This thesis presents an enhanced dynamic performance evaluation method for line-concentrating solar thermal collectors. Due to its dispatchability and large storage capacity, concentrating solar power is considered of high relevance in the future renewable energy mix for both, electricity generation and industrial process heat supply. To fully exploit this potential and legitimize investments within this sector, a reliable and meaningful performance testing is essential. The proposed flexible, dynamic performance evaluation method allows for a significant reduction of testing time, effort, and consequently costs-especially for complex test conditions as they prevail for systems of larger dimensions such as line-concentrating collectors. For this reason, the present thesis comprehensively addresses diverse aspects of dynamic in situ performance testing. It includes a wide application of the elaborated procedure to diverse test collectors, ranging from small-scale medium-temperature linear Fresnel collectors to large-scale high-temperature parabolic troughs, considering different heat transfer fluids and receiver designs. It therefore proves to be a powerful and beneficial extension of the current testing standard to more complex test situations. Flexible and simultaneously reliable certification procedures are considered crucial for the further establishment of solar thermal technologies and their global acceptance.