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Solar energy is more than just sunshine, it is also the energy of wind. It is the potential of solar energy application that holds hope for solving many of the world’s energy problems. It is a simple fact that daily sunshine provides enough energy to support all the power and energy needs of the planet. The trick is to get more energy more directly and efficiently from the sun.
Although 54% of all sunlight is lost before it reaches the earth’s surface, the sunlight that does reach the earth is about 200,000 times the total electrical energy generated everyday. This is only the visible component of sunlight, which is less than 50% of the energy of sunshine. This also doesn’t include wind energy, which is the direct result of some of that “wasted” solar energy.
Sunlight can be used in two ways to generate energy; direct heating and photovoltaic electrical generation. Using current technology it takes approximately 40 square meters of collector area to provide enough solar energy from direct solar heating for the all the energy needs of an individual each day. This is assuming the current efficiency of passive solar collectors which ranges between 20% to 80% and eight hours of sunshine in a temperate zone. While direct sunlight can be used to create heat, it is of limited value in electrical generation. Thought solar furnaces can be designed to focus light, and create steam to generate electricity, currently direct sunlight applications have limited potential in electrical generation. Photovoltaic generation, or direct conversion of sunlight into electricity, has only a 7% to 11% efficiency range, yet even at these low rates of efficiency this use of sunlight can be a competitive form of power generation.
Wind power has always been used to provide energy on farms and ranches in the American west. Wind was used to pump water and grind grain into meal and flour. Some early windmills were used to generate electricity, but with the use of steam, the abundance of fossil fuel, and the availability of hydroelectric generation relegated wind power to marginal use. Today wind powered generators are in use in practical commercial applications. For example in Germany one “Wind Farm” that uses windmills to generate electricity commercially employs 1,400 individuals directly, and generates over $700 million in gross revenues. Worldwide the use of wind power for electrical generation has grown to over 250,000 Megawatts!
The advantages of solar power as a means of creating energy are obvious: it's pollution free, renewable, and abundant. It could be argued that the disadvantages are just as clear, current technology is inefficient, underdeveloped, and in most cases too expensive to be cost effective. This view of the cost of solar power generation may seem true on the surface, yet there are some other considerations that should be made. Currently utilities generating power by the use of nuclear reaction or the burning of fossil fuels enjoy the benefit of government subsidies. Then it should be considered that most hydroelectric generating dams were build mainly with government money. If forms of solar and wind electrical generation enjoyed the same support their cost would be competitive even with today's low efficiencies!
As advances in solar and wind technology develop, and more use of these forms of electrical generation come online, it's clear that this is the way of the future. As the considerations of pollution and global warming come more into play in the decisions of those who generate power, you can expect greater use of solar and wind technology. After all it comes from the source.
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