Cloud cover doesn’t mean your solar panels switch off. While full sun gives you the best output, solar panels don’t need direct sunlight to work. They draw energy from daylight, which is still present even on grey, overcast days.
That’s why solar systems across Australia keep ticking along through winter and patchy weather. Plenty of Aussies are turning to solar to take some pressure off their power bills, but one of the most common questions we get is: do solar panels work on cloudy days?
The short answer is yes, but let’s unpack how and why, so you know what to expect on days that aren’t bright and sunny.
How Solar Panels Generate Power Without Direct Sunlight
Cloudy skies might dim the light, but they don’t switch your solar system off. Solar panels use light, not heat, to generate power. While they work best in direct sunlight, they’re also designed to pick up diffused or scattered light, which is why they’ll still be producing energy on cloudy days.
The actual output depends on the type of cloud cover and where you live, but it’s not unusual for panels to keep generating at a decent rate. Sometimes better than the old 10-25% estimate, which was based on low-level cloud cover and doesn’t affect how panels perform in real-world applications.
In other words, if you’re wondering do solar panels work on cloudy days, they do. And while you won’t get peak performance, the system does keep going. Plus, if you’ve got a solar battery, that stored energy from sunnier hours can help cover usage while output is lower.
How Much Energy Can You Expect on Overcast Days?
Different weather affects solar output in different ways. Here’s a quick look at how your system holds up:
Cloudy days
A common question is, do solar panels work on cloudy days? They do – just not at full capacity. Most residential solar panel systems still produce power under cloud cover, though output can drop anywhere between 20% and 60% depending on how dense the clouds are and the quality of the panels. Even on gloomy days, they keep generating by capturing diffused light, not just direct sun.
Rainy weather
Rain can bring a drop in solar output, especially when conditions are particularly dark and overcast. But it’s not all downside, as rain helps wash away dirt that builds up over time and blocks light from reaching the cells. It also cools the panels, which can improve performance slightly since solar cells tend to work more efficiently at lower temperatures.
Foggy conditions
Solar panels can still generate electricity in fog, usually at around 50% of their usual output. Fog scatters light more than clouds, but enough still gets through for the system to keep producing. Once the fog starts to lift, output usually picks up quickly without needing a full burst of sunshine.
Cooler climates
Areas with regular cloud cover, like parts of Victoria, Tasmania, or coastal South Australia, often see solid solar performance year-round, even with regular cloud cover. That’s largely due to lower temperatures, which help panels run more efficiently by reducing electrical resistance.
Cold mornings can give panels a slight edge, allowing them to produce higher voltage once the sun comes up. And while snow isn’t something most Aussie homes need to worry about, those crisp mornings still support strong output. Add in long daylight hours even through winter, and there’s plenty of time for systems to keep generating.
Hot days and extreme heat
Strong sunlight is great for solar, but when temperatures climb well above 25°C, panel output can start to dip slightly due to increased electrical resistance. That doesn’t mean solar is off the table, though, as Australia’s high levels of solar irradiance still make it a solid option, even in the hottest parts of the country.
Good airflow and quality hardware help reduce the impact of the heat and keep systems producing steadily throughout summer.
What Affects Solar Output on Cloudy Days?
Cloud cover doesn’t hit every solar system the same way. Some panels handle gloomy days better than others, and a few key setup choices can shape how much power you get.
Here’s what makes a difference when the weather turns grey:
- Panel quality – Higher-quality models tend to pick up diffused sunlight better, which keeps output steadier on cloudy days.
- Inverter technology – Your inverter plays a big role in how efficiently your system converts solar energy into usable electricity. More advanced inverters adjust better to fluctuations in sunlight, especially when conditions change throughout the day.
- Panel angle and placement – Panels that are tilted at the right angle and positioned to catch the most daylight will always have a better chance in poor weather. If they’re partially shaded or facing the wrong direction, output takes a bigger hit, especially during short winter days or overcast afternoons.
- Dirt and debris – Even a thin layer of grime can block sunlight from reaching your panels. On cloudy days, when light levels are already lower, that small blockage can have an even bigger impact. Regular solar panel maintenance helps your system stay as productive as possible.
Tips to Get Consistent Output from Your Solar
The question of do solar panels work on cloudy days comes up a lot, especially during winter. The good news is that they do, and there are a few simple ways to help them along:
Keep your panels clean
Dirt and dust build up over time, and that thin layer can block valuable light, especially on grey days. A quick clean every now and then helps your system work at its best.
Trim overhanging trees
Shade is already a challenge on cloudy days, so it helps to remove anything that blocks extra light. Regularly trimming nearby branches can make a noticeable difference.
Get your system checked regularly
Regular servicing can catch small issues that might drag down performance. Things like inverter quality, wiring, panel condition, and solid solar panel installation all help your system handle low light better.
Consider a solar battery
A battery can store extra power collected on sunnier days, so you’ve got backup when sunlight is limited. It’s one way to even out your usage without relying as much on the grid.
Storing Solar Power for Cloudy Days with Battery Systems
It’s a fair question: do solar panels work on cloudy days, and what happens when they don’t pull in as much? That’s where a battery comes in handy, storing any extra power from brighter hours for later use.
Solar batteries give you a backup supply to draw from when generation dips, which means you’re less reliant on the grid during gloomy weather or after sunset. A good solar battery also helps spread your solar use across the day and night, making better use of what your system produces.
Cloudy weather can reduce how much power your system produces, but solar panels still do their job even when the sun’s hiding. With the right setup, you can keep your energy production steady through all kinds of conditions.
At O’Brien Electrical & Plumbing Rowville, we can walk you through what suits your home and how to get the most out of your system.
FAQs
Is it worth installing solar panels in areas with frequent cloud cover?
Yes, solar panels still generate power on cloudy days, just at a lower rate. You can still get strong overall output across the year, especially with a good setup and system placement.
Do certain solar panel brands perform better in low-light conditions?
Some panels handle low light better than others, depending on the materials and cell design. Have a chat with us if you’re not sure what will suit your home best.
Can smart inverters improve energy yield on cloudy days?
They can help by tracking the best possible output throughout the day, even when sunlight shifts. Smart inverters also manage shading and system efficiency more effectively.
How do clouds affect solar feed-in tariffs and bill savings?
You’ll export less to the grid on grey days, which can reduce your credit. But across the year, your system still offsets plenty of usage, especially if you’ve got a solar battery in place.
Should I adjust my energy usage habits on overcast days to save more?
It can help to run energy-hungry appliances, such as washing machines or dishwashers, during brighter parts of the day, even if it’s not perfectly sunny. This lets you use more of your own solar power while it’s being generated, instead of drawing from the grid when output is lower.