Conventionally, a variety of systems for controlling power supplied to a building or the like have been proposed.  However, according to these systems, when a power customer establishes a power reception/distribution facility and receives power supply therefrom, a supply contract is often made between the customer and a power company based on power supply terms and conditions, and controlling the contracted power under that contract. “ Energy-saving Control Unit and Energy-saving System” (see Patent Document 1) proposed by the inventors of the present invention is one of them.  The present invention is created to reduce power consumption so that it does not exceed a maximum preset demand value, thereby reducing contracted power.  This is attained by controlling power supply to power consuming devices, such as air conditioners, refrigeration equipment, motor equipment, and electric light facilities, in a given order of each device (namely, ranked) using a maximum demand wattmeter as a contracted power monitoring gauge and by scheduling and cutting peak demand without any impact on business of large-scale retail stores. 
Currently, an electronic ballast, an inverter, and related devices are introduced to each of electrical facilities in a building, and an air-conditioning heat source, control of number of pumps, and a sensor and inverter control are introduced to mechanical facilities, promoting steady energy saving.  However, it is not an integrated control system appropriate for an entire building, which controls excessive operation for each room, each floor, or the entire building for seasons, periods, or days, and it operates based on the maximum amount of consumed energy.  Therefore, it is difficult to achieve sufficient energy saving. 
[Patent Document 1] Japanese Unexamined Patent Application Publication No.  2003-23729.