Spring & Summer vs Autumn & Winter: The Big Difference in Solar PV Performance
As the days get longer and brighter, solar panel owners across the UK start to notice a big boost in their energy production. If you’re wondering why solar panel output varies so much between seasons, you’re not alone — and there’s a good reason for it.
In this post, we’ll explain how much more electricity solar panels produce in spring and summer, what causes the seasonal differences, and how to get the most from your system year-round.
Why Do Solar Panels Perform Better in Summer?
There are three key factors that cause solar panels to generate significantly more electricity during the spring and summer months:
1. Longer Daylight Hours
In summer, the UK gets up to 16–17 hours of daylight, compared to just 7–8 in the winter.
That’s more than double the time your solar system can be actively generating electricity each day.
2. Higher Sun Angle
In warmer months, the sun is higher in the sky, which means its rays hit your panels more directly.
This angle increases efficiency and boosts daily output.
3. Clearer, Brighter Days
Spring and summer generally bring clearer skies and more consistent sunshine.
Even though temperatures are cooler in spring than in summer, solar panels actually work more efficiently in mild conditions, making spring a surprising power performer.
What About Solar Panel Output in Autumn and Winter?
It’s true — solar output drops in the colder months, but your system still works even when it’s cloudy or overcast.
Here’s why production falls in winter:
Shorter days = fewer daylight hours to generate energy
Low sun angle = less direct exposure to sunlight
More cloud cover and rain = less intensity of light reaching the panels
That said, even on dull days, solar panels can generate around 10–25% of their rated output. Every little helps — especially with today’s high energy costs.
Tips to Maximise Your Solar Savings Year-Round
Install a battery: Store excess summer energy for evening use or dull days.
Use high-energy appliances during the day: Washing machines, dishwashers, and EV charging are best done when the sun is out.
Monitor your system: Keep an eye on generation via your solar app or inverter dashboard.
Clean your panels: Dust, pollen, and bird droppings can reduce efficiency — especially during peak generation periods.
Final Thoughts
If you’re seeing your solar generation graph climb fast right now — that’s no accident. Spring and summer are when your system truly shines. With longer, brighter days ahead, now’s the time to maximise your savings and enjoy clean, free solar energy.
Thinking about battery storage? Want to get a quote for adding solar to your property?
Get in touch with our team today — we’d love to help.