Update on Market-Based Rate Authority for 50LW 8me LLC and Affiliates

Strategic Insights -

On July 29, 2025, 50LW 8me LLC submitted a document to the Federal Energy Regulatory Commission (FERC) to report a new affiliation with commercially operational generation capacity located in the same market as, or in a first-tier market to, the location of each Seller's respective generation facility. The new affiliates, McFarland Storage C, LLC ("McFarland C") and AES Westwing II ES, LLC ("Westwing II"), own and operate battery energy storage systems with commercial operation dates of April 9, 2025, and May 23, 2025, respectively. Both McFarland C and Westwing II have market-based rate authority and are self-certified as exempt wholesale generators.

Key Takeaways:

  • The Sellers listed in Attachment A, including 50LW 8me LLC, represented that despite the new affiliation with the New Affiliates, each of the Sellers continues to lack horizontal market power and vertical market power.
  • McFarland C, one of the new affiliates, owns and operates a 185 MW / 740 MWh battery energy storage system located within the California Independent System Operator Corporation (CAISO) balancing authority area and achieved commercial operation on April 9, 2025.
  • Westwing II, the other new affiliate, owns and operates a 119.7 MW / 478.8 MWh battery energy storage system located within the Arizona Public Service Company (AZPS) balancing authority area and achieved commercial operation on May 23, 2025.
  • The Sellers submitted a Triennial Updated Market Power Analysis for the Southwest Region on June 30, 2025, which demonstrated that Sellers lacked horizontal market power with a supporting analysis that included the New Affiliates and all the Sellers provided here.
  • The Sellers continue to lack horizontal market power following the energization of the New Affiliates' electricity generation and storage facility.
  • The Sellers also represent that the new affiliation with the New Affiliates does not alter their vertical market power in any way, as each of the New Affiliates will only own its respective generation project and the generator interconnection facilities needed to connect that project with the transmission system.
  • The Sellers have not erected barriers to entry into relevant markets and will not erect barriers to entry into relevant markets.
  • Seller categories remain unchanged as the result of the new affiliation, with all Sellers remaining a Category 2 Seller in the Southwest region and their category status in other regions unaffected.

Statistics:

  • 185 MW / 740 MWh: The capacity and energy storage of McFarland Storage C, LLC's battery energy storage system.
  • 119.7 MW / 478.8 MWh: The capacity and energy storage of AES Westwing II ES, LLC's battery energy storage system.
  • 50: The number of Sellers listed in Attachment A, including 50LW 8me LLC.
  • 6: The number of new affiliates, McFarland Storage C, LLC and AES Westwing II ES, LLC.
  • 2: The category of each Seller in the Southwest region following the new affiliation.
  • 7/29/2025: The date the document was submitted to the Federal Energy Regulatory Commission.

Sources:

  • 50LW 8me LLC, et al., Re: The Sellers Listed in Attachment A Notice of Change in Status, Docket No. ER25-451-000.
  • McFarland Storage C, LLC, Docket No. ER24-2148.
  • AES Westwing II ES, LLC, Docket No. ER24-1697.
  • 65HK 8me LLC, et al., Triennial Updated Market Power Analysis for the Southwest Region, Docket Nos. ER15-1582, et al.
  • The Honorable Debbie-Anne A. Reese, Secretary Federal Energy Regulatory Commission, July 29, 2025.