We are proposing energy storage for
Carpenter Hill Road.

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. Existing trees and the site's setback screen 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 Carpenter Hill Substation is a critical grid node where both 345 kV and 115 kV transmission lines converge, connecting eastern and western Massachusetts. Siting a BESS at this multi-voltage interconnection point allows it to provide benefits at both the regional transmission and local reliability levels, supporting the broader ISO-NE network while helping defer costly grid infrastructure upgrades. That also means minimal new transmission infrastructure and a short interconnection route. This setup 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 run with the project, not with the developer. If ESA transfers the project, the new owner inherits those obligations, along with any benefit terms the town and the project put into a signed agreement.

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.

We are starting this conversation early to ensure you have time to shape what we build and how.

This is something residents have asked about, and we are 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 will only commit to it in the Community Benefits Plan once we are confident it is 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 build the plan with the town in public. The CBP is not a gift from the developer; it is a plan the community shapes.

Every commitment we make along the way is recorded in the public Commitment Tracker with its status and proof. Design commitments are carried into the plans we file with the state, and permit conditions run with the project even if the owner changes. If the town and the project decide specific items should move into a signed agreement, that path is open.