Southwest Power Pool Expands into Western Interconnection

Southwest Power Pool on April 2 announced the launch of expanded grid operations that extend its service territory into the Western Interconnection, making it the first U.S. grid operator to span two major power systems. The organization’s expanded operations officially began at midnight central time on April 1, following months of coordinated testing, simulation, and joint operational planning with participating utilities.

The expansion brings nine load-serving utilities into the organization’s footprint, covering parts of Arizona, Colorado, Montana, Nebraska, New Mexico, Utah, and Wyoming. These utilities now participate in the operator’s wholesale electricity market and planning framework, gaining access to a broader pool of generation resources and centralized system coordination. The move is expected to enhance grid reliability and improve cost efficiency through more optimized dispatch of power across a wider region. The development follows federal approval of tariff revisions that enable western utilities to participate in the organization’s wholesale market and planning processes, establishing the regulatory foundation for broader regional integration.

SPP’s expanded operations build on its long-standing role in the central U.S., where coordinated market functions and transmission planning have supported lower wholesale electricity costs and improved system resilience. By integrating western resources, the operator can better balance supply and demand across diverse weather patterns and generation types, including renewable energy sources that vary by geography.

The broader footprint is also expected to improve real-time visibility and operational awareness, enabling faster response to system disruptions and extreme weather events. Coordinated planning across a larger transmission network may support more efficient infrastructure investment and facilitate economic growth in participating states.

As additional utilities integrate into the platform over time, the benefits of regional coordination are expected to grow, particularly as demand patterns evolve and new generation resources come online.