While parts of the United States are at an elevated or high risk for potential electricity emergencies this summer, Oklahoma falls into the lowest risk category, according to the North American Electric Reliability Corporation’s (NERC) 2021 Summer Reliability Assessment. According to NERC’s assessment, electric supply shortages may occur in the western United States, Texas, New England and parts of the Midwest.
Summer peak electricity demand is strongly influenced by temperature. NERC’s report notes that above-normal temperatures are expected for much of North America this summer, with several regions at risk of electricity shortfalls during above-normal peak temperatures.
NERC publishes a reliability assessment that tabulates anticipated electricity demand and supply changes while highlighting any regional challenges or expected conditions that may affect the bulk power system.
Above-normal summer heat increases electricity demand from temperature-dependent loads and can reduce electricity supplies if power plant outages or reduced output stems from heat-related issues. Wide-area heat waves can also challenge grid operators and may limit electricity transfers because the electricity is needed to meet local electricity demand.
In the Western Electricity Coordinating Council (WECC), which includes the western half of the United States, resource and energy adequacy is a significant concern this summer as cities like Seattle endure record heatwaves. Generating capacity and projected electricity demand are at similar levels as they were in 2020, a demanding year that brought about rolling blackouts. NERC found that WECC sub-regions in the Southwest and Northwest have enough resources to meet electricity demand under normal peak summer demand conditions, but they are at elevated risk of electricity shortfalls if demand is higher.
The highest risk of electricity emergency is in California, which relies heavily on energy imports during normal peak summer demand. Although California has gained new flexible resources to help meet demand when solar energy is unavailable, it is at high risk of an electricity emergency when above-normal demand is widespread in the west because the amount of resources available for electricity transfer to California may be limited.
The Electric Reliability Council of Texas (ERCOT) typically has one of the smallest anticipated reserve margins in the country, meaning it has relatively little unused electric generating capacity during times of peak electric load. Although ERCOT’s anticipated reserve margin is higher this summer, extreme summer heat could result in supply shortages that lead to an electricity emergency.
The Midcontinent Independent System Operator (MISO) and ISO-New England have sufficient resources to meet projected peak demand. If above-normal levels of electricity demand occur in these regions, demand is likely to exceed capacity resources. In that case, additional transfers of electricity from surrounding areas will be needed to meet demand.
To review NERC’s 2021 Summer Reliability Assessment report, click here.
