May 25, 2013
Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year. Solar energy is the technology used to harness the sun's energy and make it useable. Solar Energy is the energy from the Sun. The Sun is a big ball of heat and light resulting from nuclear fusion at its core. The nuclear reaction releases energy that travels outward to the surface of the Sun. Along the way to the surface the energy transforms so that by the time it is released it is primarily light energy. The two major types of solar energy that make it to Earth are heat and light. Today, the technology produces less than one tenth of one percent of global energy demand. Solar energy is lauded as an inexhaustible fuel source that is pollution and often noise free. The technology is also versatile. For example, solar cells generate energy for far-out places like satellites in Earth orbit and cabins deep in the Rocky Mountains as easily as they can power downtown buildings and futuristic cars. But solar energy doesn't work at night without a storage device such as a battery, and cloudy weather can make the technology unreliable during the day. Solar technologies are also very expensive and require a lot of land area to collect the sun's energy at rates useful to lots of people. Despite the drawbacks, solar energy use has surged at about 20 percent a year over the past 15 years, thanks to rapidly falling prices and gains in efficiency. Japan, Germany, and the United States are major markets for solar cells. With tax incentives, solar electricity can often pay for itself in five to ten years.
One example of our use of solar heat energy is for water heating systems. A solar panel is used to collect heat. On a much larger scale, solar thermal power plants employ various techniques to concentrate the sun's energy as a heat source. The...