Many of the world’s biggest cities have miles of underground pipes built decades ago that provide district energy. District energy systems use a central plant to produce steam, hot water or chilled water that is then piped underground to individual buildings for space heating, domestic hot water heating and air conditioning. As a result, individual buildings served by a district energy system don’t need their own boilers or furnaces, chillers or air conditioners.
Japan is a country seeking energy independence as well as environmental credibility. It has grappled with nuclear disaster at Fukushima and is currently the sixth largest emitter of greenhouse gases in the world.