Renew Risk expands solar storm model across US states

Renew Risk has extended its severe convective storm model for solar farms to all 48 contiguous US states, covering hail, tornado and straight-line wind risk for solar assets.

The expansion gives insurers, reinsurers and brokers access to a single model for mainland US solar portfolios as utility-scale solar construction continues to grow. Developers are expected to add 43.4GW of utility-scale solar capacity in 2026, according to the US Energy Information Administration.

Designed specifically for solar farms, the model addresses three weather perils that have produced major insurance losses across the sector. Renew Risk initially focused on hail modelling in the highest-risk states before expanding coverage to include tornadoes and straight-line wind across the contiguous US.

For insurers, the challenge is not only the rising value of individual projects but also the concentration of sites within portfolios. As solar farms become larger and are built closer together, a single storm can damage several assets at once.

Hail remains a central concern. A kWh 2025 report cited by Renew Risk found that hailstorms account for 6% of loss incidents for US solar farms but 73% of financial losses.

Other severe storm events have also led to large claims, including losses at Midway Solar estimated at USD 70 million and at Fighting Jays Solar Farm, where losses reached a USD 50 million sublimit.

Broader coverage

The model includes hazard data at 1km resolution and uses asset-level vulnerability assumptions based on engineering features such as panel construction, tracker systems and stow logic. It is also updated seasonally to reflect how new solar farms are being built in different locations and with different technical features.

Renew Risk said severe convective storm risk presents distinct modelling challenges. Unlike hurricanes, which are lower-frequency, higher-intensity events, hailstorms are more frequent, more localised and often affect remote sites where historical loss data is limited.

This creates a particular problem for solar farms because panels are largely made of glass and can be vulnerable to hail impact. Many projects are also located in the central US region known as Hail Alley, where hailstorm activity is especially frequent.

The model draws on research by Renew Risk's team on solar farm risk and on work with Vāyuh, which combines physics and artificial intelligence in severe convective storm modelling.

Portfolio shift

The launch also coincides with a change in how the business groups its products. Renew Risk now organises its models, data and services into three product suites: Offshore Renewables, Onshore Renewables and Emerging Demand.

Offshore Renewables covers offshore wind and interconnectors, Onshore Renewables covers solar, and Emerging Demand covers data centres. These are supported by the Global Intelligence Platform, including the Industry Exposure Database.

Founded in 2021, Renew Risk raised GBP 4.7 million in seed funding at a GBP 16 million valuation. The company typically develops new catastrophe models in about nine months, compared with timelines of three years or more at traditional providers.

Dr Joshua Macabuag OBE, Co-Founder and CEO of Renew Risk, said: "Hail has rightly been the industry's focus for solar, but many of the largest severe convective storm losses have been driven by tornadoes and straight-line winds. Insurers need to see all three perils together, across every state where they hold solar risk. That matters more as sites get bigger and closer together, because a single storm can now hit several assets in the same portfolio.

"Specialising in energy transition assets means we can build faster than traditional providers, without compromising on accuracy. Extending our model across the contiguous US gives our clients a full view of storm risk across their US solar portfolios, and the confidence to grow them profitably."