snow efficiency and my new PV panels

[EccentricAnomaly]

Outtasight, thanks, maybe I'll leave them in their box while I have a think about it...

Still, all four worked fine outside from the end of last year to the end of July this year including some pretty cold and reasonably warm weather.

[SteveH]

i have a long reach wiperblade type scraper which does not scratch the panels,a few wipes and the difference is immediate. however about 3pm the temp dropped and ice formed on the surface of the panels,so i had to leave it be.
       the quicker the snow is removed the quicker it goes onto full output.im not looking forward to this freeze, the last time we had a deep freeze,(12 below) the batteries refused to take or give the charge for 3 days, thankfully i found out from navitron that all would be well when the thaw arrived and so it was,everything returned to normal.
                             biff

 Sounds like you need to Heat the pack Biff...

 Do you have Central Heating? & can you get access close bye?

 I've just been installing UFH here in Crete (Sorry was 20C today) careful purchasing would give you enough elbow's, plastic pipe, insulation & a thermostatic valve to cure this problem in the future...

Steve.

[biff]

hi steve,
      the pack is a 650ah x 120volt forklift truck batterypacks, one 72 volt,still in the forklift but connected to another  48volt pack, they have crashed down to 114vdc tonight,the temp is -7 set to fall further.it is difficult to cuddle 2 and a half ton of battery so there is nothing to do but leave it out like before. they are 140ft from the house, so they are on their own really but all covered over.our other solar system which has its own 48 pack is also down to 46 so it is shut down also. we have a third system,the origional house system which is 800ah yousa  x 12 volt solar,this system is built into the house, so that is going to run things when our stanby generator shuts down for the night.
                                 biff

[Outtasight]

How about any insulation around the banks?  Maybe a wooden box lined with cellotex or something and a DC powered heater pad, running from the solar to keep the worst of the chill off the battery (at least stop it freezing).  Only problem is putting a lid on it would trap the gas, but if you ventilate it, you'll make it cold.  Bottom and sides should be enough to help though.

[Iain]

Hi
Snow finally arrived in Plymouth!!
Still producing 150w and appears to be slowly clearing itself.
Iain

[EccentricAnomaly]

Only problem is putting a lid on it would trap the gas, but if you ventilate it, you'll make it cold.

How about a sloped lid with a vent pipe at the highest point?  Hydrogen should find its way out quickly enough but there'd be no circulation to cause significant cooling.