Renewable Energy Essay Example for Free

Renewable Energy Essay Climate change is one of significant issues that have been considered in recent years. According to Anderson (2009), most climate researchers recognise it is essential to reduce 80 percent of global greenhouse gas (GHG) emissions by 2050 to prohibit effects of climate change. Furthermore, carbon dioxide (CO2) is one of the most important causes to produce GHG which is combusted from heating, transportation and electricity generated by fossil fuels. However, one of the solutions for reducing CO2 emissions is using renewable energy to replace fossil fuel. In addition, renewable energy is generated by natural resources such as sunlight, wind and biomass which produce less or no pollution when generate energy. Furthermore, renewable energy will be demanded for approximately half of the worldwide electricity supplies to reduce CO2 emissions by 2050, which it is estimated by The International Energy Agency (Cited in Shi 2010). This essay will focus on two forms of renewable energies which are solar power and biofuels. Firstly, solar energy has been widely used to generate heat and electricity recently. Moreover, it will show the benefits and also point out some drawbacks of solar energy. After that, the discussion will describe the second form of widespread renewable energy in the transport sector which is biofuels. Finally, it will reveal advantages and a disadvantage of this energy. This essay argues that renewable energies, which are solar power and biofuels have been extensively utilised in recent years. Furthermore, they have more advantages than disadvantages. Solar Energy The sun is the largest source of energy, which is transformed to solar power for generating heat and electricity and has been widely used in recent years. According to European Union (2011), there are several applications to use solar energy for heating such as hot water at home, heating in factory and building and swimming pool. In addition, a cooling system also uses solar energy as heat absorption system to generate air conditioning and cooling system in refrigerator. Moreover, this kind of energy can be transformed to generate electricity by two ways. First of all, Prasad Bansal (2011) state that electricity is converted directly from light by Photovoltaic (PV) via semiconducting materials, whose basic composition is solar cells. Furthermore, Concentrating Solar Power (CSP) is another way to generate electricity, in which parabolic solar tower focuses the light to be used for a single point heating, and then produces steam to impel a turbine (European Union 2011). However, PV and CSP can collect electricity in the different ways. PV plants store the energy by connects to batteries, or sent to the electricity grid. On the other hand, CSP system can store heat by itself. Therefore, this power can be generated during the absence of sunlight during the day and night time (European Union 2011). Although there are many reasons for using solar energy, there are some reasons against the use of this kind of energy such as limited condition and the high cost. Firstly, the most significant problem of solar power supply is this energy is not available during the absence of sunlight (especially at night). Furthermore, in winter that often has cloud cover, there are only a low amount of solar power is available (Lakatos, Hevessy Kovacs 2011). However, this issue can be overcome with the use of CHP as it can store the power by itself. Therefore, it can be used during the absence of sunlight. In addition, thin film photovoltaic (PV) power is another solution of the places that have cloud cover. According to Blakeslee (2012), there are three layers in thin film PV for covering a wider spectrum of light. Thus, the light is scattered in all directions by clouds more than usually block it. Secondly, another disadvantage of solar is the high cost is considered as another obstacle of solar energy. As he states that, â€Å"A recent NYU study found the following actual 2005 costs in cents/kWh: Geothermal 3.1-4.3 Biofuels Energy Another widespread renewable energy is biofuel which has been developed to use instead of fossil fuels in the transport sector. There are two principle forms of ‘biofuels’ which are biodiesel and bioethanol. First of all, most of biodiesel is created from oil which is produced by oleaginous plants such as sunflower, rapeseed and palm by reacting with methanol (European Union 2011). Moreover, the viscosity of these oils decreases when they are heated. In addition, Adelekan (2012) points out that these oils can be transformed directly to a diesel engine when they burn, or they can be generated to produce fuels as biodiesel by chemical process. Another form of biofuel is bioethanol or ethyl alcohol which is burned easily to produce a flame, which is generated by distilling products from the sugars and maize when they are fermented such as sugar beet, cereals, sugar cane or biomass (Ortiz et al. 2011). In many countries, there are an increasing number to use bioethanol as ga sohol or oxygenate in gasoline. In addition, bioethanol is elementary to process and manufacture (Adelekan 2012). As well as solar power, using biofuel also brings some disadvantages such as an impact on demand for food. According to Habibah (cited in Adelekan 2012), A huge demand for crops, sugar and oleaginous plants might be impacted from the demand for biofuels which will be result for an increasing cost of food price, increasing level of poverty and food insecurity problem. In addition, biofuels are enemy for agricultural land that would have been used for growing food crops despite being used for growing energy crops now (Adelekan 2012). Therefore, the number of lands for agriculture would be decreased that would have an effect on shortage of food. However, if the government launches the policy of regulation to use agriculture land for growing energy crops, this issue would be overcome. Conclusion In conclusion, there are several significant benefits in the use of renewable energies which are solar power and biofuels to be utilised for replacing fossil fuels. As can be seen in the discussion above, solar energy can be transformed to generate heat and electricity with Photovoltaic and Concentrating Solar Power. In addition, biofuels, another renewable energy can be used in transport sector to replace fossil fuels such as biodiesel and bioethanol. However, although there are some disadvantages of both kinds of energy, their effectiveness is greater. In addition, these obstacles could be overcome in the near future. Therefore, the use of these renewable energies could be the essential alternative way to reduce CO2 emissions for the solution of climate change.