According to the latest statistics, the number of new solar PV installations in the United States reached almost 24 Gigawatts in 2022, and those numbers will continue to grow in 2023-2024. But there is one genuine question that interests anyone who wants to install solar panels on their roof: “Do solar panels work in the winter?”.
You can be calm; with proper maintenance, solar panels are productive in any season. This article covers everything you need to know about solar power in winter, including maintenance tips, installation advice, and ways to maximize the panel’s efficiency.
Do Solar Panels Work In Winter?
Solar panels work in winter, but their efficiency may vary depending on the weather. Most U.S. states have mild winters, so you may see a great panel’s efficiency that meets benchmarks during cloudless weather.
While solar critics may say solar panels don’t work in the cold, that’s untrue. They work fine within the temperature range set by the manufacturer (from -4°F up to 120°F). Even most Alaskan cities fall into that range. Solar panels aren’t filled with water, so they can’t freeze even in harsh Arctic Circle weather. While panels may produce less electricity if the temperature drops below the minimum range, they will still operate.
The number of hours of sunlight is a more critical factor than excessive clouds. Solar panels in winter generate less electricity because they have just 6-7 hours of direct sunlight. During summer, they usually get 10-13 hours of the Sun’s exposure.
Snow on solar panels can block sunlight and further reduce efficiency. If there is light snow, panels generate the usual amount of electricity. Meanwhile, blizzards can put a snow shade on panels, negatively affecting their productivity.
During short winter days with heavy snowfall, panels may produce only a fraction of their potential. If your utility provider offers net metering, consider signing a contract. This allows you to sell excess electricity generated in the summer for credits, which can help lower your electricity bills during less productive winter days.
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Can Solar Panels Be Installed In The Winter?
You can install residential solar panels during winter colds but not in the snowfall. While cold isn’t a problem for the panels, heavy snowfall or icy conditions could make installation dangerous for the workers.
Since winter has shorter daylight hours, the installation crew might have less time to complete the work each day, potentially extending the project timeline. So, if you need to install solar panels in winter, do it on a dry, snowless day and be prepared to postpone some deadlines.
However, solar installers might be less busy in winter, so you could schedule an installation sooner and benefit from quicker turnaround times. Meanwhile, some regions might offer special incentives for solar panel installations during the off-season to encourage citizens and businesses to use green power.
Snow Coverage and Solar Panel Efficiency
Source: CSIRO Research
Snow on solar panels impacts the system’s efficiency, but not as drastically as you might think. Light snow on the roof may reflect sunlight upwards, potentially increasing the light reaching the panels. Meanwhile, excessive snow on solar panels after blizzards negatively impacts power generation:
- Increased shading. A blanket of snow creates a shade, reducing the potential sunlight that can reach panels.
- Weight of snow. Large snow accumulations can add a few dozen pounds to the stressing the mounting system. In extreme cases, it can even damage the mounting and panels themselves.
Solar panels and snow are not companions. So, you should install panels at a steeper angle facing south and install snow guards. That way, you’ll lower the possible snow coating on panels. Snow guards block your panels from excessive snow accumulation, while the panel’s steep angle allows precipitation to slide naturally from the roof.
Potential Consequences of Reduced Efficiency
Neglecting maintenance and leaving snow on solar panels may cause your panels to become less productive.
- Lower electricity production leads to a reduced return on investment.
- You’ll be forced to use grid electricity, and it will take longer to see a return on your initial investment in the solar system.
- Increased reliance on fossil fuels raises your carbon footprint and greenhouse gas emissions.
- Burning fossil fuels also releases pollutants into the air and water, impacting public health and ecosystems.
If you live off-grid, you should get powerful batteries to store all possible excessive electricity you generate during the day. If it’s possible, buy a backup power option like a gasoline generator. It’s not the most eco-friendly option, but it helps you to live off-grid life during heavy blizzards with snow on solar panels.
Beware that reduced efficiency might be a symptom of a larger problem with the solar system. Degradation due to age, extreme weather events, or manufacturing defects can lead to lower efficiency over time.
The Importance of Timely Cleaning
General solar maintenance rules stay the same regardless of the season. You should track the system’s performance and prevent shading from trees or snow. Solar panels rely on sunlight to generate electricity. When even one panel is partially shaded, it affects the whole system.
Most solar panels are wired together in series, like Christmas lights. It means the current produced by all the cells flows through a single circuit. The problem is that a shaded cell acts like a weak link in the chain.
Source: VisualProductivity
When there is too much snow on solar panels, they become shaded and “reverse-biased.” Long story short, instead of providing energy, the cell starts to absorb it from the nearest well-performing cells.
The panel can’t convert this energy to electricity, so it starts to dissipate as heat. This concentrated heat buildup creates a “hot spot” on the shaded cell. If not addressed, hot spots can cause permanent damage to surrounding cells, reducing overall efficiency and leading to fire risks.
Thus, it’s crucial to conduct solar panel snow removal once you see its buildup. While light dusting might not significantly impact efficiency, heavy snowpacks cause excessive shading.
Meanwhile, you don’t need to clear the roof or backyard from snow since it reflects the light. This process is called the Albedo effect and increases panels’ productivity.
Proper Winter Maintenance
To maximize the amount of energy generation during winter, contact the installer to adjust the panel angle. This easy action allows you to catch more sunlight even on these short days. Steeper angles not only capture more sunlight but can also prevent the accumulation of snow on solar panels. Even the small adjustments of 6-8° will help.
You can use heating systems to melt the snow when it’s landed on the panels. If that’s not possible, install the solar panel snow guard. In this case, snow still accumulates on the panels but won’t be collected in enormously large sheets. While shading from the snow may reduce efficiency, the panels won’t crack under the snow’s weight.
To ensure safe cleaning snow off solar panels, use a dry cloth mop, the softest possible bristled brush, or a snow rake specifically designed for solar systems. You should never use shovels, metal tools, or abrasive materials that could damage the panels.
If you have an off-grid or hybrid system with batteries, store them at recommended temperatures. Some can handle short-term, chilly weather lower than -4°F, but it is still not recommended to continuously use them during the extreme cold.
Solar Panel Snow Guards
Solar panel snow guards can mitigate snow accumulation from avalanching off in large sheets. There are just 2 types of guards:
- Clamp-on guards: These guards attach directly to the frame of each solar panel and break up large sheets of snow as they slide off.
- Snow fences: Long, low-profile barriers are installed along the top edge of the entire solar panel array, separate from the panels. They act like fences, catching snow before it slides off the whole row and allowing it to accumulate below the panels in a controlled manner.
You can install both snow guards for solar panels on your property. They reduce panel damage by preventing large sheets of heavy snow from sliding off and potentially cracking the glass or damaging the mounting system. Guards also minimize the risk of snow avalanches that could injure people or damage property below the roof.
Heating Systems
Another way to remove snow from solar panels is to install heating elements to combat excessive sediments. Solar panels covered in snow still function, but it’s better to prevent the shading if possible.
There are three types of heating systems: electrical, hydronic, and thermal (PVT). To save you time, we’ve gathered their crucial differences in the comprehensive table.
| Parameter | Type of heating system | ||
| Electrical | Hydronic | PVT (Photovoltaic Thermal) Panels | |
| Description | Heating cables are connected to the rear part of the solar panel. Once you turn the heating system, these cables will start to heat, causing slow snow melt. | A heated fluid circulates through a network of tubes behind the panels to melt snow. | These are solar panels that use excessive heat generated by the panels itself to melt the snow |
| Pros | Easy to use and fits small systems | The most energy-efficient variant | You don’t need to install additional equipment |
| Cons | Needs a lot of energy to work. Due to cost, it may not suit large-scale systems | Tricky and costly. In most cases, it requires additional plumbing | The most expensive option. In some cases, it’s cheaper to install traditional panels + electric/hydronic heater |
While picking the best way to revoke unwanted snow on solar panels, evaluate your situation in the long run. What may look beneficial today may become tomorrow’s hurdle. Consult with a qualified solar installer familiar with your area’s climate to determine the best choice for you.
Ensuring Solar Panel Efficiency in Winter
Solar panels can brighten your life even during the darkest winter days. Proper component maintenance ensures maximum productivity, so remember to clean them regularly. After blizzards, check mounting systems to ensure your panels are securely attached to the roof.
It’s easy to maintain panels even in the cold. Answering the question “Do solar panels work in the winter?”, we can clearly say that with proper maintenance they remain as productive as in summer.
If you see excessive snow on solar panels, use the bristled brush or special snow shovel to remove the cold fallout. If possible, install heating systems or snow guards. They will protect panels from excessive snow accumulation during blizzards.
Discover the advantages of solar energy and get your free solar quote today!
Frequently Asked Questions
Do solar panels work with snow on them?
Yes, your solar system can still generate energy during winter. A thin layer of snow on the roof can act as a reflector and increase panel efficiency. Meanwhile, excessive snow on solar panels can provide unnecessary shade during a blizzard, lowering the system’s productivity.
Do solar panels work when covered with snow?
Solar panels can work during blizzards with heavy snowfall, producing less energy than expected. Meanwhile, light snow can act as a reflector, increasing the system’s efficiency.
Do solar panels produce less in winter?
Since winter days are 3-7 hours shorter than summer, it can result in a 20-50% productivity drop. Snow on panels is a minor factor that doesn’t have that much influence on the system’s efficiency.
How to keep snow off solar panels without damaging them?
Use a soft-bristled brush or dry mop to clean the panels’ surface without scratching them. Clean the system with a special snow rake designed specifically for solar panels.
Do solar panels work in the winter?
Yes, they will remain productive with proper maintenance even on short cold days. Remove the excessive snow to prevent potential shading. Use the soft bristled brush or special solar panel snow rake for it.
Dmytro Kovtoniuk is an SEO and automation specialist at SolarPowerSystems. Dmytro’s experience in solar projects and automation and passion for applying mathematical principles to real-life tasks—a commitment shared with the rest of the team—are crucial in shaping the company’s strategy for presenting accurate and user-friendly information on solar technology.
