Electric buses to tap solar power using microgrid


The first microgrid to power electric buses will soon make its debut in the Washington region as transit agencies nationwide look to the sun — rather than diesel — to fuel their fleet.

The system will launch in September, powering a growing number of electric buses on Montgomery County’s Ride On transit system. The Silver Spring facility will be the first in the DC area to use the microgrid technology and one of the earliest of its kind nationwide.

The microgrid will use energy that originates from solar panels at a bus depot rather than the traditional electricity grid — the process used by most transit agencies with electric buses. The transition comes as jurisdictions across the country are looking to electrify their bus fleets to battle climate change and amid financial windfalls from last year’s infrastructure law, which includes $109 billion for transit.

The push for the Maryland project stems from the county’s climate goals, which include converting its publicly owned vehicles to zero-emission by 2035. The county is expecting to add 10 electric buses to its existing fleet of more than 370 gas-powered buses by the end of the summer and expects to buy 100 more by the end of 2023.

The Brookville Bus Depot eventually will charge up to 70 buses. The county is looking to install microgrid facilities in more of its bus depots to house the growing fleet.

“This is the kind of thing we have to do to meet our climate goals,” Montgomery County Executive Marc Elrich (D) said during a recent tour of the Brookville depot. “The grid is clean, so the cleaner energy we use as a source, the more likely we are to be successful in reducing our total greenhouse gas emissions. That’s the goal.”

The county funded the project through a public-private partnership with Alpha Struxure, a joint venture between the Carlyle Group, an asset management company, and energy provider Schneider Electric. Alpha Struxure provided the county with money upfront to purchase the microgrid infrastructure, then the county will pay the company back over 25 years in monthly installments, using income generated by selling electricity from the grid.

The county purchased the buses using Federal Transit Administration grants, said Calvin Jones, division chief for Montgomery County Fleet Management Services.

The Brookville Bus Depot will be the first microgrid in the county to be used for transportation purposes, although the technology is used elsewhere in Montgomery. The county’s public safety headquarters is powered by microgrids, while the county is also planning to use microgrids at its Gaithersburg bus depot and its Animal Services headquarters.

Canopies of solar panels stretching across the bus depot will capture energy to charge bus batteries. The microgrid can store energy from solar panels, natural gas power generation and the electric utility, Jones said.

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The microgrid also was designed to withstand natural disasters and disruptions to the electric grid.

The process of electrifying bus fleets across the country is “slow moving,” said Sebastian Castellanos, a senior research associate at the World Resource Institute’s Ross Center for Sustainable Cities. The technology has been available for years, but he said transit agencies must move beyond testing and pilot programs into deployments.

“Diesel engines and gasoline engines are very inefficient machines,” Castellanos said. “Even if the grid is not 100 percent clean, gains in efficiency are mostly sufficient to offset any additional emissions from the grid.”

The greatest barrier for transit agencies to electrify their fleets is upfront costs, he said, adding that the infrastructure law — which allocates $5.6 billion to help agencies transition to low- or zero-emission buses and purchase maintenance infrastructure — will help.

The Metrobus system has committed to transitioning its fleet of 1,500 buses to zero-emission by 2045. The agency said in April it is planning to buy 12 electric buses this year. Metro has one fully electric bus.

A public-private partnership might not make sense for all jurisdictions, Castellanos said. Larger jurisdictions willing to take on technical projects might prefer to lead those projects themselves, he said, while others might benefit from paying a private company to handle the logistics.

Transportation is the largest source of greenhouse gas emissions, which contributes to rising temperatures, according to the Environmental Protection Agency. But as a sector, much of the world’s emissions come from personal vehicles, making it difficult to apply broad policies. Castellanos said environmentally friendly policies that boost transit “have the biggest bang for the buck.”

“Transit buses, in particular, drive many more miles than a regular car,” he said. “Not only that, but they’re transporting many more passengers.”

Other transit agencies are eyeing similar partnerships to electrify fleets. Metrobus is considering public-private partnerships to support a transition to zero emissions. In the San Francisco Bay area, the Valley Transportation Authority (VTA) is one of the most recent agencies to announce plans for a microgrid.

Transit agencies are struggling to make ends meet. They’re also preparing for record federal investment.

“I think we’re in a very similar position as Montgomery County,” said Adam Burger, a senior transportation planner at VTA. “The difference we have is that the state of California is requiring all transit agencies to go to a zero-emission fleet by 2040, so that’s the fire under us.”

VTA is contracting with private companies and will pay for the microgrid infrastructure by the end of the project’s completion. It plans to fund the project using a $4.7 million grant from the California Energy Commission.

“A lot of our peers are doing similar projects to what we’re doing, and fortunately, private industry is stepping up to be our partner in these things and provide the expertise that we don’t have,” Burger said.

Externally, there are few differences between Montgomery County’s new electric buses and its existing diesel fleet, aside from their rounded edges and slightly smaller frame. But riding in an electric bus is a different experience altogether, drivers and passengers say.

Andre Morrison, 53, a driver with Montgomery County’s Ride On system for 29 years, was the first to be assigned an electric bus route in 2019.

“The bus itself is a totally different ride,” he said. “It’s extremely quiet, so you know, it really throws you off initially. The first day you really didn’t know what to expect because you didn’t know whether the bus is on or off.”

He said drivers agree that electric buses are more enjoyable to drive. The suspension system on an electric bus minimizes jerks and bumps, alleviating discomfort.

“Your body’s just not comfortable” on a diesel bus, he said. “It really feels as if you’ve been in a boxing ring … when you get out that seat, man, your body is just aching.”

Riders have offered Morrison generally positive feedback, he said. Most say they appreciate how quiet and smooth the ride is.

“The regular ones make noise — these don’t,” David Johnson, 62, said while on one of the county’s four electric buses on a recent morning. “This is better. Smooth ride, and much nicer.”

Morrison said he is especially excited for the county’s latest order of electric buses, which is a slightly bigger model that will include updated safety and design features. He said the appeal of the buses goes beyond their new features and comfort: It’s a path toward a greener future.

“This is the future here, as far as saving the planet,” he said. “This is where we should be heading.”

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