ISO-NE issues request for proposals for transmission solutions

At the direction of the New England States Committee on Electricity (NESCOE), ISO New England has issued a request for proposals (RFP) to address longer-term transmission needs. Although the schedule is subject to change, proposals are due in September 2025. After evaluation by the ISO, a preferred solution may be selected by NESCOE as early as September 2026. 

The goal of the RFP is to upgrade the transmission system between northern Maine, where land-based wind generation is expected to increase, and more populous regions of southern New England, where demand for electricity is highest.  

NESCOE’s request includes a list of needs that all proposals must address. These include increasing the amount of power that can flow across the Maine–New Hampshire and Surowiec–South transmission interfaces, and developing new infrastructure around Pittsfield, Maine, that could accommodate the interconnection of 1,200 megawatts of land-based wind.  

The request is in accordance with Phase 2 of the longer-term transmission planning (LTTP) process. LTTP was initiated in response to the New England States’ Vision for a Clean, Affordable, and Reliable 21st Century Regional Electric Grid, a document issued in 2020 that called on the ISO to incorporate longer-term transmission planning in its regional system planning process. Much of the framework of the RFP is drawn from the ISO’s 2050 Transmission Study, part of Phase 1 of the LTTP. The landmark study identified high-likelihood concerns and associated transmission system upgrade costs that may be driven by the states’ pursuit of policy goals to reduce carbon emissions.  

The ISO will assess proposals based on various factors, including cost benefit to the region and additional evaluation priorities identified by NESCOE. The ISO will provide updates on the process, as appropriate, through the Planning Advisory Committee.