It’s a common question from homeowners across Sussex and the South East: do solar panels work in winter? And if they do, are they worth the investment when grey skies dominate the weather forecast? The answer is a resounding yes. Solar panels absolutely work in winter, delivering excellent returns on investment and generating clean energy throughout the darker months. So, let’s explore winter solar in more detail…

What affects solar output in winter?

It’s true that your solar panels won’t produce as much electricity during winter as they do in summer. But before you dismiss solar power in winter, it’s important to understand the factors at play:

• Shorter daylight hours are the primary culprit. Met Office data shows the average number of sunshine hours per month drops to 50-65 in the winter, compared with a summer monthly average of 175-195. With fewer hours of daylight overall, it’s natural to see reduced output
• Cloudier, darker skies are typical during UK winters. Overcast conditions mean less direct sunlight reaches your panels, reducing the amount of energy they generate. However, even on the gloomiest winter day, your panels will still produce electricity, just at a lower rate. Remember, it’s daylight that counts, not direct sunlight
• The sun sits lower in the sky during winter. This means light hits your panels at a shallower angle, which in turn means some of it will be absorbed by the atmosphere before it reaches your system. This lower angle results in reduced efficiency when compared to the high, direct summer sun
• Hail, snow and falling leaves can potentially obstruct your panels. However, heavy snow is relatively rare in the UK, and even if it does snow, it’ll melt or slide off angled panels

The winter advantage: Cold weather boosts efficiency

While winter brings fewer daylight hours, cooler weather can actually improve solar panel efficiency. This might seem counterintuitive, but lower temperatures allow the electrons to move more freely within the solar cells, improving power generation capacity. Panel efficiency increases by approximately 0.5% for every degree below 25°C. So, while you’re dealing with shorter days and cloudier skies, at least the cold is working in your favour.

Most good-quality panels are constructed to withstand temperatures ranging from lows of -40°C to highs of 85°C. UK winter temperatures rarely approach anywhere near these extremes, meaning your system will perform reliably throughout the season.

How much solar power can you expect in winter?

Let’s talk numbers for a moment: the average household uses an estimated 8-10 kWh of electricity per day. A typical residential solar installation with 12 panels could generate around 4.8 kWh per day in winter – so you could still be generating half your energy.

Winter solar output in the UK typically represents 25-35% of annual generation, with summer months accounting for the remaining 65-75%. We recommend viewing your solar panel system on a full-year basis – e.g. rather than thinking in terms of output per month or season to season, consider the total output over a 12-month period.

During the lighter, brighter summer months, you’ll likely produce more energy than you need, dramatically cutting your bills and enabling you to sell your excess energy back to the grid.

The winter game-changer: Solar battery storage

If you really want to optimise your solar system’s performance throughout winter, adding battery storage is a great solution. A solar battery stores the excess electricity your panels generate during daylight hours, allowing you to use that stored energy later in the evening or on particularly gloomy days. Rather than exporting all your surplus energy back to the grid, you’re banking it for when you need it most.

This is particularly valuable during winter when most of your electricity usage happens after dark – heating, lighting, cooking and entertainment all peak during those longer winter evenings.

Why choose solar battery storage in winter?

• Store daytime generation for evening use: Even on short winter days, your panels still generate electricity during the daylight hours. A battery captures this energy so you’re not drawing from the grid when demand and prices are highest
• Take advantage of off-peak tariffs: Many households pair their battery with a smart tariff, which offers much cheaper rates overnight. You can charge your battery with cheap electricity during off-peak hours and use that stored energy throughout the day, dramatically reducing your winter energy bills
• Reduce grid reliance: Battery storage allows you reduce your reliance on grid electricity, which is particularly useful in winter when your consumption rises and energy prices may be higher
• Energy independence: Having a fully charged battery gives you peace of mind and protection against rising energy costs, even when solar generation is at its lowest.

Solar battery capacity considerations

Modern lithium solar batteries range from around 1kWh to 16kWh in capacity. For winter use, you’ll want a battery with enough capacity to cover your evening and overnight electricity needs, ready to be recharged when the sun comes up.

With the right sized battery, you should have enough stored electricity for most evenings throughout the year, though you might still need some grid electricity on the longest winter nights.

The bottom line: Yes, solar panels absolutely work in winter

Don’t let myths about solar power generation in winter hold you back from making one of the smartest investments you can make for your home. Modern solar panel systems are designed with seasonal variation in mind, and UK installation standards account for these predictable output patterns. When you evaluate solar on an annual basis rather than season by season, the financial and environmental benefits become crystal clear.

With expert installation, high-quality equipment and the addition of battery storage, your solar panels will continue slashing your energy bills and reducing your carbon footprint throughout the year – grey skies and all.

Ready to explore how solar panels can drastically reduce your energy bills and even earn you money? Contact us for a quote. We’ll assess your home and energy needs, and design a system that delivers maximum performance throughout the year.