Abstract: A coating for solar tubes has a porous absorbing layer that includes an absorbing black pigment material mixed with a porous binder having an open porosity, and a first protective layer having oxides applied on top of the porous absorbing layer. The first protective layer may penetrate to at least a portion of the open porosity. The first protective layer may include nanoparticles, to improve the filling of the pores. A second protective layer may be applied after the first layer, to improve the filling of the remaining gaps.

Abstract: Provided is a spectrally selective solar thermal coating, formed as a continuous uniform layer, combining a light-absorbing coating and an infrared (IR) reflecting layer positioned on top of the absorber coating. The coating is adapted for use in a plurality of applications, including amongst many control of stray light and absorptivity in thermosolar devices.

Abstract: A paint formulation can include an inorganic oxide-based pigment and an organic binder. The organic binder can be irreversibly converted to an inorganic binder upon curing of the paint formulation at a temperature greater than 200° C. The oxide-based pigment and/or the paint formulation itself can have an absorptivity of at least 80% with respect to the AM 1.5 spectrum. The paint formulation can also include at least one organic solvent, an inorganic filler, and/or at least one additive. Such paint formulations may be stable at high temperatures (e.g., 750° C.) and can be used as solar-radiation-absorbing heat-resistant coatings for components of a solar tower system.