“If aliens did visit us, I’d be embarrassed to tell them we still dig up fossil fuels from the ground as a source of energy” (Neil deGrasse Tyson). Although aliens are irrelevant to the topic at hand, the point that fossil fuels are an outdated source of energy nevertheless stands. Fossil fuels, such as coal, were essential to starting the Industrial Revolution that caused a rapid progression of the human race, and other fuels, such as oil and natural gases, still play a pivotal role in most forms of transportation. However, the amount of fossil fuels being consumed is still increasing at an excessive rate, yet the amount of fossil fuels being discovered is decreasing, and the gap is widening. According to the Worldwatch Institute, geologists …show more content…
Solar energy is harnessed through solar cells, which are made up of two kinds of semiconductors: p-type and n-type silicon (How a Solar Cell Works). P-type silicon is made from adding atoms that have one less electron than silicon, which has 4 electrons (How a Solar Cell Works). This allows an electron “hole” to be created, which is filled by n-type silicon, which has one more electron than silicon (How a Solar Cell Works). The p-type and n-type silicon is placed next to each other, and near the junction of the layers the free electrons from the n-type move into the “holes” of the p-type, which is called the depletion zone (How a Solar Cell Works). When all of the “holes” are filled, an internal electric field is created due to negatively charged ions being in the p-type silicon, and positively charged ions are in the n-type silicon (How a Solar Cell Works). Electricity is created when sunlight hits the solar cell because electrons are forced out of the electric field due to the photoelectric effect, which causes electrons to flow from the n-type to the p-type silicon if a metallic wire is connected between the two (How a Solar Cell Works). The electrons cross the depletion zone, and return to the n-type silicon via the external wire, which creates a flow of electricity (How a Solar Cell Works). (See Figure