According to an embodiment, server includes estimator, condition setter, calculator, receiver, and controller. Estimator estimates an energy demand in building where electrical apparatuses are equipped based on apparatus data. Condition setter sets energy consumption suppression conditions. Calculator calculates operation schedule of apparatuses which can optimize an energy balance in building based on the demand and condition. Receiver receives DR signal including energy consumption suppression condition. Controller controls the apparatuses based on operation schedule calculated based on the condition corresponding to that included in the DR signal.