Your solar panels are bound to get dirty over time. It doesn’t matter whether its dust, smog or even puffs of snow – you have to get it off. Luckily, the panels are made of glass or an acrylic surface that isn’t hard to clean.
The best way to clean solar panels is by splashing them with soaping water and using a sponge to rub them down before hosing off the soapsuds with clean water. If you don’t have a hose, you can still use a bucket of clean water to clear everything after the soft scrubbing.
Despite the efficiency and simplicity of this basic procedure, there are times when some stains or dirt sticks. Read on to find other tricks you should try if your solar panels are still dirty after using simple soap, a non-abrasive sponge and water.
Do You Really Have to Clean Your Solar Panels?
Most people rarely have to clean their solar panels. A bit of dust shouldn’t bother you especially if your followed my home or RV solar array sizing guide. The rain will more often than not take care of it. Research has shown that a bit of dust doesn’t lower your solar array’s performance as the light will still go through.
Despite this, you should still consider washing your panels if:
- You are in a dry dusty area that rarely receives rain
- Leaves and other larger pieces of debris fall on your panels
- Your array is on dusty farmland or next to a road
- There is a dusty construction or mining site nearby
- Birds like roosting on your array leaving droppings all over the panels
- For some reason, there is mold, mildew, moss, or other solid residue on the panels that rain can’t knock off
At the end of the day, you will be the perfect judge on whether you should or shouldn’t clean. Any huge piles of debris that shade the panels or thick dust that make the solar cells barely visible should call for some cleaning action.
If you want to clean your panels, start off early in the morning when they are still cold or late in the evening when the sun is setting. Hot panels will dry up first leaving them streaked and soap stained. A gloomy day will also be an awesome time to clean your panels
Does Cleaning Your Solar Panels Make a Difference?
Cleaning obscured panels can have a significant impact on how much power your array generates. Reports show that dust can reduce performance by up to five percent.
Leaves, bird droppings, and other types of debris can have a bigger impact. Some people report up to 80 percent of energy production improvements if they remove such heavy debris from their panels. This could reduce how often you have to run your backup generator.
If you have a large array, any simple form of cleaning even when it doesn’t rain in a month or two will make a difference. It is a good way to avoid soiling and keep your panels working as efficiently as possible.
Step By Step Guide to Cleaning Your Solar Panels
You can either clean your own panels or hire a professional to do it. Panels installed on steeply sloping roofs or that are part of a huge array are best left to professionals. RV installations, on-ground arrays, and panels on gently sloping roofs are fair DIY games.
If you are hiring someone to do it, you should consider doing it less often since the cost might outweigh the gains. In such cases, just wait for the maintenance team to take care of the dirt and grime when they drop by once per year to check on the system
DIY cleaning will cost you next to nothing and could be a great way to pass a weekend. Here is how to do it:
- A bucket with soapy water (use dish washing soap)
- A soft non-abrasive sponge or foam
- A very soft-bristled broom and an extension pole
- A garden hose
- Use the hose to wet the panel you will be working on. Ensure that you use a gentle stream of water as high pressure could harm the panels
- Dip the sponge into the soapy water and use it to gently rub the dust and loose dirt off the panels
- Use the hose again to rinse the soapy water and all the loose dirt. Keep the stream of water until the panel is clean of all the soapy water
- Use the soft-bristled broom or brush in place of the sponge to clean hard to reach panels as walking on a panel to reach them might lead to breakage
- When dealing with bird droppings, you might have to douse the panels with soapy water and letting them soak for a while before trying to use a brush to dislodge the grime
How Often Should Solar Panels Be Cleaned?
People living in very dusty areas can clean twice a year. Otherwise, if you inspect and maintain the array once a year as you should, make cleaning part of your maintenance routine.
Under ideal conditions, you should never worry about cleaning your panels. The gains from clearing a thin film of dust on a residential or RV array is not worth the pain – unless you drove over a dusty trail or your area was hit by a dust storm and you have observed over 10% drops in energy performance and can no longer top up your battery bank.
If you are dealing with leaves or bird droppings, it would be wiser to find a way to prevent the leaves and bird droppings from accumulating in the first place. Leaves shouldn’t be much of a problem unless your array is under a tree – which would be vain. Installing bird deterrent systems will keep birds from roosting hence doing away with the bird droppings problem.
Can I Use Windex on Solar Panels?
Windex is a bleaching agent that is too abrasive for your solar panel’s top film. Using it to clean your panels could be detrimental and harmful to the anti-reflective or hydrophobic layer. Windex wears out the top protective layer on the panels and will gradually lower your system’s life expectancy.
Can I Use Vinegar on Solar Panels?
No. Don’t Use vinegar on your panels. It might sound like a good idea for tough stains but it is not necessary. Solar panel surfaces are slippery and easy to clean. Any stains that won’t clear with gentle scrubbing using soapy water will have already damaged your panel.
If you want to use it to clean the panel frame, you could as long as you keep it off the glass. However, such an effort is purely aesthetic and won’t have positive impact on power generation. You can try dedicated aluminum cleaners like the Cameo Aluminum cleaners for better results if you are keen on aesthetics.
Do I Need to Turn off Solar Panels to Clean?
You cannot turn off a solar panel but you can disconnect it from the rest of the system at the combiner box.
It’s good practice to turn off your solar array before working on it. Go to the combiner box and flip the circuit breakers to off position or remove any fuses to disconnect as much of the array from each other and to your charge controller.
While each panel will still be producing electricity on its own, the voltage and amperage will be lower hence reducing the possibility of severe damage should something go wrong.
Can You Walk on solar Panels When Cleaning?
No. You cannot walk on solar panels. Most hard and flexible solar panels are designed to absorb the sun and have mild impact from hailstones. Your weight might either break them or cause micro-cracks that will accelerate cell degradation. Don’t step, lean, or even kneel on a panel for support when cleaning and maintaining your array.
Cleaning solar panels should only be a priority if you live in a very dusty place and it hasn’t rained in a while. Sometimes, splashing them with water to simulate rain should be enough. Wait until the dust has created almost 5% dip in performance otherwise the effort won’t be worth the gain unless you don’t expect rain any time soon.