SOMETIMES A BUS GARAGE can be far more than simply a place to store buses. This is especially true when the buses are electric. 

The MBTA’s long delayed plan to move to electric buses seems to finally be moving forward. It is a move, if the T can pull it off, that would have been unthinkable 25 years ago when I started working to improve transit in Greater Boston as an environmental advocate.  

This bus electrification plan is a laudable, albeit overdue and finally creaking forward, effort to meet the legal mandate of an all-electric T bus fleet by 2040. This initiative is the culmination of a long arc of progress: Buses put much less pollution into the air than when I started working on transportation issues at Conservation Law Foundation back in 1998.  

We were successful 20 years ago, pushing the MBTA to become a leader as one of the first transit agencies in the nation to switch to low sulfur diesel fuel — now the standard for all diesel fuel — and moving the T to put pollution controls on diesel buses. After these steps, the T began to employ newer and cleaner technologies — first compressed natural gas and then hybrid-electric buses. All these moves combined to slash emissions (which were causing real and direct harm to the health of our communities) by over 90 percent.  

But the upcoming bus electrification presents even more expansive opportunities. Our already cleaner buses have reduced asthma in kids and have meant fewer heart attacks among the elderly. Now, we can go even further than cleaning up the air in our neighborhoods: When the buses of Greater Boston go fully electric, there is a unique chance to capitalize on this moment of technological transition to meet a variety of environmental and community needs. 

We can reap even broader benefits from switching to electric buses by making the bus garages (“depots” in transit speak) into “energy hubs” that employ smart technology that allow batteries on parked buses to export power out to the grid when the energy system that powers our society needs a little help. 

Energy experts around the world have been working on designing the best algorithms and methods for coordinating electric bus fleet recharging with local electric demand and generation. The best of this work blends this theoretical calculation and modeling with case studies from the municipal bus fleet in Beijing and the Stanford University electric bus shuttle fleet where pilot efforts to coordinate electric bus charging with the needs of the grid have been implemented.  

While there are substantial efforts to deploy all types of distributed energy resources in a coordinated manner as “virtual power plants” across the United States — and many bus systems are moving towards partial or full electrification — there hasn’t yet been a full marriage of these concepts. If the MBTA were to take a leadership role, harnessing the full potential of the electric bus depot as a smart energy hub, the benefits in terms of dollars saved, improvement to the regional energy system, and pollution avoided would be substantial. 

There are big reliability, economic, and environmental benefits to charging batteries when the sun is shining, the wind is blowing, and power is cheaper and plentiful and then discharging those batteries back out to the larger grid when the system needs help and would otherwise be dependent on dirtier forms of generation. This time shifting of energy is a core benefit of large-scale energy storage generally and would be especially valuable if a solar array is placed on the bus garage roof. And in this case the energy storage facility providing these benefits would also be a needed home for electric buses that will provide much needed clean public transportation. 

Put plainly, smart design, construction, and operation of modern electric bus facilities will allow buses to not just charge quickly, but to also act as an energy storage system that can feed the grid when needed and help to power our communities. There are few opportunities to build that kind of vital energy infrastructure that also provide better and cleaner transportation. 

Keep in mind that an electric bus the length and size of those in the T’s standard workaday fleet has a battery that holds over 350 kilowatt-hours (kW-hrs) of power. Larger buses, like the “articulated” buses in use on routes like the Silver Line and the 39 bus through Mission Hill and Jamaica Plain, have a battery that holds over 500 kW-hrs. To put this into perspective, an average Massachusetts household uses about 20 kW-hrs of electricity per day and residential battery installations that provide backup power in the event of a blackout are usually between 10 and 15 kw-hr capacity. 

Imagine a scenario where an energy hub/garage housing 100 buses, cumulatively holding thousands of kilowatt-hours of power when fully charged, could supply enough power to the grid to feed thousands of houses during a moment when the grid needs a boost. 

Having these kinds of virtual power plant resources in the mix will become more and more important as the deployment of solar power continues and electrical demand rises — driven by the continuing rise of data centers supporting cloud computing, AI, and video streaming along with heat pumps during cold New England nights. 

Energy hubs like these garages will only become more and more important as we move towards a more dynamic power grid. Our grid will, increasingly, be home to variable “loads” that consume power — like the electric heat pumps that can heat our homes during the winter and cool them in the summer. 

Maintaining a stable and reliable power system will mean large scale deployment of all kinds of energy storage, both to provide power around the clock but also to avoid crises like those recently experienced in Spain and Portugal, which left millions without power. Avoiding such dire moments will hinge on whether we bring online resources that provide wonky, obscure, and vital services like “frequency regulation” — responding to a signal from ISO-NE, the regional system operator, sent every four seconds to increase or decrease output or consumption of power in order to help keep the regional energy system in balance.  

Battery energy storage resources, like a smart energy hub that actively charges and (when needed) pulls power from the batteries of electric buses, are exactly the kind of tool that is needed to do that job, and get paid for it — income that can help support the core transportation function of the T. 

Executing on a vision of electric bus infrastructure will require a coordinated effort between many different city and state agencies and authorities, as well as the T, carefully working with utility companies and our regional grid system. Harnessing the power of private enterprise through competitive processes for bringing in energy, infrastructure development, and bus manufacturing companies will be essential in building this new and better system meeting our energy and transportation needs. 

The time to mobilize to advance this vision of cleaner air and a stronger grid is now. Like the move away from the dirtiest diesels, this is an opportunity to provide cleaner air while providing critical transit to keep us all moving — and this time we can also help build a cleaner, more versatile, and resilient electricity grid at the same time.  

Seizing this moment, will allow us to add a new, clean and green refrain to a classic children’s song: The wheels on the bus go round and round – keeping the lights on all over town.  

Seth Kaplan is a consultant and teacher focused on energy policy and projects. He spent 16 years working on transportation, energy, and climate policy and projects at the Conservation Law Foundation. He subsequently worked on regulatory and government affairs efforts in the renewable energy sector, most recently at Ocean Winds North America, a Boston-based offshore wind development company.