Concentrating Solar Thermal Energy

7Materials for Concentrated Solar Power

Audrey SOUM-GLAUDE¹ and Antoine GROSJEAN²

¹ PROMES-CNRS, Font-Romeu, France

² PROMES-CNRS, UPVD, Perpignan, France

7.1. Introduction

All solar concentrating technologies rely on the implementation of components having various optical functions. Solar radiation is collected and concentrated by systems of highly reflective mirrors. The role of the solar receiver is to absorb the radiation concentrated by the mirrors and to convert it into thermal energy or heat that is transferred to a heat transfer fluid. In some cases, a transparent window is placed in front of the receiver in order to protect it from chemical and mechanical degradations and limit thermal losses (see Chapter 4).

These optical functions are most often performed by thin coatings of one or several layers deposited on a substrate. These coatings add a surface optical functionality, while taking advantage of the substrate characteristics (rigidity, thermal conductivity, etc.). Several dozens or hundreds of nanometers of materials in thin films are in fact sufficient to modify the surface optical properties and obtain the intended function. This serves to limit the costs of the components, having access to low cost substrate materials and using only small quantities of high optical performance materials.

These economic considerations are explained by the size of the solar field needed for a concentrated solar power plant. For example, the solar field of the Andasol power ...