If temperatures spike this summer, parts of the United States could face electricity supply shortages as demand for cooling increases, according to an analysis by the North American Electric Reliability Corporation (NERC). The latest summer reliability report from NERC warns that two-thirds of North America is at risk of energy shortfalls during extremely high electricity demand this summer. 

EIA Summer shortfalls chart
<em>EAI Summer Energy Shortfalls 2023<em>

In summer, electricity demand increases as temperatures rise, and homes and businesses use air conditioning to cope. Above-normal summer temperatures further push the market and can reduce electricity supply if power plant outages or reduced output stem from heat-related issues. In addition, widespread heat waves can limit electricity transfers because the electricity is needed to meet local demand.

The combination of higher electricity demand and reduced supply can cause energy shortfalls. NERC releases a comprehensive summer reliability report assessing the North American power system ahead of the summer months each year. 

All 20 NERC assessment areas have adequate power resources to meet average peak summer demand this year, according to NERC.

However, certain assessment areas are at elevated risk of electricity supply shortages if confronted with more extreme summer conditions. These areas include the U.S. Western Interconnection, SPP, MISO, ERCOT, SERC-Central, and New England.

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U.S. Western Interconnection:

Resources in the U.S. Western Interconnection, which covers the country’s western half, are sufficient to support average peak demand. However, widespread heat waves could put the area at elevated risk of energy supply shortfall because it relies on regional electricity transfers to meet peak demand and when solar power drops off in the evening. Parts of the Western Interconnection, especially California, host a large and growing share of generation from solar energy.

SPP and MISO:

SPP and MISO, which cover most of the central United States, are home to significant wind power. The intermittent nature of wind power (wind turbines only generate electricity if the wind is blowing, and how much electricity they generate depends on how windy it is) presents operational challenges for grid operators. Wind output during periods of high electricity demand is a critical factor in determining whether the system has sufficient electricity supply to maintain reliability in these areas. Low wind and high demand periods could result in energy emergencies.

ERCOT:

Resources are adequate for peak summer demand in ERCOT, which covers most of Texas. However, there is a risk that dispatchable generation, such as generation from natural gas- or coal-fired power plants, in ERCOT, may not be sufficient to meet electricity demand during an extreme heat wave with unusually low winds. In June, ERCOT asked residents to curb electricity use as a heatwave reached Texas voluntarily. As in SPP and MISO, wind plays a significant role in ERCOT’s generation mix.

SERC-Central:

The NERC assessment expects SERC-Central, an assessment area that includes all of Tennessee and parts of Georgia, Alabama, Missouri, and Kentucky, to have sufficient supply for average peak summer demand. Utilities may deploy demand-side management—the planning, implementing, and monitoring activities designed to encourage consumers to modify their electricity usage—in cases of above-normal peak summer demand or high generator-outage conditions.

NPCC-New England:

Although New England has less available capacity this summer than last summer, NERC projects that it still has sufficient capacity to meet normal peak summer demand. Operating procedures for obtaining emergency resources and electricity supplies from neighboring areas will likely be needed during more extreme demand or low resource conditions.

Source: EIA.gov