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The Best Ways To Clean Lichen & Algae from Solar Panels?

algae growth on solar panels

If you really want to get the most out of your solar panels, you need to keep them clean, not only from everyday dirt but also from lichen & algae growth.

Growth of lichen & algae on your solar panels will primarily occur when there’s constant rainfall and increased shading around where you’ve installed your PV modules.



To safely clean lichen & algae off your solar panels, you need to use something gentle yet effective such as dishwashing liquid, vinegar, and Isopropyl Alcohol (IPA).

We understand that cleaning lichen & algae is not as straightforward as cleaning ordinary dirt off your solar panels. So, we’ve created this guide to show you how to use the 3 products above to shine your solar panels off lichen and algae effectively.

How does Lichen & Algae Build up on your Solar Panels?

When conditions are supportive (extremely moist environment), fungi and algae develop on the surface of the solar panels.

If a fungus surrounds a colony of an alga, a lichen is formed.

Lichens are complex organisms characterized by a brown, yellow, silver, or gray color. Sometimes the green color of the alga forming the lichen will show up, especially during wet conditions.

Lichens have no leaves, stem, or roots but can still photosynthesize through the chloroplast of the algae, so they’ll spread on the surface of the solar panels, although slowly.

They can even absorb water without all these essential parts!

Once a combination of algae and lichens has got hold of your solar panels, it can be a bit of a task to remove them. The organisms will start out at the edges where the glass meets the Aluminum frame then spread to other parts.

But worry out, you are about to learn how to deal with the problem.

Lichen and algae under your solar panels

While it’s still possible to find algae to grow under your solar panels, the installation configuration of the modules on your roof makes it almost impossible for the spread to occur.

Moreover, the sun hits the panels from the top, so that’s where you need to put your focus.

Does Bird Poop contribute to the build-up of lichen and algae?

Definitely! Bird Poop is loaded with nitrogen which is a growth sauce for lichen. This is why you need to adopt an effective method of frequently cleaning your solar panels.

How does Lichen & Algae affect Solar Panels?

They make solar panels, and the entire rooftop an eyesore.

Solar panels are never meant to be an aesthetic feature, but no one would want an unsightly rooftop. As the coverage of these microorganisms increases, the more awful-looking your rooftop will be.

Leads to ineffective solar insolation due to shading.

If there’s a layer of algae and lichen on your solar panels, the sunlight that passes through will be limited.

With reduced solar insolation, comes damage to the solar panels’ efficiency and performance. This is the last thing you’d want from your PV module.

Keep in mind that the more lichen and algae spread on your solar panels, the more power you’ll be losing.

Creates hot spots on your solar panels.

This is another big problem that can be detrimental to your PV modules. Lichen and algae will spread in small sections, leaving spaces in between open to high temperatures.

This eventually leads to localized degradation that’ll hit hard on the system’s output in the long run.

Can damage the roof too.

Lichen and algae are not only harmful to your PV modules but also to your roof.

It only takes a matter of time for the microorganisms to set in on your rooftop and cause even more damage.

If you care about the look and integrity of your roof, you should not let these microorganisms even build up in the first place.

Benefits of Cleaning Lichen & Algae from Solar Panels

Increased efficiency

You guessed it right. The biggest benefit of cleaning algae and lichen off your solar panels is it revamps the system’s efficiency.

Do you feel like your module is operating way below how you expect it to perform? It would help if you gave it a nice little clean to eliminate all the accumulated lichen and algae.

Unless you have really old solar panels, you should see a change in the system’s output on cleaning the lichen and algae build-up.

Boosted energy savings

Lichen/algae solar panel cleaning is crucial if cutting your energy bill was your reason behind this brilliant investment.

With lichen all over your solar panels, your energy output will be negligible, the same case as the savings you were looking to achieve.

Improved longevity

Solar investment is a big one, and no one would want tiny organisms like lichens to downgrade everything and tear down the stake.

According to experts, frequently cleaned solar panels will clock their expected lifespan- 25-30 years.

If you want to reap these benefits, you need to be wide awake, moving forward.

How to Prepare the 3 Cleaning Solutions for your Lichen/Algae-Laden Solar Panels?

As highlighted in the beginning, you’ll need these 3 cleaning solutions to get lichen and algae entirely off your solar panels:

Cleaning solution 1: Pure or deionized water+Mild dishwashing liquid

Fill a bucket with the pure water, then add a ¼ cup of the mild dishwashing liquid. Stir up the mixture to get ‘cleaning solution 1’ ready.

Tip to consider: Don’t use hard water as the minerals can damage your solar panels.

Cleaning solution 2: Deionized water + Vinegar

Cleaning solar panels with Vinegar is not only effective but safe for your solar panels.

Vinegar will kill the lichen/algae up to the last spore.

Making this cleaning solution is as simple as mixing two cups of deionized water with ¼ cup of Vinegar. Put the mixture in a spray bottle, give it a nice mix, and you’re ready to go.

Tip to consider: Avoid using concentrated Vinegar as it can damage your solar panels.

Cleaning solution 3: Isopropyl Alcohol (IPA)

Isopropyl Alcohol (IPA), or what we conventionally call rubbing alcohol, is the third cleaning solution that we’ll use to shine the solar panels thoroughly.

IPA will not only kill lichen & algae and eliminate the spots they leave on your solar panels, but it’ll also disinfect the panels preventing subsequent growth.

We’ll use this solution as it is. After the primary cleaning is done, a small sponge or dry cloth will be needed to apply it to the stain sections.

Tip to consider: Use the pharmaceutical grade IPA to ensure that you’re not transferring unsafe components to your solar panels.

The Process of Cleaning Lichen & Algae from Solar Panels

Before we get into the process, I have to mention this:

It’s only recommended to clean your solar panels if they’re easy to access, say with a ladder. Otherwise, if it’ll call for something like scaffolding to access them, then it would only make sense to leave the work to a professional.

Now let’s get started with the cleaning process:

1. Switch off the system for safe cleaning. You can do this from the inverter (following manufacturer’s instructions) or the main switch (for AC systems)

2. Set up your access, wear your gloves and get all cleaning tools plus the 3 cleaning solutions up to the rooftop

3. Start by brushing off any debris and removing any algae & lichen that’s not firmly bound on the solar panels.

4. Water down your solar panels with pure water using a normal pressure hose

5. Dip your long-handled soft cloth, non-abrasive brush, or soft brush into cleaning solution 1.

6. Work your way around the entire surface of the solar panels with the cleaning product until the last cell is covered.

7. Gently scrub all the lichen until everything is lifted. If you encounter lichen that’s hard to clean off, you just have to be a little patient for it to wet and loosen up. Please avoid hard scrubbing your solar panels as you can damage them in the process.

8. Rinse off the solar panels with clean deionized water. (At this point, you should be done getting most if not all the lichen and algae off your solar panels)

9. Use solution 2 (the diluted vinegar solution) to round up the lichen killing process. Spray the vinegar solution on the solar panels, one at a time, giving each a nice rubbing.

10. Squeegee-dry the solar panels, then leave them to air dry before proceeding to this next step- (removing any stubborn stains left after the main cleaning process).

11. Spray just a small amount of solution 3 (IPA solution) on the stained section and rub the area to remove the spots. As the rubbing alcohol evaporates, it should remove the stains and carry all the marks with it.

And Voila! You have your solar panels all clean and shining and ready to produce the juice you need to power your devices!

Who should clean lichen and & algae from your solar panels?

As seen above, this can be a DIY if only you have the right equipment and tools to access the solar panels and do the actual manual cleaning.

So definitely, if it’s not a DIY, you need to hunt for a reliable solar panel cleaning expert in your area.

All in all, at least you have an idea of what a professional solar cleaner will be doing if you hire one to clean your solar panels.

A point to note: Professional solar cleaners may come in with specialty chemicals to clean lichen and algae from your solar panels. In such an instance, scrutinize it and understand if it’s right for your module before giving them the go-ahead to do the cleaning.

How to Prevent Lichen & Algae Buildup on Solar Panels?

Frequently clean your solar panels

This is the only sure and effective way to prevent not only lichen and algae from building up on your solar panels but also dirt and grime.

Depending on where you live, you should clean your solar panels every 3-6 months.

Trim trees around your establishment

This eliminates the shading problem, thus suppressing the growth conditions of lichen and algae.

Oak trees are especially notorious for supporting lichen growth, so they should not be anywhere close to your rooftop.

Emerging innovations to keep solar panels clean and efficient

Dirt and moisture repellant films

These are installed on the surface of the solar panels to repel dust particles and moisture. You should consider installing these films as they’ll make maintaining solar panels effortless for you.

Weight sensor/ electrostatic precipitator

You don’t have to keep inspecting your solar panels for dirt and grime all by yourself. These automatic tools can be integrated within the system to help with the cleaning process, thus preventing lichen and algae from thriving.

The earlier you embrace these emerging innovations, the better- they’ll make your system highly efficient and almost maintenance-free.

According to a Jordan University of Science and Technology test study, robotic solar panels cleaning is practical and has the potential to eliminate problems tied to conventional cleaning methods.

Can I use hot water to kill lichen and algae on my solar panels?

Hot water can kill lichen and algae, but it’s not the best thing to use on solar panels. Even professional cleaners just use cold, deionized water, and it does the job.

Is baking soda a nice agent to remove lichen and algae from my solar panels?

Baking soda may work for plastic solar panels, but for glass solar panels, you should stick to pure water, dishwashing liquid, Vinegar, or Isopropyl Alcohol to remove solar panels lichen and algae.

What is the best lichen and algae remover from solar panels?

Deionized or pure water is the best lichen and algae remover from solar panels. You can always add dishwashing liquid, Vinegar, or IPA to the mix if you’re dealing with a more stubborn growth.

It’s now a Breeze to Clean Lichen and Algae from Solar Panels

Lichen and algae buildup on solar panels can be messy, but hopefully, we offered a solution for the problem. And it’s not all about the manufacturer’s advice- sometimes it calls for common sense.

In fact, you’ll hardly find information regarding cleaning lichen & algae from solar panels on the manufacturer’s instructions.

Cleaning algae and lichen off solar panels are typically what you’d do for normal glass, but now keeping in mind that the upper surface is delicate.

With this 3-solutions cleaning hack, you should clean just about any kind of lichen & algae that are building up on your solar panels.

Once you’ve learned how to keep your solar panels clean, you’ve nothing less to enjoy but increased system efficiency. Isn’t this your goal as every solar power consumer?