energy

Research Paper on
The solar energy use in Africa

These days, solar energy has been the most talkative alternative energy source in the world. Unlike the gas, oil, and coal, solar enrgy is one of the clean and renewable resource, which can not only generate power but also protect the environment. Africa, has second largest population, estimated 1.6 billion, however, around one third of it’s people still live in the condition with no eletricity. (Renewable energy in Africa, 2012) Fortunetly, Solar power technology bring a hope for their life , especially for those living in rural areas. In this paper, first, I will discuss the solar technologies used in Africa and the science behind these methods. Second, I am going to compare the advantages and disadvantages of solar energy. Finally, I will conclude that solar energy is a viable resource in Africa. There are two best known approaches for directly generating power from the sunlight, which are photovoltaic (PV) generation and solar thermal technologies. PV generation technology is mostly used to transfer solar energy into eletrical energy for lighting in Africa. The principle behind PV was found in 1887 by Heinrich Hertz and illustrated in 1905 by Albert Einstein. PV systems are established by solar cells. And these cells are normally made by combining two very thin crystalline silicon, in which one of them produces n-type (negative) semiconductor and the other one produces p-type (positive) semiconductor. And the conbination of these two semiconductor form a p-n junction.This junction can prevent the flow of addtional electrical charge. Therefore, when the sunlight strikes on the solar cell, it will creat a chemical effect in the p-n junction and release the electrons. This is called photoelectric effect.
As shown in Figure 12.3 and Figure 12.4 , if the solar cell is conneted to an external circuit, as long as the photoelectric effect is created, it generates the eletric current and the lamp will then be lighten up. Also stated by Hinrichs and Kleinbach,“Under bright sunlight of 1000 W/m2, a current of about 100 milliamps per cm2 of cell surface area is produced by typical single-crystal cells. A cell 10 cm in diameter will produce about 1 W under insolation of 1000 W/m2. ”(2011 , p. 379) Moreover, cost of PV cells has decreased to about $0.25 to $0.30/kWh. (2011, p. 367) As a result, Solar energy can be used by more and more African, expecially for those in lower-medium income families. This technology changes the quality of life for those who live in remote area and cannot directly accessed to eletricity before.
Another well known method for harnessing solar power is solar-thermal technology. This technology transfers the solar energy into thermal energy. It is especially useful in sun-rich countries. As stated in Renewable energy in Africa, an article of wikipedia, the insolation of most African countries is very sufficient, average 325 days per year of bright sunlight. ( 2012) Consequently, solar thermal technology can do a significant job in helping Africa to solve one of their main problem—cooking in rural area. Accroding to Solar Cooker International (SCI), a non-profit organzation promising to bring the solar cooking to whom in need in worldwilde, there are three major types of solar thermal devices in the world, which are pannel, box and parabolic solar cookers. And the cheapest and most popular one using in rural Africa is pannel cooker, called Cookit. (How Solar Cookers Work, 2010) The Cookit is normally made of cardboard and foil shaped. This combination can maximaize the reflection of sunlight onto a black cooking pot. When the sunlight hits the pot, the power energy is transfered into heat energy. Moreover, there are always a heat-resistant bag covering the pot to track the heat from escaping, which is also known as an example of greenhouse effect. In order to transport easily, it can be fold into a size of large note book and it just weight half a kilogram. What’s more, the life of the Cookit could be extened from several months to several years base on different material. (How Solar Cookers Work, 2010)
The principle of solar cookers explained by graphics:
Step1: The fuel--sunlight
Step2: convert sunlight to heat energy
Step3: retain heats
Step4: capture extra sunlight
(http://www.solarcookers.org/basics/how.html 2012)
Solar energy, with these two technologies, has a significant impact on increasing the quality of life for African. First, solar panels produce nearly no pollution on the earth. The only pollution result from solar panels is the manufacturing of the devices, the transportation of goods and the installation during the process. There will not be any further pollution after that. Since Africa is suffering a serious air pollution, using the clean solar energy instead of fuel fossil can reduce the pollutant in the air and creat a better living environment for African. Second, unlike wind turbine, solar power not only would not emitte polluted gas but also generates eletricity very quietly. The resident near the eletrical plant would not continually tolarate the nosiy anymore. Third, solar energy allows accessing eletricity without conneted to national grid. Rural Africa where is hard to access the eletricity benefits a lot from this ability of solar energy. What’s more, the installation of solar pannel in remote area is usually much more cost effetive than laying the required high voltages wires. Forth, in a large area of the globe, solar energy would be even more efficiency. Also, a new technologies can bring a more efficient production generally. Fifth, since it is convenient to install solar panels on rooftops, the problem of finding a particular area to place the panels would be eliminated. Sixth, the long-term cost of using solar power to generate eletricity is low because the sunlight is a free source and the solar cells building cost would definitely pay off eventually. And we can using this energy freely by then. Seventh, the development of technology for harness sunlight allows us not rely on the fossil fuel supplies. It gives us more options to choose resouce supplies. (Pros And Cons Of Solar Energy, 2012)
Although there is so many Pros, like other resouces, solar power also has its own Cons. The major disadvantage of solar power is the initial cost of solar cells. As shown in Table 1, the price for one solar panel seling in South Africa is range from $350 to $5640. Just one panel is always not engoug for most of the househould. Therefore it is very costly to set up the solar panel initially. Considering most countries in Africa are still developing countries, which means the majority in Africa cannot afford the set up cost of solar pannel and couldn’t using the solar energy to produce power even though this resouce is totally free. Moreover, solar energy can only generate energy in daylight hours and there will be no production at all as soon as the sun goes down. This limitation becomes another barrier for wildspread using solar resource. Also, the productivity of solar cells depend highly on the weather. Since most continent of Africa is located in the sunny tropics or subtropic area, this shortage does not have a big effect on African. However, the unpreditable productivity is still a great concern on whether using solar power to be a core technologies to generate eletricity. Futher more, solar cells can only be effective under the envrionment where is no pulluted. Most of African cities are under a polluted condition. If the solar panels are installed in these cities, the efficiency of the solar cells would be a major concern. (Pros And Cons Of Solar Energy, 2012) Africa is perfect for solar energy due to its climate and the rich isolation. As shown in the graph1 , taking cape town, South Africa as an example, the lowest sunlight hours per day is around 5.5 and the highest one is about 11. (isolation, 2012) Let’s assume that the power an African household consuming on average is 400 watts per hour which is 9,600 watts-hours per day . Normally, one solar panel size 4' 5" x 2' 2" can generate 120 watts. Since the average sunlight hours in South Africa is around 8 per day, 120 watts X 8 hours equal 960 watt-hours per day. So they need probably ten solar panels to generate the power. As I mentioned before, the solar pannel is cost range from $350 to $5640. So, lets assume this solar panel cost 500. Then, the setup cost is $5000 for one family. This cost is afforable by medium income family in Africa. And I believe, as the technology developing, the major problem-- high initial cost for installing solar panels can be eliminate eventually. Although the set up cost is relatively high, solar energy is one of the free resource. The high initial cost can be wiped out in the long-term. For the lower economic income families, the government and some non-profit organization can helping these communities to install the solar panel and let them benefit from these free resource. What’s more, the majority is using kerosene for lighting in Africa now. But buring kerosence will increase the indoor air pollution and do harm to peple’s health. Instead of kerosence lamps, solar-powered is saver, healthier and brighter. ‘’A full solar home system typically costs between $250 and $630, and a solar lamp between $25 and $40.’’ (Davies,2010) Even the lower-medium income families can afford this lamp. Consequently, no matter technologically, environmentally or economically speaking, solar is a viable resource in Africa. Reported by Catriona Davies for CNN, in rural community of Africa, more than 95% home without accessing the eletricity. However, Solar energy, as a clean and free resouce, brings a new life for these communities. (2010)
With the help of solar energy, hunders of millions of African can have a better, saver, brighter energy access. Many non-profit organizations, such as Lighting Africa, also has a sinigicant impact on passing this new resource to rural Africa and changes those people’s quality of life. Wrriten in the brousure of Lighting Africa, “Since 2007, over 190,000 solar portable lamps which had passed Lighting Africa quality tests were sold in Africa, providing more than 950,000 people with cleaner, safer, better lighting and improved energy access.” (Lighting Africa, 2010) All in all, solar energy plays an very important role in improving life condition of African as well as helping better development of African countries. Figure12.3（ Hinrichs and Kleinbach, 2011, p. 378) Figure 12.4（ Hinrichs and Kleinbach, 2011, p. 379)

(Table1)
(The prices Solar Panels For Sale In South Africa, 2010) ( graph 1: the yellow line is the average sunlight hours)
（Isolation level in south Africa, 2011）

Reference:

Davies Catriona. (2010) Solar energy brings power to rural Africa. Cable
News Network. Retrieved February 23, 2012, from http://www.cnn.com/2010/TECH/innovation/08/10/solar.energy.africa/in dex.html

Hinrich and Kleinbach (2011). Energy: Its Use and the Environment fifth edition. USA: physics and Astronomy: Charles Hartford.

How Solar Cookers work. (2010) Solar Cookers International. Retrieved
February 23, 2012, from http://www.solarcookers.org/basics/how.html How Solar Cookers work [image] . (2010) Solar Cookers International.
Retrieved February 23, 2012, from http://www.solarcookers.org/basics/how.html Isolation level in south Africa. (2011) Climate tempinfo. Retrived February 23,
2012, from http://www.climatetemp.info/south-africa/ Isolation level in south Africa. [image] (2011) Climate tempinfo. Retrived
February 23,
2012, from http://www.climatetemp.info/south-africa/ Pros and Cons of solar energy. (2012) Renewable Energy. Retrived February
23, 2010, from http://www.solarpowerwindenergy.org/2010/01/26/pros-and-cons-of-solar-energy/ Renewable Energy in Africa. (2012). Wikipedia, the free encyclopedia (2010, February 19). Retrieved February 23, 2012, from http://en.wikipedia.org/wiki/Renewable_energy_in_Africa#Solar_power The prices Solar Panels For Sale In South Africa. [image]( 2010)Solar Home. Retrived February 23, 2012, from http://www.solarhomes.co.za/solar-panel-types-and-prices