Updated: Dec 8, 2020
If you install solar panels, what will happen to them when bad weather strikes? Solar panels may sound like a great investment in your home, but you may wonder how bad weather will affect the paneling and your energy from it. With the recent weather disasters in Florida, here in Texas and across the Virgin Islands, questions about inclement weather and solar panels makes sense. Here's how to decide if solar panels are a good idea where you live.
How are Solar Panels Tested?
Solar panel manufacturers routinely test their product to see how it will withstand hail and high wind. Facilities launch ping-pong-ball sized chunks of ice from high-pressure ice cannons to see what kind of impact they can withstand.
Currently, solar panels from reliable manufacturers are certified to withstand one inch hail falling at 50 miles per hour. Some manufacturers design solar panels that aren’t damaged by multiple strikes at 70 miles per hour.
The main threat to solar panels during a hurricane is high winds and driving rain. Panels have to be tested in a variety of situations, since some are flush-mounted while others are placed at an angle, and hurricane winds can come from any direction.
Manufacturers conduct extensive wind tunnel tests to make sure solar panels can tolerate hurricane-force winds. Most panels are certified to withstand winds of up to 140 miles-per-hour (mph).
The Photovoltaic Quality Assurance Task Force creates standardized tests for use across the industry. They develop reliability standards for manufacturing, installation and operation. Here are some of the things elements they test for using both computer and full-scale models:
Stress from being walked on
In 2012, Florida International University students created a “Wall of Wind” to test solar panels in conditions similar to those of a category 5 hurricane. They used 12 colossal fans to blast wind and sling building materials at 157 mph. The solar panels were both impact and wind-resistant.
Past Performance of Solar Panels
The National Renewable Energy Laboratory (NREL) studied more than 50,000 solar systems between 2009 and 2013. While the systems were subject to different types of inclement weather,
NREl reported only 0.1 percent of photovoltaic systems experienced damage or a reduction in performance because of weather.
Photovoltaic cells are fragile, but they're surrounded by extreme protection. They come in a protective housing made of tempered glass to keep out moisture and dust, but it also withstands projectiles. Cells have a gap between the silicone panel, the acrylic sheet and the pane of strike-resistant glass, so even a large object strike often does not break the solar panel.
Real-World Hail Results
In May of this year, a severe hailstorm hit the NREL's main campus in Golden, Colorado. The storm shattered car windshields with golf-ball sized hail and left dents in roofs and vehicles.
Of the 3,000 panels on NREL's rooftops, however, just one single panel was damaged. It experienced multiple, simultaneous strikes by large hailstones that led to tiny cracks in the glass's surface.
What About Hurricanes and Solar Panels?
When Hurricane Sandy smashed into New Jersey in late 2012, it brought 90 mph winds and caused an estimated $30 billion in property damage. Two million East coast households lost power and around 346 thousand homes were damaged or demolished.
The state had just finished installing 103 megawatts of photovoltaic capacity. A solar company had more than 200 customers in the area. Their spokesman reported minimal damage. One large system had a few loose panels and another reported a few loose conduits, but, overall, their panels weathered the storm.
Harvey and Irma Statistics
Hurricane Harvey smashed into Rockport, Texas with highest recorded wind speeds of 130 mph. Estimates put eventual losses as high as $75 billion. In Houston, the Resident Solar Panel Permit and Inspection Guide recommends solar panels be able to withstand winds of up to 110 mph. Most manufacturers make panels that exceed that requirement.
Florida requires solar installations be rated for a minimum of 160 mph winds. When Irma made landfall with 100 mph winds, solar panels were more than up to the challenge.
No situation is completely foolproof. In some situations, hurricanes tore off the entire roof. If a storm hurls your roof across the street, anything attached to it will go as well. Most insurance policies consider solar panels a structural component. If you live in an area that is prone to severe weather, it’s a good idea to take photos of your solar panels and make sure your insurance values your home at an amount that will cover their replacement.
In many situations, solar panels actually make your roof more likely to withstand a storm. Panels shade your roof from sun damage, protecting it from degradation due to ultraviolet light. Your roof is stronger when the storm hits.
Panels also protect your roof from wind blasts and debris. They act as a watertight, wind-resistant shield that resists impact better than shingles alone
What About Snow?
Some homeowners worry about the weight of snow on their solar panels. Intense storms can dump several inches at a time, and the weight adds up fast. Solar panels are built to bear the weight. Their dark surfaces collect sunlight and cause the snow to melt, running off the glass. As soon as the snow melts, they go right back to gathering the sun’s energy.
How Manufacturers are Making Solar Panels Even Stronger
Several organizations have initiatives to improve durability and cost-effectiveness.
The SunShot Initiative seeks to cut solar energy’s cost so it’s accessible to all Americans. It’s sponsored by the Office of Energy Efficiency and Renewable Energy.
The International PV Quality Assurance Task Force studies climate and provides factory inspection guidelines to make sure manufacturing is up to the highest available standards.
The Energy Materials Network is a Department of Energy program that helps speed product development to make improved clean-energy technologies available faster.
Solar panels are some of the most enduring and dependable sources of renewable energy, and they’re continually improving. Are you ready to find out for your home or business?