How Does The Weather Affect My Solar Roof?

 

When looking into solar, you may ask yourself, “How does the weather affect my solar roof?” All weather affects solar production and panels; this article briefly touches on some weather that may affect your solar roof.

Types of Weather and How They Affect Solar Production / Efficiency

Rain

While rain clouds may hinder the production of your solar for the duration of the storm, there is a benefit to be found. Dust will undoubtedly collect on the surface of your solar array over time, reducing the overall energy production of your solar system. Rain provides a hassle-free and safe way to clean your solar roof. 

Rain running off the GAF Timberline Solar™ shingles

Wind

High wind is a concern with traditional rack-mounted solar panels because of the spacing between your roof and solar panels. While unlikely due to the construction, there is always a possibility for higher winds to tear raised panels off your roof, damaging both your solar panel and your roof as well. While wind is a concern to rack-mounted solar, it is no more a concern for a GAF Timberline Solar™ roof than high winds would be to a traditional asphalt shingle roof. Because of how a GAF Timberline Solar™ roof is installed, there are no gaps between the solar shingles and the roof decking.

  Sizable gaps between the roof and the rack-mounted solar panels

Snow

Small amounts of snow, just like rain, provide a hassle-free way to clean your solar array. Regardless of the amount of snow that accumulates on your solar array, light can still penetrate down to the photovoltaic cells of the solar. While the energy that is produced with snow on your solar is less than usual, your solar array is still producing power. Snow accumulation on solar panels also melts faster than on a normal roof because it heats up as the solar panel produces energy. This, in turn, melts the snow off the panels and returns your solar array back to a normal production level.

Snow melting faster off the solar panels than the rest of the roof

Overcast/Clouds

Overcast and cloudy days are a hurdle for solar production, not a complete roadblock. Solar production is hindered by cloud cover but not entirely stopped. There is a common misconception that solar rays don’t penetrate cloud cover, but anyone who has gotten a sunburn on an overcast day knows better. If you live in a climate with more cloudy and rainy days than sunny ones, that doesn’t mean you shouldn’t get solar. You may need a more extensive solar system to offset the lower production due to the lower solar exposure.

Heavy clouds over solar panels

What Happens to Solar When it Heats Up?

While most people believe solar panels work best on hot and sunny days in the summer, this isn’t the case. Solar, just like all electronic devices, is heavily affected by heat. Solar panels are colored black, so they absorb the most light rays and produce as much solar energy as possible. There is, however, a downside to this. As the solar panels on your solar roof heat up, they produce less voltage and become less efficient at producing solar power.

Photovoltaic (PV) cells in solar panels are tested for efficiency in a standard testing condition (STC) to determine their solar energy output effectiveness. Typically, PV cells are tested at 77 degrees Fahrenheit. For every degree above 77, your panels will become one percent less efficient. Inversely, your solar becomes one percent more efficient for each degree below 77 degrees Fahrenheit.

Will My Solar Roof Catch on Fire on Really Hot Days?

A common misconception, especially in recent years, is that there is a fire concern with your solar system on overly hot days. Solar panels and shingles are designed to withstand large amounts of heat, so it is extremely unlikely that the panel or shingle would get too hot from its day-to-day energy production. Even if you live in some of the hottest states in the U.S. (Florida, Texas, parts of Colorado, etc.), there is minimal risk of your solar system catching fire because it can withstand the high heat it absorbs from the sun. With this, you do not need to watch your electricity usage on overly hot days. If you use more electricity than your solar can produce, your home will pull electricity from your utility company.

You also do not need to worry about your roof temperature on hotter days. With modern home insulation techniques, your solar array can be producing at its peak on a hot day, and you won’t notice a difference in the internal temperature of your home.

What is the “Best” Weather for Solar?

While solar can produce power on hotter days, it is not nearly as effective on warmer days. The “best” weather for solar is cold and sunny days. To know fully how much higher temperatures affect your solar roof, you will want to look at the solar specifications sheet. Regardless of the specifications of your solar, the panel will produce more energy as temperatures decrease. Just as higher temperatures are worse for producing solar energy, lower temperatures are best. This is because the cooler temperatures keep the shingle from overheating, allowing the solar panel to produce more energy.

GAF Timberline Solar Specification Sheet

Timberline Solar ES™ Specifications Sheet

What’s Next?

The weather in your area may seem like a roadblock to switching to a solar roof, but it’s only a hurdle. We here at Holladay Grace hope that we have been able to answer some of your questions about how weather affects your solar roof.

The team at Holladay Grace has been handpicked by GAF Energy as the first roofing contractor in Colorado Springs to be GAF Solar certified. Since 1979, Holladay Grace has been serving the roofing needs of the Front Range.

Are you interested in solar? Contact us for a free roof inspection today.