How to Clean Solar Panels

How to Clean Solar Panels

Solar panels can accumulate dirt, dust, pollen, bird droppings and ash in summer in Southern Oregon. Typically, the rain and snow will naturally clean your solar array in the winter and spring months. That is one of the reasons we always recommend installing panels with even a modest tilt angle. However, summers of smoke and ash or heavy soiling due to dust or bird droppings can affect the production of your array if enough build up occurs and you may find it necessary to clean the solar panels more often.

When should you clean your solar panels?

When to clean your solar panels depends on your unique circumstances. If you have a lot of pollen accumulation on them in the spring, that would be a good time for you (after the pollen stops accumulating). That would help ensure a full summer season of optimal solar energy generation. On the other hand, if your panels become covered with ash in late summer, you might consider cleaning the panels then so that you have optimal fall energy production.

We generally see enough cleaning of solar panels in our Southern Oregon winters from snow and rain that we don’t generally recommend cleaning them then. Ultimately, it’s up to you when you clean your solar panels, if at all. Observing the seasonal patterns of accumulation will inform you as to your best plan of action.

Who should clean your solar panels?

For your safety, we strongly recommend hiring a local window washing company. Both Serene Window Cleaners and Max Energy Solar Cleaning are reputable solar panel cleaners here in the Rogue Valley.

If you do it yourself, please stay on the ground. Never get up on your roof without a secure ladder and proper fall-protection equipment. Please contact us at True South Solar if you have any other further questions about cleaning or productivity of your solar panels.

If you notice large accumulations of bird or other animal droppings, you might consider protecting the panels with netting. We can make recommendations for local contractors who can do this for you.

Before and after solar panel cleaning on the True South Solar office system (Photo courtesy of MAX Energy Window Cleaners)

Our Solar Panel Cleaning Recommendations

OK, so you’ve decided to clean your solar panels yourself. Right on! Here are our recommended best practices:

  1. Turn off your solar electric system before cleaning. Consult your True South Solar manual to see how to turn off your system to protect it. If you are unsure, please call our office at (541) 203-0525.
  2. 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.
  3. Use a soft-bristle brush with an extended handle, soft sponge/seamless cloth or soft squeegee. Do not use abrasive brushes, pads or powders. Use of such abrasive materials will void the product warranty.
  4. Use non-heated, potable water with normal water pressure, over-the-counter glass cleaner (such as Windex or equivalent) OR a 3% soap-and-water solution. Pressurized water up to 1,500 psi may be used when necessary. Avoid harsh industrial strength cleaning products. Avoid 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.

A ground mount system after solar panel cleaning, all shiny and new! (Images courtesy of Serene Window Cleaners)