New materials in solar energy utilization

Abstract The radiation properties of materials determine to a large degree the performance of solar exchangers, while the physical properties determine design variables such as thicknesses of sections, etc. New materials are becoming available, and new modifications of old materials are being developed, which are of immediate and potential importance in reducing the cost of use of solar energy, and increasing the temperature range over which solar exchangers can operate. Notable among these materials are plastics for cover use or for reflecting surfaces, selective surfaces, glasses with particular properties advantageous for cover materials or reflectors, and the honeycomb absorber that limits reradiation and convection.