Energy Harvesting and Energy Efficiency

Abstract

Energy harvesting and energy efficiency are two key topics for today’s power community. In the development of modern society, one of the key factors is to save energy in order to become more independent of other resources. Two important approaches can be taken—one is to change behavior and thereby save energy and the second is to develop new technology which is able to save energy in different applications. Chapter 1 gives an overview of challenges and possibilities in terms of energy saving and also energy efficient use. Initially, the first key topic—energy harvesting—becomes one of the most motivated fields of the multidisciplinary science due to the complicated features of the harvester materials, dependences on various mechanical, electrical, and magnetic parameters, rich responses on different external excitation frequencies and strength. Strictly speaking, vibrations stem from either man-made systems or natural processes can be used as an important electric resource for low-power-consuming electronic devices such as transducers and wireless sensors. That can contribute at the batteryless applications for much sustainable and renewable power generation, whereas some technical problems should be solved to achieve the expectations of the electronics society. Although conventional harvesters work on the basis of linear resonance, there exist certain parametrical limitations on their power generation. Indeed, excitation frequency, electrical load, manufacturing tolerance, and ambient temperature play important roles in order to determine the optimized energy generation. Besides, the nonlinear nature of the vibration phenomena contributes at the power, and these nonlinear effects cannot be neglected for an optimized harvester system. Thus, Part I of this book initially gives an outline to the reader on the electromagnetic and piezoelectric energy-harvesting systems and then focuses on the theoretical and experimental techniques by introducing different harvester systems.