Developer presents 150‑megawatt battery project in Charlton; residents and fire chief press for safety assurances and benefits

ESA representatives presented a proposal for a 150‑megawatt battery energy storage system to be sited near the Carpenter Hill transmission substation in the Town of Charlton and answered extended questions from residents and town officials about safety, environmental risk and local benefits.

The presentation, delivered by ESA representatives including Wes and Ernest Calderon, outlined the project footprint, the state permitting path and the community outreach plan. "We're proposing a 150 megawatt battery energy storage system," said Wes, describing a project with site control on a 15‑acre lease and an expected equipment footprint of about 5 to 6 acres. The developer said the earliest feasible in‑service date depends on interconnection and permitting timelines and that the permitting path would be shaped by the Massachusetts Climate Act, which routes larger projects to the state Energy Facilities Siting Board.

Why it matters: the Climate Act and associated rules can move large renewable and storage projects to state review and limit the town's control over siting and zoning. That fact helped drive residents' concerns about emergency response capacity, air and water contamination risks and how the town would be compensated if it accepted a local pilot or host community agreement.

Fire Chief Rob Bart, who identified himself as Charlton's fire chief, told the board he must work with the company to develop and accept an emergency action plan. "I'm the only one that they're required to work with to develop this emergency action plan," he said, describing joint planning, training and review of response equipment and procedures. Bart said the town has participated in training with larger neighboring departments and would seek funding and third‑party review to build a site‑specific plan.

Residents pressed several technical and local‑impact questions. Commenters asked about the potential for contaminated groundwater or runoff from a thermal‑runaway fire, about a widely cited two‑mile evacuation radius used in past incidents, and about noise and visibility from inverters and heat pump equipment. One resident asked for stronger public outreach and cautioned, "I hope it's not ruined. I hope all the trees aren't cut down." The developer and the fire chief said the state permitting process and MEPA review include stormwater and groundwater protections and that modern battery chemistries and NFPA standards have changed since earlier incidents.

On environmental and engineering safeguards, ESA said the containers "do not emit any liquids" in normal operation and that some early generation incidents involved older chemistries: the company told the board it plans to use lithium iron phosphate chemistry and to make available external studies and EPRI data summarizing battery fire events. ESA also said fire suppression and emergency procedures have evolved and that mechanical and monitoring systems are designed to shut down affected cells autonomously.

Community benefits and compensation were a central theme. ESA described two paths to local revenue: if the town takes no local agreement the developer would seek state permitting and the town could receive roughly $25,000–$30,000 in annual tax revenue; towns that negotiate local pilot or host agreements have received substantially larger sums in other communities, ESA said, citing Medway and Carver as examples that negotiated in the range of $1.5 million to $2 million per year. The developer said decommissioning obligations and bonding would be part of any local agreement.

Procedural next steps: ESA said it will expand outreach and promised to return to the planning board for additional public meetings. The developer offered a July meeting (originally listed July 8) and the board discussed moving an in‑town session to July 15 to allow broader local outreach. The company also agreed to post detailed permitting materials and comparative project documents on its project website, carpenterhillpower.com.

What was not decided: the board did not take a formal vote on the project; the meeting recorded a multi‑point public Q&A and a commitment from ESA to refine its engagement plan, provide additional technical materials and reconvene with town officials and the community.

The planning board moved and approved several unrelated procedural items earlier in the meeting, including continuation of a public hearing for Blue Sky Towers to June 17, approval of binder‑course work at Depot Road and continuation of a subdivision plan to the next meeting. The meeting adjourned at the end of the session.