BOSTON – In an ideal future envisioned by the Massachusetts Senate, the transportation, housing and construction sectors all face carbon pricing mechanisms, all statewide greenhouse gas emissions are offset with reduction options, and public buses around the greater Boston region quietly hum along on electric power, free from the rumble and belch of diesel engines.
An electric vehicles bill approved nearly unanimously by the Senate last month — one prong in a broad package aimed at achieving a sustainable energy future — would force the MBTA to achieve that goal over the next two decades.
If it survives the long legislative road ahead of it, the language would require the T to begin purchasing only electric buses by 2030 and, with minor exceptions, to operate an entirely electrified fleet by 2040.
Some environmentalists contend that, because transportation emissions account for some 40 percent of Massachusetts greenhouse gas emissions, the state's largest public transit agency should begin that process sooner.
But senators selected those deadlines for a reason: the T is years away from being able to absorb the costly and complicated change.
"There's some serious planning involved here," said Sen. Michael Barrett, who co-chairs the Joint Committee on Telecommunications, Utilities and Energy and led the Senate's legislative push. "But it's time to put everything on a schedule. We can wait, but we can't wait too long."
The MBTA since July has been running five battery electric buses on the Silver Line as part of a two-year pilot program. More than 270 of the fleet's 1,026 buses were hybrid vehicles as of September 2019, but other than 28 battery-powered trolleys, the T does not run any other electric buses.
They are not alone.
Few public transit agencies in North America have committed to electrifying their bus fleets in the short term. China has tens of thousands of public electric buses running, but experts say comparisons are difficult because of the large financial incentives the Chinese government offers to accelerate a mandated switch to electric vehicles.
In Massachusetts, there are two key obstacles standing in the way of an all-electric bus system: the vehicles themselves and the T's infrastructure to support them.
Electric vehicles sometimes have shorter ranges than traditional gasoline or diesel options, and the trend is exacerbated in cold-weather climates when significant energy needs to go toward heating interiors.
A Federal Transit Administration test case found that battery electric buses tested in Washington state — which, because they frequently open doors at stops, need even more energy than a passenger vehicle to heat during the winter — had ranges about 32 percent lower in December than they did in September.
Bus performance has been increasing in recent years as manufacturers find better techniques, but because of the variance in performance, some key stakeholders believe the technology needs to grow more before it is viable for widespread introduction on the MBTA.
"Based on a survey of industry builders, existing BEB programs, various local initiatives, and peer agency experience, it appears likely that significant progress toward meeting demands for large, revenue service-ready BEB fleets will be made within the next 5 to 7 years," A Better City wrote in an August report.
Estimates range on what a total vehicle turnover would cost the MBTA. Barrett said in the current market, 40-foot battery electric buses typically cost about $200,000 more than their conventional predecessors.
Those numbers could change as technology develops. Because MBTA buses have a useful lifespan of about 12 years, every vehicle currently in operation would need to be replaced by the Senate's 2040 deadline anyway, and Dimino said the net additional cost in the long run could be negligible.
Even if the T could immediately purchase battery-powered buses that run as far as diesel or hybrid vehicles regardless of climate, observers agree that the system is nowhere near ready to accommodate a fleet change.
Maintenance facilities need to be outfitted with new equipment to charge rather than refuel. Garages need to have capacity to store every electric bus indoors, whereas chunks of the current fleet are parked outdoors overnight.
The buildings themselves need to be modified heavily, too. All 10 MBTA bus maintenance garages — with an average age of 54 years — are beyond their useful life or are functionally obsolete, according to the agency.
And the price tag for preparing every bus facility to accommodate an all-electric fleet: roughly $1 billion, according to A Better City, a business group that works on transportation issues.
"There's some existing buses that were recently purchased that can't even fit into the garages because of the height of the buses," said Rick Dimino, the group's CEO. "They're old, antiquated, inefficient, and they're certainly not well-positioned to support electric buses. They can't even support the traditional bus fleet we have."
Dimino — whose group has called for raising and spending $50 billion on transportation funding over the next two decades — said he believes the T is currently not equipped to handle the steep, long-term cost of updating every facility.
Work is already underway to modernize T maintenance garages, according to the agency.
The MBTA tapped Scott Hamwey to lead the efforts, and plans are in place to retrofit the new Quincy and Southampton diesel-hybrid garages once they open in 2024. The North Cambridge garage will be rebuilt as an all-electric bus facility, and a new electric bus garage will likely open in 2025.
Both the MBTA and MassDOT declined interview requests.
In a 718-word statement, MBTA spokeswoman Lisa Battiston said the T is committed to using battery electric buses "as an important step toward lowering greenhouse gas emissions" and described several of the steps underway.
The largest challenge, she said, is power capacity. According to Battiston, a single charge for a fleet of 100 battery electric buses — roughly one-tenth of the current fleet size — would take 60 to 80 percent the amount of energy that AT&T Stadium does on a Dallas Cowboys gameday.
"The current power infrastructure will not support an entire fleet of (battery electric buses) and substantial power equipment replacement as well as wiring and infrastructure upgrades would be required for anything more than the BEB chargers that are currently installed," Battiston wrote.
At a Jan. 21 event, Transportation Secretary Stephanie Pollack fielded a question from the audience about the T's long-term transition to electric buses. She stressed that, while the goal is a valuable one, officials need to ensure the vehicles have enough range and reliability so that passenger service is not impacted.
"We're trying to go as fast as the technology allows, but the most important thing a bus needs to do is show up and pick people up, and we need to know that the electric buses can do that before we commit to changing the whole fleet over," she said. "The first year that we can buy 100 good electric buses and start changing the system, that's the year we'll do it."
However, the level of commitment has left both environmental advocates and the Senate unsatisfied. Barrett said he "did not sense the T would move with the speed" he wanted to see, which played a role in the upper chamber's move to set hard deadlines on the transition process.
While Barrett acknowledged that administration officials may need a full decade to upgrade infrastructure and become comfortable with the available technology, others believe the transition should start as soon as possible, particularly given the volume of greenhouse gas emissions coming from the transportation sector.
"It can be done, and we shouldn't be waiting until 2030 to make that start," said Veena Dharmaraj, program manager at the Sierra Club's Massachusetts chapter. "We can be starting right now and increasing the number of electric buses we procure with each procurement the MBTA makes."