparable cost to gasoline with fewer greenhouse gas emissions, lower maintenance costs and fewer hassles of starting in the winter. 

It’s unclear how the propane buses are performing, as White Earth officials have not yet responded to a request for information for this story. Yet, other Minnesota transit agencies are looking to experiment for themselves. The Bois Forte Band of Ojibwe, Tri-Valley Opportunity Council in Crookston, and Southwest Minnesota Opportunity Council in Worthington all received a total of $2.2 million in federal grants to purchase propane buses for their fleets in the coming years.