When winter comes and your panels are covered in ice, you may ask yourself, “Are they still working?” Solar energy can be severely affected when ice blocks sunlight, as panels require clear exposure to produce energy. Thick ice acts as a shield, preventing photons from reaching the photovoltaic cells. Modern solar panels are engineered with frames and coatings to withstand extreme conditions, and given the correct tilt, some of the ice might simply melt away.

Your system can run efficiently through regular maintenance, like clearing ice buildup. Understanding the effect of ice on performance is essential when maximizing energy production in cold weather. Winter need not dampen your solar prospects. Arming yourself with information will help you take the appropriate steps to enable your panels to power through the frost. Let us look into the fundamentals of ice management on solar panels and find the best ways to keep efficiency, even when the panels are covered in ice.

Why Surface Coverage Stops Solar Energy Production

The underlying explanation for why a layer of ice or snow inhibits solar generation is that the photons are entirely blocked. The mechanism behind the operation of solar panels is based on the photovoltaic effect, which involves direct collision of light particles (photons) with the semiconductor material used in the cells of the panel.

When a photon of sunlight hits an electron in the silicon cell, the energy is transferred to the electron, and it becomes free to flow and generate an electric current. It is this movement of electrons that we use as electricity. The mechanism relies entirely on the photons being able to reach the cells. This process will be halted by any physical obstruction that does not allow these photons to reach the photovoltaic cells. A very thin veil of frost may be transparent enough to allow a very little diffused light, but a thicker, opaque veil of snow or solid ice forms an absolute barrier.

A solar panel blocked by ice is similar to a hose with its nozzle closed. No output occurs despite available potential. With the photons (the fuel) blocked, the panels cannot generate electricity. That is why a solar panel covered with snow or thick ice on a sunny winter day will generate nothing. The problem is not that the efficiency is lowered. The panel still has the power to convert light into electricity, but no activity exists.

Separating a decrease in efficiency from a complete blockage is also necessary. A panel in very high heat may lose 10 to 20 percent of its efficiency through higher electrical resistance, but it will continue to generate power if exposed to light. However, with a snow-covered panel in optimal cold temperature conditions to maximize efficiency, the panel will yield not a single unit since the light source is severed. The panel effectively produces no power, similar to nighttime conditions. Thus, the main obstacle to solar power in cold climates is not the low temperature, which is an advantage of efficiency, but the treatment and clearing of physical barriers, including snow and ice, to ensure that the critical function of the panel is not interrupted.

Can Solar Panels Work With Ice on Them?

Solar panels may still generate minimal power under a thin layer of frost, but thick ice or snow can halt production completely. Even a thin coating of ice or snow can drastically decrease the output of a panel. A thick layer will stop production altogether. This occurs since the ice is a block, not allowing sunlight to reach the photovoltaic cells. Although the cold temperature of winter is advantageous to the electrical efficiency of a panel, the physical hindrance of frozen precipitation is the primary cause of energy production decline during the colder months.

The underlying cause of this loss of production is the photovoltaic effect, which is the mechanism through which a solar panel uses light to generate electricity. This effect demands direct interaction of a photon, a particle of sunlight, with a silicon atom in the panel cells. This impact ionizes the electrons in the atom and makes them move to produce a direct current. Even a translucent sheet of ice scatters and absorbs most photons, preventing sufficient energy from reaching the cells. Some energy can be generated in a thin layer of frost, but a substantial thickness of ice or snow will drop the output to zero.

Homeowners can see this effect by comparing monitoring app data on clear versus ice-covered days. Data taken on a clear sunny winter day and a day where the panels are covered with ice will have a drastic difference. The clear-day output will represent a healthy production curve with a peak at around midday, and the output of the ice-covered day will be flatlining at zero. This observation further confirms that it is not the cold but the physical barrier. It also points out the need to select panels with characteristics that will improve winter performance, including high mechanical load ratings to support the weight of snow and ice, and durable frames so they cannot be damaged by the repeated freeze-thaw cycles. There are also panels with hydrophobic coating to make it easier to shed water and ice.

The process of removing ice from panels is delicate to prevent damage. Passive solar melting is the safest. The black surface of the panel soaks up the minimal sunlight that makes it through the ice, forming a thin water film that enables the whole sheet to slip off.

Homeowners should never use hot water, as rapid temperature changes can cause micro-cracks in the glass, permanently damaging the panel. Similarly, rough objects like shovels or scrapers may also scratch the glass, and the panel will never be as efficient again.

Testing Solar Panel Output under Cold Weather

You can keep track of its production yourself to get a feel of how ice and snow affect your solar system in the real world. Modern solar systems have a monitoring app or web portal that gives real-time and historical data about your energy creation. This data is calculated using kilowatt-hours (kWh), the standard energy production measure.

To observe the impact, do the following:

  • Pick a clear, cold day — Select a clear winter day with no snow or ice on your panels

  • Confirm your production — Log into your solar monitoring app and document the kWh production hour by hour. You are expected to get a consistent curve with a peak at noon. This is the output of your system in optimal cold-weather conditions, when efficiency is maximized.

  • Choose a covered day — Wait until a good covering of ice or snow has covered your panels.

  • Compare the statistics — Recheck your application. Your system will probably produce zero kWh or very little throughout the day.

This head-to-head comparison of the data will be a very strong argument that, whereas cold temperatures do not interfere with solar production, the physical blockage of ice and snow utterly shuts it down. This easy activity allows you to witness the science in your home.

Key Features of Winter-Resilient Solar Panels

When choosing solar panels that can withstand cold climates, it is important to look into features that make them durable and able to withstand winter conditions. Winter-resilient solar panels possess the following main features:

  • High mechanical load ratings — Solar panels are rated and tested to resist external pressure, which is usually measured in Pascals (Pa). The higher the mechanical load rating, the more chances the panel has to withstand the weight of heavy snow and ice buildup. Snowy areas typically have panel ratings of 5400 Pa and above, guaranteeing that the panels can support considerable weights. It is an important specification to verify because a substantial snow load may exert too much stress on the structure of the panel.

  • Strong frame integrity — A solar panel needs a frame to provide structure. The panels are winter-resilient with durable, corrosion-resistant aluminum frames that support the freezing and thawing cycle. This stops the frame from twisting, which may affect the internal parts of the panel and seal, and allow moisture ingress. A good frame keeps the panel closed, shielding the fragile cells against the environment.

  • Hydrophobic surface coatings — Certain high-tech solar panels are produced with a hydrophobic (water-repelling) coating on the tempered-glass surface. These finishes make water form beads and roll off. This characteristic can assist in decreasing ice adhesion and facilitate natural snow shedding, which allows the panels to clear themselves and thus continue production following a storm. Although these coatings do not prevent all snow and ice accumulation, they can help significantly decrease it.

  • Tempered glass construction — The front glass is made of impact-resistant tempered glass in a quality solar panel. This variety of glass is far more resistant than standard glass and very hard to crack or shatter upon impact, like a falling piece of ice or hail. Its durability offers a vital protection cover to the delicate photovoltaic cells beneath it, which makes the panel durable and efficient even in extreme and unpredictable weather conditions.

The Benefit of Solar Energy in Cold Climates

The fundamental nature of solar panels is that they are high-tech electronic devices. Like your laptop or phone, their best performance is related to temperature. This may sound contrary because we associate the use of solar energy with sunny and hot places, but the reality is that solar panels can work better in the cold than in high temperatures. What is the reason behind this? Photovoltaic (PV) cells determine the efficiency of a solar panel. The sunlight photons are absorbed by these cells and converted into electricity. The electrical resistance in these cells grows as the panel temperature rises. This increase in resistance lowers the voltage and hence the total power of the panel. This can be expressed numerically in a typical crystalline silicon solar panel:

A typical panel loses about 0.5% efficiency for every °C above 25°C (77°F). This phenomenon means that a sunny, yet cold, winter day is often a perfect situation to generate the maximum amount of solar energy. The panels are cool, resistance is low, and conversion of sunlight to electricity is the highest.

In addition to the general physics, cold climates have some particular benefits to solar energy production:

  • Higher efficiency — When the temperatures are lower, the electrical resistance decreases, directly increasing the panels' power output. This means a panel will generate more electricity on a winter day than on a sweltering summer day using the same amount of sunlight.

  • Improved performance — The cooler atmosphere will enable the panels to run at their optimum level, similar to a computer with a good cooling system. It creates a more uniform and quality energy output over time.

  • Clearing skies — Winter weather can also be drier and have clearer air, especially after a cold front. This will enable more direct sunlight to reach the panels without scattering or being absorbed by the water vapor, which makes them perform better.

The Main Challenge to Overcome is Snow and Ice

Although the cold is an advantage, the main issue facing solar panels during winter is not the temperature but physical obstructions. The actual enemies of winter solar production are snow and ice. These materials prevent the sunlight from generating energy on the surface of the panels and hence totally stop the energy production process. A slight snow cover can bring output down to nearly nothing.

So the trick to successful solar energy in northern climates is not fighting the cold but coping with and reducing the impacts of snow and ice. The best solutions include:

  • Correct panel angle and strategic location to promote the snow to slide away

  • The frequent cleaning to remove any buildup

Once the snow is removed, the panels can make full use of the cold weather and clear skies, and it has been shown that solar power is already a surprisingly efficient solution even in the chilliest corners of the globe.

Find a Solar Expert Near Me

Solar panels can be dulled by ice, but careful design and regular maintenance will ensure your system can continue generating power during the cold winter. Removing ice and adjusting panel orientations ensures sunlight continues flowing, generating maximum energy even during the coldest seasons. Do not allow ice to slow your solar savings. Make sure you are aware and ready.

For professional guidance in the Bay Area and Northern California, consider consulting a certified solar installer experienced in winter performance optimization. At Sun Solar Electric, our team specializes in making your panels work efficiently throughout the year with the best quality of maintenance and recommendations. Call us today at 707-658-2157 to ensure your solar system flourishes, regardless of the weather.