One of the most common questions we receive from both prospective and existing clients is whether or not solar panels require regular cleaning.
The answer to this question is - in most circumstances - no, you do not have to regularly clean your solar panels to avoid major performance loss. In Arizona, the rain received throughout the year is sufficient to remove natural residue build up on rooftop solar panels. Numerous studies have been conducted, including an investigation at the University of Arizona, showing a minimal (1%) increase in annual energy production from frequent cleaning of panels.
The main exception is in cases of overspray and spatter from house painting or roof coating. The overspray can be heavy at times and will not rinse off under normal weather conditions. Cleaning paint overspray is dangerous & physically demanding work, prevention is the best solution!
At TFS, we maintain pro-active data monitoring of all our solar installations, allowing us to track system production and alert you to any issues or potential red flags in your solar production levels. Data monitoring is also available on your end as well, providing easy access to generation levels at home. While solar panels are very durable and require little to no cleaning upkeep, occurrences such as power outages can occasionally result in a need to manually re-establish connection between your home and your solar system. Our data monitoring allows us to keep aware of such occurrences, frequently resulting in a prompt diagnosis, repair, and follow up before the client notices.
PREPARE
Make safety a priority! Going on the roof is inherently dangerous. Even if you believe the risk of falling is very low, the cost (financial, emotional, physical) of that improbable event may be extremely high to you and your loved ones. Avoid going on your roof whenever possible, use your best judgment, use proper equipment and fall protection, and always alert someone else to your plan so they can check in on your safety.
CLEANING PANELS
Clean only during early morning or late evening. Solar panels heat up in the sun much like a parked car and will be significantly hotter than the ambient air temperature. Attempting to clean them when hot can cause the glass to shatter, especially when putting cold water on hot panels.
Before getting on your roof, your first step should always be to try and clean the panels from the ground. To do this, stand on the ground and use your hose to spray water upwards so that it falls back down onto the face of your panels (mimicking rain). Don’t spray the panels directly with the hose as that will cause damage to the panels and electrical components that are rain resistant but not waterproof against high pressure.
It is recommended that you rinse panels gently with water (ideally non-ionized) for heavy accumulation of dirt and debris. If there are bird droppings or other deposits that do not readily wash off, you may use a soft sponge with a steady flow of water to remove them or a gentle dish soap.
Quick View:
Do
Use extreme caution when going on your roof
Clean from the ground by spraying a standard garden hose into the air and letting the water “rain” down on the face of the panels to rinse them.
Carefully move any debris such as sticks or leaves from the surface of panels
Gently wipe panel surface with a wet rag or soft sponge to remove persistent bird droppings* if needed
If water alone is not sufficient, use a few drops of gentle dish soap mixed with water
Wash panels in the early morning (before the sun rises) or late evening (after the sun sets) to avoid temperature fluctuation
*TFS does not install bird netting or provide cleanup for droppings accumulation.
Don't
Do not wash panels in the daytime once they have begun absorbing heat
Do not scrub the surface of the panels with any rough or coarse materials
Do not use harsh chemical cleaning solutions to wash panels
Do not douse panels in water of any extreme temperature, hot or cold
Do not pressure wash or use other forceful water
Do not use:
power tools
abrasives (sandpaper, wire brush, steel wool, plastic
“Scotch Brite” scouring pads, etc)
metal tools (razors, scrapers, putty knife, screwdriver, etc)
RE-ROOFING & PAINTING
TFS does not provide service work for panels that were damaged through contact with paint or roofing material. We recommend that homeowners and roofers are proactive to prevent damage. If solar panels do get paint or roofing material on them, repair will be the responsibility of the customer.
PREVENTION
Emphasize prevention to your contractor before work begins. In most cases, it takes less labor to cover panels than to clean them. Any accidental paint should be cleaned up ASAP before it fully dries.
Covering panels with drop cloths for a few hours won’t hurt them but for longer periods the system should be turned off using the ”AC Disconnect” installed near your solar meter. Don’t hesitate to call us (520-740-0736) with questions, we can usually talk you through this procedure
Cleaning paint overspray is tedious & tiring. Unfortunately, there is no substitute for elbow grease.
DON’T:
Don’t wash panels in the daytime once they’ve begun absorbing heat
Don’t scrub the surface of the panels with any rough or coarse materials
Don’t use harsh chemical cleaning solutions to wash panels
Don’t use tools with sharp, rigid corners (like ice scrapers or putty knives)
Don’t douse panels in water of any extreme temperature, hot or cold
DO:
Use extreme caution when going onto your roof
Cover panels with drop cloths, tarp, or plastic prior to any painting or re-coating
Clean paint or roofing material immediately before it fully dries
Wash panels in the early morning (before the sun rises) or late evening (after the sun sets) to avoid temperature fluctuation
Gently scrape wet panels with a flat plastic tool, such as an old credit card if water alone is not sufficient
Use a gentle and steady stream of water to remove paint while you clean