When it comes to clean and green energy, there is just nothing better than solar power. Solar power is of course a very reliable source of energy, mainly because the sun goes up every single day without fail.
In this sense, it’s a much more reliable source of clean energy than say, something like wind energy. You can rely on the sun coming up on a daily basis, but you can’t rely on wind, and moreover, you can’t always rely on hydro energy either. In terms of efficiency, reliability, and user-friendliness, solar energy is definitely one of the best out there.
Now, for people who are not overly familiar with solar energy, particularly with home based solar panel arrays, there might be a bit of confusion as to how the weather affects solar panels, energy absorption, and power production, particularly when it comes to those cold winter months with plenty of snowfall.
Sure, if you live in a hot and sunny climate, this isn’t something you have to worry about, yet for all too many of us that live in areas that see long and harsh winters, how well solar panels perform in the cold, particularly when there is snow present, is a big concern.
What we are here to do today is to take a much closer look at how well solar panels work in the snow, and if they work in the snow at all. There are actually a good few factors and nuances to consider here, all of which we will discuss below.
The reason for this is because falling snow is not the same as resting snow, and there’s also a difference between snow sitting on your solar panels or beside them. Let’s figure out how snow and cold weather affect those solar panels of yours.
Solar Panel Efficiency & Temperature
Before we start talking about snow, we want to talk about those winter temperatures. There seems to be this preconceived myth that solar panels require heat or warm weather to function properly. Well, this just is not true. Solar panels are designed to absorb the UV rays and photons that the sun’s light emits, but this is regardless of heat.
Solar panels are not really designed to absorb heat, but rather to absorb light. Therefore, there is no reason to think that your solar panel array will be less efficient in the winter than it is during the summer. A solar panel can produce a whole lot more power on a cold and bright day than on a hot and cloudy day. It’s all about light, not heat.
In fact, what is important to note here is that solar panels actually tend to lose overall efficiency in excessive heat. Solar panels will start to lose about 1% efficiency for every degree Fahrenheit over 90 degrees, which means that people living in deserts where temperatures often reach 110 degrees or higher, may not actually benefit from solar panels as much as people who live in very cold climates.
Yes, solar panels do also lose a bit of efficiency in extreme cold, but not nearly as much as in extreme heat. The bottom line here is that as far as those winter temperatures are concerned, they will have no real effect on your solar panel’s energy production. That said, what about snow?
Solar Panels & Snow
Ok, so the cold makes no difference for your solar panels, but what about the snow that is often associated with those cold northern winters? In some parts of Canada and the USA, each winter can see literally dozens of feet of snowfall, and yes, this does have an effect on your solar panels and their ability to produce usable power for you to cook and watch TV with.
That said, depending on the specific case, this effect may not always be negative. As you are about to find out, in some cases, snow may very well be beneficial for your solar panels and their ability to produce energy.
Let’s take a look at three specific cases, snow on your solar panels, snow that is in the process of falling from the sky, and snow that sits beside your solar panels.
Snow on Your Solar Panels
The first case that we want to look at here is if there is a bunch of snow sitting on your solar panels, directly on the cells that need to be exposed to sunlight in order to function. So, in this case, especially if there is a relatively thick layer of snow on your solar panels, it will cause them to lose efficiency, or to be exact, if the snow is thick enough, they will stop working altogether.
The main principle with solar panels is that they require sunlight to function, and although this can be indirect sunlight, such as through cloud cover, snow is pretty dense, especially heavy and moisture laden snow.
Generally speaking, it takes just a few inches of snow to totally block out all sunlight, especially if the snow is heavy and compacted together. So, if there is a heavy layer of thick snow sitting on your solar panels, they will no longer work, probably not at all. However, no worries, because things can only get better from here on out.
Snow Falling from the Sky
Ok, so a bunch of snow sitting on your solar panels is not good, but what about snow as it falls from the sky? Well, one thing that you need to consider here is that snow doesn’t fall out of clear skies.
Snow falls out of clouds, and more often than not, snow clouds are thick and dark. Solar panels can work with both direct and indirect light. Light coming through clouds is scattered and indirect, but it can still be absorbed by solar panels.
Thick and dark clouds may absorb up to 80% of sunlight, and this of course limits the efficiency and efficacy of your solar panels. They work much better on sunny days with direct light than on cloudy days with indirect light.
However, 20% of light coming through is still better than nothing. What you now need to consider is the falling snow itself. As you will find out below, snow does reflect light and this can be beneficial, given the right positioning.
However, snow that is falling from the sky is between the sun and your solar panels, and seeing as snow reflects light, you can safely assume that a thick blanket of snow falling from the sky, such as during a heavy snowstorm, will reflect light upwards and away from your solar panels, thus reducing their efficacy even more.
So, while solar panels will still absorb some indirect light on a snowy day, both the falling snow and the clouds will reduce the amount of light that your solar panels get.
Snow Beside the Solar Panels
Alright, so now comes the good part. As we have discovered, snow reflects light very well, and lots of it too. This is actually beneficial for solar panels, as long as the snow is beside the panels and angled towards it. Have you ever noticed that on a bright and sunny winter day, when there is plenty of snow on the ground, it can be blindingly bright?
Yeah, this is why snow blindness occurs, because snow reflects so much light that it can overload your eyes and make you go blind temporarily (with prolonged exposure). Well, if a snow covered winter day increases the amount of light that your eyes have to deal with, so does it increase the amount of light that solar panels get.
In other words, if there is snow beside your solar panels, it will reflect light towards them, and yes, this will increase the amount of light they can absorb, and therefore the amount of power they produce. Snow may be able to increase the energy production of your solar panels by anywhere from 5% to 15%, given the right conditions.
Snow Will Clean Your Solar Panels
While snow sitting on your solar panels is not a good thing, luckily, snow doesn’t really stay on them for long. For one, solar panels are usually always angled, and generally at a fairly steep angle too, which means that snow has trouble sticking to them, which is also true thanks to their smooth surface.
Moreover, if one small part of the panels don’t have snow on them, that small part will absorb a bit of heat and light, and will heat up the rest of the array, thus causing the snow to melt and runoff.
Now, there is an unforeseen benefit here, which is that the melting snow and the runoff actually serve to clean your solar panels. Clean solar panels that don’t have dirt and debris in the way of the sunlight work much better than dirty solar panels. As you can see, snow can be beneficial for solar panels in more ways than one.
Solar Panels & Snow – The Bottom Line
At the end of the day, the takeaway here is that solar panels don’t work when they are covered in snow, they don’t work well in heavy snowfall, but they work much better when they have snow beside that is reflecting light towards them.
Plus, a bit of snow can help clean them too. The bottom line is that if you live in a cold climate, you can indeed still greatly benefit from the installation of solar panels on your home.