Solar Panel Maintenance and Cleaning: What You Need to Know

Investing in solar panels is a big decision – a lot of time, thought and money goes into choosing the right panels, finding the best installer and arranging for the building and/or installation work to be done.

Once your system is in place, it’s easy to feel that you’ve done your bit and simply sit back and let the sun – and your solar panels – do all the work. Of course, you should enjoy the feeling of having done the right thing, generating clean, renewable energy and helping the planet move towards a sustainable future. But don’t forget about solar panel cleaning and maintenance – or you could find you’re generating only a fraction of the electricity and savings you hoped for.

To make sure you enjoy the full benefits of your solar panels for many years to come, find out how to keep them working in top condition.

Why do solar panels need cleaning and maintenance?

Being outside and subjected to the weather and atmospheric conditions means that, just like your windows, solar panels can become dirty. Dust, pollution, leaves and other debris are blown by the wind, deposited in rain or snow, or transported by birds and insects.

If the dirt is allowed to remain and build up on the panels, it blocks some of the sunlight, which prevents it from reaching the solar cells and reduces the amount of electricity that is generated.

Your system also needs regular checks to ensure that all the electrical and other components are working correctly and safely.

How much more productive are solar panels when they are clean?

A spotlessly clean solar panel will be able to work at its maximum efficiency. Any dirt on the panels reduces efficiency and cuts into your energy savings.

When Google studied the performance of their solar panel system in California, they found that cleaning the panels annually, at the end of winter, increased the energy yield by 12% [1].

Other studies have suggested that the energy yield from dirty panels can be reduced by as much as 25% – which means losing out on a quarter of your potential energy bill savings [2]!

How often should I clean my solar panels?

All solar panel installations are different – many modern panels are self-cleaning and may not need to be cleaned at all.

Your panels may need more or less cleaning depending on the type and manufacturer; location; angle (tilt); surrounding vegetation; wildlife; local industries, traffic or other pollutants; and weather conditions. Ask your installer for advice and check the panel manufacturer’s recommendations.

If you can see dirt or other deposits on the surface, they need cleaning. If your panels are difficult to inspect (up on the roof, for example) then you may be able to tell by monitoring the electricity generation figures.

A good monitoring platform can compare the satellite sunshine data against your system’s performance to see if there has been any deterioration due to dirty panels – ask your installer for advice.

The best way to clean solar panels – a do-it-yourself guide

If your panels do need to be cleaned, you can often do it yourself. Here is a step-by-step checklist to help you do it the right way:

• Ground mounted panels can easily be cleaned by hand, but roof mounted systems may be difficult to reach. Don’t go onto the roof, climb up ladders or reach out of windows without the proper safety equipment and never walk on the panels themselves.

• It’s best to shut down the system before working on the panels, but remember that cabling will still be live and can carry dangerous voltages.

• Choose the right time of day to clean solar panels. An overcast day in the early morning is best. Panels will have cooled overnight and any morning dew will help soften the dirt and make the panels easier to clean. Don’t clean panels on a sunny day as they can get very hot – adding cold water can cause them to crack.

• Before you start, check the manufacturer’s handbook for any special cleaning recommendations. Make sure you have the correct tools and cleaning products – never use metal tools, scouring pads or stiff brushes, and don’t add abrasive chemical cleaners to remove dirt. These can scratch the surface of your solar panels and affect their future performance.

• If the panels are dry, begin by brushing off any loose material with a soft brush.

• Next, simply hose down the panels with plain water. This will normally remove most of the dirt and debris, but if your panels are especially grimy, try soapy water applied with a soft cloth or sponge. Don’t use a pressure washer (jet wash) as this can damage the panels.

• If you live in a hard water area, rinse panels with rainwater (from a water butt, for example) or filtered/de-ionized water to avoid leaving any mineral residue on the surface. Otherwise, use a plastic squeegee to remove as much water as possible.

Cleaning will also give you an opportunity to check for signs of damage or other problems such as cracks or chips to the panels, loose mounting clips, damaged wiring – or even unexpected residents such as birds’ nests, spider webs or wasp nests – and call in the professionals to deal with any maintenance issues where necessary.

Other solutions for solar panel cleaning and maintenance

If all of the above sounds like just too much effort, or your panels are inaccessible, there are plenty of companies who will clean your solar panels for you.

In fact, your installer may offer a maintenance service that includes checking all parts of the system as well as cleaning the panels regularly.

A qualified technician can test your entire system to make sure the electrical components are working safely and effectively, make minor repairs and provide you with a full inspection report. This is worth considering as a standalone service even if you clean the panels yourself.

Whether you prefer DIY or a maintenance service, make sure you keep your panels clean – and enjoy all the benefits of your solar panel system to the maximum!