2 real examples demonstrate how to obtain the service life of solar collector systems Durable, providing fundamentals that will continue to be valuable over the next 5-10 years Lighting a pathway to the commercialisation of solar products Solar devices lose their performance over time. The rate of degradation controls the service life of these devices. The essential concepts used to assess durability and performance of two specific solar collector systems are described, enabling researchers to assess durability in other solar devices. The examples of modelling, testing and performance measurements give researchers a how-to approach to reach crucial service lifetime predictions. Achieving successful and sustainable commercialisation of solar products relies on the fulfilment of 2 further criteria and these are also discussed. The methodology of service lifetime predictions (SLP), which is explained in detail in the book, is crucially needed in other solar technologies and is generally applicable to a wide variety of materials, components and systems used in other solar, biomedical, aerospace, electronic and coatings technologies.