In the wake of a winter storm that pushed power grids to the brink of crisis just ahead of the Christmas holiday, the Southwest Power Pool (SPP) is recommending that extreme weather be part of the long-term planning process for new transmission lines. While that’s a welcome and positive step in addressing vulnerabilities in a system that includes utilities and transmission companies across 17 states, more needs to be done.
In its special report on Winter Storm Elliott, SPP failed to address resource accreditation—the process to determine how much capacity a particular energy resource can be expected to deliver. That’s troubling, particularly in light of how fossil fuel generators underperformed during last December’s storm that plunged much of the United States into freezing temperatures and triggered widespread outages at fossil fuel plants. While wind resources performed above expectations, all fossil fuel generators delivered well below what SPP had planned for.
Figure 1: Percentage of planned generation capacity available during Winter Storm Elliott
The report on Winter Storm Elliott comes at a critical time as SPP considers an updated policy framework for conventional fossil fuel generators. A recent Federal Energy Regulatory Commission order that set aside SPP’s proposed accreditation policy for wind and solar resources made it clear that any future accreditation policy proposed by SPP must demonstrate equal treatment of resources—renewable and fossil fuel.
Environmental groups, including NRDC, have raised concerns about SPP’s proposal to improve resource accreditation for thermal generators. While the effort is moving in the right direction, the plan under review by SPP stakeholders falls short because it fails to:
- Account for the type of weather-related gas and coal outages that we worry about during extreme weather like Winter Storm Elliott;
- Use all of the historic data to capture the worst outages for thermal resources, which is exactly what accreditation is supposed to protect against;
- Treat all resource types in the same way.
As a result, SPP’s proposal to assess thermal resource availability would disadvantage wind, solar, and battery storage resources as compared to gas and coal resources, thereby compromising reliability.
The special report on Winter Storm Elliott includes 11 recommendations to improve system performance during episodes of extreme weather, none of which cover resource accreditation. That’s a glaring oversight. Planning and preparation are the best tools we have to maintaining reliability, and a plan that ignores the repeated failures of the gas industry is a plan destined to fail. Consumers need a reliable grid, and any evaluation of generation capacity must be data-driven.
Along with the need to improve resource accreditation, extreme weather events have shown us the importance of building new transmission lines, both to bring more renewable power assets online faster and to improve connections with our neighbors, who can share excess power when we are facing emergency shortages. SPP’s own planning models show that the penetration of renewable resources in north-central Oklahoma is expected to produce severe transmission congestion points. In other words, the resources that performed best when power was most needed last December are being undermined by a lack of transmission capacity. The recommendations in the special report should help address the need for improved transmission planning, but there’s no time to waste.