Hailstorms and Solar Farms: A Holistic Framework to Assess the Risk Potential to Emerging Renewable Assets

Over the past decade, the U.S. renewable energy sector has experienced significant growth, with solar energy playing a key role in the transition to low-carbon power generation. Utility-scale solar projects are increasingly being sited in the Southern Great Plains and Upper Midwest—regions frequently impacted by severe convective storms and large hail—introducing a heightened risk to solar farms. According to a recent study by kWh Analytics, while hail-related claims are less frequent than other sources of losses to solar farms, they accounted for nearly 50% of total claim severity for U.S. solar assets between 2018 and 2023. This highlights the disproportionate financial impact of hail on solar assets and underscores the challenges insurers face in understanding and insuring such risks.

To support the (re)insurance industry in understanding and quantifying hail risk to solar farms of different capacities, a detailed, analytical, component based engineering framework has been developed to assess hail risk. This study outlines the key components of this vulnerability framework, which relies primarily on disecting solar farms of various throughout capacities into sub-components and quantifying their vulnerability to hail at the component level. Component-level damage/vulnerability functions are based on understanding the component’s resistance towards hail impact and explicitly accounting for commonly observed damage mechanisms. These component relationships are then aggregated to farm-level damage functions using component cost distributions, derived from the National Renewable Energy Laboratory dataset. The framework accounts for variation in vulnerability across different farm configurations, including ground-mounted fixed-tilt, single-axis and dual-axis tracking systems, as well as rooftop: mounted and ballasted installations. It incorporates data from the Energy Information Administration’s Solar Energy Database to reflect common tilt angles and orientation, which significantly influence exposure to hail impact. One of the key features of the framework is its ability to quantify risk using hail impact kinetic energy as the intensity measure. Kinetic energy is a robust intensity metric since it can capture both the vertical and horizontal components of impact, as well as the full distribution of hailstone sizes within the hail swath—rather than relying solely on maximum diameter—to capture the full damage potential. This component-level methodology enables a more physically representative and granular understanding of hail risk for such type of assets. By integrating engineering, cost, and observational data, the framework provides (re)insurers, asset managers, and solar farms developers with an effective tool for assessing and managing hail-related exposures in the growing U.S. solar market.