Do Solar Panels Work in Winter? 

Solar panels are designed to produce free energy via the sun. However, it’s a common misconception that solar panels will only work during the summer months when the sun is at its strongest. 

In actual fact, a solar panel installation can produce energy all year round, even in the depths of winter, as long as there is some sun shining through. This means that even on rainy days or when it’s partially cloudy, your solar panels will still work well enough for you to meet your energy needs. 

The only conditions that may cause your solar panels to not work at all would be extremely heavy snowfall, which could stop any light from reaching the panels. Luckily, this is a rarity in the UK, and only a light snowfall, if any, is much more likely, which wouldn’t dramatically affect the efficiency of your solar panels because the daylight can easily penetrate through light snow and frost. 

Do solar panels work in the rain? 

In short, yes. Solar panels can still work in the rain, provided there is still daylight. Solar panels installed by Spartek can produce energy through direct and indirect sunlight, so they will work as long as the sun hasn’t fully set for the day. Their productivity may be reduced during heavy rainfall and dark clouds, and although they are far more productive during clearer skies, they will still work just as well. 

What time of year do solar panels work best? 

Solar panels work best during the summer months purely because there are more daylight hours to allow the panels to convert the sunlight into energy. They work the same way during the winter but have fewer available daylight hours due to the earlier evenings and longer dark nights. 

Solar panel output: Winter vs Summer in the UK 

Solar panels in the UK are expected to have a better output of energy during the summer months due to the longer daylight hours, which allow the panels to convert any direct or indirect sunlight into energy and power. 

For example, according to data from PVGIS, the following was found: 

A 2.2kWp system based in Norwich should be able to generate around 82.5kWp during the month of January. It would then also be expected to reach an output high of 277.7 kWp during May. 

A 4.4kWp system on a London-based property would be able to have an output of up to 549.43 kWp during July, whereas in January, it would be reaching highs of around 164.96 kWp. 

A 6.5 kWp system in Manchester in May would be looking to create around 756.42 kWp and decrease to around 184.02 kWp in December. 

Solar panels based in Northern England may have a slightly larger gap in production during the summer and winter months than in Southern England due to their daylight hours being decreased somewhat throughout winter compared to southern areas. However, this is then countered by Northern areas also receiving slightly longer daylight hours during the summer months. 

Does snow settle on solar panels? 

Snow can, indeed, settle on solar panels; however, in the UK, the average amount of snowfall we receive isn’t likely to impact the panels’ efficiency.  

The UK usually only ever receives a light dusting of snow or frost, which still allows daylight to penetrate your solar panels, meaning they will continue working properly. Although heavy snowfall in the UK is rare, it does occur, and during these typical UK weather conditions, it could settle on your panels and impact their ability to receive sunlight, especially if the snow doesn’t slide off or melt during daylight hours. 

Does snow affect solar panels? 

Light snowfall will only reduce the solar panels’ ability to perform at peak by a little, and it isn’t something to worry about. The same applies to frost because sunlight is still able to penetrate through the light snowfall or even a heavy frost. 

Heavy snowfall could affect how much power your solar panels can generate, but any snow that does settle will slide off as it melts during daylight hours, especially as the UK is not prone to prolonged heavy snow conditions. 

Do solar panels become less efficient at certain temperatures? 

Contrary to popular belief, solar panels are actually more efficient at lower temperatures, which is great news for UK-based solar panel owners. Once temperatures reach 25C and upwards, the panels’ efficiency can begin to decrease slightly as they only need daylight to perform, not heat. 

When are solar panels less efficient? 

Solar panels have a general life span of around 25-30 years for peak performance; after this, their efficiency may begin to dwindle due to their age and exposure to certain natural elements, such as rain, snow, frost, and the temperatures constantly fluctuating between hot and cold throughout the day. 

Any temperature over 25C will cause a very slight decrease in efficiency, just as any temperature below 0C will do the same. The typically mild conditions across the UK will mean that it’s unlikely you would even notice a decrease in performance for a prolonged period. 

Final thoughts 

Ultimately, it’s excellent news for solar panel owners in the UK as it’s incredibly rare that any of the UK’s mild seasonal weather conditions would impact the productivity of any solar panels that you decide to have installed on your property. They will have slightly higher productivity during some months but will generally work well all year round.