How to clean your solar panels

Solar panels are an efficient, environmentally-friendly way to produce electricity. However, their performance is directly related to how clean they are. A dirty solar panel can lose between 15-25% of its efficiency, impacting both power output and electricity costs.

To maximise their lifespan and efficiency, regular cleaning is essential.

What’s Making Your Solar Panels Dirty

Solar panels are susceptible to a variety of contaminants that can significantly impact their efficiency.

In Australia’s diverse climate and environments, these can range from a pervasive layer of dust and dirt to more specific issues like bird droppings, leaves, and even snow in colder regions.

Additionally, elements such as air pollution, pollen, and salt deposits can form filmy layers that obstruct sunlight, while animal activity or construction work near your home can introduce unique forms of debris.

Each type of contaminant has its own effect on energy output, making it crucial to maintain regular cleaning to keep your solar panels operating optimally.

How Often To Clean Solar Panels

As a general rule of thumb, solar panels should be cleaned at least once every six months to maintain optimal performance. However, the frequency can vary depending on your location and the environmental conditions there. For instance, if you live in a region with high levels of dust, bird activity, or leaf fall, you may need to clean the panels more often. On the other hand, if your area experiences frequent rain, that could naturally help to keep the panels cleaner and reduce the need for manual cleaning.

Different seasons may also demand different cleaning protocols:

• Spring: High pollen levels; more frequent cleaning needed.
• Summer: Dust and bird droppings are more common; consider monthly checks.
• Autumn: Leaves and plant debris are common; remove promptly.
• Winter: Snow and ice accumulation; a soft broom or warm water for removal.

Keep in mind that regular inspections are also beneficial to spot any specific issues like bird droppings or construction debris that may require more immediate attention.

Always consult your manufacturer’s guidelines for cleaning, especially if you have premium panels from brands like Sungrow, Seraphim/PowerWave, or CanadianSolar.

Safety First!

Before you start inspecting or cleaning your solar panels, prioritise safety. Some of the key risks include:

1. Water entering an electrical system could cause severe shock, especially if there’s an unseen crack or corrosion.
2. Carrying cleaning equipment to your rooftop poses its own challenges.
3. The roof can be slippery and wet, increasing the risk of falls.
4. Even when switched off, solar panels can become very hot, posing a burn risk.

Ensure you minimise these risks with safety measures such as turning off your inverter/panels, using a safety harness, ensuring ladders and other equipment are functioning before using them is a must to prevent falls.

If your panels are difficult to access or located on the roof, consider hiring a professional to take care of the cleaning safely and efficiently.

Ways To Clean Your Solar Panels

There are many ways to clean your solar panels yourself – what you use will depend on the type of obstruction on your panels, equipment availability and your cleaning skills. Whatever you choose ensure you use soft, non-abrasive cleaning tools and be gentle to avoid scratching or damaging the panels.

Here’s a comprehensive list of methods to help keep your solar panels sparkling clean:

• Wait for Rain: Light to moderate rain can naturally wash away dirt and debris. However, this might not remove all stubborn stains. Effective for light dust, pollen, and rainwater residue, but not for bird droppings or sticky substances.
• Water Hose Method: Use a garden hose with a spray nozzle to rinse off dust and loose debris. Best done in the early morning or late afternoon to avoid temperature extremes. Good for removing dust, leaves, and pollen, but ineffective against bird droppings and sticky materials.
• Soapy Water: Mix mild dish soap with water in a bucket. Use a soft sponge or cloth to gently scrub the panels, followed by rinsing with clean water. Cleans dust, bird droppings, and construction material, but struggles with tough sap and algae.
• Specialised Solar Panel Cleaner: These cleaners are designed specifically for solar panels. Apply as per the manufacturer’s guidelines. Effectiveness varies depending on the cleaner used.
• Soft Bristle Brush with Extension Pole: For hard-to-reach panels, use a soft-bristle brush attached to an extension pole. Wet the brush with soapy water for better cleaning. Works well on dust, leaves, and bird droppings, but not on sticky substances.
• Isopropyl Alcohol: For stubborn stains or bird droppings, a solution of isopropyl alcohol and water can be effective. Always rinse thoroughly afterwards. Effective against bird droppings and sap, but not suitable for dust and leaves.
• Microfibre Cloth: For delicate panels, a microfibre cloth can help remove grime without scratching the surface. Ideal for pollen and light dust, but falls short on bird droppings and leaves.
• Squeegee: Handheld or with an extendable pole, a squeegee can be effective for ground-level or roof-mounted panels. Cleans dust and rainwater residue, but ineffective against bird droppings and sticky substances.
• Leaf Blower: To remove dry leaves, dust, or light debris, a leaf blower can be quite handy. Great for leaves and light dust, but doesn’t remove bird droppings or sticky substances.
• Snow Rake: In snow-prone areas, a specialized snow rake can be used to carefully remove snow buildup. Effective only for snow and ice, not for other types of debris.
• Pressure Washer: For extremely dirty panels, a pressure washer set to a low pressure could be used cautiously. Good for dust and leaves, but caution advised as it’s ineffective against bird droppings and sticky substances.
• Vinegar Solution: A mix of vinegar and water can be effective for stubborn stains but should be rinsed off thoroughly. Useful for rainwater residue and air pollution, but not for bird droppings or leaves.
• Steam Cleaning: Generally done by professionals, steam cleaning offers a thorough and environmentally friendly clean. Excellent for dust, bird droppings, and air pollution, but not for tough sap and construction material.
• Automated Cleaning Systems: These are permanent installations that periodically clean the panels, much like a sprinkler system. Efficient for dust, leaves, and pollen, but not for bird droppings and sticky materials.

Whatever method you choose, regular cleaning of your panels will help improve efficiency and the energy you produce each day.

Another Option: Professional Cleaning

While cleaning your solar panels yourself will save you money, choosing to have your solar panels cleaned by professionals offers a range of benefits that go beyond simple convenience. Along with saving you a lot of time, here’s why you might consider going with professional panel cleaners:

• Quality and Efficiency: Professional solar panel cleaners have specialised equipment and cleaning agents designed specifically for solar panels. This ensures not just a clean surface, but also helps in removing stubborn stains and residues that might be affecting your panel’s performance.
• Safety: Professionals are trained to work in potentially hazardous conditions, like high roofs or steep angles, and they know how to mitigate risks. They also have safety equipment such as harnesses and are well-versed in electrical safety protocols.
• Longevity of Panels: Regular professional cleaning can extend the lifespan of your solar panels by preventing corrosion and other types of damage that can occur over time. Professionals can also identify any issues during the cleaning process, allowing for early intervention.
• Warranty Compliance: Some solar panel warranties require certain maintenance conditions to be met, including cleaning. Using a professional service ensures you have documented proof of panel maintenance, should you ever need it.

In urban areas across Australia, the average cost for professional solar panel cleaning ranges from $10 to $15 per panel. While this is an additional expense, consider it an investment in the longevity and efficiency of your solar system.

Locating a professional solar panel cleaning service is easier than you might think. A simple search for “solar panel cleaners” in your local area will yield plenty of results. Make sure to read reviews, and possibly ask for references, to ensure you’re choosing a reputable provider.

Troubleshooting and Other Concerns

Cleaning won’t resolve all performance issues – so whilst you (or a professional) are cleaning your panels, keep a look out for:

• Micro-cracks: Tiny fractures on the panel, often due to hail or falling objects.
• Delamination: The peeling of the laminated surface, which could let moisture in.

For such issues, consult with a professional for assessment and potential replacement of the affected panels.

Conclusion

Cleaning your solar panels is a multi-faceted process involving more than just washing off visible debris. Safety precautions, seasonal considerations, and the choice between DIY and professional services all play a role in maintaining optimal performance. Addressing both cleanliness and more severe issues like micro-cracks or delamination ensures your solar panels will continue to perform efficiently for years to come.