Chelsea develops microgrid for public buildings

Taking its energy destiny into its own hands, the city of Chelsea is developing what is possibly the nation’s first cloud-based, solar-powered microgrid to power several buildings during peak energy periods and electrical outages.

The city plans to connect three buildings — City Hall, the central police station, and an affordable housing complex — to an independent microgrid battery system that will allow the buildings to disconnect from Eversource’s electrical grid when needed. Cloud-based software will control the system, and the virtual setup means the buildings don’t have to be physically connected to participate in the microgrid.

Expected to come online by summer 2023, the microgrid is expected to keep the buildings running during storms and boost Chelsea’s overall climate resiliency efforts.

Chelsea has several reasons to pursue more affordable and resilient energy alternatives. In a city where nearly one in five residents lives below the poverty line, this Environmental Justice population of roughly 40,000 faces climate challenges, as well as pollution health risks related to Chelsea’s proximity to highways, industrial facilities and Logan Airport. Microgrid proponents view the technology as providing cleaner energy and more reliable service during severe weather and peak electricity demand.

“There definitely are huge risks, as the climate is changing, for Chelsea,” said City Manager Thomas Ambrosino. “So we’re prepared to invest in any and all kinds of efforts to make the city more resilient. We have a very vulnerable population here, and our goal is to protect them.”

Recent storms have underscored Chelsea’s vulnerability to climate change. A “bomb cyclone” snowstorm in January 2018 caused widespread flooding and significant disruptions for officials and residents.

“Chelsea, being a coastal community, is going to get hit with climate crises,” said Fidel Maltez, the city’s public works commissioner. “It is obvious why we need this.”

Maltez, who will become the town manager in Reading on Feb. 14, has been leading Chelsea’s microgrid effort. Under the plan’s first phase, the city will equip City Hall, the police station and the housing complex with rooftop solar panels that generate and feed electricity to battery storage units at each location. During peak hours, the city could switch off the buildings’ connections to the main grid and activate the microgrid. It would recharge the batteries overnight when rates are the lowest, or use excess energy from the solar panels for recharging.

Chelsea will also be able to activate the microgrid during outages, meaning that City Hall could become an emergency energy hub for residents.

“Certainly, microgrids are really attractive because of their resiliency when the bigger grid goes down,” Maltez said. “But we envision this as using the battery every day.”

Chelsea has been working with several nonprofits, including the Green Justice Coalition and Chelsea-based GreenRoots. Maltez said GreenRoots had originated the idea for a local microgrid, and the Massachusetts Clean Energy Center provided funding for a feasibility study.

This past fall, Chelsea selected Ameresco to set up and maintain the microgrid, and the city must submit its plan to Eversource for its approval.

Chelsea is funding the setup costs for the three buildings, largely with $650,000 from the state’s Municipal Vulnerability Preparedness program and a $200,000 grant from the state’s Green Communities program. The city anticipates a funding gap of around $500,000, Maltez said, but might be able to close it with funds from the American Rescue Plan Act. Ambrosino said he anticipates including a funding request in Chelsea’s proposed fiscal 2023 capital plan.

Officials are now anticipating a second phase, which would extend the microgrid to additional municipal buildings and a public housing building for seniors and people with disabilities, Maltez said. In addition, Chelsea hopes to involve private entities that provide critical services, such as local hospital facilities.

Maltez estimates a $5 million price tag to connect the additional buildings, and said Chelsea may apply for a grant in 2023 through Building Resilient Infrastructure and Communities, a Federal Emergency Management Agency program.

Using a $25,000 grant from the Metropolitan Area Planning Council, Chelsea is also examining possible ownership and governance structures for the system. Intent on owning the microgrid assets, Chelsea might consider creating a board, similar to ones governing the state’s 41 municipal light departments, Maltez said.

Several nearby communities have expressed interest in Chelsea’s efforts, and the Green Justice Coalition and GreenRoots have been working with nonprofits in Boston’s Chinatown to explore microgrid technology in that neighborhood, which faces its own environmental challenges and flooding threats.

For more information about Chelsea’s microgrid project, contact Housing and Community Development Director Alex Train at ATrain@chelseama.gov.