As renewable power generation and fuel cell systems became familiar to standard homes, management technique of distributed energy source is becoming a major issue for Smart Grid in Japan. We propose a new structure of electric power network whose generation and delivery systems are separated to each other. Third-party institution called EVNO (Energy Virtual Network Operator) manages multiple distributed energy sources comprehensively, and provides a virtual energy generation system. This system is based on the idea of Mobile Virtual Network Operator (MVNO). Efficient energy supply and demand system is achieved by temporal and spatial smoothing. Furthermore, it enables low price, high quality energy supply and also widespread use of renewable energy generation equipments and household fuel cells by bringing in the concept of market mechanism to electricity transaction.