Clean Energy
Presenting a broad survey of the energy problems facing society over the coming decades and the prospects for their solution, this book emphasizes the importance of developing a strategy for the world's future energy supply.
TABLE OF CONTENTS Clean Energy
Chapter 5: Renewable Energy - Electrical
By virtue of its versatility, convenience and cleanliness in use, electrical energy has become the fastest growing sector of the energy market. The range of applications for electricity is almost unlimited. In Chapter 4, we surveyed the forms of renewable energy that give rise to heat. Heat energy is usually employed for space or water heating, for industrial processes, or for conversion into electricity via a steam cycle. In this Chapter, we examine the various forms of potential energy and kinetic energy that are found in nature and that may be utilized to generate electricity via the medium of mechanical energy. It is also convenient here to include photovoltaic and photoelectrochemical systems, both of which employ solar radiation directly to generate electricity (note, thermophotovoltaic systems are discussed in Section 4.4, Chapter 4).
5.1 Hydroelectricity
The use of water power has a very long history, going back at least until Roman times. The earliest reference to an English mill was in 762 AD, in a charter issued by King Aethelbert II of Kent. In 1086, The Domesday Book (a census of English landowners and their properties) recorded that there were 5624 mills in England. Early mills (known as Norse or Greek mills) employed a horizontal waterwheel that drove a pair of grindstones directly without the intervention of gearing. Later mills were fitted with the vertically-mounted undershot wheel as it was more appropriate to the gentle landscape of England. The undershot mill was turned by the current of water striking the lower...
Copyright The Royal Society of Chemistry 2004 under license agreement with Books24x7
