A solar thermal power plant uses solar energy to heat a fluid and turn it into steam. The steam is then converted to mechanical energy to run a turbine. The turbines are connected to generators. The running turbines power the generators to convert the mechanical energy into electrical energy. There are mainly three types of solar power thermal plants- parabolic troughs, solar dish and solar power tower.
A parabolic trough collector has a linear parabolic shape reflector that focuses the sun’s rays on a linear receiver located at the focus of the parabola. A working fluid is heated as it passes through several heat exchangers and is finally converted to steam. The steam is used to run a conventional turbine and generator to produce electricity. These plants are so designed that they operate only on solar energy.
Solar dish- The solar dish uses concentrating solar collectors to concentrate the sun’s energy at the focal point of the dish. The power generation equipment is mounted in the focal point of the solar dish. The engine in a solar dish is used to convert the heat energy of the sun into mechanical energy that heats the fluid which passes through a turbine to run an electric generator that converts the mechanical energy into electrical energy.
Solar power tower- It converts the solar energy into electricity by concentrating all the sunlight on a heat exchanger mounted on a tower. A solar power tower uses a number of heliostats that reflect and focus the sunlight onto the tower.
The use of solar power thermal plants is becoming very popular for electricity generation.