A large battery is proposed for Carpenter Hill Road.

Click to enlarge

The facility uses Tesla Megapack units — each about the size of a shipping container — arranged across a portion of the project site. All equipment is under 10 feet tall. A 32-acre preserved vegetation buffer screens views from Carpenter Hill Road and nearby sight lines.

The proposed system is rated at 150 MW / 600 MWh. In household terms, that's enough to power roughly 120,000 homes for 4 hours during peak demand.

The site is adjacent to the Carpenter Hill electrical substation — the grid connection point. That means minimal new transmission infrastructure and a short interconnection route. It's what makes this location work where most wouldn't.

As for timing, Massachusetts's 2024 Climate Act requires massive clean energy infrastructure by 2030. As wind and solar come online, the grid needs storage to stay reliable. The ISO New England interconnection queue is years long, but this site has a viable path, which is why the timeline matters.

Carpenter Hill Power, LLC is developed by ESA, an independently owned solar and energy storage development company based in Central Florida. ESA has developed over 8 gigawatts of clean energy projects across 24 states over the past decade.

The conditions of approval — including every commitment in the Community Benefits Plan — run with the project, not with the developer. If ESA transfers the project, the new owner inherits every obligation.

Explore ESA's approach to development, their operating portfolio, and background in clean energy infrastructure.

Visit esa-solar.com

No. This project has not been approved. We are currently in the pre-filing engagement phase. In 2024, Carpenter Hill Power petitioned the Town of Charlton to create an overlay zoning district to provide a local regulatory path for the site. However, we withdrew that application after several Planning Board meetings, agreeing with the town that it was best to wait and see how the state legislation unfolded.

The Energy Facilities Siting Board (EFSB) is the state authority that will ultimately review and approve the project. Their process includes public hearings, environmental review, and adjudicatory proceedings where residents can participate.

This is exactly why we're having this conversation now — while there's still time to shape what gets built and how.

This is something residents have asked about, and we're looking into it — but we want to be straightforward: we don't yet know what credit structures or direct energy benefits are available for battery storage projects operating in ISO-NE. The answer depends on interconnection rules, utility agreements, and the project's future ownership and financial structure.

We're not going to promise something we can't confirm we can deliver. If other comparable projects in the region are providing community energy benefits, we'll work to follow suit. If Charlton residents rank this as a priority, it stays on the table — but we'll only commit to it in the Community Benefits Plan once we're confident it's feasible.

You decide what the benefits are through the Community Benefits Plan process. Our role is to present feasible categories, listen to what Charlton prioritizes, and negotiate a binding agreement. The CBP is not a gift from the developer; it's a negotiated contract between the project and the community.

Once finalized, the Community Benefits Plan becomes a binding condition of EFSB approval. It runs with the project, not with the developer — if the owner changes, every obligation transfers. Non-compliance is a regulatory matter, not just a broken promise.