Why Solar Panels?

A dessert collects more energy in six hours than the world uses in a year. So, why do we still use fossil fuels and other environmentally harmful energy sources?

Almost all of current human sources of energy originate from the sun. Coal, for example, is comprised of the fossilized remains of plants and animals, which got their energy directly from the sun. Following logic, because these forms of energy originate in the sun, and solar energy does the same but skips the mid-steps, it should be more efficient. It is more efficient, but it is not less expensive.

The photoelectric effect, or the observation that many metals emit electrons – and thus, energy – when light shines upon them was discovered as early as 1839 by Edmond Becquerel at 19 years old. 

When a rod of silicon is exposed to the sun, it emits electrons. However, it emits them in an amount not nearly enough to produce meaningful energy. Scientists then discovered that if the silicon is doped with phosphorus – giving it an abundance of electrons – and then is exposed to the sun, it emits many more. This is called N-type silicon, because it is negative. If the wafer is silicon is doped with Boron, it does not have enough electrons and is called P-typed silicon, where P stands for positive.

A typical solar panel is comprised of a wafer of N-type silicon and P-type silicon connected by a wire: 

Then, the system as a whole can be linked with any machine to which you'd like to supply energy. This can range from calculators to space stations. According to NASA, "more than an acre of solar arrays provide power to the station, and also make it the next brightest object in the sky after the moon."

References

        Davidson, M. (2015, November 13). Molecular Expressions: Science, Optics and You - Timeline - Alexandre Edmond Becquerel. Retrieved November 22, 2015, from http://micro.magnet.fsu.edu/optics/timeline/people/becquerel.

       Garcia, M. (2015, November 6). About the Space Station: Facts and Figures. Retrieved November 22, 2015, from http://www.nasa.gov/mission_pages/main/onthestation/facts_and_figures.

       Redarc Electronics. (n.d.). Retrieved November 22, 2015, from http://www.redarc.com.au/solar/about/solarpanels/.

       The Science of the Silicon Solar Cell. (n.d.). Retrieved November 22, 2015, from http://science.sbcc.edu/~physics/flash/siliconsolarcell/index.html.