Current networking equipment usually provides several energy profiles with different performance capabilities. For example, in EPON systems, ONUs are able to switch their transmitters off when there is no data to transmit. This low power mode, known as doze mode, can significantly reduce power consumption in EPONs if wisely used. In this paper, we evaluate through simulation the potential power savings that can be obtained using this mode in many different scenarios. In particular, we analyze the impact of the DBA algorithm and the mode governor on both energy efficiency and frame delay with different implementations of the doze mode.