I visited Smart Network Project located in Minato Mirai 21 area and got a detailed explanation on the demonstration experiment.
It is a electric-vehicle-related house, of which electricity is provided by the solar power generation in addition to the general power line.
In that system, the battery of an EV, Nissan's LEAF, is also used for the residential appliance as a storage battery from the solar power.
I felt such smart house might be one of the forms only in large cities in the future because of necessity of many charging stations.
