How to Clean Solar Panels on Garden Lights

Anyone looking at an itty bitty garden light solar panel could be forgiven for raising an eyebrow at that question. Although that reaction is perhaps understandable, it’s totally unfounded. Solar garden lights are kinda like fairies. Small, delicate, and sensitive. And they do have itty bitty solar panels.

And that makes cleaning them all the more relevant. A 10,000 ft² commercially solar array can afford to get a bit of dust on it. A 4 inch² solar light panel can’t. And, because many solar light panels are mounted absolutely flat, they gather every bit of dirt and grime that comes along.

Solar light manufacturers strike a balance between the power demands of the light and the solar panels that supply that power. That said, there is no room for compensation and a dirty panel will severely reduce the capacity of the solar lights.

So, cleaning the solar garden light panels is really important, and it’s not always as easy as it seems.

Why pay so much attention to garden light solar panels?

Large solar panel arrays get dirty and that adversely affects their performance. The negative effects, however, are spread over a larger area and the increased array area offers an element of compensation. So the frequency required to clean the solar panels is reduced.

The very small solar panels on garden lights are far more closely matched to the exact requirements of the light. As a result, the lights suffer a greater degree of performance degradation if the panels get heavily soiled. This can lead to rapidly accelerated loss of performance and eventual failure. Solar industry expert Spheral Solar puts the potential losses as high as 30 percent even with moderately dirty panels or solar lights.

What makes the panels on solar lights get so dirty?

As mentioned earlier the great majority of solar garden light panels are mounted horizontally, or very close to horizontally. This makes them natural dirt traps. Dust collects quickly and rain-born or atmospheric contaminants find a firm footing on flat surfaces. As does ash fall-out from forest fires, salt deposits, and, of course, everyone’s favorite, bird droppings.

So it’s just dirt we have to deal with?

Unfortunately not. Although many dirt sources are truly resilient and hard to shift, one of the more serious problems is not a contaminant at all. Garden solar panels on solar lights have acrylic covers, and just like other similar light lenses, UV light causes them to become cloudy. And if left unchecked, the cover, or lens, can become totally opaque rendering the panel useless.

Fortunately, if it is caught in time this can be totally reversed returning the panel cover to as-new condition. More on this later.

The importance of regular cleaning

As is the case with most housekeeping tasks, the longer you neglect it, the worse it gets. Regular, gentle cleaning with a damp cloth is a great way of avoiding the majority of serious soiling situations. In this case, regular can be read as once a month. If this regimen is followed you’ll never have to don a Hazmat suit and spend hours scrubbing and scouring to clean the solar panels.

Dealing with stubborn dirt and grime

A soft cloth dampened with water will quickly remove contaminants that haven’t had time to set. When they have had time to oxidized and make themselves at home, you’ll need to break out the big guns.

Detergents and solvents

Garden lights with badly soiled solar panels are best cleaned with mild detergents or solvents and plenty of effort. Commercial glass, bathroom cleaners, and acetone are among the most effective ways of getting caked-on grime off solar panels.

Acetone (nail polish remover) is particularly effective but needs to be used with caution. It can totally trash certain plastics and it’s a good idea to test it before use. Apply a small amount to small, hidden parts of the lights first. and if there is no adverse reaction you can go for it.

Plastic abrasive laundry pads are great ways of using solvents or detergents to scrub away layers of stubborn grime.

Just use slowly, frequently rinsing the panel to make sure you’re not marring the surface. Generally, this will be sufficient to remove even the grimezilla of soiling.

If it doesn’t manage to produce clean solar panels it’s time for the nukes.


If all else fails very fine grit sandpaper, metal polishes, and rubbing compounds will certainly get the job done. This has to be the last-ditch attempt though as it removes quite a bit of plastic substrate from the surface of the solar panel. Again, proceed slowly regularly checking the progress, and stop when the panel is clear.

Cloudy solar panels

UV degraded solar panels on garden solar lights are relatively easy to clean if the degradation is caught before crazing and delamination occur. And much like the nuke treatment to clean solar lights, abrasion is the name of the game.

Most mild abrasives like car detailing polish, metal polish, and even toothpaste, yes you heard right, can reverse clouding. This can be done by hand if you are feeling energetic. Although a buffing ball or a polishing mop in a power drill makes the job that much easier.

A quick tip here is to mask the light cover with painter’s tape before buffing. This will avoid removing paint or powder coating from the surrounding metal surfaces.

Does rainwater help clean solar light panels?

Rain can be a great help with cleaning dust and light dirt deposits. But for the nasty stuff, it’ll do you no good. In fact, pooled rainwater that evaporates from the panel surface of a solar light may leave mineral and airborne pollutants behind. This will certainly hinder more than it’ll help.

In summary

Fact one, solar garden lights are awesome additions to any landscape effort. Fact two, dirty solar panels on those lights mean, well, zero awesomeness.

So, while the effort to clean your solar panels and lights may seem like a highly mundane task, it really is well worth any effort.

Clean solar lights are effective solar lights and effective solar lights are, you guessed it, awesome. So grab a cloth, the Windex, and your better half’s nail polish remover, and hit the garden.