Analysis of the performance of concentrated solar power facilities using different thermal fluids

Abstract

A systematic comparison of the performance and economics of concentrated solar power plants using various heat transfer fluids including molten salts and synthetic fluids (Dowtherm A, Syltherm, HELISOL, Malotherm and Therminol VP1) is carried out. First, a process systems approach is used to determine the yield of the thermodynamic cycle using different thermal fluids, their operating conditions and the water consumption. Next, an economic evaluation is performed. For reference Almería, to the South of Spain, is the location selected because of the high solar irradiance. The efficiency of the regenerative Rankine cycle increases with the maximum operating temperature. The average power production increases from 16 MW using Malotherm to 25 MW using the molten salts, while the water consumption decreases from 3.6 L/kWh to 2.1 L/kWh. A higher efficiency results in more competitive electricity prices that decrease from 0.21 €/kWh (Malotherm) to 0.12 €/kWh (molten salts) with the maximum operating temperature. Furthermore, the effect of the maximum temperature on power and water consumption are computed towards a pre-evaluation of novel fluids under development.