Technological Perspectives of Silicone Heat Transfer Fluids for Concentrated Solar Power

Silicone based heat transfer fluids exhibit interesting properties for the application in solar thermal power plants like high thermal stability, very low freezing points and high environmental acceptability. In this paper, a new silicone based HTF (HELISOL® from Wacker Chemie AG) is investigated experimentally and economically in comparison to the eutectic mixture of biphenyland diphenyl oxide which is currently the most important fluid for the heat transfer in solar thermal parabolic power plants. It was found that HELISOL®forms less low boiling and gaseous compounds at 425 °C in comparison to currently applied HTFs at only 400 °C. The techno-economic comparison shows that the LCOE can be reduced by 5% using the silicone fluid.