Water scarcity affects the African, Asian, European and American continents, causing serious problems of social welfare and stability. This book of the NATO Science Series presents the state of the art of Desalination Technologies driven by Renewable Energies, highlighting the results achieved in the research field and presenting the potentialities of such technologies. Following an Advanced Research Workshop held in Tunisia from the 23rd to the 25th of February 2006 and collecting prominent scientists from more than 20 different countries, several contributions were selected from researchers, technicians, and industrial representatives, each focused on several different aspects of the use of renewable energies for desalination. Moreover, several regional overviews illustrate the actual state of RE exploitation in most of the countries interested by water scarcity and abundant availability of solar, wind and other renewable energies.