The IEEE 802.3az amendment, known as Energy Efficient Ethernet (EEE), has been conceived to reduce the overall power consumption of Ethernet networks, defining a new operational mode, namely Low Power Idle, that allows the partners of a network link to timely enter a state characterized by a limited consumption. In this paper we focus on the application of EEE concepts to industrial real-time Ethernet networks. We firstly describe the behavior of EEE-enabled links when subjected to typical industrial traffic, providing an assessment of both actual power savings and delays that might affect frames delivery. Subsequently, we carry out a simulation analysis for a specific network, Ethernet POWERLINK, aimed at verifying its real behavior when EEE is adopted. The results show that considerable power savings may be achieved without influencing network performance.