Redefining our energy landscape by means of regenerative, volatile and decentralized organized systems represents a major challenge for the creation of distributed control solutions. Standards are required that permit describing the variety of energy conversion systems and that enable an interoperable exchange of energy amounts in an open, flexible manner by concurrently taking into account technical and market requirements. This paper introduces the concept of unifying Energy Agents. They have the potential to reduce the ever growing complexity that comes along with the various solutions presented or that are already available at the market. In contrast to that, the notion of Energy Agents stands in our view as a representative for a required methodology that enables a consistent development of decentralized control solutions. In order to demonstrate this approach, the application of Energy Agents in a smart house scenario is discussed. It is shown how arbitrary agents with different levels of sophistication and abilities can cooperate with each other in a smooth way. It is our strong believe that a stepwise and standardized development of Energy Agents representing the needed decentralized control solutions is needed for a sustainable design of an open Future Energy Grid.