How does extreme weather affect solar panels?

Solar energy systems only function through exposure to natural elements (sunlight) so it’s fair to say that weather is the primary consideration in the design, creation, and installation of solar panels. Manufacturers understand that their panels are meant to be situated with maximum exposure to the sun and that this also means exposure to every other weather condition.

Obviously they aren’t indestructible, but all solar energy system components endure rigorous tests to ensure they are durable enough to withstand a reasonable level of severe weather. It’s also worth noting that most extreme weather scenarios are accompanied by cloudy conditions, which won’t damage panels in any way, but could limit their production or efficiency by diminishing the amount of sunlight that reaches them

Since there are a variety of situations surrounding extreme weather, let’s go through the most common scenarios to see how solar panels fare.

Extreme hot and cold temperatures

One of the most common myths surrounding solar energy is that panels function best in hot temperatures. This is a classic case of conflating correlation and causation because sunlight is the key ingredient, not heat. We tend to associate warm climates with sunlight but the sun still rises each day in cold climates and that exposure to sunlight, not air temperature, is what most influences solar production. In fact, many of the places where solar is most common in the United States (like Massachusetts, New York, or New Jersey) have plenty of cold days throughout the year.

All of this isn’t to say that temperature doesn’t influence solar panels at all because there are extreme points at which panels become less efficient. But (and this further debunks the myth about heat and solar panels) extremely high temperatures are the ones to be worried about. If panels reach temperatures exceeding 149 degrees (F) then they’re likely to start losing efficiency, while cold temperatures (even extremely cold temperatures) shouldn’t negatively impact solar panel production.

Hailstorms

If you live in a state where car dealers frequently advertise cars “free of hail damage,” chances are you might also be concerned about potential hail damage on a brand-new photovoltaic system. Hail frequently occurs in Tornado Alley—the Midwest area of the USA where tornadoes appear more frequently than other states.

Fortunately, most solar panels are rated to withstand hail up to an inch in diameter falling at 50 mph. For context, the average hailstorm drops hail from ¼ to ½ of an inch thick, traveling at just 20 mph—so well within the thresholds. While the potential for hail damage occurring on a solar panel is certainly not out of the question, it is a rare event.

Heavy rain, snow, and ice

Snow or ice buildup on top of the solar panel is unlikely to cause damage—panels are strong enough to withhold extra weight and they are built to be waterproof to protect the electronic components on the inside. Snow and ice accumulation could prevent the panels from receiving as much sunlight, which would limit their power production and efficiency. But, in most cases, the snow will melt off the panels much more quickly than the surrounding regions of the roof so this isn’t a huge concern.

Tornadoes and Hurricanes

Thankfully, most solar panels are certified to withstand winds up to 140 mph, which means that they probably won’t join Dorothy in the land of Oz anytime soon. (76% of tornadoes have winds speeds that range between 40-112 mph.) Local jurisdictions where hurricanes are prominent usually enforce an even higher rating on panels, sometimes going as high as 185 mph. In cases of extreme wind, solar panel damage is most likely to occur from large debris smashing into it. But even that has proven to be relatively rare—Florida’s largest utility reported that 2017’s Hurricane Irma only damaged .04% of the 1,000,000 panels in the storm’s path.

Lightning Strikes

Unfortunately, lightning strikes can be both unpredictable and incredibly detrimental to a solar panel system, depending on how directly the lightning strikes. In the very rare case of a direct strike, a bolt of lightning can potentially melt panels and the inverter. Indirect strikes occur more often than direct strikes and can cause high-voltage surges, which could damage various components of the system.

Thankfully, manufacturers are cognizant of this and are required to adhere to requirements to ensure safety for the home and its owner—including surge suppression circuits and high-quality inverters. It is worth mentioning that some of these components degrade over time, so it’s equally important to ensure that regular maintenance is conducted on the system.