SPP: Southwest Power Pool
The Southwest Power Pool operates the electric grid across 14 states in the central United States, from North Dakota to New Mexico. SPP has achieved remarkable wind integration, regularly exceeding 70% of total generation from wind power—a world-leading achievement for a large grid operator.
Source: SPP
Coverage Area
SPP serves parts or all of Arkansas, Iowa, Kansas, Louisiana, Minnesota, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas (Panhandle and eastern portions), and Wyoming. The region encompasses some of the best wind resources in the world, particularly across the Great Plains.
Wind Energy Achievement
SPP has integrated more wind energy relative to its size than any other large grid operator in the world. Wind regularly provides 50-60% of SPP's generation on high-wind days, with peaks exceeding 75%. This achievement demonstrates that high renewable penetration is technically feasible at scale.
Kansas and Oklahoma are particularly wind-rich, with some areas achieving capacity factors over 45%—among the highest in the nation. This has made SPP-area wind projects among the lowest-cost sources of new electricity generation anywhere.
Transmission Planning & Investment
SPP has invested heavily in transmission to enable wind integration, with its Highway-Byway cost allocation methodology spreading costs across the region. The grid now has significant export capability to neighboring regions, though transmission congestion remains a challenge in some areas.
Market Operations
SPP operates both day-ahead and real-time energy markets, along with various ancillary services markets. The market has evolved to handle high wind penetration, including ramping products and enhanced forecasting. Negative prices are common during high-wind periods, creating incentives for storage and demand flexibility.
Winter Storm Uri Experience
During Winter Storm Uri in February 2021, SPP experienced significant generation outages and implemented controlled load shedding to prevent grid collapse. The experience highlighted the need for weatherization and coordination with natural gas suppliers, leading to various reliability improvements.
Frequently Asked Questions
What is SPP and what does it stand for?
SPP is the Southwest Power Pool, and the name is literal. On December 16, 1941, nine days after Pearl Harbor, eleven utilities agreed to pool their generation to power an aluminum plant in Arkansas for the war effort. It incorporated in 1994, was approved by federal regulators as a regional transmission organization in 2004, and now runs the grid and wholesale market for about 20 million people.
Which states are in SPP?
SPP covers all or part of 17 states: Arizona, Arkansas, Colorado, Iowa, Kansas, Louisiana, Minnesota, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah and Wyoming. Coverage follows member utility service areas rather than state lines — in Texas, for instance, only the Panhandle and a slice of the east. Kansas, Oklahoma, Nebraska and the Dakotas are essentially fully covered.
How does SPP achieve such high wind penetration?
Extensive transmission investment, excellent wind resources, advanced forecasting, flexible market operations, and geographic diversity across a large footprint all contribute to SPP's wind integration success.
What happens when wind exceeds demand?
During high-wind, low-demand periods, SPP exports power to neighboring regions, prices go negative (incentivizing storage and flexible loads), and in extreme cases, wind curtailment may occur.
How is solar growing in SPP?
Solar is the fastest-growing resource in SPP's interconnection queue, with developers attracted by the complementary generation profile with wind and excellent solar resources in the southern portions of the footprint.