The authors provide a practical description of the most important forms of technical utilization of renewable energy sources. They present their potentials in light of global energy issues and the thermodynamic limits of energy conversion processes, discussing their contribution to a sustainable energy system. The book covers photovoltaics, solar and geothermal energy, biomass, wind, and hydropower, thus addressing both electricity and heat supply systems. Each chapter begins with the natural and engineering scientific fundamentals, explaining the functioning of the central components and their connection to systems. Concrete planning and design examples link the theoretical foundations with a practice-oriented approach to the integration of renewable energy systems into existing infrastructures.