Pollen. Desert sand. Leaves. Algae. Bird droppings… All these things reduce the effectiveness of your solar panels. Measurements show that in practice this can quickly lead to a loss of 5%. And that’s a shame because that’s money you’d otherwise be saving. Therefore cleaning, all the experts say, should be your motto. Here are a few tips.
It is a misconception that the Australian rainfall is enough to clean your solar panels by itself. If only that was the case! Then you’d never have to wash your windows again! As we all know, wind and rain also bring lots of dirt. And this dirt collects most on angled solar panels, no longer giving sunlight the chance to penetrate any more.
When should I clean?
Regularly check to see that your solar panels are clean. At the very least, thoroughly clean them in the spring, just before the summer. The summer months provide 70% of your energy yield for the whole year. So always start the summer with clean panels to get the most out of every ray of sun!
The panels get dirty the fastest in the spring. That’s the time when the air is full of pollen and in some periods even desert sand, which is carried by the rain. This creates a haze that might not always be visible, but which results in a lower efficiency of your solar panels. Have you ever noticed that your car is dirty after a rain shower in the spring? You can assume that the same thing happens to your panels too.
In autumn, it’s mostly leaves that are the biggest culprits. They tend to collect at the bottom edge. And even if it’s only a thin strip: you are still losing in terms of square metres of panels. What if you don’t do anything about it? Then over time the leaves will turn into a thick, sticky layer. In times when the trees are shedding their leaves, the not cleaning is a luxury you can’t afford.
How do I clean?
One downside to solar panels is that they are often mounted high up and are hard to reach. Can’t reach them with your garden hose? Then buy a telescoping broom or wiper at a DIY to which you can also attach a garden hose. These are perfect for the job. Usually you can easily reach the panels using these either from a window or a ladder.
If you are climbing up on a slanted roof though, always make sure that you’re properly anchored. If you go up when it’s raining, beware: roofs often become treacherously slippery!
Very tempting, but also a no‐no is cleaning the panels with a high‐pressure washer. Even though the panels are solidly built, there is always a risk that water can get behind the glass, and once it’s in, it won’t come out.
What cleaning product should I use?
First try to get rid of the worst of the build‐up after you’ve removed the debris on top. Use a soft brush or cloth, but absolutely no hard rubbing if you’re using the latter. Fill a bucket with warm water, and add a special cleaner for solar panels. You can probably find this from your installer. If not, you can also buy it at online shops that specialise in cleaning products. In any event, do not use any all‐purpose cleaner or other aggressive cleaning product. And absolutely no abrasives or scouring pads!
You can wipe the panels best with a soft sponge or microfiber cloth. Rinse with ample amounts of water (preferably lime‐deficient soft water).
Tip: clean the glass panels after dark or in the shade. The sun dries the cleaning water up so quickly that the dirt doesn’t have a chance to rinse off. If you do, you’ll quickly see that streaks have already appeared.
Maximum efficiency of your solar panel
If you follow these cleaning instructions properly you’ll benefit from maximum efficiency of your solar panels all year round!