Schaub 4:00
L10
Brooke Arnold ( baa79@pitt.edu
)
“As a source of energy, nothing matches the sun. It outpowers anything that human technology could ever produce.
Only a small fraction of the sun’s power output strikes the
Earth, but even that provides 10,000 times as much as all the commercial energy that humans use on the planet”[1]. Since the Sun supplies the Earth with such a large surplus of energy it seems like the obvious answer to use it in our favor and harvest this energy. Solar power, which is the energy that would be collected from the Sun, is a largely researched power source and has become a major challenge in engineering, due to some of the adverse effects of attempting to utilize the Sun’s energy. The current technology used in collecting solar power is greatly flawed and inefficient.
Present models of solar cells typically convert light energy to electricity at about a 10-20 % efficiency rate, which is quite low [1]. Economically solar panels are extremely expensive and somewhat impractical. The high price and low efficiency is causing hesitation from power providing companies to fully adopt solar power. Engineers are also challenged by the need to reduce the negative impact that manufacturing of the current models of solar panels cause.
Many people have the misconception that solar power is the answer to a miracle power source that causes no pollution or environmental issues. Unfortunately, the manufacturing of solar panels is accompanied by the release greenhouse gases; even though the impact is much smaller than that of other modern day power sources it still exists and needs to be fixed before solar power can become a popular power source.
Sunlight is the single most prevalent carbon-neutral energy source; the sun can provide the Earth with more energy than is consumed in a full year on the planet in about one hour
[2]. As the world’s supply of fossil fuels depletes solar power is becoming a major topic of research and a near necessity in energy production.
What Exactly is Solar Power?
Solar power is power collected by converting UV rays, given off by the sun, to usable electrical energy. “The sun provides a tremendous resource for generating clean and sustainable electricity without toxic pollution or global warming emissions” [3].
Technology Associated with Solar Power
There are two main categories of devices utilized in collecting solar power; photovoltaics and concentrated solar power. Photovoltaics involve the use of solar cells to generate electricity directly via the photoelectric effect [2].
Photovoltaic power technologies are essentially electrical energy power generation devices that absorb the Sun’s emanated energy in the form of photons and convert them into electrical power. Simply stated, solar power cells (as long as they are exposed to solar irradiance) will produce electrical energy [4]. Concentrated solar power employs different methods of capturing solar thermal energy for use in power producing heat processes [2]. Current standard solar cells have relatively low efficiency when converting solar energy to electric energy to solve this problem research is being done on nanocrystal technology.
Nanocrystal Solar Panels
Nanocrystals made from lead, selenium, and silicon have become a popular new way of making solar panels due to their ability to increase the efficiency of these panels from around 20% up to 40% [1]. They are able to increase efficiency because these crystals can produce multiple electrons per photon whereas non-crystalline panels can only produce one electron per photon [5]. The number of electrons collected is directly related to the amount of energy produced. In most solar cells these extra electrons created from the ultraviolet photons are wasted and let off as heat
[5]. Engineers have worked to use nanocrytals in the production of solar panels to increase efficiency and economic value of the solar cells.
Many of the today’s models of solar panels are extremely expensive to make and unfortunately using solar energy can raise energy costs by approximately 3 to 6 times the current prices [1]. This price difference is one of the reasons power providing companies chose other energy sources. In order for solar energy to have a chance at becoming a main power source, engineers must find a way to decrease the price of making these solar panels. One way engineers have been working to reduce the cost of manufacturing solar panels is by focusing more on using silicon nanocrystals rather than using lead or selenium which are more rare and less
University of Pittsburgh, Swanson School of Engineering 1
2014-09-30

Brooke Arnold abundant on Earth. The cost of crystalline silicon solar cells is graphed on the next page. The graph shows the change in price of producing crystalline silicon panels per watt between 1977 and 2013 [5]. The price of making crystalline silicon solar cells has greatly decreased since 1977 and can be used as a cheaper, while still being efficient, material to make solar cells.
Solar power is important to me as both an engineer and as a consumer. The importance of solar power in engineering is enormous because once the Earth’s fossil fuels are depleted solar power will be a major and necessary power source.
Without power, which will eventually be limited to solar and other renewable sources, engineering would be impossible.
This is because many technologies, which are conducive to engineering, cannot run without a power source. As a consumer, practically everything I own that I find valuable runs on some type of power and would be rendered useless if there was no power supply after the depletion of fossil fuels.
Experimentally solar energy is being used to power anything from calculators to cars, therefore if engineers and other scientists continued research on making solar energy more affordable it could soon become a main power source.
“There’s an irony, you’re trying to save the environment by buying a solar panel, and the manufacture (of solar panels) is emitting greenhouse gases in the process,” says Ray Weiss, a professor of geochemistry at the Scripps Institution of
Oceanography [6]. Even though the idea of solar power seems like it would be much better for the environment the making of these solar panels still creates pollution. The panels also need to be put on flat land that gets plenty of sunlight, which unfortunately means that some natural habitats are destroyed to collect this power. While there are no global warming emissions associated with the generation of solar power, there are emissions created with the manufacturing, transportation, instillation, and maintenance of solar panels used in the collection of solar power [5]. The total estimated emissions throughout the solar life cycle are approximately 0.07 to 0.2 pounds of carbon dioxide equivalent per kilowatt-hour [5]. The emissions given off in the life cycle of natural gas and coal are far greater, on average being about .06 to 2 and 1.4 to 3.6 pounds of carbon dioxide equivalent per kilowatt-hour, respectively [5].
Clearly using solar power is relatively better for the environment when compared to other types of energy. Even though solar power is relatively better for the environment it is not a pollution free energy source. Therefore engineers need to focus on making the production of solar panels less harmful to the environment.
Engineers are one of the most sought-after occupations by employers in the solar power industry [7]. The industry needs a range of different types of engineers in order to fix the current problems in solar power usage. Materials engineers can continue research to find new ways of producing solar panels that will not emit greenhouse gases and harm the environment. Industrial engineers will need to work on how to make the solar panels more economically affordable. While mechanical engineers are responsible for the manufacturing and maintenance of the solar panels, they must also maintain the machines used in mass production of solar panels [7]. Engineers are a huge piece in making solar power a large source in energy production.
Solar power is becoming a huge part of power production and needs improvement before it can fully become a main power source. The technologies involved in collecting and converting energy must be made more efficient to be considered a worthwhile investment for power production companies. If efficiency is not increased than the costs of making these solar panels must be decreased. The cost of solar panels can be lowered greatly by using different materials in the production of the solar panels. Utilizing different materials to manufacture solar panels can have another advantage, different materials can also lessen the environmental impact of the greenhouse gases that are currently being released during the production of solar panels. “There’s nothing that’s completely risk-free, but photovoltaic compares very favorably with all other technologies,” says Vasilis Fthenakis, who is the head of the
Photovoltaic Environmental Research Center at Brookhaven
National Lab [6]. Fthenakis and has conducted extensive research on the environmental impacts of solar power and has compared it with other technologies like fossil fuel to get a better idea of the big picture [6]. He now sees that solar power has less of a negative environmental impact than other more popular methods of power production
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Brooke Arnold
[1] (2012). “Making Solar Energy Economical.” National
Academy of Engineering.
(Online Article). http://www.engineeringchallenges.org/cms/8996/9082.aspx
[2] D. Barlev, R. Vidu, P. Stroeve. (2011). “Innovation in
Concentrated Solar Power.” Solar Energy Materials and
Solar Cells. (Online Book). http://rt4rf9qn2y.search.serialssolutions.com/?ctx_ver=Z39.
88-2004&ctx_enc=info:ofi/enc:UTF-
8&rfr_id=info:sid/ProQ%3Apqdiearthsci&rft_val_fmt=info: ofi/fmt:kev:mtx:journal&rft.genre=article&rft.jtitle=Solar+E nergy+Materials+and+Solar+Cells&rft.atitle=Innovation+in
+concentrated+solar+power&rft.au=Barlev%2C+David%3B
Vidu%2C+Ruxandra%3BStroeve%2C+Pieter&rft.aulast=Ba rlev&rft.aufirst=David&rft.date=2011-10-
01&rft.volume=95&rft.issue=10&rft.spage=2703&rft.isbn=
&rft.btitle=&rft.title=Solar+Energy+Materials+and+Solar+
Cells&rft.issn=09270248&rft_id=info:doi/10.1016%2Fj.sol
mat.2011.05.020
[3] (2014). “Environmental Impacts of Solar Power.” The
Union of Concerned Scientists.
(Online Article). http://www.ucsusa.org/clean_energy/our-energychoices/renewable-energy/environmental-impacts-solarpower.html#.VCn7tyldWyc
[4] P. Gevorkian. (2012). “Large-Scale Solar Power
Systems: Construction and Economics.” Cambridge
University Press.
(Online Book). http://books.google.com/books?id=C_UgAwAAQBAJ&pg=
PA26&lpg=PA26&dq=Simply+stated,+solar+power+cells+( as+long+as+they+are+exposed+to+solar+irradiance)+will+p roduce+electrical+energy&source=bl&ots=94xjIowSBk&sig
=vlxAgirROHYCJuIDFKdrwObr_iQ&hl=en&sa=X&ei=N_ oqVMe-
IKaIsQTBkYD4DA&ved=0CB4Q6AEwAA#v=onepage&q
=Simply%20stated%2C%20solar%20power%20cells%20(as
%20long%20as%20they%20are%20exposed%20to%20solar
%20irradiance)%20will%20produce%20electrical%20energ y&f=false
[5] K. Bullis. (2011). “Superefficient Solar Cells.” MIT
Technology Review. (Online Article). http://www.technologyreview.com/news/408475/siliconnanocrystals-for-superefficient-solar-cells/
[6] J. Parkinson. (2011). “The Not-So-Sunny Side of Solar
Panels.” Voice of San Diego. http://voiceofsandiego.org/2009/02/16/the-not-so-sunnyside-of-solar-panels/
[7] V. Wagner. (2014). “Engineers Who Work with Solar.”
Demand Media. (Online Article). http://work.chron.com/engineers-work-solar-1835.html
I would like to thank my writing instructor Bill Kirchner for allowing me to write about this topic and being understanding of the fact that I had to change my topic. I also would like to thank Dr. Schaub, my Engineering
Analysis professor for helping me through my writing process. My parents have also helped me write this paper by stressing the importance of environmental sustainability throughout my lifetime.
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