Non-selective coating for porous materials used for solar thermal applications

Porous materials are been widely used in many solar applications such as thermal energy storage, porous receiver and thermo-chemical reactions. This work deals with the thermal analysis of different configurations of alumina pebbles, which can be used for the aforementioned applications. The alumina has lot of advantages; however its color is white diminishing the possible concentrated applications. In order to increase the solar absorptance, the alumina pebbles has been coated with two different coatings, a commercial one and a self-developed spinel coating. The main tests performed shows that the coating developed by CIEMAT-PSA increase the performance of the packed bed configuration compared to the Pyromark coating.