What happens to my solar power in Winter?

Last Updated on 20/09/2025 by owen_2023

What happens to my solar power in Winter?

Established in 2017, we have a wealth of knowledge that only experience brings. We have nationwide coverage. Please contact us for your local customer service agent.

The Solarstream in-house team brings expert skills set of knowledge to all the solar projects we get involved in. This includes full project management, technical expertise to supporting our customers grant applications right down to the highest quality products we install.

Do Solar Panels Work in Winter?

Yes, solar panels do work in winter—even in colder, darker months. While shorter daylight hours and cloudier skies reduce overall output, panels still generate electricity, making them a reliable year-round energy source.

Surprisingly, cold temperatures can improve efficiency. While heat can reduce the performance of photovoltaic cells, cooler weather helps them operate more effectively. On bright winter days, panels can perform very well—sometimes better than during summer heatwaves.

How Winter Conditions Affect Solar Performance

Lower Sun Angle

In winter, the sun sits lower in the sky, meaning sunlight hits panels at a less optimal angle. This reduces energy absorption, though panels still produce usable electricity—especially around midday.

Cold Weather = Better Efficiency

Unlike heat, cold weather improves panel performance. For every degree below 25°C, output can increase by about 0.5%. So, bright winter days can be surprisingly productive, even if overall sunlight is limited.

Shorter Days & Lower Output

With only 7–8 hours of daylight in Irish winters (compared to 16+ in summer), solar output naturally dips. A typical 4kW system may produce just 3–6 kWh per day, roughly 20–30% of summer levels.

Cloud Cover

Ireland’s frequent overcast skies can lower solar efficiency by up to 90%. However, modern panels—especially monocrystalline types—perform better in diffuse light, still contributing meaningfully to household energy.

Saving Money with Solar in Winter

Even with lower output, solar panels reduce energy bills in winter, when electricity costs tend to spike.

Snow & Ice: A Temporary Obstacle

Light Snow usually melts or slides off due to panel tilt and their dark surface absorbing heat. Heavy Snow/Ice may need gentle clearing using soft brushes—avoid abrasive tools or hot water. Panels are generally self-cleaning thanks to smooth surfaces and angled mounts.

Key Ways to Maximise Winter Savings:

Keep Panels Clean: Dirt and snow can reduce output by up to 20%

Our panels are self cleaning!!

Install Battery Storage: Store excess daytime energy for use in the evening or during low-sun periods with our amazing battery offers.

Optimize Panel Angle & Orientation: Panels should face south and be tilted more steeply in winter for better sun capture.

Time Energy Use Smartly: Run high-energy appliances (washing machines, water heaters) between 10 AM–2 PM, when solar output peaks.

In conclusion, solar panels remain a valuable and cost-effective energy solution, even in the colder months. With the right setup and a few seasonal adjustments, you can keep benefiting from renewable energy all year round.

If you are interested in Residential Solar Systems or Business Solar Systems then please contact our friendly customer service team on info@solarstream.ie or call 1800 929 009.