CAISO and SPP submit joint report to FERC on Western Market Seams coordination

The California Independent System Operator (CAISO) and Southwest Power Pool (SPP) submitted their joint report to the Federal Energy Regulatory Commission (FERC) outlining a coordinated approach to addressing future market seams issues as organized electricity markets continue to evolve across the Western Interconnection. The report reflects extensive collaboration between the two market operators and input gathered through a series of public workshops involving regulators, transmission providers, balancing authorities, market participants, and other stakeholders throughout the West.

CAISO and SPP identified six near-term objectives that reflect their shared prioritization. It includes improving data exchange, enhancing model alignment, expanding education and training efforts, supporting implementation of the Western Interconnection Loading Relief and Enhanced Curtailment Calculator initiatives, developing processes to address for transmission constraints that are affected by multiple market areas, and a commitment to develop and publish a longer-term plan that evaluates opportunities for further enhancements to seams coordination.

Looking ahead, CAISO and SPP intend to formalize many of their shared commitments through a coordination agreement and to continue working closely with each other and stakeholders across the West to advance the priorities identified in the report. As western electricity markets continue to expand, both organizations remain committed to collaborative solutions that support reliable grid operations, transparent market outcomes, and the long-term success of the Western Interconnection.

There is a thirty-day comment period for the report. CAISO and SPP have scheduled a fourth joint workshop for Oct. 22, 2026, with in-person attendance at WECC’s headquarters in Salt Lake City, UT.

Please follow this link to view the report: https://www.caiso.com/documents/sep-30-2026-joint-report-of-the-california-independent-system-operator-corporation-and-southwest-power-pool-inc-ad26-10.pdf