Solar Panel Cleaning
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 cleaning your panels from the ground is not possible, do not attempt to access your rooftop unless you have the appropriate safety equipment and training. If you don’t; hire a suitably qualified professional instead.
Clean your panels on an overcast day, early in the morning or in the evening. If the sun is beating down on the panels, any water used can quickly evaporate and dirt will become smeared.
Early morning can be a particularly good time for cleaning as dew that has settled on the panels overnight will likely have softened grime; meaning you’ll need to use less water and less energy to clean your solar 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.
Clean water and a little scrubbing with a coarse cloth covered sponge or soft brush should remove the most stubborn grime. Plastic scourers may also be used.
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-ladened water can form deposits on glass as it dries.
Dealing with oily stainsOily 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.