How to Clean Solar Panels: A Comprehensive Guide
If you have ever wondered how to clean solar panels without damaging them, this guide walks you through everything step-by-step. We will cover practical solar panel cleaning tips, the best time to clean solar panels, maintenance advice, and some do’s and don’ts that might surprise you.
Solar panels work silently in the background, soaking up sunlight and lowering your power bills. But over time, just like everything placed on your rooftop, they also get dirty. Layers of dust, bird droppings, pollen, or even salty residue (if you are near the coast) can build up and reduce their performance and can cost you money.
According to Australia’s Clean Energy Regulator, as at the end of the year 2024, a total of 4.018 million solar power systems have been installed on Australian homes and small businesses. With this rapid growth comes a greater need for regular solar panel cleaning to maintain peak performance and protect your investment.
Why Solar Panel Cleaning Is Important
Let’s start with the obvious thing, dirty panels don’t perform well.
A thin film of grime can cut down efficiency by 10% to 25%, depending on where you live and how bad the build-up is. In places with little rain or lots of airborne dust (think outback or coastal areas), cleaning becomes even more important.
Think of your panels as windows to the sun. The cleaner they are, the more sunlight hits the photovoltaic cells and the more energy they generate. If you want to get the most out of your solar system, prioritize cleaning it on a regular basis and servicing it at least every 2 years by a licensed electrician.
Regular cleaning increases the life of your solar system and also keeps it safe and performs at its best. Remember, a little care goes a long way to ensuring your solar panels keep saving you money on your electricity bills for years to come.
DIY Solar Panel Cleaning vs. Hire a Professional
Solar PV panels are designed for tolerating outdoor conditions and can handle small amounts of dust or grime on them. But excessive dust, dirt and debris can block sunlight and minimize their overall efficiency. But before we discuss how to clean solar panels yourself, it’s worth knowing when to bring in the professionals.
DIY cleaning can save money to clean your panels, if you have a single story home and panels are installed on a flat roof. But it comes with a few cautions:
- Plan for safety first, safety is non-negotiable especially for rooftop system.
- You need the right equipment, like soft cleaning instruments or solar panel cleaning kits.
- You should avoid using harsh chemicals or strong detergents.
Professional solar panel cleaners, on the other hand, cost more but ensure a thorough or safe job. They use deionized water systems, telescopic poles, and sometimes even drones. They have specialized tools, purified water, and are trained to clean without voiding warranties or damaging panels. They also inspect your solar panel and inform you early if any damage arises.
So, if your roof is steep, your system is large, or you’re not confident on ladders, hire a professional. Otherwise, keep reading.
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What You’ll Need for DIY Cleaning
Here’s a simple gear checklist for safe, scratch-free cleaning:
- Soft sponge or microfiber cloth
- Telescopic pole (for reaching from the ground or a ladder)
- Bucket with lukewarm water
- Mild detergent (non-abrasive, non-chemical based)
- Squeegee for streak-free finish
- Safety harness if working at height
- Rubber-soled shoes (extra grip)
Skip the pressure washer. The force can damage seals or even crack the glass. Not worth the risk.
Best Time to Clean Solar Panels
Timing is everything and when it comes to solar maintenance, that’s doubly true.
Best Time of Day:
Early morning or late evening is the ideal time when panels are cool. Cleaning in full sun can cause water to evaporate too quickly, leaving streaks. Plus, the panels get hot, very hot if you clean them in the daytime and it’s also not great for safety or results.
Best Season:
Late autumn or early spring are ideal. You’re prepping your panels for winter use or recovering from summer dust storms and pollen buildup.
What about rain? While rain can rinse off loose dirt, it won’t remove baked-on grime or oily residues. Think of it like skipping car washes because it rained, it helps, but it’s not enough.
How to Clean Solar Panels: Step-by-Step Guide
Ready to get your hands wet? Here’s a gentle and effective DIY solar panel cleaning method that won’t damage your system.
1. Turn Off the System
Always shut down your solar system before cleaning. Check your inverter manual if you’re not sure how. This is for both your safety and to avoid electrical issues.
2. Inspect for Damage
Before touching anything, check for cracks, exposed wiring, or loose mounts. Cleaning damaged panels can worsen the problem.
3. Rinse with Water
Use a garden hose with low pressure to remove loose debris. Nozzle off, no need for force.
4. Apply Soapy Water
Mix mild detergent in lukewarm water and apply it with a sponge or cloth. Avoid scrubbing aggressively solar panels have a protective coating that can wear off.
5. Gently Scrub and Rinse
Wipe gently to remove bird droppings or sticky residues, then rinse thoroughly. Be sure no soap residue remains.
6. Dry with Squeegee
For a streak-free finish, use a rubber squeegee to remove water. Especially helpful on cooler days when panels dry slower.
7. Double-Check Your Work
Once dry, inspect again. If stubborn grime remains, repeat gently or call a professional.
When to Call a Professional For Cleaning Solar Panels?
As we discussed previously, the normal amount of dust will be easily cleaned away by you or by rain. So, in this situation there is no need to get professional cleaners in.
But, you might need to consider giving them all call if;
- You are living within a extremely polluted or near a coastal area
- You see a tough buildup on your solar panels like bird droppings
- You notice a drop in efficiency in your panels
- You feel they are physically damaged
- You have deciduous trees around your solar panels
- You are not confident getting up on your steep roof
Simple tip: To prevent you from having to climb up on a ladder to inspect the condition of your solar panels, you could have a CCTV camera installed that points at the panels.
Solar Panels Losing Power?
How Often Should You Clean Solar Panels?
There’s no one-size-fits-all answer, but here are general rules:
- Every 6 months: Standard for most residential systems
- Every 3 months: If you live near construction sites, farms, coastal areas, or dusty roads
- After major weather events: Think storms, wildfires, or heavy pollen seasons
Some smart solar systems provide performance analytics. If your output drops unexpectedly, it might be time for a clean.
Solar Panel Maintenance Guide: Beyond Cleaning
Cleaning is just one part of keeping your panels running at peak efficiency. Here’s what else you should do:
Regular Visual Inspections
Look for cracks, corrosion, or discolouration. A quick scan every few weeks can catch issues early.
Monitor Output
Keep an eye on your inverter’s daily output. Sudden dips might signal a problem beyond dirt like a faulty panel or inverter issue.
Check Wiring & Mounts
Ensure that cables are secure and mounts are stable. Animals, wind, or weather can loosen components over time.
Keep Shade Away
Trim overhanging branches or growing plants that may cast shadows on panels during peak sun hours.
Common Mistakes to Avoid
Even well-meaning DIYers sometimes make errors that shorten panel lifespan or void warranties. Avoid these:
- Using abrasive sponges – These can scratch the panel surface.
- Walking directly on panels – Pressure can cause microcracks.
- Cleaning with vinegar or ammonia – These chemicals damage coatings.
- Skipping safety precautions – Falls are more dangerous than dirty panels.
Final Thoughts: Clean Panels, Clean Energy
If you’ve invested in solar, taking care of your system is just smart maintenance. Regular cleaning not only boosts performance but also protects your long-term ROI. Whether you’re using DIY solar panel cleaning methods or calling in a pro, keeping those surfaces grime-free means more power and less stress.
So next time you see a drop in energy output, don’t just blame the clouds. Your panels might just need a bath.
Quick Solar Panel Cleaning Checklist
- Turn off the system before cleaning.
- Use soft cloths and mild soap, no pressure washers.
- Clean early morning or evening for best results.
- Avoid harsh chemicals or walking on panels.
- Clean every 3–6 months or after storms.
- Monitor performance regularly to track efficiency.
FAQs
You can do it yourself if your system is accessible and you’re comfortable with ladders and safety gear. But for steep roofs or large systems, pros are often the smarter choice.
Not really. Rain helps rinse off light dust, but it won’t remove sticky residue, bird poop, or built-up grime. Think of it like rinsing dishes without scrubbing.
If your daily energy output drops suddenly or you see visible dirt from the ground it’s likely time to clean. Some inverters even offer alerts.
Not if done correctly. Using the wrong tools or walking on panels might cause damage, but gentle cleaning with approved materials is usually fine. Check your installer’s guide to be safe.
Expect lower performance, reduced efficiency, and possibly higher bills. Long-term neglect can also cause more permanent stains or damage.