Читать книгу Indoor Photovoltaics - Группа авторов - Страница 18

In order to do work on an object, exergy needs to be available. If a system is to use the exergy of another system, which might be surrounding energy or a converter, the systems have to be coupled. The form of coupling between energies of the same form or between different types of energy are called weak and strong. There are nine types of energies [9], and in principle, all of them can be used for energy harvesting:

 – gravitational

 – kinetic

 – heat

 – elastic

 – electric

 – chemical

 – radiation

 – nuclear

 – mass.

Besides the use of mass and gravitational energy, each form of energy has been used in micro harvestings research so far. Reviews on the principles, the history and the current state-of-the-art in industry and research have been provided by various authors, such as [10–12]. As this book focuses on indoor applications, this chapter discusses the level and usability of these types of energy for indoor applications. Some of the most important references are provided for further reading, and principles and examples of demonstrated systems or commercially available devices are included where possible. As most generators aim at converting energy from ambient energy to electric energy, the converters discussed in this chapter will focus on those.