How to clean solar panels safely from the ground

Step by step: how to clean solar panels safely from the ground

Safety first. Stay off the roof: roof work brings a real risk of falls, and Qcells warns homeowners can also be burned by hot panels. Clean from the ground with a pole, or hire a professional. If you must use a ladder for a low array, follow OSHA ladder rules (3 points of contact, base a quarter of the working length from the wall, never on the top rungs) and keep it away from the array’s wiring and overhead lines. Panels make electricity whenever light hits them, so never touch damaged panels, cables or connectors, and do not spray the inverter or junction boxes.

1. 1

   Check your warranty and monitoring first

   Read your panel maker’s and installer’s cleaning instructions, since some warranties limit what you can use or who can do the work. Then open your monitoring app and compare recent output on sunny days with the same time last year; a clear drop with no shading change suggests the panels are dirty.

2. 2

   Pick a cool time of day

   Clean early in the morning, in the evening or on an overcast day, when the glass is cool and the system is producing little. Hot panels dry water and soap into streaks, and cold water on hot glass is best avoided.

3. 3

   Rinse off loose dust from the ground

   Stand on the ground and spray the panels with a garden hose on a gentle shower setting, aiming down the slope so water runs off the bottom edge. A rinse alone often removes most pollen and dust.

4. 4

   Scrub gently with a soft brush on a pole

   Dip a soft-bristle brush or a squeegee with a sponge side into lukewarm water, adding a few drops of mild soap only for greasy film. Brush lightly from top to bottom. Let bird droppings soak under the wet brush for a few minutes rather than scrubbing hard.

5. 5

   Rinse thoroughly

   Rinse every panel again from the top down until no suds remain, since dried soap attracts dust. In hard water areas, a final rinse with deionized water helps prevent white mineral spots.

6. 6

   Let them air-dry and look them over

   Let the panels air-dry. While they are wet and the light is low, look for cracked glass, damaged frames, loose wires or nests under the array, and note anything for your installer.

7. 7

   Check output over the next few days

   Compare production on the next sunny days with your numbers before cleaning. If output does not improve, the problem may be shading, an inverter or a panel fault, which needs your installer.

Should you get on the roof to clean solar panels?

No. The best way to clean solar panels on a roof is from the ground, with a hose and a soft brush on an extension pole, or to hire a professional. Enphase’s cleaning guide recommends hiring a professional for rooftop arrays so the job is done safely, with the least personal and financial risk.

• Never walk or kneel on panels. They are not built to carry your weight and can crack in ways you cannot see.
• Wet glass and roofing near the array are slippery. If a low array needs a ladder, follow OSHA’s ladder safety card: inspect the ladder, set it on stable, level ground, keep 3 points of contact, and extend it at least 3 feet above the roof edge.
• CPSC’s ladder safety tips add: have a helper hold the base, keep your body centered between the rails, and use a non-conductive ladder near electrical lines.
• Work on a calm, dry day, and stop if you would need to reach beyond the ladder rails.

What not to use on solar panels

Skip anything abrasive, high-pressure or harsh. The glass has an anti-reflective surface, and scratches cost you output for the life of the panel.

Qcells’ maintenance guide suggests a soft microfiber cloth with lukewarm (not hot) water and air-drying, and it warns that DIY work can conflict with some warranty terms, so check yours.

How often do solar panels need cleaning?

Usually once or twice a year, which is what Enphase suggests, and more often if you live somewhere dusty, near the coast, under trees or near farm fields. Rain helps, but Enphase notes that relying on rain alone is not ideal for best output, because it leaves a film of dust and does not shift bird droppings.

Flat or low-tilt panels collect more dirt than steep ones, since water does not run off as fast. Let your monitoring data guide you, and book a professional inspection every 5 to 10 years even when output looks fine. If you are on a ladder anyway, our guide to cleaning gutters covers the same safety setup.

Mistakes to avoid

• Climbing onto the roof or standing on the panels to reach the top row.
• Using a pressure washer or a stiff deck brush on the glass.
• Cleaning at midday, when hot glass bakes soap and minerals into streaks.
• Using strong cleaners or solvents instead of water and a little mild soap.
• Spraying water at the inverter, junction boxes or wiring under the array.
• Not checking the panel warranty before cleaning, or using methods it excludes.