This workshop comprises part of the four-year (1985-1988) non-nuclear energy R & D programme for the development of renewable energy sources which is being implemented by the Commission of the European Communities. The aim of the workshop was to present work by the contracting laboratories in addition to work by numerous other research laboratories in 11 European countries. Extensive discussions were also held on the present state of this basic, directed research in photochemistry, photoelectrochemistry and photobiology, and where the future emphasis may usefully lie. Thus the book presents the proceedings of all the papers presented and summarizes the recommendations made by the participants as to where future research support may be most effectively placed. It was emphasized in these recommendations that the interdisciplinary collaboration between photochemistry and photobiology had been quite successfully achieved in this European programme. There were both high quality basic research and practical benefits accruing from the work, and these are described in the report on proposed areas for future research. This book contains work reported by 30 leading researchers and laboratories in Europe. The contents parallels and overlaps research in photovoltaics and semiconductors and therefore provides a unique link and basis of information across the field of photovoltaics, semiconductors and photosynthesis.