BENNINGTON – Encore Renewable Energy is planning a 5-megawatt battery storage facility off Murphy Road – located near an existing solar generating array.

The facility will be co-located near the 500-kilowatt capacity Paper Mill Village solar array, which Encore Renewable installed in 2017.

According to a notice of the developer’s intention to seek a permit from the state Public Utility Commission , the power storage facility will consist of three battery enclosures, each 16 feet by 60 feet and mounted on a concrete pad on a .42-acre site.

The company gave a presentation on the proposal before the town Planning Commission on Thursday. The commission’s role is to make recommendations to the Select Board on possible comments the town might file during the PUC permitting process.

Taegen Kopfler and Sam Carlson, project managers with the firm, said electricity storage would build up in the battery units while the solar array is generating and would be available for release during peak demand periods.

They said Green Mountain Power, which will manage the facility, expects to release power into the grid during peak periods, and that is expected to to reduce the amount of higher-cost and often fossil fuel-generated energy GMP has to purchase from other sources, typically from outside Vermont.

Kopfler presented a slideshow showing the preliminary layout of the project, including a map and views of the site. She said project details are expected to be refined in response to questions raised by the planners and others and during the PUC application review.

Carlson said Encore has a relationship with GMP and with some Vermont municipal utilities in a statewide effort to increase the reliability of the state’s electrical grid system.

The Burlington-based firm is now developing nine projects around the state, he said, adding, “Green Mountain Power has said these are the places where we would like to have a battery.”

The units will provide increased reliability to the grid and help during outages, he said, but the real advantage will come into play during peak electricity demand periods.

When GMP imports electricity from Massachusetts and Connecticut from so-called “peaker plants,” Carlson said, that energy carries a much higher cost and is typically fossil-fuel generated.

The advance notice of the permit application states, “The project is being developed in cooperation with GMP to provide system benefits which battery storage systems make possible. The storage project will enable the stored electricity to be dispatched into the grid on-demand during critical hours, thereby reducing the large expense incurred by GMP during times of peak system load, saving ratepayers money.”

The project “paired with the existing solar component, will promote a more resilient distribution circuit, which helps reduce the likelihood of outages for ratepayers and the need for more costly distribution upgrades,” the notice states.

Concerning the project design, the notice continues, “Once the petitioner selected the site, the petitioner worked with its consultants to configure the project in a way that would maximize the potential energy storage benefits and other electrical system benefits while minimizing environmental and aesthetic impacts. The petitioner will continue working with all stakeholders prior to filing the [permit] petition and thereafter to address remaining concerns.”

Other project details include a seven- to eight-foot perimeter fence, a 750-foot access road to the battery site, and a 750-foot extension of required 3-phase power line from an existing distribution service on Murphy Road.

The Burlington-based Encore constructed the existing solar array in 2017 on land leased from the Randall family off Murphy Road.

Kopfler said Encore will use earth-tone colors for the battery enclosures.

Encore also also expects to work with the town, abutting property owners, and consultants T.J. Boyle Associates of Burlington to address potential aesthetic impacts.

Boyle is expected to file an aesthetics report and final mitigation measures information with Encore’s complete application to the PUC.

The company officials said the estimated project schedule is for the application to be filed by February 2025, with a projected permit issuance by August, a construction to start by February 2026.

The firm’s estimate is for operation of the storage facility to begin by September 2026.

In answer to questions from the Planning Commission, Carlson said the facility’s fire prevention component includes sensors at every level, from the individual battery cell on up.

The sensors, which will be monitored 24 hours a day, can shut down the entire unit if a certain temperature is reached and disconnect it from the grid, he said, adding that the units also include an air circulation system that would vent any gasses that might be produced.

Carlson said the units also are self-contained, which would prevent any material from leaking into the environment.

He said the commission’s recommended hours of operation during construction seemed standard and reasonable.

The commission recommends limiting construction to Mondays through Fridays, from 7 a.m. to 6 p.m. and on Saturdays from 9 a.m. to 3 p.m., with no construction on Sunday.

Carlson said the company also agrees to develop a truck routing plan to avoid impacting two covered wooden bridges on Murphy Road during construction.