WSN technology involves a set of challenges ranging from determining resource characteristics of the wireless network, when and how to optimise energy and how much processing to do in each node, to principles for management of entire sensor networks and how the data produced by sensor networks can be managed, used and presented. A simulation environment seemed to be then essential, since the test of the hardware and software is hard and difficult. Beyond cost and time savings, the simulator offers the great opportunity to extend the potential and the features of WSN. As there are many simulators, we make an attempt in this paper to specify the important ones related to energy consumption. In fact, we discuss the performance, reliability and usefulness of each of them to better see the disadvantages of these simulators and their strong points to be able to develop a better model.