What Is The Best Way To Clean Solar Panels?

A car that’s well-oiled and serviced runs better, so there’s no surprise that solar panels do their job more efficiently when they’re given the same level of attention.

Beyond the set of wheels in our garages, we like to keep our windows crystal-clear and free of grime, too. So why should cleaning our solar panels be any exception? The question should more be focused on when you need to put in the hard yards, and how frequently.

So in this post, we’re covering all of your biggest questions about

  • What is the best way to clean solar panels
  • How to clean bird poop off solar panels
  • How often do you need to clean solar panels
  • etc.

We’ll look at all the requirements across what you need to clean them with and how, as well as the main sources of dirt, and when you need to call in the professionals.

The Best Way To Clean Dust From The Solar Panels

Dust causes regular problems beyond the build-up of grime over the years. But your exact location also plays a big role in how much this can affect your system, and what triggers it.

A bit of dust might not have an effect, according to tests done by Ontario Solar Installers, because light can still get through. They recommend that you let nature take its course, as rain will accomplish most of the task of solar panels cleaning.

A test done by one company found the amount the efficiency is lowered is minute – maybe 5 percent or less. And, with a typical 5 kW system, this might equate to about $20 of loss in your energy bill. Another company found that a thorough cleaning made the panels 3.5 percent more efficient.

And if this isn’t enough evidence for you, the clean technology website – CleanTechnica – reported an analysis by the US National Renewable Energy Laboratory (NREL) that showed a potential 30 percent energy yield loss per year, if they are not cleaned regularly.

Beyond this, though, it’s important to remember that leaves also block light. In an experiment carried out by the company Mountain View, cleaning flat designs “doubled their energy overnight” after 15 months of operation. However, the tests confirmed that rain on rooftop panels also tends to do the job.

Special attention should be given to PV arrays situated in dustier areas if they are near farmland or next to the main road. These arrays have far more dust and dirt to contend with and will require more frequent cleaning.

How To Clean Bird Poop Off Solar Panels?

Bird droppings on your solar power panels are more detrimental than a film of dust. Does your array include a string inverter or micro-inverters? This is important because systems with microinverters (with an inverter attached to each separate panel) can show where one part has been covered with droppings. During these instances, the inverter will stop showing current flow. 

If you have a lot of trees nearby, especially deciduous ones, they will not only drop leaves on your rooftop, but they will also attract birds. Both of these cause build-up and debris over time, making it more important to regularly employ solar panel cleaning services or efforts.

One thing to consider is the angle of your array. Flat panels will need more upkeep as water can pool up and leave a muddy residue when it evaporates. Angled ones take advantage of rain running across them to keep them clean.

The Best Way To Clean Solar Panels Is Through Professional Help

As of Dec 31, 2020, India’s cumulative installed rooftop solar capacity stood at 6.79 GW. With 1.35 GW added in the last calendar year, according to the latest figures from Bridge To India.

Many homeowners opt to clean their own solar panels. If you choose this approach, remember that it is safer to do so on the ground, where possible. To help you, we recommend you read our cleaning solar panels guide for more tips.

But tidying up these systems isn’t always as straightforward as it seems. 

A new whitepaper by solar measurement company Kipp & Zonen explores the issue of dirty panels in terms of economic, geographic and technical factors.

For instance, dirt is worse in desert areas like Rajasthan, where the air is dry and dusty. Flat-tilt array designs also trap more dust.

Meanwhile, air pollution is also a culprit. Build-up happens on arrays close to local factories or composting facilities, the whitepaper informs.

So when is it worth enlisting expert help to sort these challenges out?

Adopting professional solar panel cleaning services may not be worth it for a bit of dust building up over time. However, it’s highly effective when the job becomes too much of a hazard (or task) to do yourself. When the going gets tough and suddenly there’s a significant risk involved, we recommend using experts to ensure your system is tidied up to the best possible standards.

How To Clean Solar Panels On Your Roof – DIY

What is the best way to clean solar panels? For the DIY-minded you should find the materials at home. Because you don’t want to scratch your system in any way, it’s best to use just water and a non-abrasive sponge to apply soapy water.

Below is a small video that shows how you clean solar panels by yourself.

How To Clean Solar Panels On Your Roof – DIY

Get the most from your solar installation by choosing CEC-accredited products and installers.

Use a mild detergent, if you feel like you need some extra help.

And if you’re asking yourself if you can use a pressure washer to clean your solar panels, we encourage you to only use a normal hose. Using anything with high pressure may cause damage. Use a sponge if the birds have made a mess and nothing stronger than the detergent you would use with your dishes. You don’t want any strong chemicals marking the panels.

Safety Tips To Consider While Cleaning The Solar Panels

The best way to get the job done is on the ground with a long-handled implementation. But if that’s not possible and you choose to go on the roof, you must take precautions.

For example, a rope should be attached to a safety harness to prevent falling to the ground – a method often used by professionals. 

Additionally, no one should be on a roof without a hard hat and a safety harness. It is a potentially fatal environment. Check out this advice about working at these heights before you start. The task of solar panels cleaning is not worth your life!

One solution to prevent you from having to climb up on a ladder to inspect the system could be to have a professional company install a CCTV camera pointed at the panels so you can see for yourself when they need cleaning.

New Research To Keep Solar Panels Clean And Efficient

While there are still DIY services and professional solutions to eliminate any soiling on your array, industry innovations are also paving the way for easier upkeep.

These include:

  • Special coatings for glass to repel dust and reduce soiling.
  • Robotic cleaners remove dirt at night without using water – they use soft brushes and air blowers.
  • Kipp & Zonen’s commercial tool is designed to measure dirt levels.

Kipp & Zonen’s DustIQ monitor – for example – uses LED and a photodiode to monitor the amount of dirt building up on the array. Solar farm operators can then choose when and how often to clean their installations for maximum performance.

In addition to this, expert facilities management companies – like industry leader Royal Flush – recommend cleaning your system at least twice a year. Doing so keeps your investment in tip-top shape to ensure better efficiency and cost savings for the future. 

But if this isn’t enough to tip you over the edge and get your system in the best working order, the Royal Flush team has also shed light on just how much energy you could be losing by avoiding a productive maintenance routine for your array. And where you’re losing energy, you’re also losing money.

For example, you could be losing up to the following percentages per quarter, if cleaning isn’t on your agenda:

  • Year 1 Q1: 5% Energy Loss
  • Year 1 Q2: 10% Energy Loss
  • Year 1 Q3: 15% Energy Loss
  • Year 1 Q4: 20% Energy Loss
  • Year 2 Q1: 25% Energy Loss
  • Year 2 Q2: 30% Energy Loss
  • Year 2 Q3: 35% Energy Loss
  • Year 2 Q4: 35% Energy Loss


It is simple, the more you keep your solar panels cleaned, the more electricity they will generate. Also, don’t forget to keep safety in mind while cleaning the solar panels.

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