Energy Harvesting: Technology, Methods and Applications

BOOK DESCRIPTION: In the last decades the increasing need to produce energy in nontraditional ways has led to researchers searching for cheap and environmentally safe sources of energy. This has caused a growing interest in Energy Harvesting (EH), which is a science that tries to capture energy provided by wind, rain, or other natural vibrations to convert it into a different more useful form of energy. The first chapter of this book studies a model which simulates a 'small' cantilever beam, and evaluates the optimal thickness for the cantilever, comparing the reaction to wind force of difference devices with the same shape but different thickness of piezoelectric layer. Chapter two discusses three energy conversion schemes with special emphasis placed on micro electret-based electrostatic energy conversion mechanisms. Chapter three studies modeling on piezoelectric energy harvesting from pavements under traffic control. Chapter four investigates the Aero/hyrdro elastic phenomena such as Fluttering, Galloping, Buffering, and Vortex Induced Vibration for energy harvesting. Chapter five introduces the concept of energy harvesting from water systems, and the established technologies and projects under development to recover energy from water networks are presented. Chapter six examines a piezoelectric power supplier for underwater applications, which is optimized to feed magnetic sensors. The final chapter describes a novel power generation from algae based on the combination of exergy recovery and process integration technologies. CHAPTER 5 : Energy Harvesting in Water Systems (Giacomo Ferrarese and Stefano Malavasi, D.I.C.A. Politecnico di Milano, Italy) In recent years the interest in green energy applications is gaining ground, thus many innovative devices have been developed to produce energy from renewable and alternative sources. Regarding energy from water, great attention is reserved to small-sized hydroelectric devices based on low power production. In fact large scale hydroelectric plants represented the preferred way to produce energy from water in the past years, but today, especially in the western countries, they are considered no more sustainable. The reasons for this change are principally the scarcity of new sites and the big environmental impact of such structures. In this context water systems are proposed as a new alternative source for energy harvesting in small-sized hydropower applications. The distributed generation is increasingly playing an important role in the sustainable energy development decentralizing the production of energy. As a result the electric network and management facilities are evolving toward a new shape known as smart-grid. In the present excerpt after an introduction on renewable energy perspectives, the concept of energy harvesting from water systems is introduced, then the established technologies and the most promising under development projects to recover energy from water networks are presented.