A hose and a non-abrasive cloth will suffice. It's best to use distilled or deionized water, but municipal water works well. Using soap is not recommended, as it can leave a film or residue that not only gives shade to the panels, but can also cause dirt to stick and accumulate faster. Lubricant manufacturer Polywater produces a solar panel cleaner to help water remove dirt without leaving a film.
SunSystem technology uses a mixture of diluted vinegar and hydrogen peroxide to remove dirt. Improper cleaning practices can void the warranty, so be sure to read the details before you start cleaning yourself. The robots also clean their own onboard solar panels and recharge their batteries quickly between operations. In addition, panels in homes near airports, factories, highways, and other sources of pollution will need more frequent cleaning.
Localized soiling from solar panels occurs when materials such as bird droppings, leaves, and any other type of heavy obstructions get stuck in the panels, but only cover part of the panel. While they can be useful for cleaning other parts of the house, you should never use a pressure washer on solar panels to avoid damaging them and creating cracks. A professional solar panel cleaning company may not do a significantly different or better job than you can do yourself, but it is better equipped to safely clean and maintain roof units. Photovoltaic (PV) solar panels require minimal maintenance once installed and are designed to operate for 25 to 30 years.
Ecoppia's cloud-based platform uses sensors and machine learning to monitor a solar PV system, collect weather data, and use trackers to clean panels on an optimized schedule. An experiment in which solar panels were used on a low-sloped roof sought to determine the difference in energy production before and after thorough cleaning. Keeping solar panels clean won't automatically void the warranty, but be sure to avoid using harsh chemicals and pressure washing machines or other water-powered poles that could crack or otherwise damage the panels. The EnergySage marketplace connects you to solar energy companies in your area, which compete for your business with customized solar quotes that fit your needs.
Dust and dirt accumulated on solar panels can cause energy losses due to dirt of up to 7% per year in some parts of the US. Department of State and up to 50% in the Middle East. Applying dish soap and clean water with a sponge or soft cloth is the safest and easiest cleaning method.