Comment by boredpudding

I'm not sure if the 1800kWh is correct here. I'm guessing it's one of these two:

- You're talking about what heat pumps use in electricity. However, the system would store heat. If a heat pump uses 1 kWh to get 3 kWh of heat into the house, a heat based storage system needs to store the 3 kWh.

- You're confusing gas & electricity. 1800 m3 in gas would be about correct. However, that's about 9,5 kwh per m3 in heat.

There are interesting heat storage methods though, there is a long term basalt heat storage system in 'Ecodorp Boekel' in The Netherlands. It uses solar to heat during the summer and heats the homes with that in winter.

Due to size though, it only really works in 'collective' communities. The bigger the size, the more heat it can store per size.