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5 min Reading time In early December 2017, snow fell across the country, and in some areas, it remained for several days. Our Service department quickly received concerned calls from people noticing that their inverter was showing an error and generating no power—many had not yet realized that their solar panels were covered with a layer of snow. Here, this situation is usually short-lived, but what about areas with heavy snowfall?
For those traveling to the Alps this winter, it’s a familiar sight: huts and restaurants atop the mountains with a thick layer of snow on their roofs. Less well-known is that many alpine hiking huts are now equipped with solar panels, often because installing power lines to these remote locations is expensive and complicated. These huts are mainly used in the summer and have their own batteries to store solar energy. However, the batteries must not fully discharge during the winter months, as there is a risk that the system won’t restart when spring arrives, and the snow melts.
To ensure the system generates at least a minimum amount of power during winter, some panels are often mounted (almost) vertically against the wall, high enough above the ground to stay clear of thick snow layers. These panels contribute little to solar power production in summer since the sun is high in the sky and reaches them less effectively. However, in winter, when the sun is low on the horizon, a steep tilt angle is actually quite effective. Additionally, these vertical panels are often the only ones that snow cannot accumulate on.
In our region, snow typically melts within a few days, so we don’t need to consider vertical panel installations to avoid issues. However, if the snow stays longer while the sun is shining, many people find it frustrating that no green energy is being generated. Clearing an entire solar panel system of snow can be quite a task, so you might consider this:
If you have a string of, say, 12 panels, clearing snow from just a few (e.g., 4) can generate enough voltage to activate the inverter. Once the inverter turns on, electricity will flow through the entire string, including both the cleared and snow-covered panels. The bypass diodes in the snow-covered panels will allow the current to pass through, while also slightly warming the panels. This warming effect helps melt the remaining snow, clearing the rest of the panels more quickly.
If you decide to clear snow from your panels, avoid using hard brushes or abrasive tools! Use soft brushes or simply wipe the snow away with your gloves. And most importantly, don’t take unnecessary risks on icy roofs! Since energy generation is already low in winter, you can also choose to wait for the snow to melt naturally without worrying about significant losses.
