Montgomery County Breaks Ground on 7-MW Solar-Storage-H2 Bus Depot Microgrid
Three years ago, public infrastructure microgrid developer AlphaStruxure started construction on a groundbreaking project to electrify buses at a depot facility in Montgomery County, Maryland. The Brookville Smart Energy Bus Depot microgrid was completed amidst countless moving parts and with a single-minded desire to meet decarbonization goals in that region.
Three years later, they’re at it again—literally breaking ground on a bigger and more diverse microgrid.
Today, the two primary parties will celebrate the ceremonial start of a massive combined solar, energy storage and hydrogen project at Montgomery County’s David F. Bone Equipment Maintenance and Transit Operation Center (EMTOC) in Rockville, Maryland.
Decarbonizing to the Bone
Expected to be completed in less than two years, the Bone EMTOC microgrid will include 5 MW of solar and 2 MW/7.4-MWh of battery storage, part of which will charge electric buses along with a 1-MW electrolyzer to create carbon-free hydrogen for fuel cell buses.
“You’ve got to put a stake in the ground,” Michael Yambrach, chief of Montgomery County’s Office of Energy and Sustainability, said in reference to questions about timing to meet ambitious emissions reduction goals by the Maryland entity, which is aiming for net zero emissions by 2035.
Indeed, much of Rockville’s Bone EMTOC microgrid will be somewhat similar to what AlphaStruxure achieved at Brookville, although the earlier project does not have a hydrogen (H2) or electrolyzer component. Once completed close to 70 percent of the buses in the fleet are planned to be H2 fuel cell powered, with the rest going electric in a gradual transition to replace older diesel-powered vehicles.
Montgomery County plans to acquire about 200 of the bigger buses to be fuel cell-ready, and eventually electrify much of the rest of its approximately 3,000-vehicle fleet. The partners say that the project will be the biggest renewable energy-powered e-mobility project for public fleets in the nation. To be classified as truly green hydrogen, the H2 must be generated by electrolyzers (which split hydrogen from water) and powered by carbon-free resources such as wind, solar and hydro.
Montgomery County’s microgrids are part of an expanding portfolio for projects to meet growing electricity demand from both transportation and data centers.
“We’re seeing load growth like we’ve never seen for decades in the U.S.,” AlphaStruxure CEO Juan Macias said in the press conference with Microgrid Knowledge, Axios and other media entities. “I think Montgomery County stands alone in thinking of the energy infrastructure that has to be in place–to meet that load demand. They’re not only thinking about it but taking action.”
The Bone EMTOC microgrid will comprise Schneider Electric’s EcoStruxure Microgrid Flex system, featuring the company’s BESS (for battery energy storage system) switchgear and controls managing the input from the 5-MW solar and 2-MW/7.4-MWh storage.
A construction project with a lot of moving parts
All of the power generation will be located on-site close to where the Montgomery County bus and public service fleets will be charged or refueled. AlphaStruxure is a joint venture of Schneider Electric and private equity investment and management firm Carlyle Group.
“Schneider Electric couldn’t be more proud to contribute,” said Jana Gerber, Schneider Electric’s president for the North American microgrid business. “The goal is decarbonization, decentralization and digitalization. Microgrids are emerging as a key driver of the energy transition due to their ability to adopt clean energy resources.”
The Bone EMTOC microgrid construction is expected to be completed sometime in 2025. This comes hard on the heels of the nearly yearlong Brookville Smart Energy Bus Depot construction, which was built while the facility was in regular operation with buses and routes ongoing.
Rockville will be the same.
“These are live depots that never went down,” AlphaStuxure CEO Macias pointed out about the earlier project. With Brookville, “it was a 23-stage construction process, some 56,000 hours with zero incidents. We learned how to work closely together, how to do a complex project.
“This is a tough challenge,” he conceded. “We did that and we learned.”
Montgomery County will handle purchase and installation of the 1-MW electrolyzer on its own, utilizing more than $13 million in federal grant awards. Yambrach said the county is hoping to decide on an electrolyzer supplier soon but could not divulge any details around that.
Each H2 fuel cell-powered bus will cost up to $1.5 million each, close to double that of a diesel-powered model. However, Yambrach estimated operational costs for hydrogen buses to be close to 31 cents per mile compared with about 85 cents per mile for diesel because of the H2 fuel cell’s reportedly more efficient power train.
Fuel cells use an electrochemical process to turn fuel into electricity.
Spending money to eventually save money and emissions
Yambrach admitted that the Montgomery County government and, ultimately its taxpayers, are taking on a higher upfront financial burden with the hydrogen electrolyzer and bus plan. Electric buses, however, are limited in range to about 135 miles, while some of the county’s buses undertake nearly 300-mile journeys on regular schedules—a mileage capacity that hydrogen can handle.
“Our fleet is projecting lower maintenance costs,” he added. “Until you get on the road, you don’t know.”
The Bone EMTOC microgrid and bus depot site will include dozens of smart fast chargers, AlphaStruxure officials said.
AlphaStruxure is handling all of the upfront costs on the microgrid part of the project, including the renewable energy, battery storage and infrastructure under its “energy-as-a-service model” while Montgomery County is paying on a regular-installment, long-term contract based on energy savings.
This is a private equity transaction, so Macias did not divulge the overall cost of the microgrid project. However, Montgomery County also is utilizing several federal grants and tax credits to help round out financing for the microgrid's various components.
Transportation accounts for nearly 30% of overall U.S. greenhouse gas emissions, according to recent tabulations by the federal Energy Information Administration. Nearly a fourth of those transportation emissions derive from heavy-duty and medium-duty vehicles such as buses and trucks, according to the EIA.
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