Solar Power

Solar power is energy from the sun that may be used to generate electricity directly. Alternatively it can be used to generate heat, which can be employed either to generating electricity indirectly or to heating water or other liquids. The former of these processes is called photovoltaics, whereas the latter goes by the name of concentrating solar power. Both avoid significant emissions of greenhouse gases, for which they are considered potential renewable energy sources that ought to be better exploited in the future.

Photovoltaics refer to the conversion of light into electricity by solar cells, in which the so-called photoelectric process takes place. This technology originates in the solar cell application that was fitted at a backup battery to the satellite vanguard 1 in 1958, after which it become standard equipment for many space missions and satellite launches both in the US and Soviet. However although the Vanguard 1 battery turned out to be the first ever significant use of a solar-powered invention it was never specifically intended for usage in space.

As a matter of fact the solar cell had been developed as a potential replacement for coal, which at the time it was thought that humanity had almost used up all natural sources of. As this turned out not to be the case the technology was too pricy to be of interest to the general public through the 1950s and 60s. However prices dropped in the 1970s in response to the oil crisis of 73, making them an affordable power source for remote areas unconnected to the power network - places such as telecommunication stations, offshore oil rigs, navigational buoys and railroad crossings. Building-integrated rooftop photovoltaic system also began to appear in the US this time, but the government initiatives that encouraged their use were quickly dropped once the oil prices were restored to normal again. Not much later the initiative in solar power shifted from the US to Japan and Europe, with lots of domestic photovoltaic products installed in these two parts of the world since.

Concentrating solar power, or CLP, differs from photovoltaics in how the solar power itself is not converted into electricity. Instead it uses lenses or mirrors to focus a large area of sunlight into a compact solar beam. Many different technologies exist for this purpose, from parabolic troughs to reflectors to dishes and towers. Regardless of the system the concentrated sunlight is used to heat up a fluid, which in turn is used either for electricity generation or other energy-consuming processes. The first ever commercial CLP plant was built in Spain, and since then many similar facilities have become operational in other parts of the world.

Although solar power shows great potential as a renewable energy source and has already been tried and tested in most forms, it is only a very small percentage of the world's total energy supply that is generated from it. This is most unfortunate, as the sun beams twice the power per year of what will ever be had from coal, oil, natural gas and mined uranium together. However the solar power industry has never before flourished like it does now, for which it is probably safe to assume that it will continue to expand for a number of years. Perhaps in the near future solar power will be used on a greater scale, but at this point it might be just as well that it has yet to start growing. Suffice it to say that at this point of its development there are currently too many solar power devices on the market to tell which type will be dominant in the future.