Sign in Subscribe
Independent regulatory commissions

ISO New England Inc. and Maine Electric Power Company Submit Tariff Revisions to Federal Energy Regulatory Commission

Strategic Insights

— 1 min read

ISO New England Inc. and Maine Electric Power Company have submitted tariff revisions to the Federal Energy Regulatory Commission (FERC) for the ISO New England Inc. Open Access Transmission Tariff. The revisions aim to update Attachment H, which identifies currently effective Grandfathered Transmission Service Agreements under which Maine Electric Power Company provides transmission service. The filing includes changes to Attachment H to identify current agreements and requests acceptance for filing, effective September 20, 2025. ISO New England Inc. has joined the filing to fulfill its obligations to file changes to the tariff on behalf of Participating Transmission Owners.

Key Takeaways:

  • ISO New England Inc. and Maine Electric Power Company have submitted revised tariff filings to FERC, effective September 20, 2025.
  • The revisions update Attachment H to identify currently effective Grandfathered Transmission Service Agreements under which MEPCO provides transmission service.
  • MEPCO requests waiver of any provision of the Commission's regulations as needed for acceptance of Revised Attachment H.
  • The filing includes revised Attachment H, metadata, and redline forms showing changes made.
  • The proposed effective date of the revisions is September 20, 2025.
  • MEPCO is a Commission-regulated transmission company that owns a 345 kV transmission line connecting transmission lines in New Brunswick, Canada, with those in Wiscasset, Maine.
  • Central Maine Power Company (78.3 percent) and Versant Power (21.7 percent) own MEPCO.
  • MEPCO is controlled by Central Maine Power Company and provides open access transmission service pursuant to the ISO-NE OATT.
  • ISO New England Inc. is the private, non-profit entity that serves as the regional transmission organization (RTO) for New England and plans and operates the New England bulk power system.

Statistics:

  • 345 kV: The transmission voltage of MEPCO's transmission line connecting transmission lines in New Brunswick, Canada, with those in Wiscasset, Maine.
  • 78.3 percent: The percentage of ownership of MEPCO by Central Maine Power Company.
  • 21.7 percent: The percentage of ownership of MEPCO by Versant Power.
  • 2: The transmission owners that own MEPCO.
  • 1: The FERC Docket number for the filing ER25- -000.
  • 24 states: The number of states that MEPCO provides transmission service to.

Sources:

  • ISO New England Inc., 124 FERC P 61,297 (2008).
  • 16 U.S.C.S. SS 824d (2025).
  • 18 C.F.R. Part 35 (2025).
  • 18 C.F.R. Section 35.13(b)(7).

Read more