Hail risk to photovoltaic systems in Switzerland

 The rapid expansion of photovoltaic (PV) systems is transforming the renewable energy landscape, but extreme weather events, particularly hailstorms, pose an increasing threat to energy production and infrastructure longevity. Recent studies show that both hail frequency and intensity in Switzerland have risen over the past six decades (Wilhelm et al., 2024) and are projected to continue increasing in a warming climate (Thurnherr et al., 2025), leading to growing damage costs for PV installations in Switzerland. We present a newly launched interdisciplinary research project — a collaboration between scientific institutions, (re-)insurance companies, and industry partners, aimed at improving hail risk assessment and resilience strategies for PV systems in Switzerland. Using an open-source inventory of installed PV systems and high-resolution radar-based hail data, we identified hail damage hotspots in regions including Ticino, Thun, Basel, and Lucerne. By linking energy production data with damage claims, we find that hail can reduce the median operational lifetime of PV systems by up to two years. Preliminary analyses further suggest that tilt
 angle, orientation, and module type significantly influence vulnerability to hail. Building on these insights, we will conduct a comprehensive analysis of multiple aspects of PV hail damage. This includes:
1. Identifying the hailstorm and PV system characteristics, such as hail size, storm orientation, tilt angle, and module type, that influence real-world damages;
2. Producing high-resolution risk maps that distinguish current and future ”high-risk” from ”low-risk, high-capacity” areas using convection-permitting simulations under a 3°C warming scenario;
3. Quantifying the short-, medium-, and long-term economic impacts of hail damage on PV systems;
4. Evaluating technical and strategic adaptation options to enhance system resilience.
Our approach combines meteorological, energy production, and damage data to quantify evolving hail risks and guide actionable solutions. This work will support more resilient PV planning and help energy providers, insurers, and policymakers adapt to an era of intensifying extreme weather.