Concerning distributed energy management, virtual power plants are a frequently discussed topic. Although there are several different approaches to the coordination of distributed energy resources in this context, the inherent dynamics of this complex task especially relating to reactive scheduling have mostly been neglected. As a consequence, this paper discusses MARS, a multiagent-based coordination approach contributing to the solution of the reactive scheduling problem for virtual power plants. Following an introduction to scheduling in the energy domain, a general formalization of scheduling in virtual power plants is given. This formalization is used as starting point for the specification of the control system coordinating the distributed energy resources. Finally, the performance of the resulting domain-specific multiagent system is reviewed by means of simulation.