Solar Energy
Question one
Solar energy refers to the power from sun’s radiation which is harnessed and converted to electricity using solar panels. Solar energy can be used to dry clothes or preserve food, water heating, and manufacture of salt and generation of electricity using solar cells. When a transfer fluid is heated by solar panels, it can be used to run generators proving that solar energy can also be used to perform complex tasks (Sukhatme & Nayak, 2008).
Question 2
In 1839 Alexander Edmond Becquerel discovered photovoltaic effect that can convert solar energy into electricity. According to alexander’s analogy, when rays from the sun come into contact with photovoltaic material, electricity is produced .However, progressive research in the field proved that photovoltaic effect was not enough to generate electricity from the sun. In 1941, over 100 years after Alexander, Russell ohl came up with the solar cell . This came after the invention of the transmitter. (Perlin, 2013).
Question 3
This is how sunlight can be converted into solar energy:
A photovoltaic cell or a solar cell consists of two layers of a semiconductor material made of silicon crystals .Silicons are not good conductors of electricity but when impurities are added to silicon in a process known as doping, electric currents are generated (Hantula, 2010).
The bottom layer of the solar cells is coated with boron to form a positive charge while the upper layer is coated with phosphorus to make a negative charge. The surface between the two semiconductors is called the P-N junction which allows for movement of the electric field generated (Hantula, 2010).
When the sunlight come into contact with the solar cells, it loosens the electrons in the two semi-conductor layers. The electrons try to flow from the positive layer to the negative layer but are prevented by the P-N surface which exists between the layers (Hantula, 2010).
There is an external circuit made of thin wires which provides a pathway through which the electrons flow. The thin wire run through the positive layer and the negative layer. The external circuits enables the user of the solar panel to get electricity (Hantula, 2010).
Question 4
There are two types of solar energy that converts sunlight into electricity: photovoltaic solar energy and solar thermal energy .Photovoltaic technology uses solar panels to change light from the sun directly into power by use of silicon semiconductors. Solar thermal, on the other hand, converts heat from the sun into mechanical energy which is further converted into electricity. The electricity resulting from solar thermal is called solar power (In Reinders, In Verlinden, In Sark, & In Freundlich, 2017).
Photovoltaic solar energy converts light into electricity. For this to happen light excites electrons on the outer surface of the semiconductors which are then converted into an electric current that can be connected to a power grid (Sukhatme & Nayak, 2008).
Solar thermal technology uses heat from the sun directly. The temperature in a solar thermal panel is usually below 100degrees Celsius. Solar thermal can be installed in homes for heating water and in industries. Solar thermal panel collectors are made of a flat, dark and wide surface to maximize the absorption of sun’s rays and an insulation that prevents heat collected from escaping thus creating a greenhouse effect. They operate at an average temperature of 70degree Celsius.
Concentrate solar energy power is a type of solar thermal energy. Collectors use the heat from the sun to heat gas or oil .The heated gas or oil transfers heat to water. Heated water turns to steam which then turn turbines thus generating electricity (Sukhatme & Nayak, 2008).
Question 5
Solar energy does not emit harmful gases into the environment and is renewable .Solar energy is cheaper compared to other energy sources such as fuels and gases. Hydroelectricity is also clean energy but it relies on fossil fuels to run turbines which contribute to global warming. Solar panels can be placed in unproductive land therefore they do not take up a lot of space (Sukhatme & Nayak, 2008)
Equipments used to harness solar energy are easy to maintain. They only need occasional cleanliness and checking for repairs. Solar panel manufacturers give a warrant of 20-25 years. Inverters in solar panels, are the only parts that need changing after every 5-10 years. Therefore, after buying the solar panels, it is very easy to maintain them (Sukhatme & Nayak, 2008).
Though solar panels are expensive and rely heavily on the weather, the technology is being improved daily so that it can become more popular and meet the energy demands of the world which are increasing by the day and exhausting fossil fuels (Sukhatme & Nayak, 2008).
QUESTION 6
Japan, China, USA, Germany and France are among the countries ranked highest in the use of solar energy. Though solar energy is available everywhere in the globe, solar energy is not reliable in some places. Areas like the North Pole cannot harness solar energy. Places that are suitable for the collection of solar energy and conversion into electricity are warm areas .Germany is the leading country in the use of solar power. Solar energy covers a total of 3% of the total consumption.One of the strategies Germany has put in place to promote the use of solar energy in their country is lowering of their tariffs to compete with other sources of electricity such as hydroelectricity. In the United States, the use of solar energy increased due to leasing of solar panels at affordable prices (Findley, 2010).
REFERENCES
Findley, D. S. (2010). Solar power for your home. New York: McGraw-Hill.
Hantula, R. (2010). How do solar panels work? New York, NY: Chelsea Clubhouse
In Reinders, A., In Verlinden, P., In Sark, W. ., & In Freundlich, A. (2017). Photovoltaic solar energy: From fundamentals to applications.
Perlin, J. (2013). Let it shine: The 6,000-year story of solar energy. Novato, California: New World Library.
Sukhatme, S. P., & Nayak, J. K. (2008). Solar energy: Principles of thermal collection and storage. New Delhi: Tata McGraw-Hill.
