Solar Panels & Battery FAQs: Winter Edition

Do solar panels still work in winter?

Absolutely. Solar panels generate electricity from sunlight—not heat—so they still work in winter. While shorter days and lower sun angles can reduce output by 25–50%, your panels will continue producing energy even on cold or cloudy days.

How does cold weather affect my solar battery?

Just like EV batteries, solar batteries slow down in colder temperatures. If yours isn’t charging, it might be warming itself up to around 12.5°C before getting back to work. It’s a smart way to protect performance and keep things running smoothly.

🔋 1. Battery Chemistry Slows in Cold Conditions
Solar batteries, like EV batteries, rely on electrochemical reactions to store and release energy. In winter, these reactions slow down, which can lead to:

• Reduced charging efficiency: The battery may take longer to charge.
• Lower usable capacity: You might notice the battery doesn’t hold as much charge as in warmer months.
• Slower discharge rates: Energy delivery to your home may be slightly delayed or throttled

🌡️ 2. Self-Warming Mechanism
If your battery isn’t charging during a cold snap, don’t panic. It’s likely warming itself internally. Most solar batteries are designed to:

• Pause charging when internal temperatures drop too low.
• Resume normal operation once the internal temperature reaches around 12.5°C

This self-regulation ensures long-term battery health and safety.

🧠 3. User Behaviour Shifts in Winter
Insights from Solar and Battery Research - Full Project Insights 2024 and Solar and Battery - Phase 2 Insights Shared show that users become more proactive in winter:

• Daily monitoring increases: Users check battery charge more frequently, especially on sunny days.
• Load shifting becomes routine: People adjust timers and appliance use to align with solar generation or off-peak grid rates.
• Grid charging is more common: Some users top up their battery from the grid overnight to ensure enough energy for the next day

🧰 4. Tips to Maximise Winter Battery Performance

• Charge during off-peak hours: Use multi-rate tariffs to charge your battery when electricity is cheaper
• Keep your panels clear: Ensure no snow, leaves, or shading blocks sunlight.
• Monitor via the Hive app: Stay informed about your battery’s state of charge and adjust usage accordingly

Should I clear snow or leaves off my panels?

Yes—but only if it’s safe. Light snow usually melts quickly and can even help clean your panels. But leaves or shading from low winter sun can reduce performance, so it’s worth keeping panels clear when you can.

✅ Why It Matters

Even light obstructions like fallen leaves or bird droppings can reduce solar panel efficiency—especially in winter when daylight hours are limited. Keeping panels clear ensures maximum energy capture, even on overcast days.

🧽 Safe Cleaning Tips for Customers

1. Use a Soft Brush or Telescopic Pole

   • A soft-bristled brush or a telescopic cleaning pole with a sponge head is ideal.
   • Avoid anything abrasive that could scratch the panel surface.
   • For hard-to-reach panels, use an extendable pole from ground level to avoid climbing

2. Avoid Harsh Chemicals

   • Stick to lukewarm water or a mild soap solution.
   • Never use detergents, bleach, or pressure washers—they can damage the anti-reflective coating [2] [3].

3. Clean During Cool, Dry Weather

   • Choose a dry, overcast day to avoid water evaporating too quickly and leaving streaks.
   • Avoid cleaning during icy conditions to reduce the risk of slipping or damaging brittle components

4. Turn Off the System First

   • Always switch off the solar system before cleaning.
   • Refer to the inverter or Hive app for shutdown instructions, or consult your installer

5. Don’t Climb on the Roof

   • Customers should never attempt to walk on the roof to clean panels.
   • If panels are not accessible from the ground, consider hiring a professional solar cleaning service—these typically cost around £10 per panel in the UK

🧊 What About Snow?

• In the UK, snow is usually light and melts quickly.
• If snow does settle, it’s best to let it melt naturally—the risk of damaging the panels or slipping outweighs the benefit of manual removal

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