In the recent times, various applications are conceptualized where wireless sensor network (WSN) is used either as a subnetwork or as a complete domain. WSN having its unique characteristics, because of that the applicable protocols for congestion control, routing and security require distinguished mechanism as compared to other wireless networks such as WLAN, MANET, etc. One of the most irreversible resources is battery power. Since year 2000 a project called µAMS in Massachusetts Institute of technology (MIT), where Wendi Heizelman has introduced a communication protocol called Low Energy Adaptive clustered Hierarchy (LEACH). Since then, till today enormous amount of research schemes have been suggested to have different layers protocols in WSN, with optimal use of energy. This paper aims to study, investigate and analyze various contributions, limitations, technology used towards energy optimization based protocol development in WSN. The outcome of this paper will be quite valuable fro academicians, industries and researchers as a one hand tool to understand future research directions.