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Is Windex good to clean solar panels?

solar panel cleaning windex

Despite the inherent fragility of a solar panel, the cleaning and maintenance of most commercial products is a simple matter.

In fact, most solar installations do not require any amount of cleaning, due to rainwater washing away dust and dirt.

Over time, however, cleaning may become necessary due to bird droppings and accumulated grime. In such circumstances, Windex is an effective way of cleaning your solar panels, so long as you take extra precautions.

Why Windex Works as a Solar Panel Cleaning Agent?

Windex is an inexpensive glass cleaner product that leaves behind a few streaks and smudges. Thanks to its clean application and removal, Windex may be ideal for keeping a glass-covered solar array clean and operating at maximum efficiency.

Common cleaning techniques include splashes of soapy water and simple hose rinsing, but these may fail to remove baked-on blockages. Windex utilizes a mixture of several cleaning agents to remove the toughest problems.

Ammonium Hydroxide

Ammonium hydroxide, commonly known as ammonia, is one of the most familiar cleaning chemicals for many households.

Ammonia has long been used without any other additives as a cleaning agent for many different surfaces. While it has a notoriously strong smell that can outlast other fragrances, you probably would not notice this on an outdoor solar panel.

With a pKa value of 13.7, ammonium hydroxide is an exceptionally basic compound that directly counteracts the acidic composition of bird droppings, grease, pollen, some smoke residues, and other common biological contaminants.

Since this powerful cleaning agent is simple and inexpensive, it features prominently in all varieties of Windex. Concentrations are still low enough, however, to prevent any potential safety concerns.


Isopropanolamine is a situational but important ingredient of Windex. While ammonium hydroxide is effective at cleaning most debris, it struggles to mop up compounds on the more basic end of the spectrum, such as soap scum.

If you have washed your solar panels with soap before, this may cause problems with pure ammonia cleaning products.

An acidic cleaning agent would target these materials but nullify many of the cleaning properties present in ammonium hydroxide. Isopropanolamine solves this problem by directly counteracting soap scum and similar contaminants while maintaining a basic pH.

Together, isopropanolamine and ammonia can target any buildup of material on your solar panels.


The final component of the Windex trio of cleaning agents is 2-hexoxyethanol.

Despite its imposing name, 2-hexoxyethanol is chemically similar to ethanol, a common household disinfectant and the alcoholic component of liquor. As a surfactant, its role in Windex is to prevent the water in the solution from combining with dirt and debris.

Due to the surface tension and magnetic properties of water, it is harder to remove mud from a floor than dry dirt; on the molecular level, 2-hexoxyethanol essentially prevents dirt from becoming mud.

This organic compound is also comparable to the fats that make up many types of soap, and thus has cleaning abilities of its own.

Precautions to Take When Cleaning Solar Panels with Windex

Despite the weather-resistant shielding of your solar panels, you do need to take several precautions when using Windex to clean them.

Some of the most efficient cleaning methods are also unfortunately some of the most damaging. Avoid these mistakes to keep your solar array in pristine condition.

Avoid Rough Scrubbers

There is nothing worse you can do with your solar array than scrubbing with a rough cleaning tool.

Although dirt and debris can decrease the efficiency of your solar panels, the impact on performance pales in comparison to the consequences of a scratched-up surface.

Solar panel glass is thin and delicate to allow light to pass through unimpeded, and will not resist the same sorts of materials that your car’s windshield can.

Avoid steel wool, scrubbing sponges, and even “no scratch” scrubbers to prevent all damage. The best tool you can use is a soft sponge, a clean rag, or a mop.

Verify the Materials in your Solar Array

Windex cannot be used on surfaces with certain types of finishes, including plastic. Most home solar systems are shielded only with bare glass, on which Windex may be safely used.

However, a minority of solar panel products come with a layer of clear plastic covering the glass, designed to protect that layer against debris.

If you use Windex on a solar panel like this, you run the risk of warping and discoloring the topmost layer, significantly affecting both the durability and efficiency of your array.

Before applying any Windex to your solar array, make sure that the topmost layer is glass and not plastic.

Personal Safety Precautions

While the ingredients of Windex are not harmful in small amounts, you should still attempt to limit your skin and eye exposure to them.

Wear gloves when cleaning your solar system and wash your eyes thoroughly if you splash any cleaning agents in them.

Alternatives to Windex

Windex is not the only option available if you need to clean your solar panels. Other cleaning agents and techniques offer different pros and cons that may be worth investigating.

Depending on the size and location of your solar array, some of these may be better options.

Hose Rinsing

Most solar panel maintenance can be accomplished with a simple hose rinse. Adequate rainfall may clean your solar panels for you, but with many home solar systems being erected in dry and sunny parts of the country, dust and dirt may accumulate faster than rainwater can handle.

A splash of the hose can often solve your problems.

Soapy Water

While not as powerful as Windex, soap and water can be used to remarkable effect on your solar panels.

While some types of soap may build up over time and require additional cleaning, you probably do not need to wash your solar panels often enough for this to become a significant concern.

A mop and bucket may seem like a low-tech solution for a high-tech system, but it gets the job done quickly and safely.