You just watched a driveway come up like new in ten minutes, and the dusty panels on the roof look like the obvious next job. Keep the pressure washer on the ground.
Can you pressure wash solar panels?
No. Keep pressure washers off solar panels. The panel maker REC puts it in writing. Its quick guide to cleaning its panels states that pressure cleaners, steam cleaners and high-pressure hoses aren't permitted on REC panels and will invalidate the warranty. The same guide calls for a soft sponge, a microfiber cloth or a soft, non-abrasive brush.
REC's guide also explains why. A high-pressure jet can push harder on the glass than the panel is certified to carry, damage the cells, the laminate or the bond between glass and frame, and force water in between the glass and the frame. None of that has to show on the day of the wash.
Some guides say a pressure washer is fine on its lowest setting with a wide fan nozzle. At that point you're using an expensive garden hose. You still have tap water drying on the glass, nothing has scrubbed off the bonded dirt, and the roof under your feet is now wet.
What soft washing solar panels means
Soft washing swaps force for contact. A soft-bristle brush on a water-fed pole loosens what's stuck to the glass (droppings, pollen, the dust film a dry summer leaves), and a low-pressure flow of water carries it off. There's no soap involved, so nothing is left on the panel to rinse off later.
Soft washing with deionized water is the method Total Solar Cleaning uses. It follows published manufacturer cleaning guidelines, and the owner, Mitch McKay, is certified by the International Solar Cleaning Academy, which trains cleaners to work safely on live solar equipment.
Why the water matters as much as the brush
Pressure is only half of it. Tap water carries dissolved minerals, and when it dries on warm glass the water leaves and the minerals stay as spots. Deionized water has had those minerals filtered out, so it dries clear.
Who sets the cleaning rules for your panels
The company that made your panels sets the cleaning rules. Warranty terms come from the manufacturer, not from whoever cleans the panels, and the manufacturer's installation manual holds the cleaning instructions. If you want to see what yours says, start with the model number on the label on the back of a panel or in your installer's paperwork, then read our post on whether cleaning voids a solar panel warranty for what to look for.
Can you soft wash solar panels yourself?
Yes, you can soft wash your own panels if you can reach them without climbing. A ground-mounted array, or a single-story roof you can cover from the ground with an extension pole, is a reasonable weekend job: a soft brush, a gentle hose flow, no soap, and an early start before the glass heats up.
Height decides whether doing it yourself makes sense. A ground mount on a flat lot in Concord is a hose-and-brush morning. Panels on a steep two-story roof in Pleasant Hill mean ladder work and fall protection, and the risk shifts from the glass to you.
Residential cleaning runs $175 to $350 for 10 to 40 panels. Call (833) 444-4173 or use the contact form to book a soft wash.