The heat medium transport paths are arranged between the first building and the second building and transport heat media that transport heat energy. A temperature distribution acquisition means acquires the temperature distribution of the heat media that have temperatures being different from each other in the heat medium transport paths and that are sequentially transported in a state of having a predetermined length in the transport direction in the heat medium transport paths. A control means receives a load request of an air conditioner of the first building, and when a heat medium having the heat energy that satisfies the load request received reaches the first building, based on the temperature distribution acquired by the temperature distribution acquisition means, the control means causes the air conditioner of the first building to take out the heat energy from the heat medium reached.