New England states enlist ISO-NE support for longer-term transmission planning effort

Relieving future transmission bottlenecks between northern and southern New England and accommodating more clean energy resources in Maine are the two main objectives of the New England States Committee on Electricity’s (NESCOE) proposal for a first-of-its-kind regional solicitation under the region’s new longer-term transmission planning (LTTP) process. As part of the solicitation, NESCOE requested that ISO New England issue a request for proposals (RFP). 

The ISO expects to work on the RFP over the next several months, with proposals likely due later in 2025. The ISO will provide updates on the process, as appropriate, through the Planning Advisory Committee or with Qualified Transmission Project Sponsors. 

NESCOE’s request is in accordance with Phase 2 of the LTTP process. LTTP was initiated in response to the New England States’ Vision for a Clean, Affordable, and Reliable 21st Century Regional Electric Grid issued in 2020, which called on the ISO to incorporate longer-term transmission planning in its regional system planning process.  

A robust transmission system capable of integrating renewable resources and moving clean energy to New England’s consumers is crucial to support the states’ emission reduction goals, but transmission can take time to build. LTTP goes beyond the current 10-year planning timeframe by allowing for upgrades that will serve the region’s projected needs further into the future. 

NESCOE’s requirements for the RFP were guided by the ISO’s landmark 2050 Transmission Study, conducted under Phase 1 of the LTTP process. The study outlined concerns, potential roadmaps and associated costs needed to support the clean energy transition. One of the largest concerns raised in the study was the high likelihood of increased stresses on the transmission interfaces connecting northern and southern New England as the clean energy transition accelerates.