A solar thermoelectric plant or thermal solar power plant is an industrial installation in which, from the heating of a fluid through solar radiation and its use in a conventional thermodynamic cycle, the power necessary to move an alternator for generating electrical energy is produced as in a classic thermoelectric plant.

It consists of the thermal use of solar energy to transfer and store it in a heat carrier medium, generally water. This is one of the advantages of CSP technology, thermal storage. The most commonly used technology to store this energy is molten salts (nitrates) thermal storage. The composition of these salts is variable, the most used being the mixture of potassium nitrate, sodium nitrate and recently calcium nitrate has been incorporated.

Instructively, it is necessary to concentrate solar radiation so that high temperatures can be reached, from 300 °C to 1000 °C, and thus obtain acceptable performance in the thermodynamic cycle, which could not be obtained with lower temperatures. The capture and concentration of solar rays is done by means of mirrors with automatic orientation that point to a central tower where the fluid is heated, or with smaller mechanisms of parabolic geometry. The assembly of the reflective surface and its orientation device is called a heliostat.

The fluids and thermodynamic cycles chosen in the experimental configurations that have been tested, as well as the engines involved, are varied, and range from the Rankine cycle (nuclear, coal-fired power plants) to the Brayton cycle (natural gas power plants) through many other varieties such as the Stirling engine, the most used being those that combine solar thermal energy with natural gas. Although water is generally used as a fluid in the thermodynamic cycle, there are currently supercritical carbon dioxide mixtures in development that could provide higher performance.[1]​.

The table below shows the details of the installed power by country at the end of 2021. Spain is currently the world leader in this technology:.

• - Solar thermal energy.

• - Website of the Almería solar platform.

• - Solar thermoelectric energy (Greenpeace Document).