Draft 2050 Transmission Study Feedback and Request


Dated: December 1, 2023

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 To:                  ISO New England (ISO-NE)

From:              New England States Committee on Electricity (NESCOE)

Date:               December 1, 2023

Subject:           Feedback on the Draft 2050 Transmission Study and Request to Prepare for an Actionable Path Forward

CC:                 Planning Advisory Committee (PAC)

NESCOE appreciates the opportunity to provide feedback on the draft 2050 Transmission Study (Study), issued on November 1, 2023. The Study provides critical visibility into potential future transmission system needs and the cost of integrating clean energy resources to ensure a reliable transition to our future grid. We couple our feedback with a request for ISO-NE to (i) identify any further analysis that may be needed to allow the region to move to actionable transmission solutions as soon as possible and (ii) consider whether it can commence work with states and stakeholders in the nearest term on elements of a solicitation not dependent on such advance analysis to help move toward issuance as soon as possible.[1]  In addition, we suggest some next steps regarding public presentation of the Study results.

First and foremost, NESCOE thanks ISO-NE for its responsiveness to our call for longer-term, repeatable transmission planning.[2] We especially appreciate ISO-NE staff’s hard work and collaboration on the Study. This Study is the first longer-term transmission study (LTTS) in New England and represents an important step for the region as it seeks to better understand how system needs will evolve during the clean energy transition.

Feedback on Draft 2050 Transmission Study

NESCOE offers the following high-level observations as we continue to digest the considerable amount of information contained in the Study and its technical appendices. First, the Study clearly highlights the potential value of limiting load growth in the future, whether through energy efficiency, demand response, or other measures.[3] We appreciate that the Study incorporated an alternate 2050 winter peak load level of 51 gigawatts (GW) to explore the impact of load reduction on transmission needs, in addition to using the assumptions provided by NESCOE, which included an assumed 57 GW winter peak load.[4] Other recent studies also point to potential significant benefits from varying types of load reduction.[5] NESCOE looks forward to working with ISO-NE and stakeholders to explore ways to leverage load-reducing opportunities, such as demand response, to benefit all consumers.

Continuing Work to Lead to a Transmission Procurement in the Nearest Term

The Study results indicate that New England will need incremental transmission as soon as 2035. In light of this, NESCOE appreciates ISO-NE’s current focus on the second phase of the LTTS tariff changes (Phase 2), which will establish a process for the states to operationalize the results of this Study and future longer-term studies. NESCOE looks forward to continuing to work with ISO-NE and stakeholders to expeditiously finalize those tariff changes for filing with FERC in April 2024, with the earliest possible effective date. The timing of this process, however, leaves a gap in moving toward actionable regional transmission solutions after the conclusion of the Study.

First, we request ISO-NE’s guidance on the options to make productive use of the time before the Phase 2 effective date to position our region to act on a transmission solicitation as promptly as possible. A priority for states is understanding infrastructure needs to facilitate the interconnection of clean generation, such as offshore wind,[6] hydro, solar and storage in the near to medium term (e.g., by 2035).

For example, in locating generator interconnections for offshore wind and other resources, the Study sought to optimize points of interconnection to address system overloads.[7] To inform transmission investments that states may wish to pursue, NESCOE would like to understand from ISO-NE whether it believes advance analysis would be needed prior to any solicitation targeted at creating grid-ready points of interconnection that, among other things, also minimize costs and needed upgrades to deliver power to load centers and meet future load growth. In addition, we would like to understand what elements of the solutions reflected in the roadmaps that ISO-NE produced in the Study need advance analysis to inform a solicitation and which do not.

Second, we request that ISO-NE consider whether it can commence work with states and stakeholders in the nearest term on those elements of a solicitation that are not dependent upon such advance analysis to help move toward issuance as soon as possible. The urgent need for transmission requires our collective efforts to forge ahead from study to solicitation. Beginning work with states and stakeholders on a solicitation instrument on an earlier calendar in 2024 best positions our region to move toward actionable transmission solutions.

Public Presentation of Study Results

Finally, NESCOE encourages ISO-NE to create a short summary document written in plain language and host a lunchtime webinar to present the Study results as it has done with other key studies, such as the Future Grid Reliability Study. The summary should provide a plainly stated explanation of the Study’s purpose, and what the Study is (directionally informative) and is not (a definitive statement of need). Given the novel nature of the Study and the broad impact that transmission development can have on the public, it is particularly fitting for ISO-NE to provide accessible opportunities for the public to understand the Study and its implications.

NESCOE appreciates ISO-NE’s concerted effort to finalize tariff changes to give states the ability to translate this longer-term planning into the development of transmission infrastructure in the coming months. We also appreciate ISO-NE’s guidance in the nearest term on whether and by what means to conduct any incremental analysis and take other action to position the region to act on a Phase 2 transmission solicitation as promptly as possible. Going forward, NESCOE is also interested in discussing opportunities to better refine the assumptions as well as what additional types of data may be helpful to improve modeling in future longer-term studies and/or any follow-on work. We appreciate ISO-NE’s partnership in preparing for an actionable path forward on beneficial transmission for the New England region as soon as possible. 

Document Source Citations

[1]       The Federal Energy Regulatory Commission (FERC) referenced the complementary interaction between the Section 4A process of Attachment K of ISO-NE’s Open Access Transmission Tariff (OATT) and the longer-term transmission study (LTTS) process in accepting ISO-NE’s filing establishing the first phase of the LTTS procedures. ISO New England Inc. and New England Power Pool Participants Committee, Letter Order, 178 FERC ¶ 61,137 (2022) at PP 4, 15.

In comments on ISO-NE’s Draft 2024 Work Plan, NESCOE noted that two states had earlier indicated a possibility of asking ISO-NE to pursue the existing public policy transmission study process in 2024 as needed to advance transmission development. See at 2.  That process would require ISO-NE to trigger provisions of Section 4A by January 15, 2024.  ISO-NE’s prompt response to these requests will inform states’ consideration regarding the effectiveness of pursuing action under Section 4A in 2024.

[2]     NESCOE, New England States’ Vision for a Clean, Affordable, and Reliable 21st Century Regional Electric Grid (Oct. 2020), at

[3]     ISO-NE, Draft 2050 Transmission Study (Nov. 1, 2023), at 16-17.

[4]     ISO-NE, 2050 Transmission Study Sensitivity Results and Solution Development Plans (Apr. 2022), at

[5]     ISO-NE, Operational Impact of Extreme Weather Events: Probabilistic Energy Adequacy Tool (PEAT) Results of Stakeholder-Informed Winter 2032 Sensitivity Analysis (Nov. 23, 2023), at

[6]     Infrastructure to connect offshore wind to the regional power grid has been a shared priority of the New England states. (see e.g., New England States Transmission Initiative at

[7]     ISO-NE, Draft 2050 Transmission Study (Nov. 1, 2023), at 19.