Mount Vernon Battery Storage, LLC Seeks Exemption from FERC Regulation

Strategic Insights -

Mount Vernon Battery Storage, LLC, a Delaware limited liability company, has submitted a notice of self-certification to the Federal Energy Regulatory Commission (FERC) to establish its status as an exempt wholesale generator (EWG). The company plans to operate a 200 MW/800 MWh energy storage system in Skagit County, Washington, and interconnect it to the Puget Sound Energy (PSE) transmission system. As an EWG, Mount Vernon will not be subject to FERC's wholesale market regulations, but will still be required to comply with certain conditions, including selling electric energy at wholesale and not engaging in retail sales.

Key Takeaways:

  • Mount Vernon Battery Storage, LLC is a Delaware limited liability company that plans to operate a 200 MW/800 MWh energy storage system in Skagit County, Washington.
  • The company will interconnect its facility to the Puget Sound Energy (PSE) transmission system and sell electric energy at wholesale, not at retail.
  • As an EWG, Mount Vernon will be exempt from FERC's wholesale market regulations, but will still be subject to certain conditions, including complying with emission trading rules and selling "green" power certificates.
  • Applicant makes the following representations in order to certify that it satisfies the requirements for EWG status:

+ The company will be engaged directly and exclusively in the business of owning and operating the facility and selling electric energy at wholesale.

+ The facility will satisfy the definition of Eligible Facilities as defined in Section 32(a)(2) of the Public Utility Holding Company Act of 1935.

+ The company will not make sales of power at retail.

+ No rate or charge for, or in connection with, the construction of the facility, or for electric energy produced by the facility, was in effect under the laws of any State on October 24, 1992.

+ No portion of the facility will be owned or operated by an "electric utility company" that is an "affiliate" or "associate company" of Applicant that is not itself an EWG.

+ The company represents that there will be no leasing arrangements involving the facility under which Company is the lessor and from which Company will derive any revenues or that otherwise violate exclusivity requirements consistent with the Commission's EWG precedent.

  • Applicant makes the following representations in order to certify that there is no Ultimate Upstream Affiliate of NEER:

+ As of the end of the first quarter of 2025, The Vanguard Group Inc. et al., reported that it held 10.55% of the publicly traded shares in NextEra Energy, Inc.

Statistics:

  • 200 MW/800 MWh: The planned capacity of the energy storage system.
  • Skagit County, Washington: The location of the energy storage system.
  • Puget Sound Energy (PSE): The transmission system to which the facility will interconnect.
  • 10.55%: The percentage of publicly traded shares in NextEra Energy, Inc. held by The Vanguard Group Inc. et al.

Sources:

  • Public Utility Holding Company Act of 2005, enacted pursuant to the Energy Policy Act of 2005, SSSS 1261-77, Pub. L. No. 109-58, 119 Stat. 594 (2005).
  • Section 366.1 of the Commission's regulations, 18 C.F.R. § 366.1.
  • UGI Development Co., 89 FERC P 61,192 (1999).
  • Madison Windpower, LLC, 93 FERC P 61,270 (2000).
  • VESI 12, LLC, 186 FERC P 61,137 at P 16 (2025).
  • Quarterly Compliance Filing for Q1 of 2025, Docket No. EC19-57-002.