What happens to your solar power in winter?

Winter is the best time of year to closely monitor the output of your off-grid solar system.

In an off-the-grid solar house, a row of days with complete cloud cover can occasionally mean a drop in available power from your battery storage, due to fewer hours of sunlight hitting the solar panels.

Of course, as most solar households are also connected to the electricity grid, energy is always available even though the sun might be hidden. But it’s important to understand what happens to your solar production during winter and learn the best way to monitor your solar system.

What happens to your solar production during winter?

To understand that, let’s have a quick look at how solar panels work.

It’s a common misconception that solar panels need heat in order to produce power, but actually they need light, especially ultraviolet light (UV) which is the most effective at creating a direct current. But, put simply: when sunlight hits your solar panels a direct current of electricity (DC) is created; this is converted to alternating current (AC) by your inverter and it’s the AC current that we use in our homes.

During winter, the sun is lower in the sky and its light doesn’t hit the panels at an optimal angle, meaning your solar production is slightly reduced. In addition, winter daylight hours are shorter than during summer, so there is less time for your solar system to harvest sunlight.

So, does this mean a big drop in the energy generated?

You’ll produce less energy during winter, but it’s not always a huge drop.

Solar panel performance can drop by 2% to 15% during winter, depending on a number of factors such as where you live, the tilt of your panels and how much dirt has accumulated on the surface of your panels.

In our alpine region, which stretches from New South Wales into Victoria, snow falls from June to September. In this weather, even a small amount of snow on the panels may reduce the amount of energy output for an entire system. Researchers in the US are testing the energy output of solar panels in snowy conditions and ways to harness solar power during the snow season.

What’s the best way to keep on top of your usage in winter?

The best way to effectively use the power generated during winter is to simply monitor your solar system, note the times during winter when you have available power and use your electrical appliances accordingly. Keeping your panels clean is also a good idea.


Here are more ways you can make the most of your solar all year ’round.