Your SunPower system was designed with typical soil accumulation in mind, and seasonal rains are usually enough to adequately clear any soil or dust that might accumulate. We strongly recommend that you do not go onto your roof for panel cleaning or inspection. If severe soiling occurs and you feel it is absolutely necessary to clean the panels, you can clean them by spraying them from the ground with a standard garden hose. We recommend that homeowners only clean panels early in the morning or late evening rather than when the sun is at its peak or when the panels are warm.
To clean a module, wash with potable, non-heated water. Normal water pressure is more than adequate, but pressurized water up to 100 bar may be used. Fingerprints, stains, or accumulations of dirt on the front surface may be removed as follows: first rinse off area and let soak for a short period of time (about 5 minutes). Re-wet and use a soft sponge or seamless cloth to wipe glass surface in a circular motion. Fingerprints typically can be removed with a soft cloth or sponge and water after wetting. Important things to keep in mind:
As a rule, stay on the ground. Never get up on your roof without a secure ladder and proper fall-protection equipment. Turn off your system before you start cleaning. Consult your local Installer if you need help turning off your system. As a rule, avoid using hard, or mineral rich, water. It can damage panels over time. If your area only has hard tap water, you can buy an inexpensive water-softening hose attachment to filter out minerals. Otherwise, you can use distilled or de-ionized water.
Use soft brushes and squeegees. Do not use harsh cleaning materials such as scouring powder, steel wool, scrapers, blades or other sharp instruments to clean the glass surface of the module. Use of such materials of cleaning without consultation will invalidate the product warranty.
Clean early in the morning or in the evening when the panels are cool. During the heat of the day, water and soap can evaporate quickly, which risks smearing the soap and dirt.
When using a high-pressure water nozzle, don’t get close to the panels. While they’re extremely durable, you don’t want to damage them.
Do a monthly visual inspection to look for any dust buildup. Also, you can watch your bill for any noticeable drop in efficiency. Only then should you worry about cleaning. Even then, in most cases, nature is going to clean them for you.
Don’t expose yourself to any risk. If you have any doubts about your ability to safely clean your panels, hire a professional.