In any networks power saving is one of the most important features for the addition of devices lifetime. To enhance power efficiency of broadband wireless sensor network based on battery power. In this paper, the authors first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, they present a systematic and wide-ranging taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data attainment. Finally, they conclude the paper with insights for research directions about energy conservation in WSNs.