Solar Tower Plant
The solar tower plant is a type of solar furnace using a tower to receive the focused sunlight. It uses an array of flat, movable mirrors (called heliostats) to focus the sun's rays upon a collector tower (the target). Concentrated solar thermal is seen as one viable solution for renewable, pollution free energy production with currently available technology.
The receiver can be either a photovoltaic receiver for high concentrated solar radiation for direct electricity production (Concentrating Photovoltaic – CPV) or a thermal receiver (CSP).
Most large scale solar tower plants have a thermal receiver to produce heat in form of a heated medium i.e. fluid, steam or air. The heat can be used as process heat or to run a turbine to produce electricity. A great advantage of a solar tower with a thermal receiver is the possibility to store the heat in a thermal storage and to use the heat at a later time independently from the sunshine. Such a thermal storage is of significantly lower cost than batteries which are required for technologies producing the electricity directly such as wind turbines or photovoltaic systems.
Compared to linear concentrating solar power plants such as parabolic trough systems and linear fresnel reflectors, solar towers plants can reach higher concentration of solar radiation and therefore reach significantly higher temperatures
from 500 to 1000°C. Therefore, the turbines can convert the heat into electricity more efficiently since the efficiency of turbines increases with the temperature.
Other applications of the high temperature heat from a solar tower receiver are process heat applications such as solar chemistry or advanced oil recovery. Solar chemistry means that chemical processes are driven by high temperature solar receivers on the tower, including solar hydrogen production by methane reforming or partial steps from oil refinery.
The waste heat from a solar power plant can be used to run a solar desalination process. Thereby, solar power plants are also used to desalinate water if installed near the sea. This is a very useful application in sunny and dry regions or islands.