Introduction

Abstract

Solar thermal electricity generation, or concentrating solar power (CSP), is the production of electricity using direct solar irradiation as the primary source of energy. The amount of solar irradiation directly coming from the sun, wherever is its position in the sky, is called Direct Normal Irradiance (DNI). The first step to obtain electricity is to concentrate the solar rays to heat a fluid to a temperature which is sufficiently high to produce steam after its transit through a heat exchanger. Next, depending on the pressure and the temperature reached by the steam, a specific type of turbine connected to an electricity generator is activated. Given the high capacity of the power plant (in the order of MW), the electricity is evacuated through a transmission grid. Concentrating solar plants are, thus, a chain of energy conversions: In order to obtain electricity, a given working fluid accumulates the thermal energy contained in the direct solar irradiation which has been concentrated by the appropriate collectors. Then, the heat of the fluid transforms water into superheated steam at a given pressure in a heat exchanger.