Large Hail Poses Increasing Reliability and Cost Risk for Global Solar Assets

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Written by Aaron Studwell, Ph.D., Energy Meteorologist & Analyst for IIR News Intelligence (Sugar Land, Texas)

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Summary

Large hail is emerging as a growing risk to solar assets, driving physical damage, hidden degradation, and rising costs. As deployment expands globally, developers and operators must integrate hail risk into design, siting and operational strategies to protect long-term performance.

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A recent review in Energy Reports highlights a growing challenge for the solar industry. Large hail is emerging as a significant reliability and financial risk for photovoltaic (PV) systems. The paper, authored by Gaetano Mannino and Giuseppe Marco Tina of the University of Catania and Francesco Battaglioli of the European Severe Storms Laboratory, synthesized research on hail damage, PV systems' testing standards, and mitigation strategies as deployment accelerates globally.

Industrial Info Resources finds there are increasing weather-related reliability and cost risks tied to the expanded rollout of the asset class. PV systems are being designed for longer lifetimes and deployed across a wider range of environments. However, this increases the probability of exposure to severe storms, including potentially damaging hail. While PV modules are tested, the reviewed research concludes that current protocols do not fully replicate real-world conditions, particularly for larger hailstones, wind-driven incidents, or repeated impacts.

Hail Risk Extends Beyond Physical Damage

Hail is already one of the costliest severe weather hazards globally; billion-dollar loss events are becoming more frequent. Regions such as the U.S. Great Plains remain core-risk zones, while parts of Europe have seen increasing frequency of very large hail, i.e., in excess of 2 inches (5 cm) diameter, in recent decades.

For PV systems, the risk is not limited to shattered panels. Hail can induce microcracks, reduce output, and accelerate degradation. A May 2019 event across near the Big Bend region of Texas had reports of large wind-driven hail, required the replacement of approximately 400,000 modules. The insurance-reported cost estimates ranged from $70 to $80 million ($90 to $103 million in 2026 dollars).

Field Evidence Shows Hidden and Persistent Impacts

Real-world case studies reinforce that hail damage is often more complex than laboratory results suggest. Across large datasets of PV damage, hail events are associated with measurable production losses and increased long-term degradation rates. Even when modules appear intact, diagnostic testing frequently reveals underlying cell damage and thermal irregularities that will reduce efficiency over time.

This creates an operational challenge: system-level monitoring may not fully capture damage, particularly when damage does not immediately translate into output losses. As a result, post-event inspection strategies are becoming more critical for assessing asset conditions and projecting future performance.

Operational and Design Implications for the Energy Sector

The practical takeaway from the review is that hail risk is more than just an insurance issue. PV system development must increasingly consider both design and operational consideration for severe weather events.

For developers and asset owners, site selection should incorporate regional hail climatology alongside traditional resource and grid considerations. In high-risk regions, such as northern Italy's Po Valley, South Africa's Highveld, and central Argentina, module selection becomes a risk-management decision. Higher upfront costs associated with more robust designs must be balanced against the potential for large replacement or repair events.

From an operational standpoint, the ability to detect and respond to damage is just as important as preventing it. Visual inspections alone are often insufficient. Increasingly sophisticated combinations of electroluminescence, infrared scanning, and other tools may be required to identify hidden degradation. These issues flow to the financials with increased maintenance costs, performance forecasting, and long-term asset valuation.

At the utility scale, active mitigation strategies have become more prominent. Storm tracking systems can reduce exposure by moving into "hail stow" positions during severe weather. This temporary stationing lowers the angle of impact, limiting damage. When paired with improved short-term hail forecasting, this approach offers a practical pathway to reduce losses during high-impact events.

The financial dimension is difficult to ignore. Hail accounts for a relatively small share of solar insurance claims, but a disproportionately large share of losses. This imbalance suggests that targeted investments in mitigation, whether through design upgrades, operational controls or enhanced monitoring, may be economically justified. This is particularly important as solar becomes a larger component of generation portfolios.

A Risk That Scales with Solar Growth

The research concludes that hail risk will increase as solar deployment grows on a global scale, unless it is more deliberately addressed. As PV systems expand into new regions and operate over longer time spans, exposure to severe weather becomes unavoidable.

For the energy sector, the implication is straightforward: hail resilience is moving from a niche engineering concern to a core consideration in project development, operations and risk management.

Key Takeaways

• Large hail is a low-frequency, high-cost risk, responsible for a disproportionate share of solar insurance losses.
• Standard testing may underestimate real-world exposure, particularly for large, wind-driven or repeated hail impacts.
• Hail damage often includes hidden microcracks and degradation, not just visible panel failure.
• Module design choices, including glass thickness and construction, materially affect resilience and lifecycle risk.
• Site selection should incorporate regional hail climatology, especially in emerging global solar markets.
• Operational mitigation, including hail-stow strategies and advanced diagnostics, can reduce damage and long-term performance losses.

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About Industrial Info Resources
Industrial Info Resources (IIR) is the leading provider of industrial market intelligence. Since 1983, IIR has provided comprehensive research, news and analysis on the industrial process, manufacturing and energy related industries. IIR's Global Market Intelligence (GMI) helps companies identify and pursue trends across multiple markets with access to real, qualified and validated plant and project opportunities. Across the world, Industrial Info Resources is tracking over 250,000 current and future projects worth $30.2 Trillion (USD).