ISO New England has identified a preliminary preferred transmission project to address long-term grid needs associated with the region's clean energy transition, marking a key milestone in the 2025 longer-term transmission planning process.

The selected proposal, submitted jointly by Central Maine Power (CMP) and Eversource, would strengthen the transmission network between northern Maine and southern New England. The upgrades are intended to support the delivery of growing amounts of land-based wind generation from northern Maine to population centers where electricity demand is highest.

The project was selected through a request for proposals (RFP) issued by ISO New England at the direction of the New England States Committee on Electricity (NESCOE). The solicitation supports regional transmission planning efforts tied to NESCOE's 2050 Transmission Study and follows Phase 2 of the region's Longer-Term Transmission Planning (LTTP) framework.

According to ISO New England, proposals were evaluated based on their ability to satisfy the RFP requirements, technical feasibility, regional costs and benefits, and additional evaluation priorities established by NESCOE.

The ISO has released a draft evaluation report outlining its technical analyses, cost-benefit assessment and the rationale for selecting the preliminary preferred solution. Following a public comment period, the organization will issue a final report confirming the preferred project.

After the final report is published, NESCOE will have 30 days to either terminate the 2025 LTTP solicitation or pursue an alternative cost allocation approach for the project. If neither action is taken during that period, ISO New England will move forward with the next phase of the process.

The next steps include executing agreements with the project sponsors and conducting additional technical studies required before the transmission project can move toward implementation.

ISO New England said it will continue providing updates on the project through its Planning Advisory Committee as the regional planning process advances.