East Point withdraws 125 MW Tewksbury battery over grid upgrade costs

Hillman Energy Center, LLC, the project company East Point Energy set up for a 125 MW / 500 MWh battery at 73-75 Hillman Street in Tewksbury, Massachusetts, asked the state Energy Facilities Siting Board on September 1, 2026 for permission to withdraw its application for a Certificate of Environmental Impact and Public Interest in docket EFSB 26-02. The motion says the results of ISO New England's Transitional Cluster Study showed grid upgrade costs that "greatly exceeded previous estimates, making this project economically unviable," and that the company has withdrawn the project from the interconnection queue as well as from the Siting Board.

The board had approved the project on June 30, 2026. In EFSB 25-08, the Siting Board granted zoning exemptions by final decision that day; the motion describes the approval as subject to 104 conditions. The decision describes 134 Hithium LX5015 battery enclosures and an approximately 1,200-foot, mostly underground 115 kV line to National Grid's Tewksbury #22 substation (four hours at full output; see kW vs kWh). Two neighbors who intervened, Maureen DiPalma and Dennis Sheehan, filed a certificate of appeal to the Supreme Judicial Court on July 16, 2026, according to the docket. The certificate proceeding had opened on June 30, 2026, seeking 15 state and local permits. On August 27, in a motion for more time to answer the board's information requests, Hillman said it was reviewing the cluster study results and "its allocated share of the upgrade costs" to decide whether the project remained economically viable, and would decide by August 31. It decided.

ISO New England issued the final Transitional Cluster Study report on August 6, 2026, covering 23 projects totaling 4,826.5 MW of summer capacity network resource interconnection service. The public version blanks out every project description and redacts Section 7, on network upgrade cost allocation, as critical energy infrastructure information. Table 1-1 nonetheless lists queue position 1553 as a 125 MW project at the Tewksbury 115 kV substation, and Table 9-19 gives that position non-binding, good-faith cost estimates of $9 million for transmission owner interconnection facilities, $1 million for substation network upgrades and $55,331,093 for system network upgrades, $65,331,093 in all, with the longest element estimated at 69 months from notice to proceed. WBUR reported on September 3 that ISO New England notified the company in August that it would have to pay $65 million, more than three times what it had expected, and that the developer had expected to owe several million dollars when it proposed the project in March 2025. "Unfortunately, rising interconnection costs have made it cost-prohibitive to complete the project, and East Point Energy is discontinuing its development," Maggie Howe, East Point's vice president of project development, wrote to WBUR.

By the study's own standards, $65 million is cheap: the report's Section 9 estimates run from $672,500 to $540.6 million for the 18 positions with estimates, and ISO New England spokesperson Matt Kakley told WBUR the average across the 23 projects was $178 million and that 18 of them were batteries.

The state saw this coming. On June 25, 2026, after the interim report of June 7, Massachusetts Energy and Environmental Affairs Secretary Rebecca Tepper wrote to ISO New England's chief executive that the study identified "more than $3 billion in total interconnection costs," that, absent modifications, several battery proposals "could face" estimated interconnection costs of $300 million to $500 million and construction timelines approaching eight years, and that estimates finalized at that level "will have a significant chilling effect on investment in Massachusetts and across the New England region for years to come." Her letter cites the state's 5,000 MW storage requirement for 2030 under Section 83E and Executive Order No. 654 of March 16, 2026, which set an additional goal of 5,000 MW online or under development by the end of 2035. ISO New England president Vamsi Chadalavada replied on June 29 that the transmission investment identified in the interim report "is driven by the volume and location of proposals in the TCS," that the region already had about 2,200 MW of battery storage, mostly in Massachusetts, with completed studies and commercial operation dates on or before 2030, and that the first regular cluster study window opens on October 5, 2026.

Town Manager John Curran told WBUR the connection costs were "far in excess of what anybody anticipated" and would affect projects across the state. The Lowell Sun reported that residents of Emerald Court, a neighborhood mostly of adults over 55 beside the site, had fought the project for a year and a half over fire and evacuation concerns. "Emerald Court is celebrating. We are going to have party after party," DiPalma, who developed the neighborhood and lives there, told the paper. The motion asks that the docket be closed without prejudice, which the Sun notes leaves the company free to bring the proposal back.

On September 3, East Point's parent Equinor announced that its 100 MW Citrus Flatts battery had started merchant operations in Texas. Massachusetts has meanwhile been rearranging who pays for upgrades at the distribution end of the same grid: on August 12, 2026 the Department of Public Utilities approved a flat $225 fee, effective November 1, 2026, that covers upgrade costs up to $10,000 ($1,450 for Unitil customers) for solar and battery systems of 25 kW or less in place of last-customer-pays charges; costs above the threshold still fall to the applicant. How the cluster study allocates network upgrade costs among its 23 transmission-level projects is the subject of the report's Section 7, which the public version redacts.

Outlook

The report says ISO New England must evaluate whether a restudy is needed because of the withdrawal of queue positions 501, 1542 and 1546, "the only withdrawals that are relevant to the TCS Projects as of the date of the posting of this final TCS Report." Hillman's withdrawal from the queue came after that date, so it joins whatever the restudy determination considers once interconnection agreement deposits are due; the report scheduled agreements to be tendered by August 21 with 60 days of negotiation, which points to a determination no earlier than late October 2026. Figure 1-9 of the report diagrams QP1553 together with QP1567, a 500 MW position with a $425.6 million estimate; if the two share upgrades, Hillman's exit is the kind of change a restudy would re-price, in either direction. ISO New England says any restudy would run in parallel with the formation of the base case for the first regular cluster study and the early parts of that study, and it plans a lessons-learned session in the fourth quarter of 2026. The Siting Board had not ruled on the motion as of September 4.