Scalable video allows to decode a single video stream, or part of it, at varying quality of service (QoS). Since the amount of calculations scales with the QoS, energy dissipation is expected to scale similarly. To investigate the relation between QoS and energy dissipation we actually measured the energy dissipation of a scalable video decoder implementation on an FPGA. The measurements show how dissipation effectively scales with QoS and indicate how energy can be saved by rescaling the QoS and reconfiguring the FPGA accordingly.