The Electric Reliability Council of Texas (ERCOT) has announced that solar farm generation will significantly decline during the total solar eclipse on April 8. This will mark the first total eclipse since Texas began heavily relying on solar generation to power its grid.

ERCOT, which manages the electric grid for 90% of Texas, serves more than 26 million customers in the region.

According to ERCOT, the eclipse is expected to affect solar generation in Texas from about noon until 3 p.m. The maximum impact on the grid will occur around 1:40 p.m., when solar generation will drop to only 7.6% of its maximum clear sky output.

Solcast, a company that provides solar modelling and forecasting services, stated that the "overall effects of the eclipse will cost up to 16% of daily total clear sky irradiance in areas most affected." The company's forecast also suggests that "the rate at which solar generation drops off and then picks back up again is faster than grids normally seen in the morning and evening."

Bill Peacock, policy director of the Energy Alliance, asserts that issues with solar generation's contribution to grid reliability are not limited to unusual events such as solar eclipses. Last fall, ERCOT issued its first Emergency Alert Level 2 since Winter Storm Uri when solar generation dropped dramatically as the sun set. "Demand was falling as well, but not as fast as renewables, particularly solar," said Peacock in an article on Master Resource. "As the sun neared the horizon, solar output followed it down, falling 31 percent." Reserves fell to 1.6 percent, prompting ERCOT to issue its emergency alert.

In his article, Peacock noted that Texas has an installed generating capacity of 146,719 MW according to ERCOT. However, he said, "only two-thirds (97,138 MW) was expected to be available during the summer, largely because wind and solar always operate far below their installed capacity."