Utilities stay afloat as eclipse blocks solar resources

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Solar energy output in southeast Wisconsin and the rest of the U.S. on Monday dipped due to the total solar eclipse, however local utilities said they were able to keep the lights on with a mix of resources.

Sunlight over a combined 84.8 gigawatts from facilities from Maine to Texas was expected to be blocked out as the moon slid in front of the sun, according to a blog post from the U.S. Energy Information Administration. This lowered output from 1 megawatt or greater of solar generation in the eclipse’s path.

Solar across the continent was also affected. According to data from Midcontinent Independent System Operator, a nonprofit that operates the grid in 15 states and parts of Canada, solar energy production on Monday peaked at 3.95 GW at 10:25 a.m. GMT-5. When the eclipse peaked around 2:05 p.m., solar dropped to 0.29 GW, leaving other resources to fill the void.

“Similar to what we see on some cloudy days, our solar arrays performed as expected throughout the solar eclipse,” said Tony Palese, a spokesperson for Madison-based Alliant Energy. The utility is behind more than a dozen solar field projects across Wisconsin.

“Solar resources across Wisconsin generally performed well and continued generating power even at the peak of the eclipse,” he added. “We were able to leverage the availability of our diverse generation mix – including wind, hydroelectric, natural gas, coal and battery energy storage resources – to help meet our customers’ energy needs and ensure grid reliability.”

A spokesperson for We Energies said Monday’s eclipse didn’t impact service for its customers. The utility serves more than 1.16 million people in southeast and parts of northern Wisconsin. “We have planned and prepared for the eclipse and do not expect a significant impact,” the spokesperson added.