There are two categories of Solar energy technology.
- Solar Photo voltaic technology
- Solar thermal energy technology
In solar thermal technology, the solar radiation energy is converted into heat energy while in solar PV technology, the solar radiation energy is converted into electrical energy directly.
In solar thermal technology, a device called solar collectors, is used for converting solar radiation into heat energy. The sunlight is captured by different types of solar collectors which provide heat. This heat is then used for various applications.
In general case collectors can heat water upto 50 degree to 60 degrees. But when temperature of more than 100 degrees is required, special type of collectors are used, called concentrator collectors.
The concentrator collectors collect light from large areas and concentrate the light in a small area. Due to such concentration, higher temperature are obtained.The solar thermal heating process also can be used for steam generation which is used in the industry for many process applications.
One of the important applications of concentrators solar thermal energy is for electricity generation. The technology is normally known as concentrator solar power technology.
The CSP plants for electricity generation is similar to coal based power plants except that in the Concentrator solar power technology, the steam is generated using solar radaition while in coalbased plants steam is generated by burning of coal.
The rest of the processes used in the steam based power plants are same. The steam is used for rotating the turbine which in turn rotates the electrical generators in order to generate electricity.