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ERCOT Winter Peaks More Erratic, Partly Spurred by Electrification, Study Finds

Peak winter electric demand growth in the Electric Reliability Council of Texas has become more erratic, signaling potential concerns for system planners, according to a new study.

While summer peak demand growth has been generally stable and approximately linear with time, winter peak demand growth has been less consistent, the researchers from the Walker Department of Mechanical Engineering at the University of Texas at Austin found in the paper, Perspectives on peak demand: How is ERCOT peak electric load evolving in the context of changing weather and heating electrification?, published in The Electricity Journal.

The more erratic nature of winter peak demand likely reflects the wide variance of winter temperatures during peak demand days compared with the fairly constant summer temperatures during peak days, the researchers said. The erratic nature of winter peak demand is also likely caused by the fact that electrical heating equipment becomes increasingly inefficient at lower temperatures, they added.

In addition, historical winter peak demand has been growing more quickly than summer peak demand, which is likely the result of increases in electrical efficiency of cooling and increases in electricity consumption that result from the rising penetration of electrical heating equipment replacing gas furnaces, the study found.

The study used historical Electric Reliability Council of Texas demand data from 1997 to 2021 along with weather data for the days in which peak demand occurred and from a future climate scenario.

“Future peak demand scenarios indicate that winter peak demand will remain more erratic and will sporadically surpass summer peak demand between 2025 and 2050,” the researchers wrote, adding “resource planners in ERCOT should place less certainty on winter peak demand projections and an increased level of winter preparedness on both the supply and demand sectors appears warranted for resource planners.”

The study’s findings might foreshadow “future resiliency challenges that other regions will face as electric heating equipment is deployed in place of boilers or furnaces for decarbonization purposes,” the researchers wrote.