Extreme weather is more dangerous to solar panels than thought, study claims

Natural catastrophe events are increasing, and investing in resilience measures could reduce insurance costs.

kWh Analytics, a climate insurance provider, released its 6th annual Solar Risk Assessment report, offering a data-driven overview of risks to solar assets. Contributions came from industry leaders in technology, financing, and insurance.

The report identified 14 risks, including extreme weather and operational risks, with battery energy storage-related risks included for the first time. It highlighted that modeling assumptions underestimate losses from weather damage by 300% or more. In major solar markets like California, Texas, and Arizona, actual losses from weather events have been much higher than modeled by asset owners. kWh Analytics stressed the need for more accurate PV-specific modeling, considering differences in technology such as trackers with hail-stow protection.

Reliability testing by Kiwa PVEL found that broken cells from hail impacts are less catastrophic to solar module performance than expected, with no module losing more than 3% production after a hail stress sequence. They recommended annual aerial thermal scans instead of expensive electroluminescent (EL) testing to identify cracked modules at risk for fires. Lab-tested modules with hail-stow protection lost only 0.8% power, significantly better than the IEC standard of 5% losses from stowing.

Data from Alliant Power showed that assets in high-risk areas could reduce insurance costs by up to 50% by investing in resilience measures, such as heat-tempered panels and trackers that enable hail stowing. Natural catastrophe events are increasing, with billion-dollar weather events rising from an average of 13 per year in the 2010s to 22 per year in the 2020s, with 28 such events occurring in 2023 alone. Longroad Energy's case study found that a 75-degree hail stow tilt led to an 87% lower probability of asset damage compared to lower tilt angles. The next report in this series will review kWh Analytics' assessment of solar asset operational risks.