The direct conversion of daylight into electricity by photovoltaic solar cells is one of the most promising of the renewable energy options. The importance of the technology is reflected in the growth in the field. What was largely technology for space programmes in 1976 produced 28.6 MW of terrestrial modules in 1987. The popularity of the technology can partly be explained by its versatility. Arrays of any size and voltage can be constructed from standard modules, with the conversion efficiency being practically independent from output. Photovoltaics are also well suited to on-site generation of power in remote areas. This book is intended primarily to give students, engineers and scientists entering the photovoltaics field an overview of all aspects of the subject, with pointers to further reading. However, by using simple language and avoiding jargon, an effort has been made to make the work useful and interesting to the general public.