A commonly asked question concerning solar energy is whether or not the panels function when there is snow on them? Particularly, a point of confusion is whether or not solar is worth the investment in locations with long winter months. As a matter of fact, too much heat can have a negative effect on solar power production, so winter months typically produce solar at a higher efficiency than warmer ones. Granted, there is less sunlight to work with – but your panels do in fact function at higher efficiency! Together we’ll break down this process step-by-step to see how residential solar production works in the winter.
Light vs. Heat
Solar panels only require light for energy output, not heat. The efficiency of solar power can be impacted in extremely warm temperatures, but the colder temperature will cause your panels to run at higher efficiency.
This is partially because in the summer months, the warm weather can cause photovoltaic units to heat up, and become slightly less efficient. This is not an issue in winter months as the photovoltaic panels are less effected by cold temperatures than hot ones.
Sometimes, the difference between solar energy and thermal energy is confused. Thermal energy is dependent on heat, while solar energy is only dependent on light; and while there are some technologies that rely on thermal energy, the photovoltaic panels which are more practical for residential use rely only on solar energy. As an example, if you went skiing, your body temperature could get very cold (thermal energy) and you could still get a goggle sunburn (solar energy).
In other words, don’t worry about the temperature, just be concerned about angling your solar panels for optimal sunlight exposure.
What happens when there is snow buildup?
Luckily, standard PV solar panels are made of materials like polysilicon and monocrystalline silicon, encased in glass, which allows snow and debris to easily slide off. Also, by increasing the angle of your solar panels, snow can melt right off the side without you doing any work to clear them. Just think of how easily ice slips and slides around at the bottom of a glass. And, the steep panel angle can increase your light exposure due to the lower sun position.
Furthermore, snow buildup on the ground can lead to increased solar production because of the albedo effect. What is the albedo effect? In simple terms, sun reflects off the snow, increasing the amount of light exposure by approximately 10%. So a nice snowy day can actually be beneficial to solar energy production!
First, what is net metering? Net metering is a solar incentive that’s mandated in 42 states, including Massachusetts and Pennsylvania, allowing you to store excess energy in the grid to use later.
How does this energy storage work? When you produce more solar energy than you need in sunny months, the excess goes back into the grid, allowing others to reap the benefits of clean power production.
However, if in less sunny months if need more power than you produce you, can use energy from the grid at no additional cost. Endless Energy will look at a year of electricity bills, to determine the net amount of energy you will need to produce in the summer vs. winter so that you will have no electric bill all year long.
Think of it like a bank: if you put money into your account in the summer, then you can withdraw it later. Boiled down, net metering is a solar credit that you can draw from if you produced surplus solar energy in sunnier months so you don’t have to pay if you under-produce in the winter.
Now, because the days are shorter in winter and produce less light, does that mean your energy output could decrease? Yes. So, how does net metering benefit you in winter? If your solar production isn’t quite as high in the winter as it was in the summer, that extra production in the summer can carry over production from summer months.
Let’s take a look at an example: Germany
Germany is the second largest producer of solar energy in terms of square miles, and shares a similar climate to the Northeast United States. In the summer, Germany gets hot and humid, while winter has low temperatures, rain, and snow. We can compare the success in Germany to how successful solar panels can be in Massachusetts in the winter months as well. If Germany can be one of the largest solar producers in a similar climate, then we can see that the Northeast region of the US could produce solar on a similar scale.
All this to say, your solar panels will still work during the winter and will likely be functioning at an even higher efficiency (although the hours of sun are shorter). Thank you for your readership. If you have any further questions, please feel free to reach out; we have attached some company resources below. If you’re interested in doing more research on solar panels, below are some links to further explain the science and logistics behind solar panels’ production in the winter.