Every hour the Earth receives more than enough energy to satisfy our energy needs for an entire year. Solar technology is used to harness this renewable resource and provide environmentally friendly energy. Today the produced solar energy is less than one tenth of the global energy demand.
Many people know about the so-called photovoltaic cells, or solar panels, used for things like spacecraft, rooftops, and handheld calculators. The cells are made of semiconductor materials like those found in computer chips. When sunlight hits the cells, it knocks electrons loose from their atoms. As the electrons flow through the cell, they generate electricity.
Solar energy is lauded as an inexhaustible energy source that is pollution and often noise free. The technology is also flexible – for example, PV generated 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.
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.