NERC report outlines potential electricity disruptions in the United States this summer

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Contributed date

July 6, 2021 - 3:21pm

Critical Commentary

According to the North American Electric Reliability Corporation's (NERC) Summer Reliability Assessment, many parts of the United States are at elevated or high risk for potential electricity emergencies this summer, with several regions at risk of electricity shortfalls during above-normal peak temperatures. This is due to increasingly hot summers due to climate change which then leads to increased electricity demand due to temperature-related loads, such as use of air conditioning units. According to NERC’s assessment, electric supply shortages may occur in the western United States, Texas, New England, and parts of the Midwest.

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. Generating capacity and projected electricity demand are at similar levels as they were in 2020, when an August wide-area heat wave caused rolling blackouts. NERC found that WECC subregions 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, a WECC subregion, which relies heavily on energy imports during normal peak summer demand and when solar generation declines in the late afternoon. 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.

ERCOT typically has one of the smallest anticipated reserve margins, meaning they don't typically have leftover energy during times of peak electricity load, however due to adding new wind, solar, and battery resources into their grid, it's estimated that their reserve margin increased from 12.9% last summer to 15.3%. However, extreme heat may lead to supply shortages that then cause outages. 

MISO (Midcontinent Indepedent System Operator)  ISO-New England have sufficient resources to meet projected peak demand. However, if above-normal levels of electricity demand (which NERC calculates based on historical 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.

For all regions listed above, there is some degree of anticipated energy crises, as its almost expected at this point that demand will exceed capacity resources because of extreme weather due to climate change. The regions the least at risk for energy crises appear to be the midwest and New England, which at the most will have to transfer energy from surrounding areas to meet demand if it exceeds capacity in the summer. Although ERCOT is in a better position than they were last summer due to more renewable energy production and more capacity for energy storage, extreme heat is likely to occur in Texas which can lead to supply shortages despite the 3% increase in energy resource margins in this state. California, which is a subregion of WECC, is at highest risk of energy crises this summer due to their reliance on energy imports during summer peak times. As other regions of the country are at their threshold, importing electricity for these peak summer loads may not be an available option, which would lead to rolling outages. 

This report highlights the cyclical nature of carbon-intensive energy systems feeding climate change and extreme weather, which then leads to increased demand and reliance on those same systems.


Cite as

U.S. Energy Information Administration, "NERC report outlines potential electricity disruptions in the United States this summer", contributed by Morgan Sarao, The Energy Rights Project, Platform for Experimental Collaborative Ethnography, last modified 6 July 2021, accessed 1 March 2024.