To solve the problem that there has been no effective technology to suppress a power consumption below a threshold as the unit price of a commercial power increases stepwise in accordance with the increase in demand.

The output sum from a commercial power source 11, a non-commercial power source 31 of private power generation, and a storage apparatus 32 covers loads 14-19. When a commercial power measured by a measuring apparatus 12 is at least a threshold or larger, selection is made among the loads 14-19 for temporary stoppage. Thus, reduction in both commercial power and cost for purchasing it is attained by utilizing a non-commercial power source.