Eclipse not seen dimming electricity for Texans
Though next week’s total solar eclipse is expected to dramatically reduce solar power production, the event is not expected to impact the stability of the Texas power grid.
Electricity supply and demand forecasts from the Electric Reliability Council of Texas, the grid operator for most of the state, show ample cushion throughout the day of the eclipse, Monday, even with a noticeable drop in the available supply of power around early afternoon.
There could be only 7.6% of usual solar output available during the eclipse, ERCOT Chief Operating Officer Woody Rickerson said during a recent meeting of the Public Utility Commission of Texas, the state’s utility regulator. ERCOT doesn’t expect any grid reliability problems during the eclipse, Rickerson said, and ERCOT doesn’t expect to issue any requests for Texans to conserve electricity, as it did numerous times last summer.
The eclipse will reduce solar generation — similar to a sunrise or sunset in the middle of the day — from approximately 12:10 p.m. to 3:10 p.m, ERCOT said in a post on X, formerly Twitter. It forecasts a decline from 11 a.m. to 2 p.m. of more than 10,000 megawatts of power capacity, enough to power more than 2 million Texas homes during the hottest summer days. But even at the trough of the dip, the forecast shows around 15,000 megawatts of excess capacity relative to expected demand.
The eclipse could have more of an impact on solar generation across the United States than any previous eclipse, according to Solcast, a provider of solar power data and forecasts. That’s mostly because of the rapid growth of solar power capacity across the country, especially in Texas, the leading state for grid-scale solar farms.
At the time solar power generation is expected to decline, homes and businesses that would have drawn power from their rooftop solar panels will instead require power from the grid, adding to demand, said Harry Woods, Solcast’s head of marketing.
Still, there is little need to be concerned about the stability of the Texas power grid during the eclipse because the phenomenon will happen on a day forecast to have mild temperatures, which means Texans won’t demand a lot of electricity for heating or cooling, said Sean Kelly, CEO of Amperon, a company that sells grid forecasts and analytics.
“If this came out of nowhere, like the other weather events that we haven’t been properly prepared for, then that would be one thing,” he said. “But we’ve obviously known this was going to happen for years.”
During a partial eclipse in October, ERCOT’s fuel mix shifted to more natural gas power generation as solar power production declined. Woods said ERCOT was likely to employ the same strategy in the upcoming total eclipse.
Ramping, an industry term used to describe how quickly solar power capacity comes on and off the grid, is expected during the eclipse to be double the rate usually seen during sunrise or sunset, Woods said, adding a layer of challenge for ERCOT. To manage grid frequency or forecasting
“This presents a golden opportunity for system operators to gain some invaluable experience and rehearse for a solar-powered future.”
Jin Tan, principal engineer at the Department of Energ y’s National Renewable Energ y Laboratory
errors, ERCOT can use what are known as ancillary services, which is backup power provided by resources such as gridscale batteries that can increase or decrease the supply of electricity in minutes or even seconds.
As solar becomes a larger part of the nation’s power mix, next week’s eclipse can help grid operators prepare for more challenging sunrises, sunsets and weather events that impact solar power production, said Jin Tan, principal engineer at the Department of Energy’s National Renewable Energy Laboratory, during a webinar about how the eclipse will impact the three U.S. national grids.
“This presents a golden opportunity for system operators to gain some invaluable experience and rehearse for a solar-powered future,” Tan said.