Review of in situ Test Methods for Solar Thermal Installations

The market for large solar thermal systems is growing and with it the need to plan, design and simulate these systems precisely. This requires the ability to accurately and meaningfully measure their performance and yields. Hence activities for the development of methods to characterize such plants are on-going. The paper presents three of these methods and compares them with regard to their technical requirements and boundary conditions. The comparison includes the collector models on which they are based, the nature of their results and the use cases for which they are most suitable. It should serve as a decision-making aid for stakeholders in selecting the measurement method best suited to their needs and boundaries. The paper shows that these methods do not contradict, but rather complement each other.