Direct Absorption of Concentrated Solar Radiation by Glass above 1000 °C

This work presents the first experimental results dealing with the direct absorption of concentrated solar energy by a body of glass contained in a solar cavity receiver. Container glass of various colors was adopted as working medium in a setup tested in the ETH's High Flux Solar Simulator. Maximum radiative fluxes of 1.2 MWm(-2) and power input of 1.5 kW were directly absorbed by the glass, which reached temperatures up to 1300 degrees C. Such conditions were maintained for 5 to 10 hours and no technical problems were encountered with the containment of the hot glass. These preliminary results demonstrate that solid or molten glass acts as an effective volumetric absorber of solar radiation at temperatures exceeding 1000 degrees C.