I find this technology interesting because it won't work well for an individual, you must cooperate to make it work. The heat is stored using boreholes to heat

I find this technology interesting because it won't work well for an individual, you must cooperate to make it work. The heat is stored using boreholes to heat a volume of the earth underground. The surface area/volume ratio is against a single user, but becomes more favorable as the number of participants increases.