Do solar panels work in winter?

Aerial view of solar panels on the roof of a house.

RACV Solar

Posted May 10, 2022

While solar is still very economical in winter, there are a few factors that can impact the return you'll see from your solar system.

Shorter days

With fewer sunlight hours in winter, your solar system won’t have the usual production rate. Daylight hours in Victoria during summer average 14 hours while in winter it's just 10 hours.

Overcast days

Your solar panels will still operate on overcast days but at a reduced rate. Expect your panels to produce 10-40% of their rated capacity on a very overcast day.

Heating costs

Many people use their heaters a lot in winter which means their energy usage spikes, taking a large portion of their solar energy output. Heating at night will also impact your energy bills as, unless you have a battery, it won't be using your solar power.

Frequently asked questions

Will the cold weather impact my solar?

The cold weather won’t impact your solar panels. They use light from the sun, not the heat. Cool weather and clear skies are perfect for converting sun rays into electricity.

Are solar systems effective in winter?

Yes! While cloud cover and shorter days will affect your production, your solar system will still produce enough power to reduce your electricity costs.

How many kWh should my system produce in winter?

For north-facing systems, expect it to produce the system size multiplied by 2.6 = kWh avg daily winter output. So for a 5kW system, this would be 13kWh a day on average.

Why have my energy bills increased?

Your electricity bills might increase in winter due to the effects of solar and/or an increase in electricity usage (such as heating) during this period. If you think your system is still not performing as expected, consider whether or not these situations apply to you:

  • Have your energy rates increased?
  • Are you using electric heating?\
  • Have you bought a new appliance?
  • Do you have old, inefficient appliances?
  • Are new structures or trees shading your solar panels?
  • Are you charging more devices 24/7?
  • Have you checked your solar switch is turned on? (It can sometimes turn off in a power outage)


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