Soiling of solar panels

This is our first blog on our new website, and what an interesting one we think it is.

Last week I inspected and cleaned a solar array that had only been installed approximately six months previously. The client wanted the panels cleaned and inspected because there had been some branches hanging above and near to some of the array. The branches had been removed and they were concerned that some sap may have adhered to some of the panels. Because of the roof structure, the panels had to be installed in several different locations, approximately two thirds of the panels were nowhere near the over hanging tree branches. Upon inspecting the panels there were small amounts of tree sap where the trees had been overhanging, which was to be expected. But what I was suprised to see was strangely shaped whitish coloured opaque spots over the whole array. Now understanding that this is my second year in this industry, I have seen many interesting soiling issues that can occur on solar panels, but this was a new one. I bent down and with my finger  wiped part of the opaque soiling. To my suprise, it felt like it was an oily substance.

Now we all know this type of  business requires acessing roofs, one thing you do get is a pretty goood view of your surroundings ( that is why I enjoying working close to the coast and now and then day dreaming about camping and  fishing trips). But in relatively close proximity to these residential properties was a major fast food outlet, with large extraction flues on the roof billowing out large amounts of smoke from their cooking system.  Now although I cannot be sure as to where the oily substance came from, as this is the first time I have come upon this type of soiling, it is also the first time I have cleaned and inspected a residence that is in close proximity to this type of major fast food outlet. As this took a considerable amount of time to remove this type of soiling, I would really appreciate any constructive feedback from other similar businesses or people that have had similar experiences.