If you’ve invested in solar panels, you already know they’re a great way to save on electricity bills and reduce your carbon footprint. But like anything that lives outside, solar panels can get dirty, dust, bird droppings, leaves, and even pollen can build up over time. And when that happens, your panels can’t absorb sunlight as well, which means they won’t work as efficiently.
That’s why learning how to clean solar panels properly, without damaging them is so important. The good news? Cleaning solar panels is easier than you might think. You just need to know what to use, what to avoid, and how often to do it.
Let’s break it all down in this simple, step-by-step guide.
Why Clean Solar Panels at All?
You might be wondering: do solar panels even need cleaning? Won’t the rain take care of that?
Well, rain does help, but not completely. According to the National Renewable Energy Laboratory (NREL), dirty solar panels can lose up to 25% of their energy output in some cases. That’s a pretty big drop, especially if you rely heavily on solar for your energy needs.
Here are a few common things that reduce panel performance:
- Dust and dirt from nearby roads or construction
- Bird droppings (rain doesn’t wash these off easily)
- Leaves or pollen that sit on the surface
- Water spots from hard water
Keeping your panels clean helps them perform better and last longer. It’s like giving your car a tune-up but much simpler.
How Often Should You Clean Solar Panels?
This depends on where you live. If you’re in a dry, dusty area or near trees where birds like to hang out, you might need to clean your panels every 3 to 6 months. In cleaner, rainy areas, once a year might be enough.
Tip: Check your system’s output regularly. If you notice a drop in energy production that can’t be explained by weather, your panels might just need a cleaning.
What You’ll Need
Before you learn how to clean solar panels, gather your supplies. You don’t need anything fancy or expensive.
Here’s a basic list:
- A soft brush or sponge with a long handle
- A bucket of lukewarm water (no hot water)
- Mild soap or dishwashing liquid (non-abrasive)
- A soft cloth or squeegee
- Garden hose with a gentle spray nozzle
- Optional: safety gear (if your panels are on the roof)
Avoid:
- Pressure washers
- Harsh chemicals or bleach
- Scrub brushes or steel wool
- Abrasive pads
These can damage the anti-reflective coating on your panels, which would reduce efficiency.
How to Clean Solar Panels (Step-by-Step)
Step 1: Turn Off the System
Before doing anything, turn off your solar panel system. Check your inverter and any other instructions provided by the manufacturer. This is important for your safety.
Step 2: Check the Weather
Pick a cool, overcast morning or a day with mild temperatures. Cleaning in direct sunlight can cause water to evaporate too quickly, leaving streaks and spots. Plus, the panels can get hot.
Step 3: Remove Loose Debris
Use a soft broom or leaf blower to gently remove any leaves, branches, or dry dust. Do this before adding water to avoid making mud.
Step 4: Spray With Water
Use your garden hose with a gentle spray to rinse the panels. This helps remove most of the loose dirt. Don’t use a pressure washer, it could crack the glass or damage the frame.
Step 5: Wash With Soapy Water
Fill a bucket with lukewarm water and a few drops of mild dish soap. Use a soft sponge or brush with an extendable handle to gently scrub the panels. Work in small sections.
Be careful not to step on the panels, especially if you’re cleaning a rooftop system.
Step 6: Rinse Again
ls with clean water to remove any soap residue.
Step 7: Let Them Air Dry
Most of the time, air drying is just fine. But if you have hard water or want a spotless finish, wipe the panels with a soft microfiber cloth or squeegee.
What If Your Panels Are on the Roof?
If your panels are difficult to reach or on a steep roof, don’t risk your safety. Instead:
- Use an extension pole for light cleaning from the ground.
- Hire a professional solar panel cleaning service. They’re trained, have the right equipment, and know how to clean solar panels safely.
Things to Avoid When Cleaning
To keep your panels safe, don’t:
- Use high-pressure washers
- Clean with vinegar, bleach, or other harsh chemicals
- Scrub with abrasive tools
- Clean during the hottest part of the day
- Walk on the panels (ever)
Does Cleaning Solar Panels Void the Warranty?
Not if you do it right. Most manufacturers encourage gentle cleaning and provide guidelines in the user manual. However, if you damage the panels while cleaning, say, by using a pressure washer or stepping on them, you might void the warranty.
Always check your warranty terms first, and when in doubt, contact the installer or manufacturer.
Monitoring Panel Performance After Cleaning
After cleaning, it’s a good idea to monitor your system’s output for the next few days. You’ll likely notice a boost in performance, especially if your panels were heavily soiled.
Some solar systems have monitoring apps that show you daily output. If yours doesn’t, consider installing one, or keep a simple log of your monthly electricity production.
Final Thoughts
Learning how to clean solar panels is a simple but important part of taking care of your solar energy system. With just a little effort every few months, you can keep your panels working at their best and make sure your investment pays off over time.
Whether you decide to clean them yourself or hire a pro, the key is to be gentle, stay safe, and clean regularly.