Can solar panels withstand hail and hurricanes?

Like any outdoor equipment, solar panels are subject to the changing weather. Depending on where you live, your panels may experience heavy rain, high winds, or even hail. In this article, we’ll examine how solar panel systems stand up to intense weather conditions and what government organizations and industry groups are doing to improve their products and protect consumers from weather-related solar panel damage.

As a whole, solar panels are durable and hold up very well in inclement weather. A report from the National Renewable Energy Laboratory (NREL) on 50,000 solar energy systems installed between 2009 and 2013 indicates that only 0.1% of all PV systems have been reported as affected by damaged or underperforming modules each year. We'll briefly examine two types of weather that have the potential to damage solar systems – hail and hurricanes.

Solar panels and hail

Solar panel manufacturers test their products to ensure that they are capable of withstanding hail storms. In most cases, solar panels are tested and certified to withstand a hail of up to 25 mm (one inch) falling at 23 meters per second (approximately 50 miles per hour).

In fact, not long ago, NREL's main campus in Golden, Colorado, was hit with a severe hailstorm just last month. Of over 3,000 panels on or adjacent to the roof of a net-zero energy building, only one panel was broken during the storm. To get an idea of the intensity of the storm, the same weather system left shattered car windows and dents in vehicles and home roofs around the Denver area. The single broken panel appeared to have been hit simultaneously with several large hailstones in a very concentrated location, leading to the micro-cracking of the surface glass. The conclusion: hail may be an impressive physical force, but solar panels are well-equipped to withstand impacts even from large hailstones.

Solar panels and hurricanes

With high wind speeds and heavy rain, solar panels may be at risk of being dislodged from their spot or damaged by high volumes of water. However, similar to hail, solar panels are typically tested by manufacturers to ensure that they can survive hurricanes. Most solar panels are certified to withstand winds of up to 2,400 pascals, equivalent to approximately 140 mile-per-hour (MPH) winds. Additionally, the typical aluminum and glass casings that hold solar cells and constitute a solar panel are highly waterproof, even during extreme rain.

As with hail, real-life extreme weather events have demonstrated solar's durability in hurricanes. During Hurricane Sandy, New Jersey was hit especially hard. New Jersey also has one of the highest solar power capacities in the United States. In the second quarter of 2012, just before the hurricane hit, the state had installed 103 megawatts (MW) of PV capacity. Analysis after Sandy hit revealed little to no damage to PV systems from the storm. According to a spokesperson for a solar system, installer servicing over 200 customers in the regions of New Jersey hit hardest by the storm, a few metal casings covering wires from the panels were damaged by flooding, and one very large system had just two panels come loose.

More recently, Hurricane Maria's path through Puerto Rico has given insight into the durability of solar energy systems. A 645 kilowatt (kW) rooftop solar array on San Juan's VA Hospital installed in 2015 continued to operate 100 percent post-storm, even though it was exposed to 180 MPH hurricane winds. What kept this system intact while other local arrays weren't so lucky? As was the case with Hurricane Sandy, the racking and anchoring systems used to keep the solar panels in place were the ultimate factor in determining wind resiliency. By utilizing flexible racking devices, the VA Hospital system was able to work like a chain link fence to bend under stress rather than staying rigid and eventually breaking. Solar panels can be installed to survive the extreme winds seen in hurricanes and can be a source of reliable power when other parts of the electrical grid are wiped out.

In addition to the hail and wind certifications that solar manufacturers offer for their products, there are several organizations and initiatives within the solar industry currently working on making solar panels more durable, long-lasting, and cost-effective. Here is a brief overview of some projects in the works.

The Office of Energy Efficiency and Renewable Energy's SunShot Initiative, which aims to bring down the general cost of solar energy for all Americans, also supports initiatives to improve the durability of solar panels. The SunShot Initiative funds NREL researchers to participate in the International PV Quality Assurance Task Force, or PVQAT, which focuses on designing solar energy technology standards.

PVQAT has 12 individual task groups working on implementing their approach to PV component and system quality and bankability. Their three-pronged approach looks to establish a rating system for PV modules based on climate and application of interest, a guideline for factory inspections and quality assurance during manufacturing, and a comprehensive certification of PV systems. Combined, these efforts ensure that modern solar panels will be manufactured with the highest durability standards available.

Additionally, the Durable Module Materials Consortium (DuraMAT), a group of national research laboratories and universities, is focused on improving the physical materials and designs of PV modules. DuraMAT is part of the Energy Materials Network (EMN), a Department of Energy program working on decreasing the time to market for materials critical to clean-energy technologies.

Solar panels are one of the most durable and reliable energy technologies in the world, and industry efforts mean that they are becoming more resistant to severe weather damage every day. Installing a home solar energy system ensures that your home can produce its own power, even during severe weather events. When you register for the EnergySage Solar Marketplace, you can find the solar installer that's right for your home or business and compare offers side-by-side to find the best deal for a long-lasting, sustainable, and reliable energy system.