Green computing is nowadays a major challenge for most IT organizations. Administrators have to manage the trade-off between system performances and energy saving goals. Autonomic computing is a promising approach to control the QoS and the energy consumed by a system. This paper precisely investigates the use of synchronous programming and discrete controller synthesis to automate the generation of a controller that enforces the required coordination between QoS and energy managers. We illustrate our approach by describing the coordination between a simple admission controller and an energy controller.