Transparent insulation - new collector developments

Transparent insulation materials (TIM) offer the chance to improve thermal collectors considerably. Using a 10 cm honeycomb material, a flat plate collector has already been developed in the institute, which, at operating temperatures around 80 degree C, shows a performance comparable to that of evacuated tubular collectors. Due to the theory of TIM, further improvements are possible with larger air gaps between the absorber and the TIM, if the convection within the air gap is suppressed. This can be accomplished, for example, by evacuating the cover system to approximately 10 high -3 bar. First experiments have been made in this field. Secondly, a shallow solar pond has been set up on the testground of the institute to investigate the possibilities of integrated storage collectors, supplying thermal energy for 24 hours a day. Simulation calculations show that in certain applications, for example for seawater desalination by transmembrane destillation or for operting a thermal pump, th is may have system advantages.