FERC Orders CAISO, SPP to File Sept. 30 Western Grid Seams Plan
Updated
Updated · POLITICO · Jul 16
FERC Orders CAISO, SPP to File Sept. 30 Western Grid Seams Plan
2 articles · Updated · POLITICO · Jul 16
Summary
Thursday’s FERC order gives CAISO and Southwest Power Pool until Sept. 30 to explain how they will manage power transfers where their Western day-ahead markets meet.
Two competing markets could let California’s midday solar and interior-state wind move more efficiently across the West, but mismatched rules, schedules and pricing at their boundaries can raise congestion, transmission costs and customer bills.
CAISO’s Extended Day-Ahead Market launched in May and is expanding from Oregon to New Mexico, while SPP’s Markets+ is due in October 2027 and would stretch from Colorado to the Pacific Northwest.
FERC Chair Laura Swett said similar seams problems have long plagued the East’s five organized power markets, and the commission wants the two Western operators to craft a fix themselves before inefficiencies deepen.
FERC is patching the grid's 'seams,' but is a single unified power market the only real long-term solution?
As AI power demand soars, can rival grid operators unite in time to prevent blackouts across the West?
Could market competition, not forced cooperation, have ultimately built a stronger and more innovative Western grid?
FERC Orders CAISO and SPP to Resolve Western Grid Seams: Joint Report Due September 30, 2026
Overview
On July 16, 2026, FERC addressed the growing complexity of Western grid coordination by formally requiring CAISO and SPP to submit a joint seams coordination report by September 30, 2026. This directive follows earlier calls from FERC Commissioner Judy Chang for stronger collaboration between the two operators as their day-ahead markets—CAISO’s EDAM and SPP’s Markets+—become adjacent. The report must outline detailed plans for operational coordination, robust modeling, reliability, and stakeholder engagement. This move highlights the recognized challenges of managing seams in the evolving Western energy landscape and aims to ensure reliable, efficient grid operations through proactive, transparent cooperation.