Design, maintain, mitigate: Prepping renewable energy sites for catastrophes
Insurers and brokers can play a key role in encouraging the resilience of solar and wind farms exposed to tropical cyclones.
The global energy transition to renewable sources is accelerating its pace. Sites are being built right across the globe, including outside the temperate zones, where the risk of high-impact weather events is greater. The severity and frequency of catastrophic weather events are also growing, with the geographic distribution of sites and climate change combining to increase the risk of catastrophic damage to new projects.
This is something all stakeholders must work on together to navigate successfully. With a growing number of solar and wind farms exposed to tropical cyclones and, therefore, wind and flood damage, it is vital to understand and prepare for these events to mitigate risk, particularly ahead of each Atlantic hurricane season. Crucially for our industry, insurers can play a key role in encouraging resilience at all stages of the process and therefore help to avoid future losses.
Predicting the weather
At the beginning of this year, the National Oceanic and Atmospheric Administration (NOAA) changed its thirty-year review period for the Atlantic storm season to 1991 to 2020. This change has increased the average number of expected storms from 12 named storms to 14 and six hurricanes to seven. Developers should take note of this trend.
Preparing for these events relies on a combination of factors. Design and quality are imperative. Looking at historical data, including the probability of a direct tropical cyclone hit and possible rainfall, is an essential part of the design process. Considering NOAA’s average numbers are increasing, it is important to think about a possible increase in these averages during the lifecycle of the project.
International building codes such as IEC 61400-1 for wind turbines have been adopted to standardize design for renewable energy projects, providing one effective risk mitigation measure. But these are not sufficient in and of themselves; the quality of the completed construction work must be checked at the commissioning stage to ensure safety and reliability.
It is key that wind turbines are properly selected for the possible conditions. During a cyclone, extremely high wind speeds can cause poorly selected wind turbines to spin out of control, which ultimately can lead to catastrophic failures. Modern wind turbines can reach up to 250 meters in height, and if they’re not robust enough, serious damage can occur. Wind turbines go into survival mode by feathering their blades once functional wind speed is surpassed, stopping the rotor until it is safe to resume normal activity. If the blades do not feather, damage may occur which requires costly repairs and significant downtime.
Solar farms, in turn, are exposed to a different set of risks. As hurricanes increase in size and strength, they also tend to bring more severe rainfall as shown by hurricanes Harvey and Michael in recent years. Being much closer to the ground, flooding is a key issue, and where possible, equipment should be elevated to mitigate this. Drainage must also be properly designed to deal with large amounts of water and kept clear of vegetation. As well as causing issues with project equipment, flooding can also delay access to a site after an incident. If poorly designed or installed, there is also a risk of panels being torn off their foundations by the high-speed winds, and if the site is not tidy, modules can be broken by thrown debris.
Limiting risk during the construction phase is perhaps the most efficient measure. Ideally, neither wind nor solar farms should be built during hurricane seasons. Using good contractors with experience in both the region and with projects of comparable scale is crucial, as is conformity to building codes. The combination of good design and high-quality construction reduces storm impact and disruption to the energy supply.
Mitigating catastrophic risk
While it is possible to limit risk, wind and solar farms need to have measures in place in the event a catastrophe does occur. In addition to good housekeeping, an emergency response plan is essential. When a hurricane hits, grids can often be knocked out as well. Turbines need power to keep running in survival mode so with no grid power the emergency response plan must include provision for temporary emergency generators to minimize further damage to the turbines.
A good insurer will ask for information upfront. Those with an experienced risk engineering team are in a better position to advise risk managers throughout the lifecycle of a project. This allows insurers to understand the specific relationship between design, construction, and risk with regard to renewable energy sources and adverse weather conditions. The insurer should monitor risk and quality control, as well as ensuring that everything has been thoroughly tested and inspected as intricately as possible.
The renewables industry has embraced innovation to mitigate catastrophic risks. Manufacturers are, for example, developing increasingly sophisticated products such as “typhoon-rated” turbines, but a continuous dialogue between all stakeholders is required. In the insurance chain, the insured, broker, and risk carrier all have roles to play. Some insurers offer risk surveys during the operational phase (including AXIS) and brokers are working closely with the policyholders to promote their use.
When looking to the future, cooperation is key, and the insurance industry has a significant role to play in building resilience. Insureds should ensure that the design, construction, and operation of their farms are optimized to minimize risk. Experienced insurers, with a risk engineering team, will have a comprehensive understanding of all three, which will help in making sure that solar and wind farms are of proper construction quality and standard. The broker should encourage open dialogue between all parties and facilitate transparency. This symbiotic relationship will only increase in importance in the face of progressively trying weather conditions ahead.
Dan Stevens is renewable energy risk engineer at AXIS Insurance. He has been involved in the renewable energy industry for 20 years, starting at National Wind Power (now Innogy Renewables) running their wind measurement campaigns. Dan’s career has seen him work at both utilities (RWE, SSE) and a consultancy firm (Renewables Consulting Group, RCG) before joining AXIS in the insurance sector.
Ekow Monney is business development manager – Renewable Energy at AXIS Insurance. He has worked in the renewable energy industry for more than 18 years, working for several media and exhibition companies. In addition, he worked as a marketing and PR consultant for several renewable energy companies before joining the AXIS Renewable Energy team.
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