How to Clean Solar Panels: a Complete Guide | O’Brien Maintenance Group
post-template-default,single,single-post,postid-16397,single-format-standard,bridge-core-3.0.7,qode-page-transition-enabled,ajax_fade,page_not_loaded,,qode-title-hidden,qode-child-theme-ver-1.0.0,qode-theme-ver-29.4,qode-theme-bridge,qode_header_in_grid,wpb-js-composer js-comp-ver-7.7.1,vc_responsive
closeup of cleaning solar panels

Cleaning Solar Panels: Everything You Need to Know

Share this:

Currently, millions of households and small businesses across Australia have already installed their own solar PV systems. Tapping into sunlight as a valuable source of renewable energy, solar panels offer an eco-friendly alternative to traditional power sources. However, to ensure their optimal performance, occasional cleaning is essential. In this article, we’ll delve into the hows and whys of cleaning solar panels and provide a comprehensive guide on maintaining their efficiency.

Why is It Important to Have Clean Solar Panels?

Solar panels are ingeniously designed to take advantage of natural elements for maintenance. A majority are installed with a tilt, leveraging rainwater to wash away the day-to-day accumulation of dust and grime naturally. At first glance, it might seem like this built-in self-cleaning feature negates the need for any manual intervention. However, there are several factors at play that determine the efficacy of this passive solar panel cleaning method.

Challenges with Natural Cleaning

During prolonged periods of drought or in regions that see little rainfall, the self-cleaning aspect of tilted solar panels is rendered ineffective. Moreover, if panels are located near leafy trees or in areas with a lot of bird activity, the likelihood of stubborn build-ups increases. This kind of dirt, often sticky or thick, won’t be easily washed away by the occasional drizzle.

Flat installations present another challenge. Without a gradient for water to flow off, rainwater tends to pool or settle on the panels. Over time, this water evaporates, leaving behind a residue of dirt, minerals, and other contaminants.

The Impact of Neglect on Efficiency

While a bit of dirt might seem inconsequential, the reality is starkly different. Build-ups of dirt, pollen, bird droppings, and other debris can significantly hinder the efficiency of your solar panels. Research indicates that uncleaned panels can suffer from a drop in efficiency ranging from 5-10%. In areas with sparse rainfall, this inefficiency becomes even more pronounced. And while these percentages might seem small, when viewed over an extended period, especially for larger installations, the cumulative loss in energy generation can be substantial.

The Need for Regular Maintenance

While nature does its part in keeping our solar panels clean, it’s clear that human intervention is sometimes necessary to ensure they remain at peak performance. This is when professional solar panel cleaners come in. For a more sustainable and efficient energy future, occasional cleaning is paramount. Regular maintenance doesn’t just prolong the lifespan of your panels but also ensures they consistently operate at their maximum potential.

How to Clean Solar Panels

washing solar panels with water

The method of cleaning solar panels is pretty straightforward. But depending on the size of the panels and the extent of the mess, you may need specialized tools or professional help. Regardless, the first step in cleaning your panels is to shut them off to ensure your safety and then evaluate them. Check the extent of the dirt, debris, and substance build-up. From there, you can decide on how you want to proceed.

Minimal Dust Build-up

If your solar panels have minimal dirt or dust build-up, you can hose them down to keep them clean. Spray them down with a garden hose, as long as it can reach your panels, and let them dry in the sun. 

Remember, however, that you should not use pressure washers or high-pressure jets as they might damage your panels. But if you want to ensure you avoid damage, it would be better to call for professionals to clean your solar panels

Extensive Build-up

Sometimes, solar panels can accumulate more than dirt and dust. Sticky substances, such as plant materials and bird droppings, can also get stuck on your panels. If that’s the case for your solar panels, it’s time to give them a good, gentle scrub. Remember to use a soft brush or squeegee, so you don’t scratch or damage the panels. 

Here’s a step-by-step guide on how to clean your solar panels:

  1. For mild stains, fill a bucket with warm soapy water (use a small amount of mild soap/detergent).
  2. Rinse your solar panels down using a low-pressure hose or sprayer (never use high-pressure washers).
  3. Dip your cleaning tool in the bucket of warm soapy water and scrub the panels gently to get rid of debris or build-up. Use a soft brushes and don’t put pressure on the panels.
  4. Thoroughly rinse the panels to remove traces of soap. Make sure to squeegee the panels when using hard water (mineral-rich) for your final rinse since this type of water can form deposits on the glass when it dries.
  5. Leave your panels to dry in the sun.


closeup of dirty solar panel

Additional Cleaning Tips


  • Clean stubborn stains with isopropyl alcohol – Oily substances can accumulate in areas near the airport or downwind of major highways. In such cases, you can use isopropyl alcohol to spot-clean areas with oil stains.


  • Brush off loose materials while the panels are dry – Before hosing down your panels, brush off any loose materials first. This will help shorten your cleaning time as you will likely have gotten rid of most of the dirt already. 


  • Use a squeegee to prevent water streaks – Water streaks form shadows that can affect the efficiency of your solar panels. To avoid this, finish up with a squeegee after hosing your panels down during the final rinse. 


Solar Panel Cleaning Don’ts


  • Do not use harsh detergents – Harsh soaps or detergents may contain chemicals that may be corrosive to your panels’ surfaces.


  • Do not use rough cleaning tools  These cleaning tools can scratch and damage the surface of your panels. Some examples are metal objects, abrasive cloths, hard sponges, and brooms with heavy bristles. 


  • Don’t stand on your solar panels – Never put any weight on solar panels when cleaning them, as your weight might cause them to crack.


  • Don’t forget about your safety – If you are planning to clean solar panels installed on your roof, make sure to attach yourself to a harness or wear a hard hat. If you don’t have protective equipment like that, better call for professionals instead.


  • Don’t clean in the middle of the day – Solar panels can get extremely hot on sunny days. So, better schedule your cleaning duties early in the morning or evening. But cleaning in the early morning is still the best option as hard-to-clean grime will have softened thanks to the dew that has settled overnight.

When to Call a Professional Solar Panel Cleaner

Yes, you can choose clean your solar panels on your own, but not everybody has the time or resources for that. So, if you want to make sure you get the most out of your panels, consider hiring professionals for the job.

Consider calling in the professionals if;

  • Your solar panels are installed near leafy trees.
  • The area you live in is heavily polluted.
  • You live in a coastal area.
  • Your sola panels have build-up that’s tough to clean.
  • You don’t have time to clean on your own.
  • You don’t have proper safety equipment.

Furthermore, solar panels, much like gutters, require consistent care to ensure optimal functionality. Just as clogged gutters can lead to property damage and reduced efficiency, unclean solar panels can substantially diminish their energy output. Accumulated dirt and debris on the solar panels prevent them from capturing sunlight effectively, leading to a decrease in energy production. Regular maintenance by professionals ensures that the panels operate at their maximum efficiency, providing you consistent energy savings. By entrusting your solar panel maintenance to experts, you safeguard your investment and ensure a seamless flow of green energy for years to come.


worker cleaning solar panels

A Solar Panel Cleaning Company You Can Trust

At O’Brien Maintenance Group, we specialise in commercial solar cleaning services tailored for property managers and other commercial clients. As a trusted name in the industry, we are committed to delivering the highest standard of service, ensuring our commercial clients always receive the excellence they anticipate.

If you’re a property manager or represent a commercial entity keen to understand more about our solar panel cleaning methodologies, or if you’re ready to engage our services, please reach out to us today.

Share this: