[The Vector] Winter Wonderland and Solar Panels
In light of another stormy winter and plenty of snow falling around the country, there has been more talk about the following question: can PV solar panels work in snow and cold?
Solar PV panels can indeed work in a cold, snowy climate especially if there are sunny days and good exposure of the panels. In fact, several companies point out that PV panels work best in the cold, as the output of silicon can reduce in very hot weather. However, when snow piles up on panels and blocks all sunlight, the panels obviously stop working. Most say this happens after a few inches accumulate, but that a light dusting doesn’t stop functions and the light dusting will most likely melt off in sunlight. But many areas of the country are getting more than a light dusting of snow. What to do?
The majority of companies and experienced users say tilted panels are a good defense. Many panels are tilted at an angle to catch the sun and the tilt may often help the snow slide right off and away. Several experts including Canadian company True North Power Systems says that a winter angle of 65% or more is optimal for snow to slide. The sun is lower in the sky during winter and days are shorter, so a winter tilt makes good sense even without snow, says a number of experts.
Another tool against snow that does cover panels? Snow rakes with long handles have been making inroads. These rakes are made for snowy panels and they have a squeegee-like strip on them, helping not to damage expensive solar panels. Snow rakes are more common in New England.
Some users of rakes say beware the avalanche of snow when you sweep. And if you decide to stand on a ladder or use any other precarious position in slippery winter conditions, take care. Keep in mind – if there’s not enough sun to melt off the snow, there’s probably not enough sun to harvest by the panels either. On the other hand, PV panels can get extra power from sunlight reflected off nearby snow.
One PV user said that she did nothing to clear her home roof panels of snow in December and had very low PV production, but had worked out a system to clear the panels with a snow rake and had 25% more production already in January. However, other bloggers whose panels did not or could not tilt the panels and who had no easy access to clean them reported there was nothing they could do and did not get much solar power.
Founder of Dynamic Solar LLC, Michael Perillo, said that as far as maintenance of solar panels go, bird droppings, bird nests, pollen and squirrels are more of a hindrance than snow to solar panels working properly. Light maintenance is required to keep the panels in good working order in any season, and the investment into the panels means homeowners should work it into an annual maintenance, like with anything.
What about the product Rain-X, which helps to keep car windshields clear during heavy rain or snow? While some say they have used it on solar panels, a little research shows that a number of solar companies say beware – it is slightly conductive and can cause some electrical problems or affect the framing materials. Rain-X is apparently for glass only. Most say that simple soap & water works best, though there are some commercial cleaning fluids. Check with your solar company.
