how do you clean your solar panels?

[terracore]

How do you clean your solar panels?  I imagine the PV ones can just be pressure washed, but was wondering if that might damage the seal on the panels for the hot water?  The last 2 times they were cleaned Drainpipe did it under some energy rebate deal.  I wasn't here for either time but the wife said they used a hose and some kind of chemical.  I'm not fond of putting unknown chemicals into our catchment tank but imagine bleach would be safe in small quantities, though I don't know if it would be bad for the seal.  How do you do it?

[kalianna]

I was told never to pressure wash them. Hose, soapy water and sponge on a nice warm day--if you can find one.

[Durian Fiend]

Pail of water, soap, sponge and elbow grease.

[Carey]

May want to divert the water when you are cleaning, if not with a "first flush" diverter, just unfasten the downspout while cleaning/rinsing the panels..
Of course, do not forget to refasten that downspout!

[MarkP]

I bought some panels second hand that had never been used but had been laying stacked on a lawn. the roots of vegetation had wormed their way deep into the groove between frame and glass. I pressure washed them. I don't know if it affected them long term. I think they are OK but I can certainly see the logic of not pressure washing them. Unfortunately for me the reason for pressure washing them was because of the tiny roots and the place the roots liked was right in the crevice between the glass and the frame. If you felt you had to go there and you had the discipline you could perhaps direct the jet against the frame from the perimeter towards the center. Any dirt hiding in the crevice would be protected but so would the seal between the frame and the glass.

I have used soft scrub tub cleaner and a brush with bristles and a long mop handle. I took the cap off of the first flush leg so soap and dirt wouldn't go into the tank. I used a hose and I also "waited" for a day when it was raining (amazing how many ways my wise decision to buy in upper Puna has payed off). Having soap dry on the panels mid wash is just something it is nice not to have to deal with.

[MarkP]

My comments above are about PV panels.