PNW · 10-Q · 2026Q3 · Full report

Western Energy Market Expansion

PINNACLE WEST CAPITAL CORP · 2026-11-03 · Importance 35 · Surprise 42

APS expects to begin participating in the Southwest Power Pool’s Markets+ day-ahead and real-time market in October 2027; FERC approved the Markets+ tariff on January 16, 2025. APS is also participating in the Western Resource Adequacy Program and plans to transition to full-binding participation in November 2027. APS expects the markets to reduce fuel and purchased-power costs, improve operational situational awareness, and support integration of its resources, while it continues participating in the Western Energy Imbalance Market as feasible before Markets+ replaces its real-time function.

Key facts

• APS expects its participation in WEIM and future participation in Markets+ to lower fuel and purchased-power costs and improve operational situational awareness and resource integration. source
• Markets+ was approved by FERC on January 16, 2025, and APS expects to go live in the market in October 2027. source
• APS plans to transition to full-binding participation in the Western Resource Adequacy Program in November 2027. source