"Various transparent and translucent thermal insulation materials are now being investigated or are ready for the market as new products. In combination with other components, they are giving an impetus to the wide field of solar energy utilization. In 1986 tha program "Energetic Optimization of the Solar Aperture" sponsored by the Minister for Research and Technolgy, FRO, was started. This research and development program includes work on materials, components and active and passive systems, for instance daylighting of buildings, low temperature heating for houses and domestic hot water, process heat, for example for drying, absorption cooling and thermosolar water pumping."