Solar Transmission of Aerogel Pellets

Abstract

During the past few years there has been increased interest in aerogel as a transparent insulation material, for instance as a window filling, because of its superb insulating properties. Also, apart from some scattering, the high-quality aerogel tiles are highly transparent, allowing a good view through such a window /1/. However, to become commercially viable, the production of aerogel has to become much cheaper. Luckily, for certain applications only the total transmission of the incoming solar radiation is relevant. Examples of these applications are windows in factory halls, solar collector covers or transparent insulation of walls. In these cases, fillings of aerogel pellets are adequate, and moreover may be produced in a possibly much cheaper production process. We have investigated experimentally and theoretically the solar transmission of such pellets, which have been produced by BASF Ludwigshafen.