Solar photovoltaic energy
June 13, 2009
Photovoltaics deals with the conversion of solar energy directly to electricity, and is related to the technology and the research it involves. Because renewable sources of energy are much in demand now, solar photovoltaic energy is increasing in importance, and many options have been explored, in recent years. In fact, every two years, photovoltaic energy has been doubling, the increase is by almost 48-49% each year, since 2002, and thus, it is the world’s fastest growing energy technology.
In a gist, photovoltaic cells are responsible for producing electricity from sunlight. The photovoltaic modules are connected electrically in multiples, as solar photovoltaic arrays, and this converts the sun’s energy to electricity. The photos from sunlight turn the electrons into a higher condition of energy, and this creates electricity. The kind of electricity produced is DC electricity – direct current electricity, this is used to power equipment, or even for battery recharging. Initially, photovoltaic energy was used to power satellites that were orbiting, and for other kinds of spacecraft. However, with better technology, today it is used in grid connected power generation. However, the DC power needs to be changed to AC power, so an inverter is needed. Off grid power is also required in roadside telephone booths, remote sensing, and remote dwellings.
Since the cells need to be protected from the environment, they are kept tightly behind a sheet of glass. When larger amounts of power are required, then the cells are connected together, electrically, and form photovoltaic modules, these are also called solar panels. One single module by itself can give sufficient power for an emergency telephone, but in the case of a power plant, or a house, it is required that the modules must be arranged in arrays. Spain, in 2008, installed almost 50% of all photovoltaics.
It is estimated that by the year 2030, solar photovoltaic systems will probably be generating 1,864 GW of electricity, all around the world. This means high energy efficiency, and almost 14% of the population of the world would be satisfied by the solar power produced globally in about 25-26 years’ time. There are many advantages of solar photovoltaic energy. Firstly, the 89 petawatts of sunlight, which reaches the surface of the earth is quite enough, considering that humans consume, on an average, 15 terawatts of power. Also, solar energy, or photovoltaic energy does not cause pollution. So there is no waste or emission. Minimum maintenance and intervention is required, after the facilities are initially set up. Also, as a form of energy, photovoltaic energy is superior, economically, where fuel transport is always expensive and difficult, and in some cases, even impossible. The cost of operating a solar plant is quite low once the plant has been built.
Solar electricity, which is grid-connected, can be used locally. This reduces the losses incurred in transmission and distribution. However, it’s important to remember that not much research has been done on photovoltaic energy, so there is much scope for improvement.