Updated: Apr 12
When you had your solar panel system installed, you probably asked the installer several questions. One of them should have been about what you need to know about cleaning them.
Of course, they need to be cleaned, but how?
Do I Need to Clean Solar Panels?
The top way you can maximize the energy production of your panels is by keeping them clean. If you give your panels a good examination and find that they are dust-covered or grimy they need to be cleaned. If they aren’t clean, your panels aren’t saving you as much money as they could.
Dust and pollen build up on the smooth surface, leaving grime behind that reduce the energy production of the panels. A small amount of grime could cause as much as a 5% decrease in output; a very dirty panel could be losing as much as 20% of its potential output. If you live in a region with a lot of dust or very little rainfall, you need to examine your panels more often to make sure they remain clean and efficient.
Is It Time to Clean Them?
You need to plan ahead to make sure you can clean them. Clean the panels at least once a year but, if you live in a region where there is more dust or soot, a second cleaning may be needed. More pollution is carried by winds in the winter, so schedule your annual panel cleaning in the spring. If your location is unusually subject to dust and dirt collecting on your panels, then schedule a second cleaning in the fall.
The panels design helps them remain clean if enough water is present. If you live in a region that has plenty of rainfall, the panels won’t need to be cleaned as frequently.
How Do I Clean Solar Panels?
You can clean the panels yourself or hire a professional service to do the job. If you leased the panels, then you aren’t responsible for maintaining them. The leasing company, on the other hand, may have a different definition of what constitutes clean. They may not consider cleaning as a part of the contract, even though dirt and grime reduce their product’s effectiveness and increase your energy costs. If your contract includes cleaning, call them and schedule a cleaning.
You may think cleaning the panels will be a difficult task. However, if you follow these steps, you’ll have an easy time. Remember to practice safety. If possible do the cleaning from the ground; if not, anchor yourself and have help on hand.
You will need the following materials to get the job done:
A tall ladder (it should be tall enough that the top end of the ladder extends above the roof enough for you to step off onto the roof while your hands are still on the ladder)
Soft bristle brush (car cleaning brushes are perfect)
Foam or rubber squeegee
An extender handle for the brush and squeegee
Wide-bottom bucket (make sure it can sit safely on your roof if you clean from up there)
Low-pressure setting water hose (shower setting is perfect)
Mild liquid soap
Shoes with grip
Make sure your hose can reach from your water source. You can get special cleaning tools made for cleaning solar panels, but they aren’t always necessary. You may want to use deionized water but it isn’t a requirement. You will damage your panels if you use abrasive scrubbing cleaners or metal scourers. Scratches reduce panel efficiency permanently.
Check the weather for your cleaning day, looking at wind speeds and chance for precipitation. Be mindful of the heat index, as you wouldn’t want to be up on the roof when the temperature exceeds 100 degrees.
If you cannot clean the panels from the ground, make sure you have the equipment necessary to keep you safe. Anchor yourself with rope to something on the opposite side of the house that you are cleaning. You can use a sturdy tree, an actual fence post that is sunk into the ground, or the actual frame of your car. Tie the rope around your waist securely and have a spotter on the ground who can render aid or get help, if necessary.
Here are the steps we recommend for cleaning your panels
Spray the panels with your hose, aiming for the corners as that’s where most of the grime builds up. Be prepared to scrub if this step doesn’t clear all the dirt off.
Using your soft bristle brush, wipe down each panel. Attach the extender handle if you are reaching for panels farther away.
Squeegee your panels until dry, particularly if you have hard water. Any mineral residue left on the panel reduces efficiency.
Do not clean the wiring beneath the panel. Any dust or dirt located there will not impact your electricity production and you risk dislodging important components if you do this.
Remember to check your panels regularly for any damage or sudden increase in grime. The solar panels provide great savings, but only if they run efficiently. Keep them clean to make sure you are realizing the maximum return on your investment.