Energy consumption in Information and Communication Technology (ICT) is 10% of the total energy consumed in industrial countries. Recently, Virtualized Network Environment (VNE) has been emerged in this technology. Therefore, it is essential to develop novel techniques that reduce VNE's energy consumption. In this paper, we formulate a Binary Integer Linear Program (BILP) that reconfigures already allocated virtual networks to minimize VNE's link power consumption, during off-peak periods. Because the formulated BILP is NP-hard, a novel heuristic algorithm is also suggested. The simulation results confirm the proposed solutions save notable amount of energy in VNE's substrate links, during off-peak hours.