If your solar panels are looking a bit grubby and you’re thinking about blasting them with the pressure washer—hold up for a second.
That might actually do more harm than good. Yeah, we know—it seems like the fastest way to clean anything.
But when it comes to solar panels, high-pressure water can crack the glass, mess with the seals, and even void your warranty.
Not exactly what you want after spending a few grand on a solar setup. A lot of Aussie homeowners don’t realise how delicate solar panels really are.
They’re built tough enough to handle the weather, sure—but they’re not made to be sprayed down like a dirty driveway.
There are better, safer ways to keep them clean without risking damage or costing yourself big in repairs.
Let’s break it down so you can keep those panels in top shape, save on your power bills, and avoid the drama of a dodgy clean.
Can You Pressure Wash Solar Panels?
Pressure washing sounds like a solid way to clean anything dirty, especially when it’s up high and hard to reach. But when it comes to solar panels, it’s a different story.
The glass on those panels might look sturdy, but it’s more delicate than you’d think. That powerful blast from a pressure washer can easily cause small cracks in the surface.
Even a hairline fracture can mess with performance and lead to bigger problems down the track.
You might not even notice the damage straight away. And it’s not just the glass you have to worry about.
The high pressure can shift or loosen parts under the panel—like wires and connectors. Once that happens, you’re opening the door to electrical issues, safety risks, and expensive repairs.
Most manufacturers are very clear about this in their care instructions. Using a pressure washer can void your warranty.
Even if the panels seem fine now, you won’t be covered if anything fails later on due to improper cleaning.
It’s just not worth it.
There are safer ways to get the job done—ones that won’t leave you with cracked glass and a rejected warranty claim.
Why Pressure Washing Solar Panels is Risky
When you blast solar panels with high-pressure water, it’s not just the surface that’s affected. The seals around the panels can take a real hit. These seals are designed to keep water and dust out of the internal parts.
When they’re damaged, moisture can seep inside and cause electrical problems. Over time, this can mess with how well your panels work and even shorten their lifespan.
The cells inside the panels are delicate. High-pressure water can push its way through small openings and cause those cells to crack or break.
You won’t always notice the damage straight away, but over time, the performance of the system drops. And in most cases, that’s something you’ll end up paying for.
There’s also the issue of grit.
If there’s any loose dirt or debris on the panels—and there usually is—pressure washing can push that grit across the surface. That causes scratches. Scratches reduce the amount of sunlight the cells can absorb, which means you get less energy from your panels.
Here’s what can go wrong when pressure washing is used:
- Seals can break, letting in water
- Cells can crack under the force
- Wiring can loosen, especially with older systems
- Surface scratches from sand or debris get worse under pressure
- Water damage builds up inside the panel, causing long-term faults
These problems don’t always show up right away. Sometimes everything looks fine on the outside, but behind the glass, parts are wearing out faster than they should.
And once water gets into the panel, it doesn’t just go away.
Even if the surface dries, the damage inside keeps spreading.
There are plenty of better ways to clean panels without these risks—methods that don’t involve shooting high-speed water at fragile equipment.
Best Way to Clean Solar Panels in Australia
Use a soft brush and deionised water
Solar panels don’t need heavy scrubbing or harsh chemicals. A soft brush—the kind you’d use on a car—works well to loosen up dirt and dust without scratching the surface.
Deionised water is great for rinsing because it doesn’t leave behind mineral spots or streaks. That helps your panels absorb more sunlight and stay efficient after cleaning.
You don’t need a lot of pressure—just a gentle wash-down and a careful wipe is enough in most cases.
Clean in the early morning or late afternoon
The best time to clean your solar panels is when the sun isn’t blasting down. Early morning or just before sunset is ideal.
The panels are cooler, which makes them safer to touch and less likely to crack from sudden temperature changes.
It also helps prevent the water from drying too fast and leaving marks behind.
Avoid detergents unless they’re approved
Most solar panel manufacturers warn against using regular cleaning products. Detergents can leave residue on the glass, which actually attracts more dirt.
Unless the product is specifically recommended by your panel brand, skip it.
Stick with water and a brush, or hire someone who knows what they’re doing. It’s safer for the panels and keeps you covered under warranty.
Tips for Cleaning Solar Panels Safely
Use a hose with low pressure
A regular garden hose is usually all you need. Keep the pressure low—you’re rinsing, not blasting.
Stand back a little so the water flows over the surface gently. This helps remove dust and light grime without risking damage to seals or glass.
Skip the high-pressure nozzle altogether. It’s just not worth the risk.
Consider a solar panel cleaning kit
If you want a more hands-on option, a solar panel cleaning kit can make the job easier. These usually come with a soft brush, an extendable pole, and sometimes a squeegee or hose attachment.
They’re designed to clean panels safely, so you won’t scratch the surface or apply too much force.
Great for single-storey homes where the roof is easy to access.
Hire professionals for roof safety
If your panels are hard to reach or you’re not confident climbing up, get a pro to do it.
Professional solar panel cleaners know how to move safely on roofs and use the right tools.
They also understand how to clean without voiding your warranty or damaging anything. Sometimes spending a little saves a lot in the long run.
What Australian Solar Panel Warranties Say
Solar panel warranties in Australia usually come with some clear-cut conditions. One of the biggest ones? You’re responsible for cleaning your panels the right way. If you use the wrong method—like a pressure washer—the warranty can be voided straight away.
Manufacturers don’t leave much room for guessing here. Most of them include cleaning instructions in the user manual, and they’re very specific about what’s safe and what’s not. High-pressure water is almost always on the “don’t” list.
Here’s where things can go wrong with warranty coverage:
- Panels damaged from pressure washing won’t be repaired or replaced under warranty
- Cracked glass caused by harsh cleaning methods is considered user error
- Dislodged wiring or broken seals from forceful water spray won’t be covered
Even if your panels are still working, any damage that affects performance or causes safety issues might be blamed on how you cleaned them.
The Clean Energy Council also recommends gentle cleaning techniques. They back the idea that using soft brushes, low-pressure hoses, or professional services is the safest way to maintain your system.
If you’re unsure, it’s worth looking up your panel’s brand name and checking their website for care guidelines. Some brands even list approved tools and cleaning agents. Following those instructions helps protect your warranty, and gives you peace of mind every time you do a clean.
Alternatives to Pressure Washing
Robotic cleaners
If your solar panels are tricky to reach or you want a hands-off solution, robotic cleaners can do the job without damaging anything.
They move slowly across the panel surface, using soft brushes and low-water cleaning systems. Most don’t use any chemicals or pressure, which makes them a safe choice for modern panels.
Some systems are even automatic and set on a schedule, which helps keep performance consistent.
Professional solar panel cleaners
For most Aussie homeowners, hiring a professional is the easiest option.
They’ve got the right tools, know the right techniques, and follow manufacturer guidelines to avoid damage.
They also know how to move safely on different types of roofs, which lowers the risk of slips or falls.
If your panels are under warranty or your roof is steep, this is probably the smartest way to go.
Rain (natural cleaning)
Rain can help, especially in areas that get regular, light showers. It can rinse off basic dust and pollen, which helps your panels stay efficient without much effort.
But rain isn’t great at removing bird droppings or built-up grime. It’s useful as a light maintenance tool, but don’t rely on it for deep cleaning.
Key Takeaway
Solar panels are an investment, and like anything that lives outside, they need a bit of care now and then. A quick clean can make a big difference in how much power they’re pumping out, but how you clean them really matters.
Pressure washers might seem handy, but they’re just not worth the risk. A cracked panel or damaged wiring can cost more than the power you’re trying to save.
Gentle cleaning is the way to go—something as simple as a soft brush and a bit of patience does the trick. And if your roof’s tricky or you’d rather not deal with it yourself, getting a professional to handle it safely makes a lot more sense.
We help people all across WA take care of their off-grid and solar setups the right way. If you’re looking for support, advice, or someone to handle the job properly, we’d love to help. You can check us out at Off Grid WA and see how we can keep your system running at its best.
Frequently Asked Questions
Can I use a hose instead of a pressure washer?
Yes, a hose is a much safer option. Use it on a gentle setting to rinse off dust or dirt. Avoid using any strong nozzles or attachments. High pressure can damage seals or glass, while a regular garden hose gets the job done without risking your panels.
How often should solar panels be cleaned in Australia?
Most panels should be cleaned once or twice a year, depending on your location. Dusty, dry areas or spots with lots of birds may need more frequent cleaning. If you notice a dip in your system’s output, that’s a good sign your panels could use a wash.
Is it worth paying for professional solar panel cleaning?
If your panels are on a steep roof or hard to reach, yes—absolutely. Professionals have the right tools and know how to clean safely without voiding your warranty. It’s a small cost compared to potential damage or injury if you try to do it yourself.
