Building resilient solar projects: Tips and best practices
Solar

Building resilient solar projects: Tips and best practices

Contributed by Jason Kaminsky, CEO, kWh Analytics

The solar industry is losing $2.5 billion annually from equipment underperformance, likely caused by equipment malfunctions and weather conditions, according to an article in kWh Analytics’ 2023 Solar Risk Assessment. With the global solar energy market projected to reach $300 billion by 2032 and the market expected to grow from today’s 3% of U.S. electricity supply to 40% by 2035, it is imperative that the industry resolves these issues.

Although solar has historically been focused universally on generating the cheapest electron, we are entering a new era of building and operating more resilient assets. This is in part driven by the potential for long-term insurance benefits to asset owners with resilient operations – a significant incentive to reduce steep increases in insurance costs that have resulted from sizable damages caused by natural catastrophes.

Insurance as a driver of resilience

Solar assets, forecasted by financial investors to generate electricity for thirty years or more, are exposed to some of the country’s harshest conditions for their entire lifecycle. Growth in the sector and rapid technology improvements have led to a vastly different insurance landscape than just a few years ago. Prior to 2019, it was relatively easy and inexpensive to procure as much insurance as necessary, but in more recent years the market has been more challenged.

While some resiliency factors are cheap or free to implement, others do have some costs associated with improved construction and operations. Although not universal, some insurance providers are taking these efforts into account in their risk assessment. Insurance-driven resilience incentives can lead to a more robust and cost-effective insurance program, largely or totally offsetting the costs of increased resilience. Asset owners are wise to work with brokers to understand available carrier incentives to ensure the best possible coverage.

The insurance markets are dynamic, with carriers entering and leaving every year, so it is important to work with an insurance broker who is dedicated to promoting a drive toward resilience. It is also reasonable to ask an insurance broker to canvas the insurance markets each year for the right terms and limits and review with them the list of carriers they approached, to ensure you are getting the best possible coverage.

Choose hardy, weather-resilient materials

As solar modules have increased in size, manufacturers have begun changing from 3.2mm, heat-tempered glass to 2mm, heat-strengthened glass, to help manage weight and cost. Many projects utilize 2mm heat-strengthened glass for their PV modules, especially since they can reduce costs.

RETC’s Hail Durability Test program for severe hail is designed to subject PV modules to higher kinetic energy values than basic product safety and qualification tests, in order to investigate impact resistance at the threshold of damage. The results revealed that 3.2mm heat-tempered glass modules are twice as resilient to impact when considering the kinetic energy associated with a 50% probability of breakage.

As a result, solar projects should look to deploy hail-resilient PV modules in hail-prone regions to mitigate severe weather losses, reduce module downtime, and lower stakeholders’ financial risk exposure.

GO DEEPER: Jason Kaminsky, CEO of the clean energy project insurance provider kWh Analytics, joined Episode 51 of the Factor This! podcast to share the data behind solar’s biggest risks, along with pathways to avoid potholes down the road. Subscribe wherever you get your podcasts.

Further, as bifacial modules are becoming much more commonly installed, the prevalence of glass//glass (G//G) modules has increased. However, data from PVEL reveals that 89% of G//G modules experienced broken glass in a hail stress simulation compared to 39% of glass//backsheet (G//BS) modules.

Additionally, a mechanical stress sequence test that applies weight on top of the module to the IEC 61215 minimum standard shows that 17% of G//G modules experience broken glass. Over time, G//G modules outperform G//BS modules in terms of degradation rates, making them a reliable choice for many project sites, but current G//G module designs aren’t suited for extreme hail or heavy wind and snow locations.

As developers scope out areas for potential solar projects, they need to be aware of the extreme weather conditions that impact the region and select modules that can withstand them.

Stow panels early and often when there’s potential for bad weather

Hail is becoming a prominent issue for the PV industry as more sites are being built in the central U.S. — a hail-prone region — and modules are moving towards larger formats with thinner glass. To mitigate the damage that hail can cause, moving panels into hail stow is an effective technique. But since it requires moving the panels out of the optimal production angle, there is concern that utilizing hail stow will lead to a material loss of revenue.

To examine the financial impacts of hail stow, kWh Analytics simulated one year of production for a 200 MW single-axis tracker site located in Texas using PVLib and the National Solar Radiation Database. The site was modeled under two scenarios: (1) assuming no hail stow and (2) assuming a 60-degree stow during all National Weather Service severe thunderstorm watches, warnings, and advisories (collectively called WWA events). Moving into hail stow during WWA events throughout the year for this particular site resulted in a total production loss of 0.1% of the estimated annual revenue.

Hail severely damaged a solar farm in Scottsbluff, Nebraska on June 23, 2023. (Courtesy: Nebraska Public Power District)

On the other hand, not stowing modules until it’s too late could result in hundreds of thousands or millions of dollars being spent to repair or replace multiple modules or other project components damaged by the hail.

The choice is clear: stow early and stow often when there’s a chance of severe weather near solar projects.

Electrical performance resiliency

In addition to physical risks, electrical performance resiliency is also impacted by location; when selecting a site for a PV project, solar energy potential isn’t all that matters. Developers also must consider how the region’s weather may impact certain project performance characteristics, specifically the inverters. PV plant inverters are a vital component of the project since they convert the current of the solar panels into a current that can be utilized by the connected power grid. A PV project without properly functioning inverters means that the energy absorbed by the modules is wasted.

Inverter selection is based on a number of factors, including nominal inverter efficiency and expected climate conditions at planned locations. Research from Envision Digital shows that inverter efficiency loss varies across different climates, with greater losses observed in climates with higher temperatures and harsh operating conditions.

If developers want to truly optimize PV plant design, they need to understand the impact observed in different climate zones to achieve maximized performance and return on investments.

Closing the loop

Building resilient solar projects is an area ripe for collaboration and the sharing of best practices: since insurance is a global marketplace, any significant industry loss ripples through the ecosystem. As developers and operators make decisions to promote resilience such as the ones covered in this article or beyond (improved vegetation management in fire-prone regions; spare parts strategies to quickly bring power plants back online; design considerations for flooding events; etc.), it will be increasingly important to communicate these enhancements to other stakeholders, especially brokers and insurance carriers, and take advantage of the unique cost-saving measures that some insurance markets are beginning provide.

About the author

Jason Kaminsky is the CEO and co-founder of kWh Analytics, a leader in climate Insurance and a specialty provider of property insurance for renewable energy assets. He is passionate about activating insurance capital into climate-forward opportunities and has helped grow the company from its creation. kWh Analytics specializes in unique risk transfer products using real-world project performance data and decades of expertise, such as the Solar Revenue Put production insurance and kWh Property Insurance. The company has insured over $4 billion of assets to date.