How do you clean rooftop solar panels without getting on the roof?
Clean rooftop solar from the ground with a carbon fiber water-fed pole and deionized water under 100 PSI. A 24 foot pole reaches most single-story San Diego roofs and a 40 foot reaches second-story arrays. Deionized water dries spot free, so no drying pass is needed. A 20 panel array takes 45 to 60 minutes.
Last updated: August 2026
Nearly every array we clean in San Diego gets done without a boot touching the roof. Not because it is impossible to walk one, but because the two most expensive things that happen during a panel cleaning are a cracked concrete tile and a person coming off a ladder.
Tile roofs are the reason. Half the housing stock in Scripps Ranch, Poway, and Rancho Bernardo is S-tile or flat concrete tile, and those crack under a knee before they crack under a foot. A single broken tile is a $200 roofer callout on top of whatever the panel cleaning cost.
What the ground setup actually is
A carbon fiber pole, a soft monofilament brush head, and water run through a two-stage filter: carbon prefilter, then a deionizing resin bed. We check output with a TDS meter and will not start above 10 ppm. San Diego tap water runs 350 to 550 ppm depending on the blend that month, which is exactly why hose-and-squeegee cleanings leave white spotting.
Pressure at the brush head stays under 100 PSI. Panel glass is tempered and tough, but the frame seals and the junction box gaskets are not, and a pressure washer at 2000 PSI will drive water past them.
The brush does the work. The deionized water carries the dust off and evaporates clean.
What about the pitch and the reach?
Reach is the real limit, not the technique. A 24 foot pole handles a single-story ranch. Two-story homes in Carmel Valley and Del Mar Heights need a 40 foot pole, and past about 45 feet of extension the pole flexes enough that brush contact gets unreliable.
Steep pitch is the other one. On anything over about 8:12 the far row of a three-row array sits outside working reach from any ladder position, and that is when we set up roof access with a harness and standoff rather than pretend the pole gets there.
| Setup | Works for | Risk | Typical time, 20 panels |
|---|---|---|---|
| Ground pole, 24 ft | Single story, pitch under 6:12 | None to roof | 45 min |
| Ground pole, 40 ft | Two story, front-facing arrays | None to roof | 60 to 75 min |
| Ladder plus short pole | Wide arrays on low tile | Ladder contact points | 60 min |
| Roof access with harness | Steep pitch, deep arrays | Tile breakage | 45 min plus setup |
What it costs in San Diego
We price per panel: $8 to $12, with a $150 minimum for the visit. A typical 18 to 24 panel residential array lands between $150 and $265. Second-story and steep-pitch arrays sit at the top of that range because setup takes longer, not because the cleaning does.
Coastal arrays in Point Loma, Ocean Beach, and Solana Beach need it about twice as often as inland ones. Salt film is sticky and it holds dust in a way that dry inland dust does not.
What not to do
Do not use dish soap. It leaves a surfactant film that grabs dust within a week and you will be back up there sooner than if you had done nothing.
Do not clean panels at 2pm in August. Cold water on 150 degree glass is a thermal shock risk, and everything you spray evaporates before the brush reaches it. We work arrays before 10am.
And do not walk the array itself. Standing on a panel voids most module warranties even when nothing visibly cracks, because microfractures in the cells show up as output loss months later.
More on frequency and output recovery is on our solar panel cleaning page, and the hard water spotting problem is covered in this post on white spots.