The Wireless Sensor Network (WSN) is composed of sensors. These sensor nodes sense the physical parameters like temperature, pressure, humidity etc. In real time environment these sensors have different energies. In this paper, the authors have assumed three types of sensor nodes. Now-a-days, most researchers are focusing on how to increase the network lifetime through efficient use of the energy. Generally the network is divided into a certain number of clusters and then a cluster head is selected from all these sensors randomly. There is a Base Station (BS) or Sink which receives aggregated data from the cluster heads and sends it to the end computer.