Yes, Solar Panels Still Work During Snowy Weather

Contributors
Written by Dr. Charlie Gay
on January 17, 2017 5 Comments
Categories : Featured, New & Noteworthy

If you live outside of the sunny Southwest, the weather can bring sudden changes this time of year. Many parts of the U.S. have already seen snow, and the polar vortex has extended far enough south that even our nation’s capital has experienced a few deep chills. Although at first blush it may seem that solar power is ideal for the summer, solar photovoltaic (PV) panels actually produce useful power throughout all four seasons.

Tackling weather-related challenges is one reason why the U.S. Department of Energy’s (DOE) SunShot Initiative funds Regional Test Centers, where solar panel performance can be time-tested in widely varying climates. Researchers at the test centers have shown that solar can still successfully generate electricity in snowy areas and other harsh environments.

Light snow has little impact on solar panels because it easily slides off. It’s a different story when heavy snow accumulates, which can limit the amount of energy produced by PV panels. But while snow accumulation does block some light from reaching the solar circuit, light is still able to move through the snow and forward scattering brings more light to the solar cells than one might expect. So, even when panels are completely covered, they can still generate electricity.

Heavy snowfall can present a problem when the weight of the snow places stress on a PV system’s support structure. The majority of PV panels in the field today have frames, which tend to create localized stresses at the mounting points. At the Vermont Test Center, researchers are characterizing impacts such as microcracks formed by the non-uniform load of the snow. As can be seen in this article’s main photo, the absence of a frame allows the snow to slide off. This research has the potential to make solar a more economic option for energy generation in northern climates.

With or without frames, though, it’s important to note that snow can actually help clean a PV module as it melts away. It’s similar to what happens to a car’s windshield: If the snow is allowed to melt off, the windshield is left without a speck of debris. That’s because any dirt on the glass will bond with the snow, washing it away when the sun melts it off. The anti-soiling properties of snow inherently make solar panels cleaner and able to reach higher efficiencies.

SunShot is exploring other ways to help PV panels withstand the elements of winter through our support of the DuraMat Consortium, led by the National Renewable Energy Laboratory. DuraMat researchers are investigating how a variety of materials used in the packaging and mounting of PV components perform in different climates. These studies will allow lower-cost, more reliable, and more predictable new products to find their way to mass production. DuraMat is also investigating approaches that optimize frameless modules and make them more readily adaptable to outdoor extremes. DuraMat’s newly developed materials will be tested at the Regional Test Centers to evaluate their functionality over a wide range of real-world conditions.

This winter, even if the snow piles high, we can remain confident that our solar panels will generate power and that research conducted at the Regional Test Centers will help PV perform even better in the future.

Solar Performance During the Winter

What do you get when you mix #snow and #solar panels? Watch the video below to find out.#SunShot

Posted by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy on Thursday, January 12, 2017

Dr. Charlie Gay is director of the Solar Energy Technologies Office for the DOE’s Office of Energy Efficiency and Renewable Energy and leads the SunShot Initiative.

Photo courtesy of Sandia National Laboratories: At the Regional Test Center in Williston, Vt., researchers are examining how framed (in the background) and frameless (in the foreground) solar PV modules handle snowy conditions.

Comments

  1. Doesn’t matter much here, we only had sun appear (not full days) five days since the beginning of November (60 days and counting) in the great lakes region, permanent clouds east of lakes!

  2. What about the use of a product like Rain-X applied on the surface of the array to aid in the snow slipping off of the modules? Would this be beneficial in winter?

  3. For sure PV modules like to be cold! In that sense winter’s good but the days are short, the sun is low and well, it rains and snows as we are seeing in Northern California. Fafco’s recently introduced CoolPV (www.coolpvsolar.com) system keeps PV modules close to ambient temperature when they need the cooling the most in the hot summer. Even better, CoolPV sends the heat to any needy thermal load such as swimming pools or pre heat for bottle washing, laundry, destination resort, pharmaceutical and other uses.

  4. Sounds way more rosy a picture than reality. Low sun angle in winter, combined with less sun-hours means way less output at the end of a good, sunny day. Add an inch of snow, and output goes to zero.
    Yes Michael, surface treatments can help incrementally.

  5. On angled rooftops, the snow sometimes slides off well enough – but then piles up on the 2 feet of roof between the panels and the roof edge. This pile eventually stops additional snow from sliding off the panels.

    Perhaps NREL could suggest a best management practice that some sort of slippery surface be installed in that space so when the snow slides of the panel it also goes all the way off the roof?

Leave a Comment