any extra insulation that you could whack on a fridge has got to be beneficial, however you must be carefull not to block up any "ventilation" holes front and back but apart from that it is a good thing, I would estimate about 5%- 10% points of thermal exclusion for every 10 mm of foam, also a thermal fan strategically positioned to remove the vented hot gases would be an enormous benefit

it gets to the stage ( and this is well proven) that enough foam or any good insulation could aleviate the need for any further cooling input, in other words it will keep the temperature inside a "constant" for an extended length of time which is a good thing for us campers

take the case of a good quality esky, put ice in there and with no additional cooling required  I have seen ice emerge after ten days (the big green fibreglass ones come to mind, dont know who makes them)

the idea is edzacary the same

now with  wind turbines, a big one will generate a large ammount of power very efficiently and quietly but little ones dont generate a great deal but do it very efficiently and quietly

I am a big fan (pardon the pun) of wind turbines and I have been lobbying the council to let me erect one in my backyard (approx 90 feet high and a blade span of 60 feet) I had intentions of cornering the market, well our block anyway, world domination would come later, but council will not approve such a thing

now what was I saying OH YEAH!! wind turbines, big ones good, little ones good too but not much power output but where they win is that they do it 24 hours a day and seven days a week, for no cost, now as anybody knows if you have a pinhole in a 5,000 gallon water tank  eventually that tank will run dry

same principle with the little turbine it is meant as a "trickle" or "maintenence" charge, small ammout all the time, if you leave a battery discharged or partially discharged (particularly lead acid) then the thing will "calcify" and bugger up very quickly it is much more desirable to have a battery "fully charged" than slightly charged

now fully charged is not as it seems, the maximum you will achieve with a vehicle alternator driving down the road is about 65%-70% charge these figures are argued by experts but commonly accepted as being between these figures, BUT with a "trickle charger" such as a small solar panel or a turbine over an extended period you can actually achieve a figure way above the above rated percentage points, which is highly desirable by campers, I will not quote figures here because even the experts differ highly here with their figures

this opens up another prospect if there are people out there contemplating doing this (please bear with me, simple question complex answer) if you charge a lead acid battery or batterys beyond the 70% stage then you will produce enormous ammounts of hydrogen and oxygen, far too much for a sealed box, you must ventilate these gases or an explosion at these concentrations will be imminent, below 70% and the gases are far less significant and NOT AS dangerous

because hydrogen and oxygen are both lighter than air they will gravitate to the top so when charging above the 70% mark please put large air vents straight above the batterys and also place one in the bottom of the container as well, in case of a bit of wind pushing the mixture back down

a sealed battery will also produce these gases and they have a pressure valve built in which releases excess gases so vents are still needed when charging over the 70% magic barrier, agm and gel Batts produce the gas as well but it is usually taken up by the opposing plates and therefore are not a danger these can be sealed in a container without fear