Solar power has been researched for centuries. Thanks to space research and the continued energy crisis, the technology has come a long way in a very short time. While we are still quite a distance from a solar-powered world, we can now see what technology can get us there very quickly.
The Sun's Energy
Worshipped by primitive man for millenia, the sun fuels plant life and the earth's weather. To take a moment and ponder the staggering energy output of our nearest star is a humbling exercise indeed. Every moment, the fusion reactions that occur in the sun's core emit more radiation than if all of the nuclear bombs ever constructed were to simultaneously detonate.
Early Experiments into Solar Energy
It is pretty difficult not to try to harness the energy of the giant ball of fire in the sky. Cultures have used the sun's energy for such tasks as water heating for thousands of years. Even at the very beginning of the industrial revolution, machines that operated exclusively from the energy provided by the sun were developed and proven to work by French scientists seeking an alternative to buying coal from England. However, they failed to become widespread after the French renegotiated coal prices.
Solar Power and the Space Race
The vacuum of space makes use of fossil fuels a scientific impossibility. Early spacecraft's lifespan was limited by the life of their batteries. But with the addition of photovoltaic cells to satellites, the usable life of the machines went from a few hours to up to a decade. Any spacecraft designed for a long-duration mission to the sunny side of Jupiter is equipped with a solar power kit. There has even been talk of how a fleet of satellites could collect solar energy without interference from the atmosphere, and beam it down to earth!
Advantages and Disadvantages of Solar Power
To start with, sunlight is abundant and free. There is no need to transport raw materials to the power plant, and there are no waste products produced in the process. On the downside, some areas are richer in sunlight than others. The weather can drastically reduce the amount of energy produced by a solar power plant, and the fact that there is no sunlight at nighttime means that most types of solar power plants sit idle at night.
How Does Solar Power Measure up to Other Energy Sources?
While energy efficiency is constantly improving, it is still much more expensive to produce energy from solar technology than from coal or natural gas. One could say it is a better energy source than wind, as sunlight is more predictable than then the weather.
Solar Power Generation Methods
Electricity is produced from solar energy through photovoltaic cells, which directly convert the sunlight into electric current, or via tower designs that use the sun as a passive energy source to heat either air or water. The latter technologies are preferred for commercial power generation as they use common materials such as mirrors rather than delicate and costly photovoltaic cells. Each design is suited to one environment or another. Solar updraft towers require less space, and therefore could be constructed closer to urban areas, while photovoltaic arrays and heliostat towers are best suited to empty desert expanses due to the vast acreage they require. Years of research has resulted in many competing designs of solar panels, many of which are ideal for powering a full sized home independent of the grid. Solar energy is also used for passive purposes such as water heating.
Major Solar Plants and Applications
While only making up a small fraction of global energy supply, there are many industrial scale solar power plants in operation today. Some are powering entire districts, while others are little more than demonstration facilities for the particular technology they employ. These plants serve a valuable purpose in that their existence proves the viability of the concept, while exposing any remaining bugs in the technology that need to be worked out. In addition to commercial plants, thousands of homes are now powered by solar arrays that the owners have installed. It is belived by many that photovoltaic technology's main application is for small-scale yet widespread use such as this, as well as a portable charging medium for portable electronic devices.
So What Does The Future Hold?
Many developed countries, like Germany, are investing heavily in solar energy, in part to break reliance on foreign energy supplies. Spain is making use of its sunny environment to take an early lead in heliostat tower plant construction. The United States also has some generous subsidies in place to assist entrepreneurs in building and profiting from this abundant energy source.
This work is in the public domain in the United States because it is a work of the United States Federal Government under the terms of Title 17, Chapter 1, Section 105 of the US Code.
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