Solar Energy

Most of the energy that reaches the Earth's surface comes from the Sun. About 44% of solar radiation is in the visible light wavelengths, but the Sun also emits infrared, ultraviolet, and other wavelengths. 

Of the solar energy that reaches the outer atmosphere, ultraviolet (UV) wavelengths have the greatest energy. Only about 7% of solar radiation is in the UV wavelengths. The three types are:

  • UVC: the highest energy ultraviolet, does not reach the planet’s surface at all.
  • UVB: the second highest energy, is also mostly stopped in the atmosphere.
  • UVA: the lowest energy, travels through the atmosphere to the ground.

The remaining solar radiation is the longest wavelength, infrared. Most objects radiate infrared energy, which we feel as heat.

Some of the wavelengths of solar radiation traveling through the atmosphere may be lost because they are absorbed by various gases. Ozone completely removes UVC, most UVB, and some UVA from incoming sunlight. O2, CO2, and H2O also filter out some wavelengths.

Source: Solar Energy on Earth. Retrieved from http://www.ck12.org/book/CK-12-Earth-Science-Concepts-For-High-School/r16/section/9.11/ on August 26, 2013. 

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Last modified: Friday, 9 December 2016, 11:56 AM