It's a good topic, actually the best solution I've seen is "compressed air energy storage system":
Not sure if anything is available on the consumer market, but it's something worth making yourself, maybe.
I expect it to take a lot of space and be pretty loud....
Poor energy density, poor efficiency if you're not recovering the heat, you need to turn all that into electricity, a ton of maintenance compared to a simple battery, simply not feasible at a small scale.
Since the price of the electricity fluctuates a lot during the day/night (at least here in Norway), I was thinking about a small household/mining rig solution, a power storage which can be charged during the "cheap" hours and when the electricity price is hits the top then used the stored power to mine/powering the house. In addition you can add additional charging from solar/wind sources.
I think that will be the future.
Anyone knows about/have experience with such solutions like Tesla Powerwall?
A tesla powerwall goes for $11500, we don't know how much electricity you use and how big is the difference between the day and night tariffs.
Let's assume it's 60 cents ? as I see
6.08 kroner per kWh, let's say cheap at night is 10 cents and you get 7$ a day, so 4.5 years you're going to recover the investment. Oh, add another half a year because it too has an efficiency, on paper 92% but, that's paper.