The present invention provides a coordinating node in an energy usage control system. The coordinating node receives trade-off functions from energy consuming nodes. The coordinating node and the energy consuming nodes collectively form a domain. A trade-off function from an energy consuming node describes a relationship between a result of energy consumption by the energy consuming node and a degree of satisfaction towards the result. The coordinating node develops policies respectively for the energy consuming nodes, based on the received trade-off functions. The policies each contain at least one goal and/or at least one procedure to guide the respective energy consuming node to control its energy usage such that the energy consuming nodes collectively achieve an optimum energy saving for the domain.