Here in the southern hemisphere, where the sun shines more prominently over north facing objects, no one in the know would ever advise you to put solar panels on the south side of your roof. Why not? Because the better their clear access to sunlight, the better their performance. But what a lot of people miss is that clear access to sunlight goes beyond the direction that their solar panels face.
Over time, things get dusty – it’s just a fact of life. There’s nothing that you can do to prevent it. But what you can do, in fact, what we all do, is clean our things – shelves, tables, vases, cars, windows… Well, you know, because you do it! In fact, when we clean windows (admittedly this reaction is only typical on a sunny day of which Ballarat is not famous for) people are often shocked at just how much brighter their rooms look. They hadn’t realised just how much of a light filter their dusty windows were.
Out of Sight – Out of Mind
Taking this notion back onto your roof with your solar panels, it is very easy to forget about them. Out of sight, out of mind. Yet they get dusty, and this dust filters the light that they need to operate at capacity. Worse yet, once a layer of dust has formed, your solar panels become a very shallow planter box for lichen and moss, with just enough soil to create ideal conditions for the growth of these energy sapping weeds. Whatever portion of your solar panels are covered by lichen or moss is under total shade. So if lichen covers 5% of your solar panels, then you have lost 5% output from your solar system just there before even considering the film of dust that is likely on your solar panels to accommodate said lichen.
How Bad Could a Little Dust Really Be?
Solar Panels can lose up to 25% of their efficiency just from dirt alone – that’s before the lichen and the moss show up to the shade party. Solar panels also reduce their output capacity by about 0.5% per year as they age. Whilst it is quite counter intuitive, solar panels don’t do so well in the heat! They lose about 10% of their capacity for output on a 25 degree day.
So, coming back to the title of this article, it would obviously be badly advised to spend thousands of dollars setting up a solar panel system on the southern side of your roof where they won’t get optimal sunlight. But similarly, it would not make sense to allow a film of shade to develop on them which could cause loses of output to the sound of 25%! Most manufacturers recommend cleaning annually, some say every 6 months! In our experience with the conditions in Ballarat, we find that once every two years is generally enough, but of course, there may be other factors like if there is construction or road works in your area that increase the amount of dust in the air or if you live near a pine plantation and have extra pollen build up as a result. In any case, just click here to arrange a free quote and we can come and take a look and give you our professional opinion of the best maintenance cycle for your home.