When hail hits PV: New research maps damage, testing, and mitigation

<p class="p1"><span class="s1">A new review examines the impact of large hail on PV systems, covering damage, testing methods, and mitigation strategies. Researchers highlight risks across Europe and the U.S. and explore ways to improve module resilience.</span></p><p>A European research group has published a comprehensive review of hail-induced damage to PV modules, examining laboratory tests, simulation studies, and outdoor analyses.</p>
<p>“Large hail causes billions in economic losses annually, affecting crops and property worldwide. An emerging concern is the impact of hail on renewable power plants, particularly PV, with significant damage reported in Europe and the U.S., driving increased research interest,” the team said. “As global PV installations grow, the threat posed by hail to system reliability becomes increasingly critical. Current literature on this topic is fragmented and regionally focused. This review addresses that gap.”</p>
<p>The researchers report that in 2023, Europe experienced 9,882 large-hail events, resulting in one fatality, at least 328 injuries, and billions in economic losses. In July 2023 alone, northern Italy suffered €6 billion ($7.1 billion) in hail damage. The study also highlights a 2019 hailstorm at a utility-scale PV plant in Texas, where 400,000 of 650,000 modules required replacement.</p>
<p>The review covers several research topics, including module construction, focusing on glass thickness, encapsulant, and cell technology in hail events. It also examines novel testing methods such as digital image correlation (DIC) and high-speed imaging. Simulation studies assessed variables including glass thickness, ice-sphere diameter, and hail velocity, as well as the effects of turbulence, temperature, and multi-hazard stress.</p>
<p>Outdoor studies included analyses from the U.S., Austria, Croatia, and Italy, as well as past and ongoing mitigation strategies. Passive mitigation strategies explored included glass thickness and module tilt angles. Active strategies covered single-axis trackers that adjust tilt and protective netting deployed above systems.</p>
<p>The researchers noted that future laboratory studies could explore additional parameters such as module and ice-sphere temperature, impact angle, variations in ice density, irregularly shaped hailstones, and the interval between multiple impacts. For installed systems, assessing module response under varying wind conditions and PV technology is crucial.</p>
<p>“Future research could also refine models to predict hail events more accurately, evaluate active mitigation techniques such as mobile netting systems, and improve PV system design based on site-specific hail and wind characteristics,” the team added.</p>
<p>The review emphasizes that while PV modules must meet the IEC 61215 standard for commercialization, the IEC TS 63397 standard provides a more stringent testing framework, enabling more accurate identification of hail-related damage.</p>
<p>The “<a href="https://www.sciencedirect.com/science/article/pii/S2352484726000259">Large hail impacts on photovoltaic systems: A review of damage, testing, and mitigation</a>” researh paper has been published in <em>Energy Reports. </em>Scientists from Italy’s <a href="https://www.pv-magazine.com/2023/08/23/floating-pv-plant-operators-may-achieve-additional-revenue-through-non-evaporated-water/">University of Catania</a> and the European Severe Storms Laboratory (ESSL) in Germany contributed to the study.</p>