How do you clean solar panels?

[#1]

Apparently you should get a pro in. "...utensils may be needed that could cause issues with the panels if not used correctly. Unfortunately moss and Lichen cause large amounts of shading to panels and can have a detrimental effect on the performance." - Isobel

If you want to go up and clean panels but you’re concerned about roof safety, then fit an eyebolt on the opposite wall to your solar panels, near the bottom (in the mortar would be fine). Attach one end of a long rope to the eye bolt, then hurl rest of it over the rooftop to the other side and use rappelling gear. 

Clean panels are a good thing. You're maximising their efficiency, when your own draw during the day is lessened and you can trickle in some export credit to help offset your non-solar consumption.

I too have noticed that some solar companies do recommend pro cleaning only, but then others don't. I think if people are careful and use some form of fall protection, then it's pretty straight forward and safe.

To me, solar panels are made to withstand harsh environments and need to be very tough, imagine the turmoil if there was a full on hailstorm and everyone's panels got wrecked.

The precaution of washing them early morning, early evening to avoid thermal shock, makes a lot of sense. As a bonus, there's less likelihood of smears being left on the glass.

I agree that cleaning agents need to be chosen with care, but a splash of dishwashing detergent in a bucket of water, won't do any damage & I can't see how it would. Rinsing it off after the clean is common sense, & using a squeegee to remove excess water will prevent smearing. To be doubly sure, wrap a slightly damp microfibre cloth around the broom head & sweep the panels to remove micro-droplets (if there were any). - Andy_Mann

I got some moss on my solar hot water system where the glass meets the frame. It will hose off easily or get burnt off with some decent sun. - Brad

Used to live in Canberra where lichen on tiled roofs was common - people would install a line of copper wire on top of roof and water running down roof would carry minute amounts of the copper down the roof and slowly kill and remove the lichen. - PappaGabba

I've seen this stuff around - Glitz Outdoor Cleaner Concentrate - and perhaps this might be useful. - Henno

[CSParnell]

Within the solar industry it is well known that a soft bristle brush and water is the ONLY thing to use on solar panels due to the coating on the panels themselves.

They are designed to self clean to a degree.

I was also involved in a trial of a large scale commercial solar panel robot cleaner where I was carrying out independent solar analysis on the panels.

That commercial cleaner was made up of soft bristle rollers and clean water.

It is always best practice to follow manufacturers guide when it come to this sort of thing, you don't want to ruin your panels or your warranty.

Cheers

[CSParnell]

Some images and links for reference of the types of equipment and processes I was working on.

https://www.cpsnational.com.au/wp-content/uploads/2020/01/Case-Study-HCB-Solar-PV-EL-Testing.pdf

[daniknight4]

Our panels do need a clean every so often because we have trees surrounding but my husband gets up there with a hose and household mop and gives them a clean. It does the job and I think it's noticeable around bill time too!