Facing the daunting problems of fossil fuel depletion and increased greenhouse gas emission, worldwide attention has turned toward the development of renewable energy systems. Among all the renewable sources available, solar energy has by far the highest theoretical potential. The earth intercepts an average of 89 PJ of solar radiation each second, which is three orders of magnitude larger than the current global energy demand Abbott (2010). To harvest part of this enormous solar power, an innovative concept consists of a transparent collector that allows direct solar absorption in the heat transfer fluid. This design is usually referred to as a volumetric receiver due to its capability of absorbing heat in a volume instead of on a surface (like the more classic parabolic trough receiver). The heat derived from solar concentration can then be converted into electricity through power cycles such as Rankine and Brayton cycles or chemical products such as CO- and H2-based fuels through high temperature dissociation reactions (Lougou et al. 2018).