There is a rapidly growing need to understand and manage the energy consumed in discrete manufacturing systems. In order to enable more accurate and detailed energy consumption estimation, several recent studies have focused on energy consumption dynamics of specific manufacturing processes and associated equipment. However in discrete manufacturing systems consisting of multiple machines, energy consumption of individual machines can be expected to be influenced by the higher-level production control systems and its associated policies. This paper presents a simulation model that integrates the machine-level energy control policies together with production control policies to develop a holistic approach to characterize energy dynamics in discrete manufacturing systems. Results from an exploratory study indicate that production control policies can significantly influence the amount of energy wasted in manufacturing systems.