Compared to other mechanical components in your home, solar panels are relatively maintenance-free. But much like your furnace filter or clothes dryer exhaust, they do need occasional TLC to maximize their efficiency. Over time, dust, dirt, bird droppings, and pollen can build up and impact your long-term solar production. In this article, we’ll walk you through how to clean your solar panels, why it’s important, the best times and methods, and safety tips to ensure the process goes smoothly.
Why is it important to clean solar panels?
The silicon cells in your solar panels need exposure to sunlight in order to produce electricity. While a light dusting of pollen across the glass won’t measurably impact real-world output, long-term concentrated buildup can block sunlight and reduce power production. Even a small amount of direct shading can affect overall efficiency when it occurs on every solar panel in the array.
Cleaning your panels also provides a perfect opportunity to give your system a quick visual check-up. As you work, keep an eye out for any cracks, loose wiring, or anything else that looks out of place. Clear away any leaves or debris that may have piled up and to check for signs of critters making a home under your array. Catching these things early can help keep your system running at peak capacity and prevent bigger problems down the road.
Pollen accumulation before cleaning
After cleaning: pollen-free!
How often should you clean your solar panels?
The frequency of cleaning depends on several factors:
- Location: For homes near gravel roads, large fields, or dense trees, yearly cleaning may be required to prevent significant pollen or dirt accumulation.
- Weather: Rain can help rinse off light dust, but it won’t remove heavier things like bird droppings or sticky pollen.
- Panel tilt: Solar panels on steep roofs typically see a reduced buildup of debris and grime, compared to lower-pitch roofs.
Some homeowners find that they can go 5+ years without breaking out the scrub brush, whereas others require annual or biennial cleaning. We recommend keeping a casual eye on it, and if you notice any buildup, work out a cleaning schedule that fits you and your system.
Step-by-Step Cleaning Guide
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We like this telescoping microfiber brush and squeegee kit from Amazon.
Gather cleaning materials.
- Soft brush or sponge (non-abrasive)
- Mild detergent or soap (avoid strong chemicals)
- Hose with a spray nozzle or bucket of water
- Extension pole (for hard-to-reach areas)
- Choose a time. The best time to clean your solar panels is either in the early morning or late evening when the panels are cool. Early morning lets you take advantage of any dew or moisture that might have helped soften the grime. Avoid washing your array in the middle of the day; heat can cause water to evaporate too quickly and leave residue behind.
- Prioritize safety. If your solar panels can only be accessed from the roof, use proper safety gear, such as a harness, or consider hiring a professional.
- Rinse the panels. Start by rinsing the surface of your panels with a hose to remove loose dirt and debris. A soft spray is best to avoid damaging the glass or seals.
- Gently scrub. Use a soft brush or sponge to gently scrub the surface of the panels. If you encounter stubborn spots, a bit of mild soap or detergent diluted in water should do the trick. Avoid using any abrasive materials or harsh cleaning agents, as these can scratch or damage the panels.
- Rinse again. After scrubbing, thoroughly rinse the panels to ensure no soap residue remains. Avoid streaks by rinsing evenly.
- Dry if necessary. While air-drying is typically sufficient, you can use a soft squeegee to ensure a streak-free finish. This is especially useful in areas with hard water that may leave mineral deposits.
Safety guidelines when cleaning your solar array
- Do not use high-pressure washers, abrasive brushes, or strong chemicals. These can damage the anti-reflective coating on the glass and void the warranty.
- Do not wash in hot temperatures. Never spray cold water on hot panels, due to the risk of cracking the glass due to thermal shock.
- Don’t walk on the panels. Solar panels can be fragile, and walking on them can cause cracks or other damage.
- If roof access is required, use caution and proper fall protection. If your panels are in a hard-to-reach spot, hiring a professional might be the safer and more effective option.
When to call a professional
Not everyone enjoys the idea of climbing ladders and scrubbing solar panels, and that’s okay! Hiring a professional is often the safer and more convenient choice, especially if your panels are difficult to reach. Pros come equipped with the right tools and know-how to clean your panels thoroughly without risking any damage to your system.
If you’re the DIY type, cleaning your panels can be a rewarding way to save some money while keeping your system in top shape. Just keep an eye out for any signs of damage, like cracked panels or loose wiring, or any signs of animals nesting under the array. If you spot anything concerning, don’t hesitate to give Western Solar a call.
An active squirrel nest under an old solar array
Squirrel damage on solar panel wiring
Whether you choose to tackle the job yourself or hire a professional, regularly cleaning your solar panels is a simple way to keep them operating at peak performance and extend their lifespan. With a little care and attention, your system will continue delivering clean energy for years to come!
