How to clean and maintain your solar panels

Solar panels do need cleaning, but far less often than most people assume as the payoff is smaller than many cleaning companies suggest unless the panels are genuinely grimy.

This guide covers how often to clean based on where you live, the safest DIY method (and when DIY isn't the right call), and what a clean actually does for your bill.

The key is finding the sweet spot between paying a professional every few months for a marginal gain and ignoring panels that genuinely need some attention.

Do solar panels actually need cleaning?

The case for cleaning solar panels is about output, not appearance.

Dust, pollen and grime sitting on your panels block a small amount of sunlight from reaching the cells.

A light, even layer might only shave a small percentage off your generation. That's enough to notice on a full year's bill, but rarely dramatic on its own.

It's heavier, patchy soiling that causes real problems: bird droppings, leaf litter or bushfire ash sitting on part of a panel can create a "hot spot" that drags down the output of the whole string it's connected to, not just the dirty cell.

In most parts of Australia, rain does a reasonable job of naturally rinsing dust off a north-facing, reasonably pitched roof.

Cleaning becomes worthwhile when your location or roof pitch stops that natural rinsing from doing its job - think low-pitched roofs, long dry spells, or homes near the coast, a dusty road or heavy tree cover.

How often should you clean your solar panels?

These are general guidelines only and not set in stone.

If your monitoring app shows a sudden drop in output, clean your panels regardless of when you last cleaned them or what the calendar says.

How to clean solar panels safely yourself

The most important thing to remember is to never get on the roof to clean your panels.

Falls from roofs are a leading cause of serious injury and death in Australia every year.

The small saving from doing it yourself isn't worth that risk.

The following tips assume you're cleaning your panels from the ground or another secure, stable position, not standing on the panels or roof.

• Pick the right time. Clean early in the morning or late in the afternoon, when the panels are cool. Cold water hitting hot glass can cause thermal shock, which in rare cases can crack a panel.
• Use the right tools. A soft-bristle brush on an extendable pole, paired with a standard garden hose, is the go-to combination. Avoid pressure washers; the force can damage the glass coating, the seals around the frame, or the wiring underneath.
• Work top to bottom. Hose off loose dust and debris first, then use the soft brush with plain water (no detergent, which can leave a residue) to work over any stubborn marks, before rinsing again.
• Stop if you can't reach safely. If a section of your panels isn't reachable from the ground or a stable ladder position without leaning or overreaching, that's your cue to call a professional instead of improvising.

When to call a professional instead

Some situations call for a professional cleaner rather than a DIY job, even if the cost feels like an unnecessary extra.

• Double-storey or multi-storey homes. The higher the roof, the greater the fall risk and the harder it is to clean safely with ground-based tools.
• Steep-pitched roofs. Even on a single-storey home, a steep pitch makes it difficult to reach panels safely without roof access.
• Heavily soiled panels. Baked-on grime, bird droppings or bushfire residue that a hose and soft brush won't shift can need specialised equipment or techniques.
• Warranty concerns. Some manufacturers specify approved cleaning methods in their warranty terms, and using the wrong technique or equipment yourself could affect a future claim; check your panel warranty before attempting a stubborn clean.

A professional cleaner will typically use purified or deionised water (which dries without leaving mineral spots) and specialised soft-bristle equipment designed not to scratch the anti-reflective coating on your panels.

Signs your panels need cleaning now

You don't need to wait for a scheduled clean if you notice any of these:

• Visible dirt, dust or grime built up unevenly across the panels.
• Bird droppings or leaf litter sitting on the panel surface, especially if it's been there more than a few days.
• A sudden or steady drop in your system's output that isn't explained by weather or shorter daylight hours - check your inverter's monitoring app to compare against previous months.

If you're not sure whether a dip in output is normal seasonal variation or a sign of dirt buildup, your system's monitoring app and Finder's solar power payback calculator can help.

Use the app to see what your panels are actually producing, then compare that with what you'd typically expect for your system and location.

Does cleaning actually improve your solar savings?

Cleaning your panels can help, but don't expect a huge difference.

For most Australian homes with typical suburban dust levels, cleaning your panels will usually recover a modest single-digit percentage of the output lost to dirt.

That's still useful, but it's unlikely to slash your power bill as dramatically as some cleaning companies suggest.

The gain is much bigger if your panels were genuinely dirty (heavy dust after a long dry spell, coastal salt buildup, or a bird's nest situation) than if you're cleaning already-reasonably-clean panels "just in case."

Frequently asked questions

• Does rain clean solar panels enough on its own?

  Often, yes, particularly on a well-pitched, north-facing roof in a standard suburban area. Rain is less effective at fully clearing salt spray near the coast, and it won't shift stuck-on grime like bird droppings or bushfire ash, which is why those situations need an active clean rather than waiting for the next downpour.

• Will cleaning my panels void the warranty?

  Cleaning itself generally won't void your warranty, but using the wrong method can. Some manufacturers specify approved cleaning techniques and products in their warranty terms, so check your panel's documentation before using anything beyond a soft brush and plain water, and avoid pressure washers and detergents unless your manufacturer explicitly allows them.

• How much does professional solar panel cleaning cost?

  Professional cleaning for a typical residential system in Australia generally runs somewhere between $250 and $400 per visit, depending on your system size, roof height and pitch, and how soiled the panels are. Costs tend to sit toward the higher end for double-storey homes or steep, hard-to-access roofs.

• Do I need to switch off my solar system before cleaning the panels?

  For a normal clean from the ground with a hose and soft brush, you generally don't need to shut anything down — panels are sealed and built to handle rain. If you're doing a more involved clean, or your inverter or panel manual specifically recommends switching the system off first, follow that guidance. Never open, poke at or spray directly into any wiring, junction boxes or the inverter itself.

Written by

Mariam Gabaji

Senior Utilities Editor & Tech Expert

Mariam Gabaji is a journalist with 13 years of experience, specialising in consumer topics like mobile services and energy costs. Her work appears in the ABC, Yahoo Finance, 9News, The Guardian, SBS, 7News, A Current Affair and Money Magazine. Mariam holds a Bachelor of Arts in Journalism and was a finalist for the 2024 and 2025 IT Journalism Award for Best Telecommunications Journalist. See full bio

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