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Snow and solar panels

Useful reading > Snow and solar panels

Scandinavia’s bright spring and summer days, sunlight and low ambient temperatures provide the perfect conditions for solar energy production. During the winter season days are shorter because the sun is lower and shines less, which affects the amount of solar energy produced by solar panels. However, there are still certain misunderstandings and assumptions associated with the winter season, snow, and solar panels, so take a moment to dive into some of these snow & PV myths.

Effect of snow on the operation of solar panels

The potential impact of snow and snow loads on solar panels, especially in the northern hemisphere, should be considered at the design stage as there may be a lot of snow during the winter season. The quality of snow also varies from year to year, so it is essential to think about how best to prevent snow from staying on top of the solar panels. It is known that the snow layer blocks sunlight from radiating to the solar panels and is therefore unable to generate energy.
The mounting angle of the solar panels can significantly affect the quantity of snow collecting on the solar panels. In new, large facade structures, wall PV panels may be a viable option because the panels don’t accumulate snow. Wall panels, as well as snow-free rooftop integrated solar panels produce good energy, especially on sunny, bright and cool winter days in March-April, as the reflection of snow enhances the radiation of sunlight onto the solar panels.

Efficiency and practicality of snow and de-icing methods

Critical writings and opinions on the effects of snow and snow mass on solar panels can be seen in the media, social media and forums, especially during the winter. In social media various mechanical de-icing and chemical de-icing methods suitable for solar panels are often discussed. Let’s debunk some.

1. Chemical de-icing and de-icing methods

Chemical de-icing and de-icing methods commonly used in wind turbine blades and aircraft wings are not suitable for use in solar panels because they can corrode the surface of the solar panel, are expensive and generally harmful to the environment, i.e. the risk of damaging the panels outweighs the benefits.

In aircraft wings, the focus is on safety, while in solar panels, the goal is low energy consumption and minimization of mechanical damage.

2. Mechanical de-icing and de-icing methods

For melting snow, the addition of electric resistance to solar panels has also been tested. Implementing the idea would require additional technology so that the heating current would turn off automatically when the snow from the solar panels has melted.

3. Mechanical snow removal

Removing snow from the roof may be necessary for the durability of the roof, but solar panels do not need it. Light snow is of little importance, and cleaning the solar panels can, at best, slightly improve the onset of yield. On the best winter days in February, the return can be around 30 kWh / day, in monetary terms, just a few euros per day. So consider whether it is worth it or whether you would rather go skiing instead.

The general recommendation is to allow solar panels to hibernate under snow throughout the winter, especially if cleaning them from snow seems too laborious or dangerous. An increase of one hundredth in the annual production of solar electricity is unworthy of the risks. In addition to the risk of falling from a slippery roof, too harsh cleaning can damage or even break the solar panel.

At the turn of February-March, the sun will warm the solar panels enough so that the snow simply slides off on its own. Above all, snow is a great cleaner for solar panels, because when it melts, it washes away all the dirt that has accumulated on the solar panels.

Let the spring sun melt the snow, you enjoy winter activities!

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