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Posted: Fri Jun 06, 2008 10:09 am
by contadino
165 ltr freezer for €1.318.56 ex works in Germany is pretty steep. Needs 444Wh/day which they reckon you can get from a single 75w PV panel. Hmmm....
Our neighbours electricity's been off for 48 hours now thanks to a
temporale and it kinda brings these things up the list of priorities doesn't it?

Posted: Fri Jun 06, 2008 11:23 am
by DominicJ
So maybe a 600w inverter?
As I said, I'm more interested on if its possible than if the bits I pointed at are capable right now.
It just seems like the perfect way to get into alternative energy, if it works of course
Posted: Fri Jun 06, 2008 9:47 pm
by Turtuga Blanku
you don't really need electricity (or gas) for cooling, right? I mean, what you basically need is heat. Maybe something could be worked out with using PV-heating systems?
It seems sort of a waste to use solar energy captured by your solar plates to turn it into electricity (having to use batteries and inverter), which you then are going to use to produce heat..
Posted: Fri Jun 06, 2008 10:17 pm
by ENIGMA
Yeah,I remember when I was a kid ( a long time ago) I used a magnify glass,to start fires.
So if some device could be invented to track the sun across the sky and to magnify and direct the suns rays using lenses and mirrors.
This would produce enough heat to power a fridge/freezer,efficiently,during a sunny day.
Re:
Posted: Thu Jul 03, 2008 10:21 pm
by Karmanaut
Martin wrote:IF it's that efficient, you'd need something like a 150w pv panel, plus suitable batteries, controllers and inverter to run year-round - circa £1,000 - 1,200 all-in!

Is that right? This fridge consumes 0.1 kwh in 24 hours. (This is because the compressor runs very infrequently.)
If you had reliable sunshine, say 7 hours a day, wouldn't a 150W pv panel generate a maximum of 1.05 kwh per day? (150W * 7 hours = 1050 watt hours) I don't know if my maths are wrong, but it seems to me that the 150w would generate enough juice in one day to run that fridge for ten days (in ideal conditions).
Wouldn't a 20W pv panel give out a maximum of 0.14 kwh per day, if you had 7 hours sunshine? (20*7 = 140 wh = 0.14 kwh) Enough to run that fridge for 24 hours?
Apologies if I've missed something. I'm a solar newbie.
Re:
Posted: Thu Jul 03, 2008 10:24 pm
by Karmanaut
contadino wrote:
165 ltr freezer for €1.318.56 ex works in Germany is pretty steep. Needs 444Wh/day which they reckon you can get from a single 75w PV panel. Hmmm....
Our neighbours electricity's been off for 48 hours now thanks to a
temporale and it kinda brings these things up the list of priorities doesn't it?

This firdge freezer is a lot cheaper, but it uses 540Wh/day.
http://www.thekbzine.com/WeeklyFolders/ ... 2B%2B.html
Re: fridge off grid.
Posted: Thu Jul 03, 2008 10:56 pm
by John Headstrong
for a fridge is anyone using something like this.
http://tinyurl.com/6jt78t
running off a 12v wind and solar system, I know that it would not be exactly like a "real" fridge but would keep things fresh and cool.
Re: fridge off grid.
Posted: Wed Jul 16, 2008 10:05 am
by Wombat
Yup, but those little fridges run on a peltier effect device and consume about 4 amps no matter what you do. I have just had a standard (fridge 245 litre) fitted out with a 12 volt Danfoss compressor, will pick it up soon. They are much more efficient if you use 12 volts directly rather than supplying 240v through an inverter. Will let you know how it runs!
Nev