Great American Solar Eclipse Could Affect Weather and Power Grid

Pam Wright
Published: August 8, 2017

An array of mirrors at the Ivanpah Solar Electric Generating site in Primm, Nevada.
(AP Photo/John Locher)

This month's Great American Solar Eclipse will not only have the nation riveted as the first total eclipse to traverse the United States in four decades, it could also have implications for local weather and a power grid that relies more on more on solar energy.

According to a study by the Royal Society, temperatures can significantly drop on the Earth's surface under the shadow of a solar eclipse. With the drop in temperature, warm air ceases to rise, which changes wind speed and direction. Scientists call this phenomenon "eclipse wind." The change is short-lived and as soon as the shadow of the eclipse passes, temperatures and surface winds return to normal. 

"We're learning new stuff about how the atmosphere behaves," Angela Speck, director of astronomy at the University of Missouri, told WMAR. "It's doing something we cannot do any other way."

During the Aug. 21 eclipse, Speck and other researchers at the University of Missouri will use grants from NASA to study the sudden temperature shifts.

As for the nation's power grid, utilities that rely on solar power will need to use fossil power plants, nuclear stations and dams to compensate for the loss of an estimated 9 gigawatts of solar energy as the shadow moves across the nation at 1,000 mph. The amount of solar energy that will be lost is equivalent to the power generated by 15 coal-generated plants.

"At night, think of how long it takes to get dark. It slowly cools off," Speck said. "And now you've got this, where the maximum you're going to get is just over two and a half minutes, but that onset of darkness is pretty fast."

Interestingly, utilities will have to be cautious because as soon as the sun returns from behind Earth's shadow, solar panels will begin to add power into the system immediately, which could overload the system if there are too many sources at the same time.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.