Abstract-In this paper we propose a lower bound on the energy required for synchronizing nodes in a Wireless Sensor Network (WSN) by using statistical estimation techniques. The energy required to synchronize a pair of nodes within a network with predefined synchronization accuracy is modelled as function of the transceivers power and the number of transmitted messages. In our analysis, we have considered the dynamic nature of nodes communicating within a correlated Rayleigh fading channel. A unified mathematical model has been defined to analyze the impact of nodes' relative velocity on the pairwise energy and synchronization accuracy trade-off.