The purpose of SIMON is to test the applicability of new silicon-based heat transfer fluids at higher temperatures than those currently operated in parabolic trough technology solar thermal power plants and to accelerate market introduction by reducing all the obstacles that have been identified. The project will consist of laboratory tests, fire assessments and tests on the reconditioned PROMETEO test loop in the SITEF project at the Solar platform of Almeria. A viscosity sensor suitable for these applications and temperatures will also be developed, as well as an efficient maintenance concept to separate compounds such as hydrogen, methane and silanes.