Solar Panels for Cold Climates
Updated: Dec 1, 2022
Do solar panels work in Snow and during Winter
As long as sunlight is hitting a solar panel, the panel, also known as a solar PV module, will generate electricity - even in extremely cold temperatures!
In fact, solar panels work most efficiently in cooler temperatures. A cold, sunny environment is the optimal operating condition for solar panels. Counterintuitively, it's heat that actually reduces a solar panel's efficiency.
Do solar panels work in the snow?
Snowfall certainly affects the performance of a solar panel. Sometimes positively and sometimes negatively.
An interesting scenario is during a windy day, with light snowfall.
The wind blows snowflakes present in the atmosphere around, scattering the sunlight, and increasing the amount of sunlight reaching the panels. This aids power generation.
The wind also helps in clearing off the snowflakes. As long as they are not deposited on the panels, blocking sunlight, snowflakes aid in solar power generation.
Solar Panel Performance in Snow:
When snowfall is light to moderate, two factors come into the picture allowing solar panels to function satisfactorily.
The first factor is sunlight. Moderate depositions melt away as soon as the panels are exposed to sunlight. Once the snowflakes melt away, the panels function properly.
The second advantage of light to moderate snowfall is that any dust particles, which are present on the panels are carried away with the molten snowflakes. This cleans the panel's surface and thus increases it's performance.
When the snowfall is heavy, the panels are completely under the snow. Under such circumstances, their performance can either completely stop or be reduced to a minimum depending on the availability of sunlight.
Heavy snowfall also leads to added weight on the panels. Accumulated snow exerts a downward force or pressure on the solar panels and their mounting structure. This is called 'Snow load'.
Solar Panels are capable of withstanding a certain amount of snow load e.g. RenewSys DESERV Panels can withstand a snow load of 5400 Pa (i.e. equal to 540 kgs/m2).
However, the strength of the mounting structures also needs to be considered. They need to be strong enough so that they do not collapse under this increased weight.
Operation and Maintenance Tips for Solar Panels in Cold Climates?
Here are some tips which help ensure better performance of PV panels during snow:
Panel Angle: In places where the snowfall is heavy, raising the panels by increasing their angle of mounting ensures that the snowflakes slide off the panels. Once the snowflakes are off the panels, the panels will function at their full capacity.
Cleaning, Panels with a Broom: If the snowfall is very heavy, the snow will completely cover the modules. Once this happens, the panel performance will go down. In such cases, the snow can be shoveled off the panels with the help of a soft broom. One must take absolute precautions not to hurt oneself or damage the panels while cleaning them. If the snowfall is too heavy, cleaning is also essential for the safety of the mounting structures.
The debate about cleaning the snow off solar panels.
Several solar system owners do not consider cleaning off the snow to be a viable option for solar panels.
In many parts of the world, during heavy snowfall, sunlight is not available for days or if available, then only for a short window of a couple of hours. At such places, it is recommended to leave the panels as they are, even completely under snow as cleaning them would not lead to any significant energy generation from them anyway and cleaning them might impose a risk to the personnel as well as the panels.
To summarize, light to moderate snowfall will have no adverse effects on the panel or its performance. Heavy snowfall certainly affects the panel performance. In such cases, cleaning panels with a broom could help the panels start generating electricity.
Do Solar Panels Work in the Winter?
In winter, since the sun rays come at a low angle, the amount of solar radiation is limited which leads to lesser power generation by the solar panels . Also, in winters if the sky is cloudy, solar panels will generate less amount of energy. Many types of research show that except for the extremely cloudy days, solar panels generate a substantial amount of energy even in winters.
Solar panel productivity in winter:
Three things affect solar panel productivity: temperature, cleanliness of the panels, and the amount of available light. Let's look at how winter conditions affect these factors.
Temperature: Believe it or not, solar panels work better in the cold. Heat tends to increase electrical resistance, so the colder your panels are, the more efficiently they will operate.
Light availability: Here is where your solar panels operate at a major disadvantage in winter. There are fewer daylight hours on a winter day than in the summer. The angle of the sun is also much steeper in the winter, which is less favorable for the typical installation.
Panel cleanliness: Anything that obstructs your panels will affect their efficiency. This includes dust, dirt, and snow. We usually think of snow as clean, but if snow and ice build-up on your panels they can shut down your power production. However, this is not usually a problem, since snow generally slides off them quickly.
One last thing to note is that temperature swings can cause panel components to expand and contract. This is a major cause of damage to cheap, poorly made panels and can severely shorten the life expectancy of a panel.
Maintaining solar panels for optimal winter production:
The beauty of solar panels is that they require no maintenance under normal conditions (Standard STC conditions). However, to reap the full advantages of solar energy, there are two things you can do to improve panel efficiency during winter.
The first is to adjust the angle of your panels to take advantage of the lower winter sun angle. This requires a special, adjustable rack. Most people don't consider the hassle of adjusting panels twice a year to be worth it, but if you are determined to get the best possible return on your solar investment, it is an option.
The second is to be vigilant about removing any accumulated snow or ice. You will probably be surprised at how fast snowmelt off panels after a snowstorm without having to lift a finger. Though if you do notice a persistent accumulation, and your panels are safely accessible, you can remove it with a push broom or a windshield ice scraper. Don't put yourself at risk, though. The little extra power you gain is not worth an injury from falling off the roof. This activity is best reserved for ground-mounted panels.
Data Credits: https://www.revisionenergy.com/
Image Credits: https://www.revisionenergy.com/