Solar panels maintenance involve generally self-cleaning, but in particularly dry areas or where panel tilt is minimal, dust and other substances such as bird droppings can build up over time and impact on the amount electricity generated by a module. Grime and bird poop doesn’t need to cover an entire panel to have an effect. This is where cleaning solar panels may have to be done.
For safety reasons, it’s also wise to clean your panels from the ground if possible. A good quality soft brush and a squeegee with a plastic blade on one side and a cloth covered sponge on the other coupled with a long extension can make for the perfect tools allowing you to stay on the ground. Use a hose with a suitable nozzle to allow the stream of water to reach the panels.
If the panels are dry, before tackling the modules with water, brush off any loose materials first – this will make cleaning easier and faster. Don’t use metal objects or harsh abrasive products for removing caked on materials. Scratching the glass on a solar panel can affect its performance as scratches will cast shadows. Avoid using detergents if possible as these may streak the glass of the panel. Use of abrasive powders also risks scratching the panels.
Given the nature of good quality solar panel glass, clean water and a little scrubbing with a coarse cloth covered sponge or soft brush should remove the most stubborn grime. If your mains-supplied water is hard (mineral-rich) and rainwater is available; use that as a final rinse; then squeegee dry. If hard water is all you have, just be sure to squeegee well as mineral rich water can form deposits on glass as it dries.
Oily stains can occur in some installation scenarios, such as if you live near an airport and are under a flight path or if you live adjacent to and downwind of a major roadway frequented by trucks. If oily stains start appearing on your panels; isopropyl alcohol can be used as a spot-cleaning substance.
In most scenarios, cleaning solar panels just isn’t worth the bother – or the potential danger if accessing your rooftop. Unless dirt is clearly visible or performance is noticeably impacted; there is no need to do anything to your panel.