A system for planning energy supply for energy consumers includes a first sub-system operatively associated with an energy coordinating body, such as an energy management system, and second sub-systems operatively associated with corresponding energy suppliers, such as power plants. A global communication network, such as the Internet, is employed between the first and second sub-systems. Each of the sub-systems includes an interface for exchanging energy planning information between the sub-systems and for negotiating an energy supply specification from the energy supplier to the energy consumers.