Why, When & How to Clean Solar Panels?

The solar panel is a device that collects sunlight and converts it into electricity. Nowadays, solar energy is one of cleanest, renewable energy sources available, and is the largest current energy source for the globe. Do you know why, when & how to clean your solar panels? If the answer is “no”, this article will show you the answer.

Why do solar panels need cleaning?

When solar panels are installed outdoors, they are exposed to the elements and naturally accrue dust, road grime, salt spray, bird droppings and other substances. Dirt that builds up on the solar panel prevents sunlight form reaching the solar cell. The more dirt, the lower amount of electricity they will produce. It is reported losses as high as 40% for customers who failed to ever clean their panels.

When and how often to clean solar panels?

As solar panels are tilted, most dirt will fall off or be washed away as soon as it rains. However, if you live in a dry area or there is a lot of ambient dust or sand, they will be cleaned a little more often. Most manufacturers recommend cleaning at least twice a year. This tends to result in a 3 to 5% increase in efficiency. The best time to clean solar panel is early morning or in the evening (ideally on an overcast day).  Too much sun on wet panels can cause them to evaporate too quickly and dirt will become smeared.

How to clean solar panels?

1.      For safety reasons, be sure to check your panel manufacturer instructions for shutting down the system before cleaning, if necessary. Try not to go on the roof to clean your system. It’s risky both for you and your panels. It’s wise to clean your panels from the ground if possible.

2.      Brushing any loose dirt off before spraying them with water will make the squeegeeing process quicker and easier.

3.      A good nozzle attachment on your garden hose might work just fine. If a lot of dust and dirt has accumulated, you might need to clean more thoroughly. Try to clean with a squeegee with a long extension.

4.      Don’t use metal objects, harsh abrasive products or detergents. Scratches on a solar panel can create shadows and affect efficiency. Simply use clean water and a cloth-covered sponge or soft plastic brush.

5.      Rainwater is low in mineral content, but some people have “hard water” or mineral-rich water from the tap. If this is the case for you, just be sure to squeegee the panels dry to avoid mineral deposits and streaking.