Solar thermal power plants with their large thermal storage system provide dispatchable electric energy at low cost. Their collector fields extend over square kilometers. Collectors consist of light-weight steel structures tracking the sun in a way allowing conversion of concentrated solar radiation into heat to drive a steam power process. Requirements placed on the collectors in terms of costs, rigidity and precision jointly define an exciting challenge for engineers. The report briefly introduces the functional principle of these power plants and their collectors. Using the example of two modern collectors – parabolic trough collector and heliostat – the respective design and their special features are explained.