Aras Shakir
Jae Wan Koo
6A Writing
24. 8. 2016
Literature review
1.
Morgan Anne Wampler, (2011), “Cost-Benefit Analysis of Installing Solar Panels on the Schnoor Almond Ranch”.
According to Morgan, installing solar panels to pump water on a ranch at Schnoor results benefit over a 30 year-period. He examined this project in regard of net present value (NPV) and internal rate of return (IRR). They are indicators that show if certain business will be successful or not. “Since the NPV, estimated at $360,005.40, is greater than zero, it will be a financially beneficial investment. Since the IRR, estimated at 11.91%, is greater than the discount rate of 6%, this again shows the investment is beneficial.” (Morgan, 2011) Positive NPV and IRR show that although it demands a lot of money at the beginning, after 11 years, it starts to gain profit. Thus by 30 years, installing solar panels is definitely beneficial to the almond farm (Morgan, 2011).
2.
Askari Mohammad Bagher, Mirzaei Mahmoud Abadi Vahid, Mirhabibi Mohsen, Types of Solar Cells and Application, American Journal of Optics and Photonics, Vol. 3, No. 5, (2015), pp. 94-113. doi: 10.11648/j.ajop.20150305.17
In this article, Askari illuminates about various types of solar cells, or Photovoltaic solar panel (PV), which directly converts sun radiation to electricity. So far, PV technology can be divided into three generations. The first generation solar cells consist of crystalline silicon. Then there are again two kinds of silicon cells, which are mono-crystalline and multi-crystalline. These cells are most common and commercial in now PV technology industry. The second generation cells are thin-film cells. They include amorphous silicon, CdTe and CIGS cells. Literally because they are thin, they don’t require much space to be installed. Also, they consumes less materials, it is cheaper to build them. “The third generation of solar cells includes a number of thin-film technologies often described as emerging photovoltaics.” These cells aren’t developed completely, thus they don’t have much commercial value yet. In brief, Askari classifies PV development in three generations. Some of them are already being applied commercially, but some are still being studied. Definitely usage of PV will increase, and it will be utilized to various fields, such as solar cars. (Askari et al, 2015)
3.
Yinghao Chu, (2011), “Review and Comparison of Different Solar Energy Technologies”, Global Energy Network Institute (GENI)
According to Yinghao Chu, most energy we use is produced from fossil fuels, which cause great amount of pollutions, and this resource will certainly be exhausted. Thus, technology of solar energy, which is clean energy that doesn’t emit pollutants, is growing rapidly. There are several ways to utilize the energy from sun. Solar Thermoelectricity uses heat from sun. By using a parabolic disc, it concentrates the heat to certain device and there thermal energy converts to electric energy. Photovoltaic Solar Panel (PV) directly produces electricity in semiconductors itself. Radiation from sun hits the panel, and electrons in the semiconductors move by photoelectric effect. Then movement of electrons generates the electricity. Concentrated Solar Power (CSP) also uses the heat from sun, but unlike Solar Thermoelectricity, there is no device that converts heat to electricity. Instead, it raises temperature of water to make steam. That steam operates turbines that make electricity. Each way of utilizing sun has advantages and disadvantages. Since it is very hard to improve problems that already developed technologies have, we should consider other factors, such as geographic location, to use these technologies efficiently. (Yinghao, 2011)
4.
M. Chegaar et al, “Effect of atmospheric parameters on the silicon solar cells performance”, Journal of Electron Devices, Vol. 6, (2008), pp. 173-176
M. Chegaar simulated an experiment in Algiers, which is the capital of Algeria, to figure out how atmosphere conditions affect the efficiency of three kinds of solar panels. Those three panels were mono-crystalline, multi-crystalline, and amorphous silicon solar cells. The experiment was focused on three factors; turbidity, air mass and water vapor. When turbidity increased, the efficiency of mono and multi crystalline solar cells was increased, while amorphous silicon cell’s decreased. Likewise, increase of air mass made the mono and multi crystalline solar cells’ efficiency higher and amorphous silicon cell’s efficiency lower. Unlike other factors, increased water vapor in atmosphere enhanced the efficiency of all devices. In regard of turbidity and air mass, mono and multi crystalline solar cells and amorphous silicon cell showed the opposite tendency, but water vapor effect was same to all of three cells. (M. Chegaar, 2008)
5.
Edoff, Marika. “Thin Film Solar Cells: Research in an Industrial Perspective.” Ambio 41 (2012): 112-18. Web.
Jackson, P., D. Hariskos, E. Lotter, S. Paetel, R. Wuerz, W. Wischmann, and M. Powalla, (2011), “New world record efficiency for Cu(In,Ga)Se2 thin-film solar cells beyond 20%”, Progress in Photovoltaics; Science and Applications 19: 894-8
According to Edoff, among fast growing photovoltaic technologies, field of thin film solar cell is being expanded. It occupies about 20% of the PV industry. The reason why the thin film cells are growing is because of common feature of thin film cells, such as CdTe, CIGS, or CZTS. Their production cost is relatively lower than other cells and efficiency has increased. Also they have “high absorption coefficients for the solar spectrum,” and it is able to adjust their bandgap to utilize the sun radiation maximally. A CIGS cell from ZSW, a German company, performed efficiency of 20.3%. (Jackson et al. 2011) Although the silicon crystalline solar cell is far more predominant in market yet, the growth of the thin film is rapid and it is aiming the efficiency of 30%, which is the theoretical limit. (Edoff, 2012)
6.
Wang Limao, Li Hongqiang, and Cheng Shengkui. “A Study of the Ecological Effects of Solar Energy Development in Tibet.” Mountain Research and Development 32.1 (2012): 83-91. Web.
According to Wang, it is hard to supply conventional energies in Tibet, such as energy from fossil fuel, because of its complex geographical features and scattered residence. However, Tibet is one of the regions that gain a large amount of solar energy in the world. Thus, it is reasonable to utilize it and in fact, Tibet is already taking advantage of it. Tibet’s high altitude, atmosphere transparency, and long duration of sunshine are factors that present abundant solar resource. The average radiation intensity among 7 cities in Tibet is greater than 7000 MJ/m2, which is the top in China. Use of solar energy “has solved the problem of inaccessibility to electricity of households in over 400 towns.” It is being applied to various fields, such as television systems, traffic lights, and school. There are over 400 photovoltaic power stations built. Due to its geographical benefit, the development of solar energy in Tibet is growing rapidly and its utilization also expanded a lot. However, “inadequate repair, maintenance, and technical services” still remain as a problem that should be solved. (Wang et al, 2012)
7.
M.A. Mosalam Shaltouta, M.M. El-Nicklawyb, A.F. Hassanb, U.A. Rahomaa, M. Sabrya. “The temperature dependence of the spectral and efficiency behavior of Si solar cell under low concentrated solar radiation.” Renewable Energy 21 (2000) 445-458
Mosalam suggests that the performance of solar cells depends on the variation of temperature. To clarify the relationship between temperature and performance, he conducted experiments varying two factors. He adjusted temperature from -3 to 90°C and divided brightness of illumination into five stages; 1154, 1329, 1740, 2812, and 4010 W/m2. When temperature got increased, the point where the solar cell’s response to light was strongest also increased. At temperature 5°C, the cell responded highly at wavelength 950nm, and at 83°C, 1000nm was the peak point. Electric current measured from the experiment started to decrease after temperature rose. Moreover, when the illumination level was 4010 W/m2, it declined more sharply. Max power of the cell showed the similar tendency with the current. Temperature and max power was inverse proportional and reduction ratio was greatest at the highest level of brightness. In conclusion, the author figured out that the efficiency of solar cell is lowest at high temperature and high illumination. To optimize the performance of the solar cells in practice, not only should intensity of sun radiance be considered, but also temperature be regarded. (Mosalam et al, 2000)
8.
Tatuo Saga, (2010), “Advances in crystalline silicon solar cell technology for industrial mass production”, NPG Asia Mater. 2(3) 96–102
According to Tatuo, in 2008, crystalline silicon photovoltaic (PV) recorded 90% of “90% of the world total PV cell production”. It is definitely number one in the solar energy market, and it is expected to show this tendency in the future. This article covers present condition of crystalline silicon solar cells. So far, the highest energy conversion efficiency of PV is about 25%. However, performance of commercialized cells just reaches 15% to 18%. It’s able to raise the efficiency, but it demands more complex process, thus its production cost increases. Since the low-cost production is one of the desirable goals, money spent on raw material is an important issue. As a solution, wire-saw wafer slicing technology has been developed since 1997, and it successfully reduced the thickness of silicon wafer from 370 μm to 180 μm. To compete with coal power generation, the cost of total system should be less than $1/Wp. New technologies are being studied to reach that point, but utilizing those technologies itself consumes much money in process of manufacturing PV cells. “Yet the electrical power generated by all PV systems is less than 0.1% of the total world electricity generation,” its market grew about 40% in last decade. The solar cell will take large part in energy industry in the future. (Tatuo, 2010)
9.
Chi-Jen Yang, “Reconsidering solar grid parity”, Energy Policy 38 (2010) 3270–3273
Solarbuzz, (2009), Solar Module Price Highlights: October 2009. http://www.solarbuzz.com/ModulePrices.htmS.
Chi-Jen claims that expectation for solar grid parity (grid parity is the point which cost of renewable or clean energy starts to be competitive with conventional energy) is too optimistic. A realistic examination informs that it is not that much promising as much as many people hope. “Cost-effectiveness doesn’t guarantee commercial competitiveness.” Technology of using sun to heat water has already proven its high effectiveness, but it is adopted less because of unfamiliarity. Most customers were not brave enough to examine new technology. The cost of producing PV cells has decreased from over $100 per watt to about $1 per watt. However, no one sells the product in manufacturing cost. One company had achieved $1/W in manufacturing cost, but the average retail price was of product was around $4.38/W. (Solarbuzz, 2009) Moreover, the upfront cost of those products is an obvious hindrance. For example, PV system on the roof required $33,172 in total, including installation. (Table1) Customers weren’t favorable to this high upfront cost. Even though the cost of solar energy is decreasing, that doesn’t simply means it will replace the conventional system. Not only technological advance, but also should policy development, institutional innovations, and change of customers’ attitude be realized. (Chi-Jen, 2009)
10.
Daniel M. Kammen, Deborah A. Sunter, (2016), “City-integrated renewable energy for urban sustainability”, Science
According to Daniel, to accommodate a large amount of people in urban by 2050, cities should be “low-carbon, resilient, and livable.” For highly growing energy consumption, the author suggests solar energy, which is sustainable energy, as a solution. Since 2010, “the installed price of solar energy has dropped by as much as 50%.” Also, the efficiency of photovoltaics (PV) in laboratory recorded over 40% already. If condition is optimal, it performs 120 W/m2. In India, there are many regions expected to be urbanized, and those regions catch a lot of solar energy. It has high chance of getting huge benefit. Several studies claim that city-integrated PV will be able to supply 62% of the daily electricity demand in Oeiras, Portugal, and 66% in Bardejov, Slovakia. Also, it is able to raise solar irradiance by optimizing the form of city. In brief, since technology has developed tremendously, relying on solar energy is getting more feasible. (Daniel, 2016)