Access documents related to the Extended-Term/Longer Term Transmission Planning Tariff Changes Key Project.
This project, initiated in response to the and in alignment with 黑料网’s Strategic Plan, proposes changes to Attachment K of the Open Access Transmission Tariff in two phases.
The first phase of changes, approved by the Federal Energy Regulatory Commission (FERC) in February 2022, creates a process that allows the New England States Committee on Electricity (NESCOE) to request the ISO to perform system planning analyses that may extend beyond the 10-year planning horizon and that identify, at a high-level, transmission infrastructure necessary to meet a New England state’s energy policy, mandate, or legal requirement.
A second phase of changes, accepted by FERC in July 2024, creates a process to move transmission upgrades identified via the above analyses forward into developable projects, and includes a cost-allocation mechanism for those transmission improvements.
All information related to these studies and resulting regional solicitations for solutions are posted on the Longer-Term Transmission Studies (LTTSs) webpage. This includes documentation for the 2050 Transmission Study (the first LTTS requested by NESCOE), and NESCOE’s December 12, 2025 request that the ISO issue a regional solicitation (the first under the LTTP process).
The Extended-Term/Longer-Term Transmission Planning Tariff Changes project is just one of several key projects at the ISO, which continuously undertakes a variety of short- and long-term projects to enhance the region's competitive wholesale electricity markets and ensure reliable operation of the power grid.
