Kaleigh Harrison
As severe hailstorms become more frequent, solar project losses are climbing—making current
certification standards increasingly outdated. In response, VDE Americas and the Renewable Energy Test Center (RETC) have introduced the Hail Resiliency Curve (HRC) Test, a method designed to better reflect the unpredictable, high-energy impacts that PV panels face in actual storm conditions.
Unlike conventional testing methods that rely on limited scenarios, the HRC Test uses a progressive approach: panels are struck by projectiles of increasing size and velocity until failure. The result is a detailed performance profile rather than a simple pass/fail outcome. This protocol doesn’t just test glass—it
maps out vulnerability across an energy spectrum.
This granular data is supported by Weibull statistical models, allowing developers, insurers, and manufacturers to evaluate failure probability with high confidence. The method also uses significantly larger sample sizes than traditional tests, increasing statistical reliability and eliminating blind spots in product characterization.
For RETC’s CEO Cherif Kedir, the protocol marks a shift:
"The solar industry has long needed a more rigorous approach to hail testing. The Hail Resiliency Curve Test fills this knowledge gap by providing our customers with actionable data on solar panel hail resilience across the complete impact energy spectrum of real-world hailstorms. Moreover, the rigorous sample size ensures a more thoroughly vetted solar panel characterization." It allows manufacturers to pinpoint where their designs fail—and how to fix it.
Implications for Developers, Insurers, and Manufacturers
The HRC Test has already begun influencing decision-making across the solar value chain. For developers, access to quantitative resilience data opens up more informed cost-benefit analyses when choosing between module suppliers, racking systems, and stow strategies. Factoring in potential hail loss during procurement can lead to more stable project returns and smoother financing discussions.
Manufacturers benefit by using the data to refine product design and differentiate in an increasingly competitive market. Panels that demonstrate higher resilience under HRC conditions can be marketed with empirical backing, particularly valuable in regions where hail risk is growing.
Insurers, perhaps more than any other stakeholder, stand to gain from this protocol. Outdated models and vague certification data have long complicated risk assessment for underwriters. The HRC Test gives insurers performance-based insights that allow for more accurate premium setting and risk modeling.
Adoption is already underway. Erthos, known for its Earth Mount Solar system, is leveraging the protocol to qualify glass suppliers for durability. The test's ability to generate statistically significant comparisons between panel models allows companies like Erthos to select materials based on real-world resilience, not just lab certifications.
As climate volatility intensifies, tools like the HRC Test will likely play a larger role in shaping solar project strategies—from procurement to protection. It's a sign that the industry is beginning to treat climate risk not as a possibility, but as a certainty that requires smarter, data-driven solutions.
