A solar array is simply a collection of devices for converting sunlight into some other form of energy. Strictly speaking, a solar array can be any of the following:
1) a group of solar panels linked together to generate electricity;
2) a group of solar greenhouse heat-
3) a group of mirrors in a solar-
In practice, when we speak of a solar array we generally mean no. 1 (a collection of photovoltaic solar panels), and so this article will concentrate on that meaning of the term.
Solar Arrays And the Photovoltaic Effect
The photovoltaic effect was discovered by scientists at Bell Labs in 1954, but has become practical for large-
The photovoltaic effect works through an application of quantum mechanics in which the energy of a photon is absorbed by an atom of an appropriate substance, increasing the energy state of an electron surrounding the nucleus of that atom.
When the energy state of the electron increases sufficiently, it escapes the atom altogether and, along with other electron refugees, becomes an electric current. That is how solar energy works in a nutshell.
Certain materials are in common use to take advantage of the photovoltaic effect; solar cells, and thus solar panels and solar arrays, are constructed of these materials.
Crystalline silicon is one such material; cadmium telluride is another. Thin layers of photovoltaic cell materials are exposed to sunlight under protective glass and connected to metal leads that collect the resulting current.
The currents from many solar cells are collected together to provide a flow of energy sufficient to meet practical needs.
Some thirty or forty solar cells are put together into a solar panel, and a number of solar panels are combined together to produce a solar array.
How Big Is A Solar Array?
A solar array may consist of any number of solar panels and solar cells. A rooftop solar system may have only ten to twenty solar panels generating energy in the range of two or three kilowatts.
An industrial solar array, such as Apple’s solar array powering its data center in Maiden, North Carolina, may be substantially larger and more powerful. Apple’s solar array covers 100 acres and generates 20 megawatts of power.
The largest solar arrays of all are found in solar farms producing power for commercial distribution. These can consist of thousands of solar panels generating in some cases hundreds of megawatts of electric power.
As long as there are at least two solar panels connected together to generate electricity, the system can be called a solar array. There is no top limit except what’s prescribed by demand, geography, and common sense.
Commercial Power Production Using Solar Arrays
The use of photovoltaic solar arrays to produce power commercially, commonly known as solar farms, represents a growing industry. Solar panels are becoming increasingly efficient and cheap to build, while fossil fuels increase in price as they become scarcer and as global demand for energy soars, and nuclear power has encountered public concerns due to periodic mishaps such as Three Mile Island, Chernobyl, and the more recent disaster in Japan.
Other ways to produce solar power are also in use commercially, such as solar thermal turbines and solar chimneys, but the big recent advances in technology have mostly been in methods using the photovoltaic effect, so that the popularity of solar arrays for large-
Several new power plants of this nature are in the planning and construction stage in California alone, and are expected to produce more than a billion and a half watts of power by 2015. Similar efforts are under way in China, India, Australia, and other parts of the world.