A systematic approach to energy policy making is particularly important due to high cost of energy in recent years. The energy crisis has increased the attractiveness of biomass fuels as well as other renewable energy technologies such as solar, wind, etc. They re-emphasize their role as significant source of energy. Renewable sources of energy are most frequently able to compete with conventional commercial energy mainly in rural or remote areas of the developing countries. The first paper included in this book is by Jhirad, that deals broadly with new and renewable sources of energy and discusses some examples of their applications in several Third World Countries. The other paper by McNelis and Fraenkel focuses on two forms of renewable energy technologies which have generated much interest in recent years: Solar and Wind. The next paper by Luque focuses on recent technology developments in photovoltaics. Editor is confident that the papers included in this book will make useful contributions to energy research and policy whether they are driven with the objective of augmenting supplies to reduce oil and coal dependence to increase the economic benefit per unit of energy consumed, or to reduce the impact of energy use on the environment.