Southwest Power Pool

Southwest Power Pool (SPP) is a nonprofit organization that manages the electric grid and wholesale power market across a vast region in the central United States. As a Regional Transmission Organization (RTO), SPP is mandated by the Federal Energy Regulatory Commission (FERC) to ensure reliable power supplies, adequate transmission infrastructure, and competitive wholesale electricity prices for its members.

Established in 1941, SPP's service area spans approximately 557,546 square miles, encompassing 14 states: Arkansas, Colorado, Iowa, Kansas, Louisiana, Minnesota, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, and Wyoming.

The organization serves a diverse membership base, including investor-owned utilities, municipal systems, generation and transmission cooperatives, state agencies, independent power producers, and power marketers.

Primary Services

• Reliability Coordination: Monitoring power flow throughout the region and coordinating responses during emergencies or blackouts.
• Tariff Administration: Administering an Open Access Transmission Tariff with consistent rates and terms, facilitating the use of the region's transmission lines.
• Regional Scheduling: Ensuring that the amount of power sent matches the power received.
• Transmission Expansion: Identifying system limitations and developing transmission upgrade plans to reinforce the grid.
• Market Operations: Operating the Integrated Marketplace, which includes a day-ahead market, real-time balancing market, and price-based operating reserve procurement.
• Training: Offering continuing education for operations personnel at SPP and throughout the region.

Capacity and Generation Mix

In 2024, SPP's accredited generating capacity was 63,908 MW, with a generation mix comprising 47.5% natural gas, 33.6% coal, 8.6% wind, 4.6% hydro, 3.0% nuclear, 2.1% petroleum, 0.6% solar, and 0.1% other sources.

The organization processed an average of 6,946 member transmission service requests per month in 2020, with transmission service transactions totaling $5.9 billion in 2024.

Locations

• Headquartered in Little Rock, Arkansas, USA
• Operates across its 14-state service area in the central United States, including Arkansas, Colorado, Iowa, Kansas, Louisiana, Minnesota, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, and Wyoming.

Recent Expansion

In March 2025, SPP expanded its territory to become the first regional U.S. grid to operate in both the eastern and western interconnections of the country's electrical system.

This expansion allows additional power providers to participate in the broader market, benefiting from transmission planning and other grid services starting in April 2026.