Rational and economic use of energy, with the least damage to the environment, is vital for the future of our planet. Achieving energy efficiency and reducing environmental pollution are increasingly important aspects of professional engineering. This course equips graduates and practicing engineers with an in-depth understanding of the fundamental issues of energy usage in the industrial and commercial sectors. It gives a wide overview on solar thermal systems and their main components. Starting with basic issues of physical processes and design options for non-concentrating and concentrating solar thermal collectors, systems engineering based on these technologies will be presented. Here the complex systems for different applications ranging from solar water heating to process heat for industry to solar thermal power production will be described.