Hard stop – Using a pressure washer to clean solar panels is riddled with risk and highly discouraged by all solar panel manufacturers.
Solar panels are made of delicate components including glass, photovoltaic cells, and electrical wiring, all of which can easily be harmed by high-pressure water streams. Furthermore, the force of the water pressure can actually push dust and debris deeper into the panel's crevices, making it harder to clean. Pressure cleaning can also cause cracks in the glass and dislodge sealing materials. They can even puncture the panels, leading to reduced efficiency or complete failure, and boy, would you and your partner be mad if you broke the solar.
When you need to clean your solar panels—and you will—always opt for the safest tools and materials you have to protect your investment in solar energy.
What are safe tools and materials for cleaning solar panels?
Manual cleaning improves performance and energy production. However, not all cleaning products or conventional methods are suitable for solar panels, especially pressure washing. Instead, refer to your owner's manual to see what solar panel cleaners they recommend. In all likelihood, they'll steer you towards using these safer alternatives for regular cleaning:
- Soft-bristled brushes, microfiber cloths, and soft sponges. Keep it soft!
- Garden hose with a nozzle attachment. A regular hose with a gentle nozzle attachment is useful, but remember to use a softer sprinkle setting that offers a gentle cleaning. Fight the urge to use any "Jet Stream."
- Mild detergent. We recommend mixing a 1/2 cup of mild detergent mixed with two gallons of warm water to create a gentle, soapy water cleaning solution. Avoiding harsh chemicals and strong cleaning fluids is important for spot cleaning your panels, and this mild solution is still tough enough to cut through bird droppings and pollen.
- Squeegee. A squeegee can be useful for removing excess water or cleaning solution from the solar panels after washing. Choose a soft rubber squeegee to avoid scratching the panels.
- Extension pole. If the solar panels are installed on a roof or in a hard-to-reach area, getting an extension pole is a must. Use it to safely clean the panels from the ground, or from a safe height on a ladder.
How do professionals clean solar panels?
Professionals use similar techniques as listed above, but they're more likely to have access to specialized equipment such as water-fed poles with soft brush attachments, or automated cleaning systems. These systems are worth the investment if you need to clean large arrays of solar panels in less time, without causing damage.
How to Clean Your Solar Panels
How often should you wash your solar panels?
The general recommendation is to clean solar panels at least once or twice a year. This varies mostly due to your climate and environmental conditions.
- Dry and dusty? You might need to do it more.
- Lots of pollen? You might want to do is twice in the springtime.
- Do your panels experience an influx of bird droppings? Plan to clean – at least spot clean – pretty often. (You might also want to invest in bird deterrents).
Regardless of your schedule, performing a regular inspection can help you determine when it's necessary.
