While solar power lends itself to a decentralized approach in which solar arrays adorn rooftops to provide electricity for individual customers and, as further technological refinements become commercially available, office buildings are designed and built with solar tinted windows to produce power for the building, the same methods can also be used to generate power on a large scale.
Many solar power plants are on line throughout the world generating hundreds of megawatts of power already, and many more are planned or under construction.
Two forms of solar power generation are in common commercial use. One of these is the photovoltaic effect, which is the same technology used for solar panels for your home.
The other is the use of mirrors to focus sunlight and create high temperatures that replace the burning of fuels for the same purpose in a fossil-
A third way to produce power from sunlight, the solar chimney, is not as commonly used, but a few power plants using this method are on line and there may be places in the world where it is the most economical way to make use of solar energy.
Solar Farms
A large, commercial-
The photovoltaic effect is an application of quantum mechanics in which solar energy is absorbed by electrons in the atoms of a photovoltaic material such as crystalline silicon, until the electrons reach a sufficiently high-
Solar cells, solar panels, home solar arrays, and solar farms all make use of this principle. Solar farms typically include motors that keep the solar panels aligned with the sun for maximum power production, as well a large-
The largest solar farm in the world (actually a collection of solar farms) is the Gujarat Solar Park in India. It has a production capacity of 605 megawatts, which makes it the largest solar power facility currently in operation.
New solar plants making use of photovoltaics cells are planned or in construction currently with combined outputs measured in the thousands of megawatts (or terawatts).
Solar Thermal Power Plants
The other commonly used method of generating commercial-
Two principle designs of solar thermal plants are found in operation. One is the parabolic trough, in which a parabolic mirror in a long tube focuses sunlight on a tube containing a heat transfer medium (typically oil) which is then used to heat steam which drives a turbine. The other is the use of a Fresnel reflector to achieve very high temperatures and run a gas turbine.
Typically the sunlight from the reflectors is focused on a solar power tower where a gas is heated to drive the turbines. The combined output capacity of all solar thermal power plants currently in operation worldwide is about 1.7 gigawatts. Some new solar thermal power plants are in plans or under construction.
The problem with solar thermal energy is simply that it is a mature technology in which not a lot of improvement is to be expected in the future. As the technology of photovoltaics continues to improve, and the price of PV power to drop, competition with this other form of solar power presents the main challenge to solar thermal conversion.
Despite this, many more solar thermal stations are still being built worldwide and the technology is expected to represent a significant part of global energy production in the future.