Energy

Thermoelectric solar plants

Solar towers
Concentration collectors include solar towers, which consist of a system of mirrors (called heliostats) that follows the movement of the Sun and that reflects the solar energy on a receptor located on the top of a central tower. The solar heat is collected by a fluid (a melted salt) that has the task to accumulate energy. With the heat accumulated on melted salts, vapour is produced (565°C), in order to make an electric turbo-generator turn (see image).
Linear parabolic mirrors
Linear parabolic mirrors are called SEGS (Solar Electric Generating System): they are used to concentrate sunrays on a long receiving pipe positioned on the concentrator line. A heat-carrier, i.e. oil, pumped by receiving pipes, supplies a plant. The solar heat is transformed into vapour in order to activate an electric turbo-generator. The typical operational temperature is 390 °C. These installations today work with 30-80 electric megawatts and also burn a certain quantity of fossil fuel (sometimes natural gas) in order to produce energy when the solar energy is not sufficient.