Fridges: energy loss isn't that bad, especially when your fridge is decently filled. Most of the heat capacity is in the contents, not in the air. My current fr

Fridges: energy loss isn't that bad, especially when your fridge is decently filled. Most of the heat capacity is in the contents, not in the air. My current fridge is already off for multiple hours at a time. With a couple degrees of margin and a little bit of high-heat-capacity padding, this is realistic to do. Clothes dryers: Agree, don't start a wash cycle, then wait 8 hours after finishing to start the drying cycle. But delaying both at once does work. Hot water heaters: Already being done at a smaller scale, look up Quooker. Given known usage pattern, the replenishment of hot water can also be delayed. Ice cooling: The math checks out. The temperature difference of 200 gallons of water from 5F to 70F provides over 400.000 BTU of heat capacity. A quick Google tells me that the upper size of air conditioning capacity is 14.000 BTU / hour, so that's more than enough. Given proper isolation, this can probably be lowered by at least an order of magnitude. 20 gallons isn't that much, in my opinion. Besides, this is already being done in practice, using the underlying soil as heat buffer. It has enough capacity for a whole season. It's not ideal, but mathematically it checks out.