SPP and CAISO file joint report to FERC on Western market seams coordination framework

SPP and CAISO jointly submitted a report to FERC outlining a coordinated approach to future market seams issues across the Western Interconnection, identifying six near-term objectives and signaling intent to formalize commitments via a coordination agreement.

As organized markets (EDAM, Markets+) expand across the West, unresolved seams issues—data misalignment, model inconsistency, and multi-area transmission constraints—threaten reliable and transparent market operation; this joint SPP-CAISO framework represents the first formal operator-level mechanism to address these cross-market coordination gaps.

This filing marks a structural shift from ad hoc bilateral coordination to a formalized, FERC-visible seams governance process between the West's two largest ISO/RTO market operators. The six objectives—data exchange, model alignment, education/training, WILR and Enhanced Curtailment Calculator support, multi-area transmission constraint processes, and a longer-term seams plan—suggest the framework will primarily affect operational and reliability coordination rather than price formation directly, though misaligned models and curtailment processes have historically distorted price signals at seams. The explicit intent to pursue a coordination agreement signals this report is a foundational step rather than a final design; the 30-day comment period and the scheduled Oct. 22, 2026 workshop are the immediate levers through which stakeholders can shape the eventual agreement's scope, particularly around transmission constraint allocation methodologies that could affect cross-border capacity calculations between SPP and CAISO balancing footprints.

Joint report filed with the Federal Energy Regulatory Commission (FERC); subject to FERC comment procedures

Fourth joint SPP-CAISO workshop on Western market seams coordination · 22 Oct 2026

Primary sources