Solar panel cleaning (lichen, moss etc) - the big imponderable 21 June 2022 at 5:11PM in Green & ethical MoneySaving 11 replies 1.2K views

Doc_N

Any up to date thoughts on the best way to tackle moss and lichen on solar panels - and for that matter the general question of keeping them clean?

It's a long time since ours were installed and they really do need cleaning.  Manufacturers all seem to say water only (no chemicals) and no brushes - but reality says that chemicals and brushing are probably the only way to remove lichen.

What's the current thinking on this, and what are long-term owners doing about cleaning - if anything?

JKenH

Mine are quite high and a struggle to reach but I bought a very, very long (around10m) pole with a brush and water feed attached. It is very difficult to manoeuvre as something very light when 10m long becomes very heavy. (Ok, that’s not great terminology but I hope you get what I mean).  I just use mains water. 

gefnew

The general rule is not to use tap water.

Water rules for cleaning solar panels! (renewsysworld.com)

The_Green_Hornet

My installation is coming up to being 12 years old and I haven't cleaned my panels, or plan on getting them cleaned, but then I haven't noticed any build up of moss/lichen or seen a reduction in generation.

I suppose the question is are you seeing a significant reduction in generation and if so would the cost of cleaning them be recovered.

QrizB

As far as I can tell from ground level, mine might be a bit dusty (and there's definitely lichen on the return surface of the frames) but there's no growth of anything.

I suspect they get too hot to support meaningful life.

paul991

mine are now  7 yrs  old and the  rain keeps  them as  good as  new,<Canadian solar> if i ever needed  to clean then id  only ever use rain water not tap due  to limescale   

Ectophile

I did have mine cleaned when I had the gutters cleared (pigeon problems!).  There was a noticeable increase in output when he'd finished the cleaning.  Not huge, but noticeable.

He used purified water and a brush to do it.

EcoScruples

I washed the orange sand off mine with plenty of rinsing and a soft micro fibre cloth on an extendable handle, don't think I'll bother again, I'll let the rain do the job for me.

JKenH

I was aware of the advice not to use tap water but unless you have a professional window cleaning set up I am not sure how else you are going to get water onto the roof of a two storey house. I am open to suggestions.

Doc_N

JKenH said:

I was aware of the advice not to use tap water but unless you have a professional window cleaning set up I am not sure how else you are going to get water onto the roof of a two storey house. I am open to suggestions.

Good point! They use 'pure water' don't they, but anyone costed a professional lately? My worry would be potential damage.

QrizB

JKenH said:

I was aware of the advice not to use tap water but unless you have a professional window cleaning set up I am not sure how else you are going to get water onto the roof of a two storey house. I am open to suggestions.

I've got a rainwater butt, so that covers the "pure water" requirement. Maybe get one of my kids to pump enthusiastically with one of these?
https://www.ebay.co.uk/itm/353574401274

Or maybe one of these for the pressure washer (you could probably build your own for half the price):
https://www.ebay.co.uk/itm/123763208451