We wash panels for a living, and we will still tell you this: a lot of solar arrays are perfectly fine to clean yourself. A ground mount in a pasture, a carport you can reach from a step stool, a low single-story roof you can work from the yard with a pole.

What matters is how you do it. The wrong water, the wrong tool or the wrong hour can scratch glass, leave spots, or put your panel warranty in question. And the wrong ladder plan can put you in the emergency room.

This guide covers when DIY makes sense, what manufacturers actually ask for, and the steps that keep you, the glass and the warranty intact.

Is your array a good DIY candidate?

Start here, because the honest answer is sometimes no.

Good candidates:

  • Ground mounts. Every panel is within reach from the ground or a short step. Our page on ground-mounted arrays covers why they also get dustier.
  • Carports and canopies. Often reachable with a pole from the drive.
  • Single-story, low-pitch roofs. If you can reach the top row with a pole while standing in the yard, you are in good shape.

Leave it to someone harnessed:

  • Two-story homes. The ladder alone is the risk.
  • Steep roofs. Anything you would not walk on dry, in sneakers, without thinking twice.
  • Any plan that involves standing on the roof. Wet shingles and wet glass are slick, and nobody should step on a module.

Our crew works two to a roof, one up and one on the ground, and harnesses on anything steeper than a walkable pitch. If that sounds like overkill for your roof, you are probably fine. If it sounds about right, skip the DIY.

Do you actually need to wash?

Check before you spend a Saturday on it. A thin film after a dry month may cost very little, and the next good storm may take care of much of it.

Open your solar app and compare a clear day this week with a clear day just after your last good rain. Our guide to reading your solar app shows how. If clear-day output looks normal for the season, the panels can wait.

The exceptions are bird droppings and sap. Neither moves in the rain, and both block light hard. Those are worth spot-cleaning even when the rest of the glass is fine.

What does your panel manual say?

Read it before you pick up a hose. Manufacturers are specific, and their warranties often depend on following their instructions.

Two examples:

  • REC. REC’s cleaning guide says panels must be cleaned with water at ambient temperature, and that the warranty is valid only if the installation manual’s instructions are observed.
  • Panasonic. Panasonic’s EverVolt manual specifies deionized water free of grit, at ambient temperature, with a sponge, microfiber cloth or soft brush.

Your panels may be a different brand with different wording, but the pattern is consistent: gentle water, soft tools, no shock to the glass. Our warranties and cleaning guide collects what to look for in your own manual.

What tools do you need?

Less than you think:

  • A soft brush on an extension pole. Wide, soft bristles, the kind sold for washing cars or RVs. Nothing stiff.
  • A garden hose with a gentle nozzle. A soft shower setting, not a jet.
  • Microfiber cloths. For droppings and sap you can reach by hand.
  • A bucket of clean water. For rinsing the brush between rows, so you are not dragging grit back across the glass.
  • Optional: a deionizing filter. Small hose-end filters sold for car washing remove the minerals that leave spots.

That is the whole kit. If something in your garage makes you think “this would be faster,” it is probably on the list below.

What should never touch the glass?

  • Pressure washers. High pressure can strip coatings and drive water past seals. We wrote a whole piece on why we never pressure wash solar panels.
  • Soap and detergents. Residue holds the next round of dust, and some manuals forbid them.
  • Glass cleaner, vinegar or anything with solvent. Not what the glass coating was designed for.
  • Abrasive pads, scrapers or blades. Scratches are permanent, and they catch dirt forever after.
  • Squeegees. One trapped grain of grit drags a scratch the full length of the panel.
  • Your feet, knees or weight. Never stand, kneel or lean on a module.

When should you wash?

Early in the morning or late in the afternoon, on a mild, calm day.

Midday sun heats panel glass well above air temperature. Cold hose water on hot glass is the opposite of what REC and Panasonic ask for, and the sudden change in temperature is a risk you do not need. Morning glass is cool, and the night’s dew has already softened whatever is stuck on.

Skip the wash if it is windy, if a hard freeze is due that night, or if lightning is anywhere in the forecast.

How do you wash a panel, step by step?

  1. Check the ground and the setup. Stable footing, the hose untangled, no one under where you are working. Turn off sprinklers so they do not mist the glass afterwards.
  2. Rinse first. A gentle shower over the whole array floats off loose dust and grit before anything touches the glass.
  3. Brush top to bottom. Light pressure, long strokes, working down each panel. Let the bristles and water do the work.
  4. Rinse the brush often. Dip it in the clean bucket between rows so you are not spreading grit.
  5. Treat droppings separately. Soak the spot for a minute, then lift it with a wet microfiber cloth. Do not scrub dry.
  6. Rinse again, top down. Make sure no film is left drying on the lower edge.
  7. Let it air dry. No wiping, no squeegee.

A typical ground mount of 16 to 24 panels takes an hour or two at this pace. That is normal. Rushing is where scratches come from.

Why do panels spot after a hose wash?

Because tap water carries dissolved minerals. When a drop dries on the glass, the water leaves and the minerals stay, as a faint white ring. Our page on hard water spots on solar panels shows what that looks like over a few washes.

There are three ways around it:

  • Wash in the cool morning, so water runs off before it dries in place.
  • Do a final rinse with deionized water, from a hose-end filter or a pump sprayer filled with it.
  • Accept a few light spots. On most panels, a handful of faint rings cost far less than the film you just removed.

This is also why we carry pure water on the truck. Water with almost nothing dissolved in it dries without leaving anything behind.

What if you find damage while cleaning?

Stop and photograph it. Cracked glass, a chipped corner, a burn mark, a loose clip or a cable hanging below the frame are not things to fix with a brush.

Cracks and electrical concerns go to your installer or a licensed electrician. Roof damage goes to a roofer. After a hailstorm, start with our after a hailstorm checklist before anyone touches the array.

When does it make sense to call us?

When the ladder is the hard part, or when you want a second set of eyes. A single wash includes a glass-level check of every module and before and after photos. You also get a production comparison from the next clear days, so you can see the result in your own numbers.

Plenty of owners mix both: they rinse a ground mount themselves in spring and book a professional wash for the roof array in late summer. That is a perfectly sensible split.

The short version

  • Ground mounts, carports and low single-story roofs are fair game.
  • Stay off the roof and off the panels, always.
  • Follow your manual: gentle water at air temperature and soft tools.
  • Wash early or late, never on hot midday glass.
  • No pressure washer, no soap, no scraper, no squeegee.
  • Photograph damage and send it to the right trade.

Our step-by-step clean it yourself guide is the short, printable version of this article. If your array is on a roof you would rather not climb, you can book a wash and we will send photos the same day.