A method is presented for adjusting power consumption in a network node of a cellular communication system. The method is performed in a power adaption device and comprises the steps of aggregating bitrates for all traffic flows associated with a power amplifier of the network node to an aggregated bitrate, determining when to adjust power consumption by determining whether power consumption of the power amplifier can be reduced with acceptable effect on the traffic flows associated with the power amplifier, and adjusting power consumption by reducing power consumption of the power amplifier when it is determined that the power consumption of the power amplifier can be reduced with acceptable effect on the traffic flows associated with the power amplifier. A corresponding power adaptation device is also presented.