The solar section of OnGreentech is still in development. Bear with us. If there is another sector you would like to see us cover, please email on [email protected]
However, it will bear a similarity to the current version of the wind power index covering both companies and turbines.
Solar power is in reality a generic term that refers to two processes, photovoltaic (PV) and Concentrated Solar Power (CSP).
Ok, so how is electricity produced from PV?
Well, the photoelectric effect was first discovered by Edmund Bequerel, a French physicist, in 1839. He discovered that an electrical current was produced from certain materials when they were exposed to light.
However, it wasn't until 1954 that the first product designed to produce electricity in this way was designed by Bell laboratories.
Like many discoveries of the 60s it was used in the space race to provide power.
The standard PV cell is extremely simple to understand. Firstly, it is made of polysilicon that is produced in such a way as to provide a positive and negative field.
When the sun's light hits the cell electrons are displaced. These are captured by electrical conductors that are attached to the positive and negative sides of the cell.
In the solar industry a number of these cells place together is called a module. Although wind and solar power are very different, a module is probably the closest equivalent to a wind turbine in that it produces a set amount of power.
A large number of modules is called an array. Just as a large number of wind turbines is a wind farm.
CSP works in a very different way to PV. Although it uses the sun's light to produce electricity, it does this by using its heat.
Some CSP plants produce electricity by using U-shaped parabolic mirrors. These heat liquid that is contained in pipes in the middle of the mirror, which in turn heat water. This water in turn is used to run conventional turbine generators.
Some systems use molten salt, which can retain heat for a number of days. This means that the array can produce electricity even when there is no sun.