Solar thermal technology update

Various designs of collectors on the market today as well as potential future developments are discussed. A collector is the most important component of a solar thermal system. A collector needs to fulfill the technological requirements of the operating, meteorological and climatic conditions of a specific project, as well as being appropriate in terms of design and architecture, economics and ecology. The transparent cover of a collector should ideally have the highest possible transmission in the entire wavelength range of solar radiation. New concepts under development include vacuum-insulation panels, filling the collector with inert gas, complete evacuation, and insulation using micro-foam products based on polyisocyanate. When assessing panels available on the market it is important to take into account not only the price/performance ratio but also durability, reliability and ease of installation.