Massachusetts’s Department of Energy Resources (DOER) has completed the evaluation of bids received in response to the Section 83E Storage request for proposals (RFP), selecting projects totalling 1,268MW of energy storage capacity.
DOER selected projects Energizar and Salt Cod from developer FlatIron Energy, River Mill Storage from developer Rhynland Energy, and Trimount ESS from developer Jupiter Power, for a total of 1,268 MW of energy storage capacity.
The Salt Cod battery energy storage system (BESS) was proposed with a capacity of 168MW, at the former coal-fired Montaup Power Plant.
According to FlatIron, Energizar will have a capacity of 250MW/1,000MWh and will commence operations in Q2 2027.
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Jupiter Power’s Trimount ESS will have a capacity of 700MW and will be constructed at the site of a former ExxonMobil oil depot.
Rhynland has not listed the capacity for its River Mill Storage BESS, but given the other projects’ capacities, it will likely have a capacity of around 150MW.
Massachusetts’s electric distribution companies (EDCs) and DOER issued the RFP in summer 2025.
In May 2025, the DOER and the EDCs, which are also the state’s investor-owned utilities (IOUs), initiated efforts to secure 5,000MW of energy storage by 2030. They filed a draft RFP with the MA Department of Public Utilities (DPU) for 1,500MW of mid-duration ESS.
The state’s EDCs include Eversource, National Grid, and Unitil. Unitil is also referred to as Fitchburg Gas & Electric Company. National Grid functions through either Massachusetts Electric Company or Nantucket Electric Company. Eversource is also known as NSTAR Electric Company.
The approved RFP for 1,500MW of mid-duration BESS marks the start of a phased procurement plan. It will be succeeded by 1,000MW due by 31 July 2026, another 1,000MW by 31 July 2027, with the remaining capacity scheduled for 31 July 2030.
In November 2024, Massachusetts Governor Maura Healey enacted a comprehensive energy bill. This legislation mandates increasing the procurement of ESS to 5,000MW by 31 July 2030.
The final acceptance of bids and the awarding of contracts for the recently accepted projects depend on successfully negotiating mutually acceptable long-term agreements between the bidders and each of the EDCs, along with obtaining the necessary regulatory approvals for the contracts, as outlined in the RFP.
The Energy Storage Summit USA will be held from 24-25 March 2026, in Dallas, TX. It features keynote speeches and panel discussions on topics like FEOC challenges, power demand forecasting, and managing the BESS supply chain. For complete information, visit the Energy Storage Summit USA website.
