So, i’ve been thinking — a large percentage of my energy consumption is from air conditioning, energy demands on the grid vary through the day, and the temperature usually is cooler at night, when the sun isn’t out.
So, why can’t we build big “coldness reservoirs” underneath our homes. The idea is this: get an extremely insulated system. When energy rates are cheapest, make the system cool off the fluid inside the system. Later, when energy rates are higher, use the fluid productively. You could use it as part of your air conditioning system, you could use the heat difference as part of a reverse-peltier effect to generate some electricity, etc.
Of course, you could change the actions depending on what the situation is (heat vs. cold and when the rates are high) — you could imagine some future scenario where rates are higher at night because there’s no sunlight (and thus we’d have to rely on gas, coal, etc)
Anyway, why doesnt this work? I could imagine that you’d need to store way more energy than would be possible to do economically. Water’s got a pretty high specific heat — if you could use water, you’d probably need to store so much water that you’d end up having to have a couple swimming pools full of water stored underneath your home, and that can’t be cheap. Also, to be effective, you’d probably need to supercool/superheat the water to the point where you’d be losing energy through system inefficiencies.
Anyway, it’s an idea.