Another thought on using the freezing temperature outside for refrigeration;
Keeping a large container of antifreeze (water/ethanol mix) outside could accomplish refrigeration inside the ice box without having to add or remove ice blocks. Why not just circulate the cold fluid from the container outside into the refrigerator, then back to the outside container again? The bigger the outside container, the more area it could constantly cool inside. The flow rate through that loop would dictate the temperature inside the refrigerator. Low flow rate in the refrigerator, high flow rate in the freezer? A small pump wouldn't use much electricity. A few
solar panels and a couple of deep cycle batteries would keep the pump going 24/7.
A system like that could probably be integrated into a regular refrigerator, assuming manufacturers want to offer true energy efficient refrigerators to the permies, something I'm not entirely convinced of at present.
Better still, integrate this into an absorption refrigerator. During the summer, heat thermatic oil via
solar, then circulate the hot oil into the fridge at the point where the refrigerant is heated to provide the cold inside the fridge. During the winter, let the outside temperature cool the antifreeze and circulate that. A solar trough
should heat the oil
enough for the absorption cycle. A stove or furnace could also be used. (I posted something about solar cooling via hot oil & absorption chillers/refrigerators/AC in the
rocket stove section)
If either of these systems are viable, why haven't manufacturers already built them? Either system would reduce the energy you have to purchase. What am I missing here?