Solar panels are a marvelous invention that just seems to get better every year. But one thing that remains unchanged is that they must be exposed to sunlight in order to make electricity. This means that they are also exposed to dust, pollen, rain, snow, and ice. Anything that creates a film over your collector is going to impair its efficiency.
In areas of high rainfall, your panels might not need frequent cleaning, but in locations where conditions are dry and dusty, cleaning might be required more often.
Solar panels can be mounted in all sorts of different places. Some are attached to simple frames at ground level, some are on sides of buildings, but most are attached to roofs. One of the challenges of cleaning solar panels could simply be reaching the panels safely, and without damaging them.
Material and Panel Type Matters
Not all solar panels are created equal. Some are well-sealed rectangles of glass and plastic, some are set up to be shingles, while still others have a fabric back that can be folded for storage. The kind of solar panel in question can make a difference in cleaning methods.
Beginning with the Easiest First
If your solar panel is one of the standard sealed-behind-glass types, and it is mounted where it is easily reached from the ground, your cleaning chore is as easy as cleaning windows. For a home DIY small array, the easiest way to clean your panels is to first brush them gently with a soft brush, then wipe them down with a soft, lint-free cloth that has been dipped in de-ionized water.
Roof-Mounted Standard Solar Arrays
Climbing around on your roof isn’t very safe for you or good for your roof or your panels. There are several options for getting the grime off your panels. One method is to attach a commercial, outdoor cleaner that is rated for glass to your garden hose. First, dampen the panels. Second, spray down the panels and roof area with the outdoor cleaner. Finally, rinse off the panels.
If you want to use less water, and still avoid climbing on the roof, you could purchase a solar panel cleaning kit. These usually include an extension pole with squeegee and soft wipe attachments that can be used to gently remove grime from roof or ground-mounted solar panels.
Really Big Solar Arrays
Manual cleaning of large arrays would be costly and time-consuming. The answer to keeping a large array clean is to use specialty robots that run on tracks alongside the panels. These little robot cleaners work very much in the same way as a Roomba works on a kitchen floor. While somewhat expensive, they are a lot cheaper and more efficient than hiring someone.
Folding Solar Panels
Cloth-backed solar panels that are sold for camping also need to be kept clean. Because of their portable nature, they are inherently a little more fragile than permanently mounted arrays. First, keep your panels in a location where they are protected from pets, small children or vermin between uses. This will help keep them from being scratched or damaged. Second, after each use, lightly dampen a cloth with distilled water and gently wipe the face of the panels. Make sure it is completely dry before storing.
If you plan to place your portable solar collector on the dash of your car, clean your windshield for the best results. The added layer of glass does reduce efficiency, and your vehicle needs to be parked so that it faces the sun for best results.
When to Clean Your Solar Panels
The frequency needed for cleaning your panels will vary by location and season. If the weather is dusty, you are likely to need to clean your solar array more often.
If it is winter, it might need snow or ice brushed off it. In many cases, frozen moisture is a self-correcting problem. As soon as the sun hits the collectors, a thin layer of ice will melt right off. Deep snow is another matter. Sometimes it will need to be brushed away, preferably before it can develop a hard crust.
Clean the panels at a time when they are not extremely hot. Cold water applied to hot glass can easily cause the panels to break or for a seal to come loose. Early morning or late afternoons after the panels have had a chance to cool down is a good time for cleaning.
Checking for Damage
Although solar panels are well-proven, sturdy technology, they can become damaged over time. While you are cleaning your panels is a good time to check them for trouble spots.
Things to look for include cloudiness at the corners of panels, which can indicate the beginning of a moisture leak, breaks in the joining filaments inside the panels, or heavy scouring, such as can occur during sandstorms. Also keep an eye out for damage near areas where panels are wired together, as well as look for mounting brackets that might have come loose.
Things to Avoid When Cleaning Solar Panels
Avoid using hard water to clean your solar panels. This can cause water spotting or even create an added film over the panel, which can impair its efficiency.
Likewise, steer clear of harsh cleaning chemicals, especially with panels that are covered with Plexiglas or similar clear, artificial compounds. Do not immerse portable solar panels or solar panel chargers. Instead, wipe them gently with a soft cloth. Always make sure they are completely dry before storing.
Solar panels are not hard to clean. Dirt, dust, snow or ice can impair the efficiency of your collectors, so it is well worth your while to dust or wipe down your panels. The frequency needed will depend on your local environment. Cleaning time is a good time to keep an eye out for potential damage to your collectors. Clean portable collectors used for camping after each use, and store in a safe place until it is wanted again.