How to Clean Solar Panels

[Ferdinand]

Some of the trees shading our solar pv have now been removed or pollarded.

Now I can see better that some of our panels covered in pigeon productions.

How to clean them? What do people here do?

Our window cleaner offers a service using an extended wand, but his price is £2 per panel for a warm water clean, and for 35 panels that is a lot - even for the 15 or so with pigeon poo it is a lot. Suspect his prices are set for 8 panels on a house roof - ours are effectively on a bungalow roof and easier to reach.

My current thought is for some kind of extending telescopic sponge mop following up a hose or power jet spraying an arc to avoid spraying under the tiles. 

Ideas would be most welcome.

Thanks.

Ferdinand

[Onoff]

On windows the "proper" way using a pole is generally known as "reach n wash" in the trade and utilises de-ionised water either from a tank in the back of the van or via a wheeled trolley that looks like an oxyacetylene trolley and holds damn great cartridges. In the old days cleaners would go to back street filling stations to get their de-ionised water. The dirt on the window is wetted then agitated / loosened with a brush or dolly on the end of the pole which is water fed and controllable. The water is then used (no soap) to wash the debris off and downward. Leaves a fairly streak free finish. Kit's pretty expensive.

If done regularly reach and wash is OK but if engrained then a proper dolly / squeegee together with nylon Scotch type pad is used. If you have heavy staining the cerium oxide powder or CO2 can be used.

Window cleaners who miss the corners are referred to as "Sinbad" (think portholes).

Listen to a couple of windows talking and you might hear one say "I did a Dionne!". Translated this means he knocked some or all of a particular job as in Dionne Warwick's Walk On By. 

EDIT: Meant to add that the lads I know who clean solar installs on commercial buildings use the de-ionised water fed pole generally. 

Edited May 23, 2016 by Onoff

[Ferdinand]

I've done a test with a floor sponge, and I think it will work with tap water x 20 or possibly mild detergent mix followed by many rinses.

The next step is to obtain an appropriate cleaning device.

I'm thinking about one of these water fed extending mops for window cleaners:

http://www.hgpromotions.com/products/6/Solar_Panel_CleanerIdeal_for_removing_salt_spray_seagull_mess_in_coastal_locations_Water_Fed_Pole

Just need to decide on the 17ft version or the 26ft version :-). Both cost roughly the same as one and a bit cleanings of all the solar panels.

Ferdinand

 

[Ferdinand]

I bit the bullet and ordered a window cleaner's professional cleaning kit.

The parcel arrived today while I was out,  and it is the small matter of 10 feet 12 2 inches long.

Since I ordered the 26ft reach version I guess that means it is in 3 telescopic sections.

Guess who is having some fun this weekend?

Edited June 3, 2016 by Ferdinand

[Declan52]

My avatar is me up on the roof giving them a hose down.

[Ferdinand]

I don't like toddling about on roofs.

The package:

Edited June 4, 2016 by Ferdinand

[Ferdinand]

And here is the pole, with one of the two extensions extended.

Quite jury-rigged really - cable ties and hose connections, and the only unusual bits are the extending poll, the sprinkler head, and the 8mm coil pipe.

It seems to be reasonably solid, but cumbersome as you would expect. Many people on here could put one together.

Cost was about £120, and spares should be easy to come by.

Personally I would prefer an extra 3m of hose attached to the handle, so my dodgy hose conenction is not so close to my clothes and feet.

Edited June 4, 2016 by Ferdinand

[Ferdinand]

And this is the thing extended. That is 26ft, and tilted away at 50 degrees, albeit without a scale object.

Seems to work well, but I think I will need a scrubber and in line detergent to get the first lot of ingrained poo off.

Easy to use, though, and I can reach 6 panels up from the ground, which is better than clambering around on a 50 degree roof, which is not my idea of hilarity.

 

[Ferdinand]

Full Review:

 

This is a 3 section hose-attached aluminium telescopic pole, which is 26ft long = just under 8m. There is a shorter 17ft 2 section version. Costs are £95 and £50 respectively.

 

It is a professional one from a firm called HG Promotions, and attaches to a hose. The web page is - shall we say -  "keyword optimised":

 

http://www.hgpromotions.com/products/6/Solar_Panel_CleanerIdeal_for_removing_salt_spray_seagull_mess_in_coastal_locations_Water_Fed_Pole

 

Add ons available include inline detergent device (£10), hand pressurised 5l pump water supply (£25) for hosepipe bans (and 16l backpack version £40). Various types of head include cloth, brush, double sided, a swan-neck for leaves in gutters, and an inline lever-turn-off device.

 

For cleaning algae from panels, I think you would be looking at the inline supply with the applicator, using an appropriate liquid. I have not tried the inline detergent device which attaches to the hose, but I expect such things tend to eat money if used with the branded product regularly. Diluted oxygen bleach or similar?

 

I guess one could also try attaching copper or zinc wire to the top of each panel, which sounds painful.

 

My main panel array starts at about 7ft with 6 rows of horizontal panels, so the shorter pole was not quite enough. I have not tried cleaning the ones on the high gables,thought it would reach, as my main issues are trees and pigeons. 

 

The setup is robust enough for what it does. If you order online as a consumer you have a right to return.

 

I would *never* be using something like a pole on top of any ladder or steps (very bad idea imo). Hop up step or work platform ... maybe, but in that case the longer one is better. Up and down or tilting some way off centre is fine (I have to do 40 degrees off which is too much die to a garage). 

 

My intention is to clean panels 2 or 3 times a year. The window cleaner was proposing a charge which would pay for it in 12 months (we have 35 panels of which 28 are in the main array).

 

A couple of pics with the "porcupine" microfibre-with-rubber-bits cloth. More on the other thread.

 

An alternative system from Sureclean seems to be more extensive, but also more expensive - it is made from carbon fibre. 

 

Ferdinand

 

 

Edited April 12, 2017 by Ferdinand

[Jeremy Harris]

Thanks for this.  Our water is quite hard at the outside taps, so I've been looking at the systems used to supply deionised water for these things.  It looks easy to put together a system that doesn't cost a massive amount, using components that are very similar to our water filtration system.  The flow rate needed seems to be around 2 litres/minute, which would only need a pretty small DI vessel, and if only used two or three times a year the resin would last many years before needing to be replaced.  I have a spare vessel head and riser, albeit a long riser that would need to be cut down, so for around £100 I could buy a pressure vessel and enough resin to refill it three times, probably around 20 or more years worth for our application.

[Ferdinand]

Bumping this thread.

 

A few of my solar panels have now suffered serious attention from lichen and algae. They are under a tree and have got quite a lot worse over the winter.

 

Now that we are nearly back in the serious generation season, they need some attention. There are a couple of photos. The bottom of the array is at about 2.3m from the ground, so access is not that difficult. I may be able to reach most of them by hand with care.

 

Questions:

 

1 - Is there a cleaning agent I can add to my long hose-connected solar panel cleaning pole (see start of thread)? Mild bleach? Vinegar?

2 - Is there any kind of copper tape that I can add to each panel to help keep then clean in future? I am wondering about either adhesive tape (eg the sort to control slugs) or perhaps copper wire as used on roofs.

 

Thanks

 

 

 

 

[Jeremy Harris]

I found a bit of ordinary detergent helped with the aid of a water fed brush.

 

I'd be very wary of using copper, as the frames of PV panels are aluminium, and they are practically at the opposite ends of the electrochemical series, so there is a strong probability that this would induce corrosion of the alloy frames.

 

After cleaning, you could try spraying the panels with a copper sulphate solution.  With luck this will kill off any lichen residue and slow regrowth.  I've found that copper sulphate can work surprisingly well at killing lichen and moss, although it doesn't last forever.  With luck, it may inhibit regrowth for a year or two, and it's safe to re-spray the panels with copper sulphate solution annually if you want to try and prevent regrowth.

 

When sprayed on concrete tiles, copper sulphate solution can keep the tiles lichen and moss free for a few years I've found.  It seems that the copper sulphate soaks into the tiles and acts to prevent lichen regrowth for a fairly long time.

[Ferdinand]

Thanks.

[Ferdinand]

On 26/03/2018 at 19:25, JSHarris said:

I found a bit of ordinary detergent helped with the aid of a water fed brush.

 

I'd be very wary of using copper, as the frames of PV panels are aluminium, and they are practically at the opposite ends of the electrochemical series, so there is a strong probability that this would induce corrosion of the alloy frames.

 

After cleaning, you could try spraying the panels with a copper sulphate solution.  With luck this will kill off any lichen residue and slow regrowth.  I've found that copper sulphate can work surprisingly well at killing lichen and moss, although it doesn't last forever.  With luck, it may inhibit regrowth for a year or two, and it's safe to re-spray the panels with copper sulphate solution annually if you want to try and prevent regrowth.

 

When sprayed on concrete tiles, copper sulphate solution can keep the tiles lichen and moss free for a few years I've found.  It seems that the copper sulphate soaks into the tiles and acts to prevent lichen regrowth for a fairly long time.

 

@JSHarris

 

Can you give me a steer on how much to buy, and the dilution rate?

 

The cheapest suppliers seem to be to the horse riding community, where they treat paths with a 1kg to 10l dilution and buy sacks of 25kg of copper sulphate for about £75 in order to help keep bugs out of hooves.

 

I have about 25 solar panels to treat and will probably use a floor squeegee for application.

 

Ferdinand

 

 

 

[Jeremy Harris]

I use the maximum strength you can get by using copper sulphate pentahydrate crystals, which you can always get right by just pouring crystals into a plastic container with warm water in (that you never want to use for anything else - it will get permanently stained, in all probability) until no more crystals will dissolve.  If you end up with a thin layer of crystals in the bottom the strength is right, just take the blue liquid off the top.

 

You can buy copper sulphate pentahydrate pretty cheaply from places like ebay, I bought a 25kg bag for around £50 years ago and still have half of it left.  To do a whole roof you probably need around 2 to 4 kg, depending on the size, I'd guess, so a 5kg bag or tub may be enough.  If you have a good equestrian or farm supplies place nearby they probably stock it for treatment of fungal infections (works on humans, too, and will kill Athletes Foot, but it does tend to stain your feet............).

[Stones]

Out of interest, is there a risk that roof tiles / slates would end up getting stained if using copper sulphate?

[Jeremy Harris]

54 minutes ago, Stones said:

Out of interest, is there a risk that roof tiles / slates would end up getting stained if using copper sulphate?

 

 

Concrete tiles are the most susceptible to having their colour slightly changed, I think, based on my experience.  I doubt that there would be any colour change at all on slate, as it seems pretty impermeable.  Even the colour change on concrete tiles wasn't really noticeable; it didn't turn them blue, but just slightly lightened their original colour, which may well have been due to the copper sulphate just killing off stuff growing in the top surface of the tiles.

 

The biggest problem I found at the old house is that it takes a few weeks for the copper sulphate to kill off the lichen and moss, and then over the next few months you have big chunks of dead moss falling off the roof.  We had hedgehog brushes in the gutters, so the moss just rolled over the top and on to the drive, making a nasty mess.

[Onoff]

Would soda crystals work?

 

I only ask as in the States soda blasting is a big thing and they sell the residue from the cleaning process to the rail companies who use it for weed control on the tracks.

[SteamyTea]

8 hours ago, JSHarris said:

You can buy copper sulphate pentahydrate

Is that the blue stuff we used at school to copper plate things?

[Jeremy Harris]

5 minutes ago, SteamyTea said:

Is that the blue stuff we used at school to copper plate things?

 

 

Yes.