Extreme hailstorms are devastating solar farms, but defending them may be easier than you think

This story originally appeared on Inside Climate News and is part of the Climate Desk collaboration.

When baseball-sized hail hits a solar panel at more than 90 miles per hour, the effect is not pretty.

We saw this in March when hail destroyed parts of the 350-MW Fighting Jays solar project in southeast Texas. Photos of thousands of panels covered in white circles of broken glass circulated on social media and in the news. Right-wing media wanted to publicize what they saw as proof of the reliability of solar energy.

The reality regarding hail and solar panels is more complicated, but not as grim.

Developers and manufacturers of photovoltaic systems have taken steps to reduce the risk of hailstorms, including a combination of sophisticated weather forecasting and panels that can turn to avoid direct hits. I recently spoke with some of the people doing this work.

First, let’s outline the problem: climate change is contributing to the increase in the intensity of storms, including hailstorms.

At the same time, according to the International Energy Agency, solar energy is the fastest growing source of electricity in the world and part of the package of renewable energy sources that are likely to constitute the majority of global electricity demand by mid-century.

These days, examples of hail storms destroying solar farms are rare enough to still be noteworthy, like one this year in southeast Texas and one last year in western Nebraska. But what about 20 years from now, when hail storms are likely to be more severe and solar power will cover a much larger area?

There is no perfect way to protect solar panels from hail, but there are ways to reduce the risk.

“There are real opportunities to mitigate the impacts,” said Renny Vandewege, vice president of weather operations at DTN, a Minnesota-based company whose subscription-based products include weather forecasting for use by utilities.

“We have patented the ability to measure hail size in radar technology,” he said. “When you scan storms, you get feedback that says that the storm is producing two-inch hail or whatever the scenario is.”

This data is most useful if the solar panel is equipped with hardware that can respond to an approaching storm by adjusting the angle of the panel to reduce damage.

Almost all utility-scale projects being built today use trackers, systems that rotate panels throughout the day to follow the sun. Some of these trackers have the ability to go into “hide” mode, which means they turn around quickly to avoid a direct hit.

For example, Nextracker, a California-based manufacturer of solar tracking systems, sells a hail-mitigation product that combines weather forecasts from DTN and others and uses the data to adjust panel angles ahead of hail storms. The systems are operated by software that can be used both on-site and remotely, and have battery backups to operate during power outages.

“Will solar continue to be developed and built in hail regions? The answer is yes,” said Greg Beardsworth, senior director of product marketing at Nextracker. “The way that will happen is a combination of understanding the scale of risk based on location, selecting the right combination of module technologies and tracker storage capabilities.”