An Overview of Silicone-Based Heat Transfer Fluids in Concentrated Solar Power Systems

Abstract

This paper investigates the potential of silicone-based heat transfer fluids (HTFs) for use in Concentrated Solar Power (CSP) systems. These fluids, primarily composed of polymethylsiloxanes, offer significant advantages over traditional organic oils and molten salts, including superior thermal stability (up to 425–450 °C), low viscosity, chemical inertness, and reduced environmental impact. Commercial products such as HELISOL® 5A and SYLTHERM™ 800 demonstrate excellent performance in long-term stability tests and real world CSP applications, with reduced degradation and maintenance requirements. Case studies and simulation models confirm improved efficiency and lower levelized cost of electricity (LCOE) when silicone fluid replace conventional HTF. Although initial costs remain higher, their operational reliability and safety make them attractive for next-generation solar thermal systems. This study concludes that silicone-based HTF is an excellent substitute for CSP applications and suggests more investigation into long-term deployment, recycling strategies, and performance optimization across various climatic and industrial contexts.