Why your home solar panels need cleaning?

Why your home solar panels need cleaning?

In most cases the loss of energy due to dirt on your solar array is quite low, you may decide it’s not worth the effort, or the expense to clean solar panels. We live in a climate which brings rain in all four seasons, rain rinses most obstructing dirt away.

The exceptions that make cleaning panels worthwhile include, if installed at less than a 5° angle, they should be washed periodically because rain alone will not carry away accumulated dirt, If local conditions encourage rapid growth of bacterial spores, which, when germinated, create light reducing blankets of algae, lichens, moss and moulds, left untreated will seriously reduce performance. Another issue is bird droppings, which can block enough sunlight to make cleaning necessary.

University of San Diego research engineers also found that sites where panels were dirty enough to warrant cleaning had specific, environmental circumstances. For example being directly next to and downwind of major roads, factories, or farms can generate enough dirt to warrant periodic cleaning.

Maintenance and Upkeep

In general, let the rain take care of your solar panel cleaning. Monitor your system by paying attention to your energy bills and usage month-to-month. If you notice changes in your bill or feed-in, maybe it’s time to think about cleaning.

Residential solar energy systems are generally tilted on your rooftop. How often do you clean your roof? Probably not very or never. If you do decide your panels need to be cleaned, there are two decisions to make - hire a professional - or do it yourself.

There are many solar cleaning companies who offer this service. They may suggest it as part of an annual maintenance service, only you can decide what you’ll get back cost-wise on your energy bill versus professional charges. This article is aimed at those who have made the decision to undertake their own work. The ways to determine if your solar panels need cleaning:

Physical inspection for debris, dirt, bacterial staining or bird droppings.

A monitoring system that alerts to how well your panels are functioning. This can alert

you to maintenance needs, whether mechanical, electrical, or cleanliness.
If carrying out the cleaning task yourself, take special precautions from not falling off the roof. Two obvious measures:

Don’t spray a hard blast of water on panels

Don’t use abrasive cleaners, as these can damage panels.

If you do it yourself, you’ll generally have – with the exception of a biocidal cleaner - all you need at home. In most instances it will involve nothing more than a hose, a garden sprayer, sponges or soft brushes and you’re good to go.

What Do You Use to Clean Solar Panels?

There are a variety of products you can use to clean. But first check with your installers and providers to determine if there are any do’s or don’ts when it comes to cleaning your system.

The most effective way to clean panels is with a hose and a bucket of soapy water - essentially as you’d wash your car. You want to avoid anything which might scratch the panels, it’s best to use just water and a non-abrasive soft and bristle-free brush, sponges or fabric mop head to apply soapy water. NEVER use any type of high-pressure water sprayer when washing off your solar panels. A high- pressure attachment can damage solar panels.

If using something other than just water – especially on bird droppings, lichens and moss, make sure you know what you’re using. If deciding to use just soap use something like washing-up liquid. Avoid laundry detergents and other stronger chemicals, if you aren’t sure what’s in them you may find they will interact with your solar panels in a negative way. Many laundry cleaners contain bleach or solvent based additives which are “oxidisers” and will seriously corrode some elements of your panel array.

Greener Kleener is unique in performance excellence on solar and photovoltaic panels. Derived from Soya the active ingredient oil has two functions, firstly it’s a powerful surfactant, like soap it foams when sprayed or agitated with a brush, like all soaps it attracts and removes dirt, grime and grease. It’s second, and primary function, is that of a biocidal cleaner and sanitizer.

Like a magnet is attracted to metals, Greener Kleener is attracted to bacteria. When it finds living cells, it punctures that cell wall and prevents reproduction (killing it). This is a cationic action so, giving off all its energy, this depletion of energy makes it biodegradable, leaving no environmental footprint.

Greener Kleener is a pure form of Didecyl dimethyl ammonium chloride (DDAC), with nothing added, so contains nothing which can harm any components used in the manufacture and assembly of your solar array.

Greener Kleener at 5% is the highest concentration HSE permits to be sold for public use.

To ensure panels remain algae, moss and lichen free dilute Greener Kleener with 4-part water to 1- part Greener Kleener for light to moderate staining, 3-part water to 1-part Greener Kleener on heavy staining.

Apply by spray to saturation at normal tap pressure (a back pack sprayer or garden pump sprayer will do), leave to dry naturally, there is no need to rinse.

If heavy staining is evident you may wish to agitate in with a brush, sponge or similar – as the suds will collect grime and grease, rinse with clean water as you would if cleaning windows, following treatment.

Solar panels can get extremely hot when the sun is beating down. It’s best to pick a cool, dry, overcast and wind free day to clean panels. If you attempt to clean panels in extremely hot weather, soapy water will evaporate quickly and may leave smears on panels, which can affect their performance.

Always wear suitable clothing when spraying including safety glasses, or even better full-face visor and waterproof gloves.



Be careful of overspray, you may find that overspray or product run-off will, over a few days, alter the appearance of your roof tiles – this is not “bleaching” or damage to your tiles.

It’s actually Greener Kleener cleaning your tiles and returning them to their “as new” colour


Greener Kleener can be used to clean and sanitize ANY external hard surface including children’s play equipment, patio’s, driveways, decking and dog kennels.

Keep children and pets away during wet work.
Do not use as a moss killer in lawns.
Do not spray Greener Kleener onto plants it will not kill them but may scorch foliage. Safe for animals and children once dry.

For additional HSE information, dilution rates for other substrates or general information contact your supplier or email enquiries@gkpro.co.uk