Many solar operators believe damage or poorly performing PV panels are protected by manufacture warranties. However, we surveyed several major manufacturers and found that every single one exempted damage resulting from lightning.
Solar panels come with two different warranties a performance warranty and an equipment warranty. Performance warranties guarantee the expected output over time. This guarantee determines the acceptable amount output degradation that is acceptable, such as 90% output at 10 years and 80 percent at 25 years. If the panel degrades at a faster rate, the warranty will cover its replacement. Performance loss outside of these expected ranges related to transient surges from lightning are not covered. The same is true to total panel failure due to lightning events; your equipment warranty will not cover the damage.
Because solar panel operators are concerned with continuous, uninterrupted output, it is important to consider protection from harmful surge events. Proper grounding/bonding, surge protection, and a lightning protection system are effective solutions to mitigate these risks.
There are several factors to consider when determining lightning risk. Solar farms installed in opened areas without tall trees or high buildings have an increased risk due to the interplay of high solar radiation, humidity, and lightning frequency. Arrays are not the only target. Other expensive equipment such as batteries, inverters, monitoring systems, tracking controls, weather stations, and generators are susceptible to lightning related damages as well.
The NFPA 780 Standard for the Installation of Lightning Protection Systems only recommends the minimum requirements for solar arrays: PV panels should be grounded with a ground conductor, which can leave the inverter and transformer stations vulnerable. However, a myriad of interpretations exist for solar project installations and they differ from state to state, county to county, and even inspector to inspector. Compliance is also voluntary. Thus, when time or money is an issue, it is the first line item that gets cut from the project.
Repair or replacement of damaged electronic components is very expensive not to mention the costs associated with power interruption and downtime. ALLTEC recommends installing appropriate lightning protection, and properly grounding and bonding that protection in addition to grounding your arrays.
Not sure where to start? Alltec is happy to assist! Most lightning protection systems begin with a site survey to evaluate any existing systems in place and determine weak spots in its defenses. Another activity commonly started along with the site survey is a design analysis so that we can provide an ideal future state recommended lightning protection system. Below are some posts that dig deeper into the services mentioned above and as always, we are here to help, so reach out with any questions you may have!