I remember we had my grandparents' old ice box. We used it as an antique decoration, but in the day it served as a refrigerator.
Anyway, it occurred to me that we now have better materials and insulation to build a better icebox, if we wanted. We even have those gel packs we can freeze, instead of using a block of ice and dealing with the tray of runoff from that melting block of ice.
In the winter months up north, one frozen gel-block could be in the icebox and the other outside refreezing. Switch them as necessary.
I assume a chest freezer could be run mostly using the outside temperature as well.
During summer months, use the plugin or gas operated freezer to refreeze the blocks. I'd run the gas freezer during warm months using homemade methane from a digester, but that's just me. Even if using a plugin freezer during warm months, it seems like it would still use a little less energy than running both the refrigerator and the freezer. I could be wrong about that, though. The freezer will be working harder for sure during those warm months.
Anyone really looked into this for off-grid living?
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 public, 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?