Can one dropping really matter?
It can. A dropping blocks light from part of a cell, and a shaded cell can pull down more than its own share on a string. On microinverters the loss stays with that one panel.
When does it land?
All year
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
How do I spot droppings?
White spots from below
Chalky marks you can pick out with binoculars, often near the top edge.
A favorite perch
A chimney, antenna, power line or branch above the array where birds sit.
One panel lagging
In a panel-level app, a single module reading lower than its neighbors on a clear day.
Spots that stay
Marks still there after a good rain, baked on by the sun.
Why do spots matter more?
Dust dims the whole panel a little; a dropping blocks one patch completely. Cells in a panel work in series, so shading one cell on a string can drag down more than its share. Microinverters or optimizers limit the loss to that one panel. Either way, a solid spot left all summer costs you on every clear day.
What can I do myself?
Do
- Scan the panels with binoculars once you notice birds perching overhead.
- Check panel-level data in your app for one module lagging on a clear day.
- On a ground mount, soak the spot with a hose early, wait, then lift it with a soft sponge.
- Have an arborist trim any branch birds use above the array.
Don’t
- Don’t scrape with a blade, a fingernail or the rough side of a sponge.
- Don’t climb onto a roof for a spot or two.
- Don’t use vinegar, cleaners or soap on the glass.
- Don’t pressure wash it off; that risks seals and coatings.
What does our crew do?
Soak first
Pure water sits on the dropping until it softens, so nothing is scraped.
Microfiber by hand
Soaked, then lifted by hand with a damp microfiber cloth from the roof edge.
Glass-level check
We look at each cleared spot afterward and photograph any mark left behind.
Perch noted
If birds roost above or nest below, we photograph it and say who can help.
What do owners ask about bird droppings?
Will rain wash bird droppings off solar panels?
Usually not. Droppings dry hard in Colorado sun and cling to the glass, so a rain that clears dust often leaves them in place. A long soaking storm may soften fresh ones. If spots are still visible from the ground after rain, they will likely stay until someone soaks and lifts them.
How do I get bird droppings off solar panels?
Soak, wait, then lift. Wet the spot with plain water, let it soften for several minutes, and wipe it with a soft sponge or microfiber cloth. No scraping and no cleaners. Do this only on panels you can reach from the ground; roof work is for a crew with fall protection.
Is one dropping worth a service call?
Not usually on its own. One spot on a 30-panel roof is rarely worth a visit by itself. Several spots, a lagging panel in your app, or droppings on top of dust and pollen make a wash worth it. A single wash starts from $149 for up to 20 panels.
Why does one panel show lower output?
A dropping, a leaf or a shadow on that panel is the usual cause on a sunny day. If the panel stays low after a clean rain and nothing is on the glass, the cause may be electrical, which is a job for your installer. Our photos help you rule soiling in or out.
Why do birds pick my roof?
Birds like a perch with a view: a chimney, an antenna, a ridge cap or a branch above the array. Droppings land on whatever sits below. Trimming a branch helps. If pigeons are nesting under the panels, that is a different job for your installer or a wildlife specialist.
Seeing this on your glass?
Send a photo from the ground or a screenshot of your app, and we will say whether it needs us.