Learning how to remove dried bird poop from solar panels is critical to avoid damage, If you have birds nesting under your solar panels, you inevitably have a secondary problem: the mess on top of them.
Bird droppings are not just an aesthetic issue. In the solar industry, we view bird poop as “hard shading.” Unlike dust, which casts a light haze over the panel, a solid dropping blocks 100% of the sunlight hitting that specific group of solar cells. This kills the output of that panel and can drag down the performance of the entire string.
Worse, if left to bake in the Australian sun, dried bird poop becomes a serious liability to the physical integrity of the glass.
The Danger: Acid Etching and Hotspots
Bird droppings are highly acidic (uric acid). When this sits on your solar panel glass and is heated by the sun, it begins to eat into the anti-reflective coating on the surface. If left long enough, it can etch the glass itself.
Furthermore, the “hard shade” caused by the poop can create hotspots. Because the blocked cells are not generating power, they begin to consume energy from the surrounding cells, heating up intensely. Over time, this concentrated heat can burn through the backsheet of the panel and cause permanent failure.
You need to get it off. But you have to do it carefully.
The Golden Rule: Never Scrape Dry
The biggest mistake homeowners make is taking a dry brush, a scraper, or a fingernail to a hardened dropping.
Do not do this.
Solar glass is tough, but the coatings are sensitive. Dragging a dry, calcified bird dropping across the surface acts like sandpaper. You will leave micro-scratches on the glass that will catch more dirt in the future and reduce light absorption.
The “Soak and Wait” Method
To clean this safely, you need patience and water.
- Safety First: Ensure your system is shut down if you are cleaning manually, and never climb a roof without proper safety gear. Ideally, stay on the ground and use an extendable pole.
- Soak the Area: Use a hose (not a high-pressure washer) or a wet sponge to thoroughly saturate the droppings.
- The 5-Minute Rule: This is the secret. Walk away. Let the water sit on the droppings for at least 5 to 10 minutes. This rehydrates the organic matter and breaks the bond with the glass.
- Wipe Clean: After soaking, the droppings should slide off with a soft squeegee or a soft-bristle brush. No scrubbing should be required.
- Rinse: Give the panel a final rinse with deionized water if available, or tap water if that’s all you have (just be wary of calcium spots).
Prevention is Better Than Cure
Cleaning dried poop is a temporary fix. If the birds are living under the panels, the mess will return within 24 hours. You will find yourself in a constant cycle of climbing on your roof and cleaning, which increases the risk of you falling or damaging a tile.
To stop the poop, you must stop the nesting.
Learn how to stop the mess at the source in our ‘Solar Panel Bird Proofing Guide’]