Concentrating Solar Thermal Energy

1Solar Power Plants: State of the Art

Gilles FLAMANT

PROMES-CNRS, Font-Romeu, France

1.1. Introduction

The concentration of the direct component of solar radiation allows the generation of heat at high temperature. This heat can be used directly in an industrial process or to generate mechanical energy or chemical energy carriers by thermochemical processes (Chapters 10 and 11). The focus is here on electric power generation. In this case, solar energy is transferred to a heat transfer fluid flowing through a solar receiver. Through a set of heat exchangers, this heat transfer fluid releases its heat to a working fluid that converts this thermal energy into mechanical energy through a thermodynamic cycle. Finally, a generator coupled to this power cycle produces electric power. The second part of this conversion chain is identical to that of a classical thermal power plant, but the source of primary energy is solar energy in the case of concentrated solar power (CSP) or solar thermal electricity (STE). These two terms will be used in this chapter.

By the end of 2019, the CSP installed in the world reached 6.3 GW for a generation of around TWh (IEA 2020a). The National Renewable Energy Laboratory (NREL) in the United States proposes a database containing the technical characteristics of various operating, under-construction or under-development solar power plants in the world (NREL 2020). Over 100 operating solar power plants with a power ranging between 1 and 280 MW are included ...