Mobile Ad Hoc Networks (MANET) are autonomous, infrastructure less and self-configuring networks. MANETs has gained lots of popularity due to on the fly deployment i.e. small network setup time and ability to provide communication in obstreperous terrains. Major challenges in MANETs include routing, energy efficiency, network topology control, security etc. Primary focus in this article is to provide method and algorithm to ensure significant energy savings using re-configurable directional antennas. Significant energy gains can be clinched using directional antenna. Key challenges while using directional antenna are to find destination location, antenna focusing, signal power and distance calculations. Re-configurable directional antenna can ensure significant energy gains if used intelligently. This article provides a brief insight into improved energy savings using re-configurable directional antennas and an associated algorithm Keywords: Directional Antennas; Energy Efficiency; Antenna Re-configuration; Mobile Ad hoc Networks; Genetic Algorithms I. INTRODUCTIONMobile ad hoc networks (MANET) are versatile kind of network and are able to work in numerous situations and places where provision of fixed infrastructure is not feasible. MANETs are amenable to topology change as the topology changes over time. The participating nodes are mobile and support unrestricted movement in a limited geographic area [1]. MANET works over wireless communication medium and wireless medium is susceptible tohigh interference and connection failure. Due to this the participating nodes should be able to heal themselves and reconstruct the network state. MANETs usually operates using mesh topology and a conventional mobile node uses Omni-directional antenna (which emanates isotopic radiations) for communication. Using these antennas mobile nodes cannot easily find the location and distance of the destination nodes and suffer huge energy losses. Reconfigurable directional antennas are panacea for these problems. These kinds of antennas are highly adaptive to topology change and provides other numerous advantages. Reconfigurable directional antennas (RDA) are able to reduce collisions in the communication and second major advantage is the antenna gain. The increased gain improves the transmission range of nodes and significantly reduces the number of hops required to reach the destination [5]. Reconfigurable antennas offer following explicit advantages over conventional directional antennas [9,14].