Electric buses to harness solar energy using a microgrid
The microgrid will use power from solar panels at a bus depot rather than the traditional electric grid – the process used by most transit agencies with electric buses. The transition comes as jurisdictions across the country seek to electrify their bus fleets to combat climate change and amid financial windfalls from last year’s Infrastructure Act, which includes $109 billion for the public transport.
The push for the Maryland project stems from the county’s climate goals, which include converting its public vehicles to zero emissions by 2035. The county plans to add 10 electric buses to its existing fleet of more than 370 gas-powered buses buses by the end of the summer and plans to purchase 100 more by the end of 2023.
The Brookville Bus Depot will eventually load up to 70 buses. The county is looking to install microgrid facilities at several of its bus depots to house the growing fleet.
“That’s the kind of thing we need 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 the energy we use, the more likely we are to be successful in reducing our total greenhouse gas emissions. That’s the point.
The county financed the project through a public-private partnership with Alpha Struxure, a joint venture between the Carlyle Group, an asset management company, and energy supplier Schneider Electric. Alpha Struxure provided the county with money to purchase the microgrid infrastructure, and then the county will repay the company over 25 years in monthly installments, using revenue generated from the sale of electricity from the grid.
The county purchased the buses with grants from the Federal Transit Administration, said Montgomery County fleet management services division manager Calvin Jones.
The Brookville Bus Depot will be the first microgrid in the county to be used for transportation purposes, although the technology will be used elsewhere in Montgomery. The county’s public safety headquarters is powered by microgrids, while the county also plans to use microgrids on its Gaithersburg bus deposit and its Head office of animal services.
Canopies of solar panels stretching across the bus depot will capture energy to recharge the buses’ batteries. The microgrid can storing energy from solar panels, natural gas power generation and electric utility, Jones said.
The country’s neglected bus stops are an early test for infrastructure money
The microgrid was also designed to withstand natural disasters and power grid disruptions.
The process of electrifying bus fleets across the country is “slow,” said Sebastian Castellanos, senior research associate at the World Resource Institute’s Ross Center for Sustainable Cities. The technology is available for years, but he said transit agencies need to move beyond testing and pilot programs to embark on rollouts.
“Diesel engines and gasoline engines are very inefficient machines,” Castellanos said. “Even if the network is not 100% clean, the efficiency gains are usually enough to offset any additional emissions from the network.”
The biggest hurdle for transit agencies to electrify their fleets is upfront costs, he said, adding that the Infrastructure Act — which allocates $5.6 billion to help agencies transition to low- or zero-emission buses and to purchase maintenance infrastructure – will help.
The Metrobus system has pledged to take its fleet of 1,500 buses to zero emissions by 2045. The agency said in April he plans to buy 12 electric buses this year. Metro has a fully electric bus.
A public-private partnership might not make sense for all jurisdictions, Castellanos said. Larger jurisdictions willing to undertake technical projects might prefer to run those projects themselves, he said, while others might benefit from paying a private company to handle the logistics.
Transportation is the biggest source of greenhouse gas emissions, which contributes to rising temperatures, according to the Environmental Protection Agency. But as a sector, a large portion of global emissions come from personal vehicles, making it difficult to apply general policies. Castellanos said eco-friendly policies that boost public transit “have the best value for money.”
“Transit buses, in particular, travel far more miles than a regular car,” he said. “Not only that, but they carry a lot more passengers.”
Other transportation agencies are considering 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.
Transport agencies are struggling to make ends meet. They are also preparing for a record federal investment.
“I think we’re in a very similar position to Montgomery County,” said Adam Burger, senior transportation planner at VTA. “The difference we have is that the state of California requires all transit agencies to adopt a zero-emissions fleet by 2040, so that’s fire under us.”
VTA contracts with private companies and will pay for the microgrid infrastructure by the end of the project completion. He plans to fund the project with 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 thankfully 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, other than their rounded edges and slightly smaller chassis. But traveling in an electric bus is a completely different experience, say drivers and passengers.
Andre Morrison, 53, a Montgomery County Ride On system driver for 29 years, was the first to be awarded 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 baffles you at first. On the first day, you really didn’t know what to expect because you didn’t know if the bus was on or off.
He said drivers agree that electric buses are more fun to drive. The suspension system of an electric bus minimizes jolts and shocks, thereby alleviating discomfort.
“Your body just isn’t comfortable” on a diesel bus, he said. “It’s really like you’re in a boxing ring…when you get out of that seat, man, your body just hurts.”
Riders offered Morrison generally positive feedback, he said. Most say they enjoy how quiet and smooth the ride is.
“Regulars make noise – these don’t,” David Johnson, 62, said while riding one of the county’s four electric buses one recent morning. “It’s better. Smooth ride and much more enjoyable.
Morrison said he was particularly excited about the county’s latest electric bus order, which is a slightly larger model that will include updated safety and design features. He said the appeal of the buses goes beyond their new features and comfort: they are a pathway to a greener future.
“It’s the future here, as far as saving the planet is concerned,” he said. “That’s where we should be heading.”