How weather resistant are solar panels

How weather resistant are solar panels

Having solar panels can bring up a lot of questions. One of the first questions I was wondering before I had mine installed, was how weather resistant are solar panels? They look very fragile, and I don’t want to spend all that money to find out that their weather resistance doesn’t hold up in my area.

How weather resistant are solar panels? Most solar panels are extremely weather-resistant, if installed properly, any normal hail, hurricane, thunderstorm, supercell, would not affect the durability of the solar panel. Solar panels are usually UL tested and certified for safety.

Solar panels are built to withstand some pretty erratic weather situations. Everything from earthquakes to 160mph winds, and even hail and hurricanes. The tempered glass won’t shatter even it does crack, and most manufacturers send their panels off to get UL certified. 

What Extreme weather conditions can solar panels withstand

Extreme weather can happen anywhere in the world, and in every part of the world, there seems to be a different solution to dealing with those specific problems. Solar has become more popular over the last few years with more homeowners investing in green energy worldwide.  With that, some extreme weather concerns are, how weather resistant are solar panels when it comes to extreme weather conditions.

Most weather is fairly predictable and has certain characteristics that allow manufacturers to plan for, such as:

  1. Hurricanes and Hailstorms
  2. Tornadoes
  3. Thunderstorms and Lightning
  4. Earthquakes
  5. Extreme heat
  6. Snow and Extreme cold
  7. Flood

Analyzing some of the more extreme weather patterns, manufacturers have been able to build some strong weather resisting solar panels.

Hurricanes and Hailstorms

Most solar panels are built to withstand high-velocity winds. Solar panels can handle a speed of up to 140 miles per hour in most cases. That would be the equivalent to category four hurricane in Florida, and some states even have laws stating how much wind resistance a solar panel must-have.

In Florida, the wind-resistant number is 160mph or enough for a category four hurricane. The hail damage is something that most people are also concerned with. Solar panels must be UL tested before installation.

During the UL certification phase, a UL scientist drops a 1-inch steel ball onto the solar panel at a 90-degree angle, which would be a flat roof, However, even if the glass cracks it still passes, but they are measuring for safety.

With hail, you must have the correct circumstances for the glass to break on a solar panel. A 1-inch hailstone only hits the ground with an impact of 1.44 ft-lbs., or 1.44lbs per square foot of pressure.  This, of course, is a free-falling stone, if higher winds are involved, then the pressure is increased.

Tornados

Tornados are another windstorm that most people can be rightfully concerned about. The average tornado has a wind speed of 50-100mph. Depending on your state’s requirements for solar installation, the rack that holds the panel to the roof is what is more concerning.

Getting a steel rack may be the better option if you live in tornado alley, or somewhere tornadoes are common. Solar panels do not weaken your roof, so having them on top of a building does not change the structure or durability of your building or panels.

The worst thing that could happen is faulty installation causes the panels to blow off the rack during the storm. This is still highly unlikely if the panels were properly installed. Generally, if your building is in the destructive path of a tornado, then the solar panels are going to be damaged from debris before the tornado itself.

Windstorms

The biggest concern with a windstorm is the updraft as the wind moves under the panel. The wind moves under the panel, and then it can potentially rip the solar panel off of the rack, however, if properly installed the lag bolts should hold the panels in place.

Solar panels are installed using preventative measures against high winds such as

  1. Lag bolts
  2. Lightweight panels
  3. Secure steel brackets
  4. Mounting brackets specific to roof type

Thunderstorms and lighting

A direct lightning strike can severely damage your solar panels; the problem with this logic is that it too is highly unlikely that lightning will directly strike your solar panels or building. Most solar panels are grounded by a copper rod, as well as the inverter.

Since lightning occurs when a positive ion comes in close proximity to a negative ion and is not grounded, the closest path to the ground becomes the way the lighting goes. Since the solar panel systems are grounded, a direct strike is highly unlikely.

An indirect strike can cause a power surge and short out the power inverter, but this too is also unlikely if properly installed. A more likely scenario that a direct strike is a flash strike, or debris falling from a bolt of nearby lightning striking an object.

A flash strike could cause a power surge if the electricity interacts with the solar panels, some aluminum siding can help with this, or having a lightning arrestor installed to help prevent damage from severe thunder and lightning storms.

Snow and Extreme Cold

Surprisingly enough, snow can improve the efficiency of your solar panels. As the light reflects off of the snow, and back onto the solar panel, the silicon produces more electricity. The extreme cold has virtually no effect on the production of electricity.

The amount of sunlight available to convert is what the biggest concern would be for owning a solar panel in a snow rich environment. Solar panels actually fair better in the extreme cold than they do the heat, if your solar panels are covered in snow, they will not produce.

Solar panels work well in cold, but also don’t crack under the temperature pressure of the cold. Any water on the panel will freeze, which will make it harder to produce electricity but don’t fret. This is normal operation, and they probably won’t stay frozen too long.

Solar panels retain heat and are mostly installed at an angle, so snow usually quickly comes off of the panel. There are a few things that you can do to clear them off safely if you like.

Extreme Heat

Despite popular belief, heat is actually really bad for solar panels. Solar panels produce electricity by taking in the solar rays and converting the suns rays and irritating the electrons in a silicon cell. The sun’s photons react to the electrons in the cell, and this produces electricity.

Summer sees higher production simply because of the prolonged days, not because of the higher temperatures.  Extreme heat can damage a solar system with cell burn and other damaging situations. The silicon itself should be fine; it’s the other components that will simply melt together.

Solar panels also produce their own heat from movement, as well as the material that they are made from. In a car can reach temperatures upwards of 172 degrees on a typical 100-degree day in direct sunlight. That being said, it is much hotter inside the solar panel than on the outside.

Having the solar system mounted in a way that maximizes airflow to the system, mounting on the ground is another option that combats high-temperature areas.

Earthquakes

Most contractors are aware of the risk of earth movement in these area’s and have taken the necessary precautions to avoid damage to the solar panels themselves. Most solar panels are roof-mounted in earthquake-prone areas like California.

Since they are held on to the roof via a bracket, the panels will most likely move with the roofing structure. Having a professional installation to make sure your roof is up to the California earthquake authority standards before installation is a helpful tip.

Solar panels are meant to withstand some pretty tough elements, similar to your car windshield; the tempered glass will most likely not break during an earthquake. California building code does have regulations for solar panel installations.

Having the system on the ground during an earthquake could cause some damage. However, a licensed contractor would be able to help provide some preventative measures however most contractors probably wouldn’t recommend this measure in a high-risk zone

Flood

Solar panels are made to withstand high amounts of pressure on the glass, as well as being waterproof. The panels themselves are water sealed, and most of the connections are sealed also to prevent water damage from heavy rains.

If you are in the unfortunate event that your house becomes flooded all the way up to your roof, your solar panels will still work, they are properly sealed, and most manufacturers guarantee against flood damage.

If you have a ground unit and it happens to flood, it is going to depend on what type of flooding occurs to the damage. A Flash flood can damage solar panels if they are directly in the path of the flash flood. They can tear the panels off of their brackets and send them floating downstream

Most flood zones do not allow ground solar panels to be professionally installed. Your system could, however, short out from a power surge due to flooding in the area if connected to the local power grid, which most are.

Mounting Systems and Weather

There are several different types of mounting systems, and depending on where you live, and the roof type that you have would depend on the type that you would choose. A tilt leg mounting system allows you to tilt the panels to the suns angle.

The nonpenetrating roof mounts are not recommended in high wind areas or areas with extreme weather. The ballasted mounts are held down by concrete blocks or draped over the slope of your roof placing the panels on both sides.

Ground mounts, including pole mounts, are good for easy maintenance and normal weather conditions. These would probably be okay on a ranch that sees a few feet of snow every year, but not anywhere with a lot of flooding.

Iron mounts or rail mounts are the most recommended mounting system for extreme weather areas. These rails can be heavy-duty or light-duty and use lag bolts to fasten the panels to the rails, and the rails to the roof. The only downside to this mounting system is the expensive removal or addition of panels.

System mountWind stormExtreme heatExtreme cold
Ground mountMinor Best case Great
Tilt mount Okay Okay Okay
Rail mount Best Okay, with proper ventilation Best at the proper angle

Cleaning off my Solar Panels

To get dust and grime off of your solar panels simply spray them down with your water hose early in the morning, or in the late evening when the sun is at its coolest point. Rinsing them off at the peak of the heat will surely result in cracked glass panels similar to pouring cold water on a hot windshield.

If snow is an issue on your solar panels, the recommended method is to take a long stick or pole and tape a piece of cloth at the end, making it soft with no jagged edges. Then simply brush or gently push the snow off of the solar panel. Be mindful and careful not to scratch the panel using this method.

Hire a professional company to come and clean off your solar panels, as well as do periodic checks on the production of your installed panels. Depending on your region, these services can range from $80-upwards at $500.

Use a leaf blower to blow away and debris that winds up on your roof or on your solar panel. Clearing away leaves and debris build-up from the mounts can have huge benefits when living in an extreme weather area.

What Do I Do If my Solar Panels are Damaged

In the event of a total loss, most insurance companies are covering home solar systems that are professionally installed as an add on to your current homeowner’s insurance plan. You want to check with your local agent to see if this is coverage is available in your area.

If you have a panel that is damaged due to weather, and your panels are insured, then your insurance company may pay for the repair minus any deductibles you have on your homeowner’s insurance. Most panels range from $800-$2500 plus installation.

Sometimes if your panels are leased, the leasing company will pay for the damages via their insurance, it depends on your contract with the solar company. Most leasing contracts may not permit any responsibility for damages caused by acts of nature, but also may require to you carry insurance on the property.

The manufacturer warranty only covers defects, not damage. The weather damage is considered an outside force, and most manufacturer warranties only cover defects. Same thing with the inverter, net meters, and battery installations.

Solar Shingles versus Panels

Solar shingles seem to be the latest technology in solar-powered homes. This type of system works by installing a solar cell directly onto the framing of the roof and integrating the system into the houses electrical grid.

Solar shingles or tiles work the same way that solar panels do, only with the added weatherproof benefits of a roof. Solar shingles are flat with your roof instead of on a bracket. The thin design allows them to have good resistance to extreme weather.

Solar tiles are not a new development, but their lack of energy efficiency has placed them at the bottom of most solar companies list. Only recently has the solar industry improved the productive capabilities of solar shingles.

Solar tiles are making a big impression recently in the solar world, these rackless solar panels are becoming more stylish as the days go by. Some of these tiles mount directly to the roofing plywood and blend in; others use a flat overlay to produce the electricity for the building owner.

D.I.Y. Solar Systems

All solar systems work in the same manner, a silicon module is attached to a conductor, and when photons, come in contact with the electrons in the silicon it spins to react. Most of the D.I.Y solar panels are made to the same standards as your normal commercial grade installs.

The biggest concern with D.I.Y solar panels is going to be the correct installation. If you are using the solar panels for light to moderate projects, they should hold up just fine. A good solar vent on your roof attic will stand the test of time against hurricanes and hail damage.

Solar-powered camping equipment is meant to be used sparingly, and should not be left out in extreme conditions. These quick strips usually have a USB attached to the end and are used for mild solar power projects, such as charging a cell phone. Solar-powered lights are lighting up gardens all over the world, and these seem to be pretty weather resistant. I have owned several different versions, and they all work virtually the same. The sun heats up the photovoltaic pad, it stores the electricity in a small battery, and the shines at night. These are prone to sun damage after a while though, and would not survive a flood.


Title Image by Jesse Wagstaff

spgenie

Hi I'm Harris the spgenie! As an engineer, I found myself doing tons of research about solar power, the types of panels, how to store the energy and the best way to finance the project. I thought I'd start this blog to share my findings. I hope you find this useful.

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