The Washington, D.C., suburb has rolled out microgrid innovation after microgrid innovation in recent years. And now it’s stepping into the green hydrogen world with a microgrid project that includes not only using the fuel but also producing and possibly selling it.
To be built at one of the county’s bus depots, the 7-MW microgrid project was announced last week by the county and AlphaStruxure, a joint venture of Schneider Electric and financial giant Carlyle.
“It's a movement in that direction of being able to do electric buses and hydrogen buses at the same place without affecting the electric grid,” said Steve Pullins, AlphaStruxure’s senior vice president and chief technology officer, in an interview with Microgrid Knowledge last week at Microgrid 2023 in Anaheim, California.
The bones of the microgrid comprise 5 MW of rooftop and canopy solar generation, 2 MW/7.35 MWh battery energy storage, existing backup generation and up to 4.5 MW of charging capacity. While it will be grid-connected, it can run indefinitely in island mode.
The microgrid will serve five buildings and at least 140 buses, some running on batteries, others using fuel cells, at the county’s Equipment Maintenance and Transit Operation Center (EMTOC).
The buses now run on compressed natural gas (CNG) or diesel. The project’s first step is to decrease the costs for the 1 MW of electricity used to press the natural gas into the buses. The process takes place at night and is incurring hefty demand charges from the local utility. To reduce the charges, the facility will offset the grid power with discharge from the on-site battery.
The high demand charges will become less of a problem once the project enters its second phase when the depot will phase out CNG and instead employ 70 electric and 70 fuel cell buses. The hydrogen for the fuel cells will come from a 1-MW green hydrogen production plant that will be built on-site.
“The power situation changes a little bit as many of those buses, those compressed natural gas buses start going away, and electric and fuel cells start showing up. Then we can just transition our solar and our energy storage into supporting charging of electric buses and creating hydrogen for fuel cells,” Pullins said.
The on-site hydrogen plant will serve 13 fuel cell buses. What about the remaining 57? Pullins said the hydrogen will come from another source, one that is local. A plan is underway to procure the hydrogen, but details have not been made public.
Nothing is typical about microgrids, but a relatively average on-site distributed energy platform for a commercial and industrial customer could cost more than $4 million. Perhaps that’s a drop in the accounting bucket for a large-scale manufacturer’s bottom line as it works to achieve ESG promises and decarbonization with solar, battery and backup generation that can island when the grid is down.
Those price tags are different matters for startups and smaller business use cases. But Schneider Electric is focusing on this market with a new modular, standardized “microgrid-in-box” product, called EcoStruxure Microgrid Flex.
“Flex helps shorten the time to realize deployment,” said BaLa Vinayagam, senior vice president for microgrids at Schneider Electric, during the press event at Microgrid 2023 at the Anaheim Marriott.
Read more about Flex in this article by Rod Walton at EnergyTech.
The fuel cell and electric buses each offer different benefits. Buses that must travel a longer range will be better served by fuel cells because of their light weight, while heavier lithium ion battery charged buses require less capital investment. “So there are trade-offs there,” Pullins said.
With the coming of lighter lithium iron phosphate batteries, the dynamic may change, and it’s possible the 50-50 split between fuel cell buses and EV buses will change. Using a microgrid gives the county the flexibility to make the switch should it choose to, Pullins said.
The county is also thinking beyond transportation when it comes to hydrogen use. Several county facilities use combined heat and power. Because the county will be doing its own hydrogen production, it is considering converting those plants from natural gas to green hydrogen.
The plan is in keeping with the county’s participation in a proposed Mid-Atlantic Clean Hydrogen Hub, which is vying for federal funds through the federal H2Hubs grant program.
Eventually the county may also sell green hydrogen to customers it has identified in the hub.
Given the costs and controversies surrounding green hydrogen, its sourcing is important. By producing its hydrogen with on-site renewable energy, the county will ensure it is truly green.
This project is expected to begin construction late this year and be in operation by early 2024. Supply chain issues are keeping the project from coming online anytime sooner, Pullins said. The delay is not caused by the newer technologies — hydrogen, batteries or solar — but by the more traditional electrical equipment being used in the project, he said.
While capital costs for the project are elevated, they are offset over time with use of the microgrid’s on-site solar which flattens the cost, Pullins said. AlphaStruxure will finance the project through an energy-as-a-service agreement. The company also will provide aspects of design, construction and long-term operations and maintenance.
Meanwhile, use of green hydrogen, produced by the microgrid's solar, advances the county's goal to achieve net-zero carbon emissions by 2035 and also reduces criteria pollutants.
Montgomery County began pursuing microgrids in earnest after a derecho caused widespread power outages in 2012. Since then it has developed microgrids at its public safety headquarters in Gaithersburg and a correctional facility in Boyds, its Brookville Smart Energy Bus Depot and an animal shelter.
Few local jurisdictions have moved as aggressively into microgrids as Montgomery County. “The nature of the county is progressive. It wants to do things in a sustainable fashion,” Pullins said.
Congressman Jamie Raskin, a Democrat from Maryland, described the EMTOC bus depot as a model for communities nationwide.
"Montgomery County is a pioneering leader in making an effective transition to sustainable energy at the local level. I'm thrilled to support the county's efforts, and I'll keep advocating for major federal climate investments for Montgomery County and the rest of our nation,” Raskin said.
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