This paper presents Energy analysis of Wireless Sensor Network. Energy is the main concern of any node including cluster heads. The authors have measured mainly LEACH & DIRECTED DIFFUSION protocols with their associated energy models on different values. They observed the lifetime of wireless sensor nodes and cluster heads in the maximum capacity of their performances in the form of their lifetime (Number of Rounds). They found that LEACH (Low-Energy Adaptive Clustering Hierarchy) protocol is better than DIRECTED DIFFUSION.