Energy management is one of the main hurdles in the quest for autonomous and reliable Wireless Sensor Networks (WSN). This thesis examines several scenarios where mobility is added to the network components in order to carry out energy management tasks. The main goal is to increase network availability by recharging or redeploying “depleted” sensors with the help of mobile entities. For static sensors networks we provide a cluster-based solution where (1) workload is balanced, (2) the movement of the maintenance entities is minimized and (3) there is a small number of sensor communications. This problem is a variant of the so-called Facility Location Problem (FLP). Although finding the optimal network partition and placement of the facilities is a NP-hard problem, we show a simple and efficient solution that provides partitions of remarkable quality. The experimental analysis shows that sensor communication cost remains low as the size of the network increases,there is a rapid progression towards convergence and the quality of the final partition is similar to centralized clustering benchmarks. We also study a particular instance of the Frugal Feeding Problem (FFP), where mobility becomes a sensor’s attribute and service stations are static. In this scenario, we examine the mobility strategies, underlying topologies and network parameters that guarantee an autonomous sensor recharge. The experimental results show that taking a proactive approach to energy redistribution and network fatigue outperforms passive strategies. The greedy closest-first swapping-based mobility strategy offered the best overall performance among all the proactive approaches studied and the proposed Compass Directed Graph provides a good underlying topology to achieve energy equilibrium.