How to Clean Solar Panels with Windex (Do This!)

Picture this. You’re looking at your new solar panels and wondering, “how much money are these beauties going to save me?”. Suddenly a bird flies over and leaves a #2 care package just for you.

Can’t wait to get that messy annoyance off your panels? In this post, you’ll be surprised to learn how easily and effectively Windex cleans solar panels.

Here are some of the key points we’ll cover, plus some additional tips you’ll need for clean solar panels.

  1. How to Clean Solar Panels with Windex
  2. Why Clean Your Panels With Windex?
  3. Windex Cleaning Precautions
  4. What are the Benefits of Clean Panels?
  5. Are There Different Cleaning Methods?
Dirt and Dust Covered Solar Panel

1.How to Clean Solar Panels with Windex

One of the most obvious questions is, can you use Windex to clean solar panels? Yes, you can!

Most of the time, rainwater and mother nature can take care of most of the cleaning for you. Sometimes, however, you must clean off certain kinds of dirt and grime on your panels to increase solar power effectiveness.

For example, California solar owners experience smog and dust from wildfires that affect their panels’ effectiveness. Bird droppings are another element that can affect power.

Using Windex to Clean Your Panels – Step by Step

  • Do not clean panels on a sunny day. Make sure it’s cloudy or early morning when you clean your panels. Solar panels get VERY hot during the daytime.
  • Turn off your solar system before cleaning. Also, disconnect any solar connections to a swimming pool or water source, as well as the grid electricity (if you’re on an on-grid system).
  • Use Windex Outdoor with the adjustable hose module and a scalable ladder. This product is a mild cleaner and easy to use. It’s also non-toxic so that any runoff won’t harm your plants.
  • Use the rinse setting and spray down the top of your panels. Make sure and remove all the grime and any droppings left on the panels.
  • Switch the setting to soap and apply an even coat to the entire solar structure. Let it sit for 15 minutes. No longer than that as air bubbles can start to form.

Why Clean Your Panels With Windex?

Windex has an excellent reputation as an all-purpose cleaner, and for a good reason. If you plan on cleaning your panels with just soap and water, you’re missing out on the cleaning agents Windex provides to remove burned-on grime.

It’s cheaper than hiring a professional. Companies that clean solar panels can charge a steep fee while doing it yourself requires minimal effort and equipment.

Windex leaves a streak-free appearance. Soapy water and hose cleaning can leave air bubbles and scratch the panels.

Windex has three specially formulated cleaning ingredients that make it ideal for solar panel cleaning

  • Ammonia The primary ingredient, ammonia, acidifies grease, smoke stains, pollen, and bird droppings. The concentration used is also mild enough so it won’t harm plants.
  • Isopropanolamine Isopropanolamine washes away the soapy scum that’s left behind. Isopropanolamine counteracts soap residue that ammonia leaves behind while maintaining a basic pH.
  • Hexoxyethanol Hexoxyethanol is a component of ethanol and is similar in structure. Like an alcohol-based cleaner, it prevents the dirt from combining with the other ingredients from becoming mud.

Windex Cleaning Precautions

Although there is no worry about encountering electrical components, as the outer cover protects them, there are specific measures you need to be aware of when using Windex to clean your panels.

Personal Protection
Although the chemicals in Windex are harmless in small amounts, you should take care to limit exposure to your skin and eyes. Gloves and safety glasses are recommended.

Don’t Use Windex with Plastic Coatings
While Windex works excellent with most solar panels, there are exceptions. Most solar systems are glass, which makes Windex ideal. However, some solar manufacturers layer their solar glass with plastic covers to protect it from dirt and pollen.

Using Windex on plastic surfaces can warp and damage the top layer, seriously affecting the panel’s output and lifespan. Make sure your solar structure’s outer layer is glass before applying any Windex.

What are the Benefits of Clean Solar Panels?

Clean solar panels are essential for effectiveness. Grime on the solar panels prevents the entry of light, which means up to 10% less energy production.

How Often Should I Clean Them?

Experts in the industry recommend one every six months. Early autumn and late spring are generally the best times to clean.

However, if you live in an area with a tremendous amount of smog or other adverse conditions, you may need to clean more often.

Are There Different Cleaning Methods for Solar?

Windex is not the only way to clean your solar panels. There are other ways to clean your solar panels that are also effective.

Specific home installations make it impractical and potentially dangerous to clean, as well.

Soap and Water

While not as effective as Windex, good old-fashioned soap and water can be an effective cleaner for your solar panel. The only con, of course, is that some soap can leave behind soapy buildup.

If you don’t get a tremendous amount of dirt and grime, you may not need to clean as often as someone in a more congested area.

If you’re one of those solar homeowners, soap and water can be an effective cleaning solution.

Cleaning Solar Panels with Vinegar

Vinegar is a natural cleaning product and is excellent for cleaning glass solar panels. Mix 1/4 cup vinegar with 1/2 teaspoon non-abrasive soap (such as Dawn) with two cups of water to form your cleaning agent.

Pour the solution into a spray bottle attached to a hose and use it just as you would with the Windex outdoor solution.

When to Call a Professional for Solar Panel Cleaning

There can be various reasons it may be impractical or inconvenient to clean your solar system. Here are listed some reasons why a professional might be better suited to do the cleaning for you.

Large Commercial Systems
For extensive solar systems, such as commercial or solar farms, it’s simply impractical to clean yourself.

Age or Physical Limitations
As we all age, there are certain things we shouldn’t do. Most solar systems are on a roof and require a ladder to perform maintenance – never a good idea if you have limited mobility.

Time and Money
For some people, it’s just a matter of convenience to have a professional do the job for you. Although an experienced cleaner will charge a high fee, they will most likely do a great job.

What Should I NOT Use to Clean My Solar Panels?

Hard water
Hard water is water that has high levels of magnesium and calcium, like most tap water. Harmless to humans, hard water can leave mineral deposits that reduce solar output and can even destroy the panels with prolonged use.

You can have your water tested for hardness by sending a sample to a local lab for a small fee. Other options are installing a water softener or reverse osmosis system.

Power Washer
Powerwashing can be an attractive choice, especially if there’s a lot of buildup on your panels. Their pressure and high reach make cleaning large panel sections easier, but you run the risk of damaging them, as well.

Scrubbing with an Abrasive Tool
Scrubbing, especially with an abrasive cleaning tool, is the worst cleaning method for solar panels. This can result in scratches, which can impact the ability of your panels to capture light adequately.

Avoid all scrubbers and steel wool sponges to prevent surface scratches. The best thing to use is a regular garden hose and Windex Outdoor. If you feel you need to brush, gently use a soft cloth or brush.

Hard and Abrasive Chemicals
The cleaner, the better, right? Yes and no. Effectively cleaning your panels is possible with non-abrasive tools and chemicals.

Some of the pollen and dirt can be tough, but, by all means, do not use abrasive ingredients to clean your panels. The chemicals found in abrasive soaps can damage the panels, which causes less power output.


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Elliot has 20+ years of experience in renewable technology, from conservation to efficient living. His passion is to help others achieve independent off-grid living.

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