Texas has emerged as a leader in solar power generation in the U.S., but its susceptibility to severe hailstorms poses a significant risk for energy companies. However, there has been no substantial damage reported during the recent hail season, which is attributed to advancements in solar panel durability and risk assessment methodologies. Improvements in testing for hail resilience, as well as better predictive weather systems, have allowed companies to manage and mitigate these risks effectively, underscoring the solar industry’s adaptability amidst climatic challenges.
The solar industry has improved the durability of panels and developed testing methods that help answer questions about how certain panels will perform when slammed with hail. Much of that testing occurs in a lab in California’s Bay Area where technicians fire balls of ice from a “hail cannon” and then review the damage. I spoke with Brian Grenko, CEO of VDE Americas, about what happens in the lab and how his company is using the results. “If you really want to understand how a solar panel, or how anything, can withstand hail, you have to test it until it breaks,” he said. “Otherwise, you don’t really understand the actual properties.” His company is a technical consultancy based in San Jose, California, a subsidiary of VDE Group of Germany. The testing is done by another VDE Group subsidiary, Renewable Energy Test Center, or RETC, which has a lab in Fremont, just down the road from San Jose. RETC’s employees get to fire the hail cannons and VDE’s employees do a lot of math based on analysis of the results.
This month, the companies announced that they have jointly developed a new test of hail resiliency. Lab employees simulate a hailstorm, with varying wind speeds and sizes of hailstones. The goal is to determine how much punishment a solar panel can take before it breaks and also to see which part of the panel is the first to break. Using the test results, the teams create a report that shows the probability of a panel’s failure as the impact energy from hail increases. The detail in the results is in contrast to what would otherwise be available. Solar panels must meet international testing requirements that were updated most recently in 2016. These requirements were not written with hail in mind, Grenko said. Solar companies, banks, and insurance companies use data from the test to determine a solar project’s risk of hail damage and how to reduce that risk. For example, a developer may find that hail risk is high enough to invest in panels that are more expensive and durable.
But there is more to this research than determining the strength of materials. As I wrote last year, one way to reduce hail damage is to use trackers—systems that shift the panel angle to follow the sun—that have a “stow” mode with a vertical angle to avoid direct hits from hail. Simply having a stow mode isn’t enough, though. The operator of a solar project needs to have access to high-quality weather reports that provide a warning of incoming hail. And, the operator needs to push the button to shift into stow mode or have an automated process in place to do so. If that doesn’t happen, the result can be a situation similar to what happened last year at the Fighting Jays solar project in southeast Texas, where thousands of solar panels were destroyed. Right-wing news outlets highlighted the damage and interviewed neighbors who spoke about their fears of environmental damage from chemicals leaking from the panels. (I have seen no evidence from reputable sources that leakage from chemicals in solar panels is a danger to human or animal health.)
Texas’ solar power growth has happened in spite of its vulnerability to hail damage. A cluster of states from North Dakota to Texas has the highest frequency and severity of hailstorms, according to the Federal Emergency Management Agency. Hail is most common in places that also have a high incidence of severe thunderstorms and tornadoes, which is tied to a region’s topography, according to the Midwest Regional Climate Center at Purdue University. Grenko explained