What's the most effective and safest way to clean solar panels?

March 14, 2018

Benz Softwash supply softwash chemicals to the professional softwash cleaning trade

A customer asked us about the most effective, and safest, ways to clean solar panels on a roof.

The fact is the majority of solar panels are designed to be self-cleaning, and as such require relatively little cleaning.

However, "self-cleaning" is a bit of a misnomer, like "self-cleaning" windows. For sure they don't need cleaning so frequently ... but they do need regular cleaning to remain efficient.

Quick tip: Grime and bird poo doesn't need to cover an entire solar panel to have a negative effect on it's performance.

In certain situations, such as solar panels mounted in a particularly dry area (allowing dust and bird droppings to build up) or where the solar panel's tilt angle is less than five degrees, most manufacturers recommend regular cleaning to ensure the panels continue to work efficiently.

How to clean solar panels?

Solar  panel manufacturers suggest that using plain fresh water will be sufficient for cleaning most solar panels most of the time. They also recommend not using detergents that cause streaking and thus compromise the effectiveness of the panels.

Quick tip: In hard water areas it is crucial to wipe all water from the solar panels to prevent limescale/calcium building up.

If you have a window cleaning WFP set-up with de-ionised water, that is the best way to clean solar panels. And of course add a few drops of Benz Window Cleanze to your de-ionised water help remove bird droppings and spider poo.

Quick tip: Benz Window Cleanze does not leave streaks.

Softwashing a roof that has solar panels

When softwashing the roof with Benz Bio Cleanze or Benz Lightning Cleanze it will be important to ensure the solar panels are not splashed or covered with spray drift. It is highly unlikely that they would be damaged but it's best to be too safe now than sorry later.
The solution is simple: Use a brush for applying the biocides, which will enable you to easily avoid getting biocide onto the solar panels. And of course cleaning the solar panels after softwashing the roof with de-ionised water and Window Cleanze will remove any biocide that accidentally got onto them.

Contact the manufacturers of the solar panels

If you are in any doubt about the best way to clean solar panels we suggest contacting the manufacturers of the panels and asking for their advice.

Materials are continually evolving and it would be wise to check that they have not introduced some new substance into the construction of the panels that cleaning could inadvertently compromise.

Quick tip: Get hold of the manufacturer's product data sheets, which will tell you the recommended ways to clean their products.


How to clean solar panels contaminated with algae?

Benz Bio Cleanze diluted 40-50:1 is a good choice (after checking with the manufacturer of the solar panels).

Simply spray the panel, let Bio Cleanze activate for at least 30 minutes, then agitate with a solar panel WFP brush and de-ionised water (treated with Window Cleanze) to clean the panel.
Use the correct brush: A normal water fed pole window cleaning brush should not be used on solar panels but rather a special one for cleaning solar panels.
As always, test a small area of one of the panels, then get your customer's agreement that the result is to their satisfaction and their permission to treat all the panels.

We hope this information about softwashing solar panels is helpful and helps you succeed in your softwashing business.


Ben, Leo & Fiona

PS: Softwashing solar panels is a great market. Think of the many fields of panels that are popping up in fields all over the country, as well those on rooftops. All will need professional cleaning.


Click Here to explore the full range of Benz popular softwash cleaning products

Benz Softwash Bio Cleanze DDAC biocide & Benz Softwash Lightning Cleanze SH sodium hypochlorite biocide

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