“This temperature corresponds to 0 degrees Fahrenheit, so it was “probably a round, easy number to remember”
That’s what Allouche and team will be working on next, as they build their research summary into a full report, to be published in September 2024. “These findings give good reasons for ‘3 degrees of change’ to be further explored,” Allouche says.
Three Degrees Of Change: Frozen food in a Resilient and Sustainable Food System (PDF)
Look into the “cool cupboard” associated with David Holmgren, who talks about it in his book Retrosuburbia. IIRC it uses simple geothermal and natural convection to keep certain foods cool.
I live in a cold place and lately I’ve been taking water jugs outside to freeze, then bring them in once I go out in the morning. With them, the fridge hardly runs any more. I’d prefer something automatic like a cool cupboard for certain things and a well insulated fridge running straight on DC solar.
How many liters do you need to put in the fridge to keep it cold all day with minimal power usage?
Quick answer to your question: I’m using about 12 liters.
But a good answer depends greatly on some variables specific to your own circumstances:
I’ve noticed the fridge consumes more electricity in summer, as we don’t have AC, and I keep the house between roughly 54-60F (12C to 15C) in winter. In summer the kitchen ranges from 16C in the morning to up to 33C, although with shading improvements it’s now more often 26-27C in summer.
I’ve also noticed a big difference in the jugs when the overnight low is -26C vs. -6C. At the coldest level, the jugs don’t thaw in the fridge for 2 days at least, while a minor freeze gives at most a day of free cooling.
Our fridge is of the style with a refrigerator section above and a freezer drawer below. They are in separate, insulated compartments with their own access doors. I assume that with the ice in the fridge, almost all if not all of the electricity used is to keep the freezer cool.
I’m guessing at the usage based on a couple observations: 1) our LFP battery that we use for the fridge etc. during peak pricing times drains much slower with the ice and 2) the fridge is noticeably quieter with the ice jugs. It would be better to measure for a month with a kill-a-watt tool.