Electricity Production from Renewables Energies

5.3. Thermodynamic solar power generation

5.3.1. Introduction

In Chapter 2, we highlighted the significance of the solar energy resource. This can be used via photovoltaic conversion for a direct conversion of radiation into electricity. However, when a big power plant is considered, the solar energy can be used to heat a fluid, which will undergo a thermodynamic cycle similar to those previously presented in the context of geothermal power plants. In the literature, this type of power plant is called a “thermodynamic solar power plant”, “solar thermal power plant” or “concentrated solar power (CSP) plant”.

In order to reach an interesting efficiency for thermodynamic conversion, it is important to produce a high temperature fluid and thus to concentrate the energy supplied by the Sun’s rays. Several types of power plants will thus be encountered in practice according to the methods used for the capture and concentration of this renewable primary energy. In the following sections we will thus present these methods and specify their field of use.

5.3.2. The principle of concentration

The incident solar flux at the Earth’s surface is 1,000W/m². This energy is not very dense and obtaining a significant temperature of thermodynamic fluid requires a large absorption surface. A first solution would consist of covering this surface with the help of the fluid, but the thermal losses of the fluid being proportional to the absorber surface, they would be significant. It is thus better to ...