With Colorado-based Flatiron Energy withdrawing its widely unpopular proposal for an enormous battery energy storage facility in New Milford, town officials and environmentalists are relieved — for now.
Flatiron late last week told attorneys for the town that it was no longer pursuing its plan for Treebeard, its name for a 140-megawatt lithium-ion battery storage facility to be built on 10 acres near the West Aspetuck River.
But the company still has an option on the land, and last winter said it was also exploring other potential sites in New Milford. So far, it has not advised the town on whether it’s leaving the area altogether, seeking a nearby location instead, or simply postponing its campaign for the original proposal.
“Since January the only communication they gave the town is through their legal representation — their attorneys talking with the town attorney,” Mayor Pete Bass said Tuesday. “They told us they’re not moving forward on that property. We know that property is still under option, but we haven’t heard more than that.”
A message seeking comment from the company on Tuesday was not answered.
But as of Tuesday afternoon, its website still described the proposal as active with a project operations start date in mid-2028.
“Treebeard Storage is a battery energy storage system currently in the early stages of development by Flatiron Energy in New Milford,” it reads. “When completed, Treebeard Storage will store up to 560 megawatt-hours (MWh) of energy and provide reliable electricity to local homes and businesses during peak demand. The facility is scheduled to commence operations in Q3 2028.”
The company has said Treebeard would generate more than 40 construction jobs and provide more than $40 million in local tax revenue during its lifetime. Flatiron has insisted that the battery farm would operate safely while promoting clean energy and helping to shield power customers from blackouts.
Public opposition has been strong since the proposal was publicized last winter, and more than 1,400 people have signed an online petition opposing the plan.
“This project is being proposed directly over our main New Milford aquifer, in our aquifer protection area,” the petition states. “Peagler Hill and Indian Fields well fields, owned by Aquarion Water Company, supply water to roughly 12,000 New Milford customers.
“That system continues down Route 7 and interconnects into the Brookfield system and beyond. Due to unforeseen circumstances surrounding previously discovered harmful PFAS substances and low yields in certain parts of town, the main system is being expanded to become the primary potable water source for most of New Milford,” it said.
The proposal was for property near 2 Timothy Lane, an area of woodlands near the West Aspetuck River. The New Milford Clean Water Coalition opposed it, creating the petition on change.org and sponsoring the New Milford Guardians Against Flatiron group.
Flatiron’s plan was typical of Battery Energy Storage Systems nationwide: It would create a huge field of industrial storage containers with batteries to store excess energy from power plants, solar arrays or wind farms during times when demand is low. When demand peaks, the units release energy to the power grid, improving the reliability of service.
But opponents argue that a fire at a lithium battery facility could jeopardize firefighters and potentially become an environmental disaster.
Because Flatiron’s plan would involve the region’s power grid, decisions would be in the hands of the Connecticut Siting Council and the Public Utilities Regulatory Authority.
Bass said New Milford will remain ready to oppose the project if it’s revived. In addition to its proximity to the river, the Treebeard facility was going to be in a residential zone. Bass said that prospect wasn’t acceptable.
“We have let the parties and the public know we will defend ourselves against anything that could be an environmental catastrophe,” he said Tuesday. “Our legal team is prepared if we need it.”
State Sen. Stephen Harding credited Bass, other town officials, New Milford’s legislative delegation and local community groups that publicly opposed Treebeard.
“This is great news for New Milford. I was proud to stand with the New Milford community in raising concerns about this proposed project, and I’m very pleased to see this outcome,” Harding said in a statement.