How Often Should You Clean Solar Panels

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Any homeowner with solar panels should know that regular cleanings are part of proper solar panel maintenance. If you never knew, now you know (though most solar panel installers and manufacturers make it very clear that regular maintenance is important). 

Cleaning solar panels not only helps maintain them in good order, but it also maximizes their efficiency. Solar panels are a significant investment in your home, so you always want to leverage the best return on that investment. Read on to learn more about why your solar panels need regular cleaning, as well as some tips for DIYers. 

Why Do Solar Panels Need To Be Cleaned?

This is simple science: the more sunlight passing through the transparent panel covers, the more electricity they generate. If there is dirt, dust or debris obscuring the solar panels, they will not generate as much electricity. To maintain your solar power output, you will need to clean the panels every so often. 

Doesn’t Rainfall Clean Solar Panels?

Most homeowners ask this question first, and it’s a good question to ask.  While rainfall can help remove dirt and other debris, it does not create sufficient pressure to remove debris. More importantly, it would take a significant amount of rainfall to remove more stubborn debris like tree sap and evergreen pollen. 

How Often Should My Solar Panels Be Cleaned?

The answer to this question largely depends on your geographic location, local foliage and the prevailing weather. Here are some general tips every homeowner with solar panels should observe to get you started regardless of where you live:

1. Check for Debris Weekly

Give your solar panels a once-over inspection every week. Look for leaves, dust, dirt or any other build up that may be accumulating. If it’s visually significant, it’s probably time for cleaning.

2. Do Not Depend On Rainfall To Keep Your Solar Panels Clean

Much of the debris that can collect on your solar panels may actually stick to the surface and allow other debris to collect on top of it. When it rains, the water running down the panels causes the debris to move around and collect in thicker layers towards the bottom of the solar panels. Cleaning with a hose, warm soapy water and a squeegee is the only way to ensure the panels are spotless.

4. Even washing panels annually improves efficiency

If you are concerned that investing in solar panels has just resulted in more of a home maintenance headache, don’t worry. Even cleaning your solar panels once a year is enough to improve their efficiency and maintain them in good working order. There’s no need to be up on the roof with a bucket of suds and the garden hose every other month.

How Do I Clean My Solar Panels?

The DIY crowd will find that cleaning solar panels isn’t all that different from washing a car. All you need is a garden hose, some warm soapy water or solar panel cleaning solution, and a sponge and squeegee window cleaning tool. Here are some tips for handling the cleaning yourself.

1. Refer To Manufacturer Cleaning Instructions

Always read what the manufacturer recommends for cleaning procedures. Using the wrong cleaning solution or failing to follow protocols could result in damaging your panels or personal injury. Start by reading manufacturer recommendations, and then move on from there. 

2. Clean Panels In The Early Morning Or Late At Night

Solar panels can heat up significantly during the day as part of their normal function. This means it is extremely important to only clean panels early in the morning or late in the evening before/after they heat up during the day. Cleaning during these times helps prevent injury, and it’s significantly more comfortable to clean on a rooftop at these times of day, too.

Also Read: How Hot Do Solar Panels Get?

3. Use A Garden Hose to Spray Down Panels

Pressure washing isn’t necessary if you have good water pressure and a sufficiently long hose. Spraying down your panels before and after cleaning with soap/solution helps loosen any debris and ensure it’s spotless. 

4. Use Warm, Soapy Water Or Solar Panel Cleaning Solution

It’s important to use an appropriate detergent, soap or solar panel cleaning solution. Partially cleaning solar panels just means they will need to be cleaned again sooner. DIY solar panel cleaners should also consider using a window cleaning tool to apply soapy water and squeegee it away. 

This ensures you thoroughly remove all dirty water from the surface of your solar panels before hosing them down for the final rinse. A window cleaning tool also has a better chance of breaking up stubborn dirt, grime and debris than simply using the hose and soap water. 


All in all, most homeowners only need to clean their solar panels between once and twice a year. Checking your panels once a week is a great way to ensure that debris and dirt aren’t building up faster than anticipated. If you aren’t a big fan of DIY projects, you can also contract locally to have your solar panels cleaned as often as you believe it necessary. Remember, cleaning solar panels is all about maximizing their efficiency and power generation. That being said, your solar panels don’t necessarily need cleaning all that often. Use your best judgment, and if they look dirty to you, clean them or get them cleaned.

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