Energy plays very important role in any kind of network. As most of routing protocols and strategies are designed by considering the well-connected network but because of the mobility of nodes these routing protocols do not work effectively. For such kind of intermittent connectivity, Delay Tolerant Network is used. Amongst all the mobile nodes, many have a very limited amount of energy and to perform any kind of operation energy is required. So, it is necessary to reduce the consumption of energy. The effective and efficient use of energy increases the lifetime of node and network. Hence, there are some approaches which proposed different schemes to reduce the energy consumption of node and also increase the delivery probability. By using different aspects of the conservation of energy the energy efficiency has been increased. Amongst them, few recent approaches are explained in this papers which consider the energy prominently. © Springer Nature Singapore Pte Ltd. 2018.