Application And Environmental Impact Of Geothermal Energy - Research Paper Example

Application And Environmental Impact Of Geothermal Energy The heat that comes from the bottom of the Earth is an excellent source of thermal energy that can be converted into manifold highly useful outputs. This energy is generally known as the geothermal energy. Geothermal energy is ubiquitous, which means it can be found in any geographical region. Due to the deteriorating environmental conditions caused by the excessive emissions of carbon compounds in the atmosphere, many countries around the world are drawing on the use of alternative sources of energy such as geothermal energy. Fossil fuels, being the most widely exploited energy source is starting to deplete with respect to time and the world’s growing demand for energy; it produces harmful upshots to the environment and to the health of the surrounding communities. In general, geothermal energy is a thermal energy stocked beneath the Earth surface. The Earth's geothermal energy stems from the initial configuration of the planet and from the radioactive decay of minerals, which account to 20% and 80% of the whole composition of the earth (Turcotte and Schubert 136-137). The variation in temperature between the central, inner part of the Earth (core) and the planet's surface, which is called the geothermal gradient, pushes an uninterrupted of thermal energy as heat that travels from the core to the exterior or face of the planet. Literally, geothermal means "hot earth.” The thermal energy is produced by the radioactive decay that takes place at the innermost portion of the Earth, the core (Union of Concerned Scientists, "How Geothermal Energy Works") and extreme temperatures could reach up to 5000 degree Celsius - about 14 times the boiling point of Mercury, more than four times the boiling point of Radium, and almost twice the boiling point of Gold. Due to this very high temperature, it causes some rocks to melt down, which then produces magma - "a molten rock material within the earth from which igneous rocks result by cooling" (Merriam-Webster’s Dictionary, "Magma"). Rocks and water in the crust are heated up by magma to up to 700 degrees Fahrenheit (Nemzer, "Geothermal Heating and Cooling"). Geothermal energy is better used for generating electricity. As a matter of fact, more than 10 megawatts is produced by geothermal power plants by 24 countries. Geothermal power is low-cost, dependable, maintainable, and ecologically friendly (Glassley, "Geothermal Energy"); nevertheless, thermal energies are best captured only at the edge of tectonic plates where temperature levels are at the highest. Modern, innovative technologies are invented to tremendously enlarge the variety and extent of possible thermal sources, especially in developing techniques that would reduce energy consumption by directly using heat from the Earth's crust for conventional use. While geothermal boreholes release greenhouse emissions in the air, they do not go beyond the Earth's atmosphere unlike fossil fuels. Seen this way, we can concede that geothermal energy and its outputs can help lessen the effects of global warming so long as it is extensively employed by many countries around the world. According to the Geothermal Energy Association (GEA, “US Geothermal Power Production and Development Update”), almost 900 megawatts of large geothermal facilities in 24 countries around the world can fully meet the electricity needs of 12 million US households annually. Further, geothermal power plants produce more or less 25 % of the nation’s total electricity production in the Philippines, Iceland and El Salvador (Holm et al. 7). In addition, the United States of America is the world’s leading producer of geothermal power today, with a production of 3,086 Megawatts of installed capacity from 77 power plants (7). Today, the United States is developing a new approach to employ revolutionary technologies in harnessing geothermal energy. This new development is called the enhanced geothermal system (EGS) which is an “artificial stimulation of geothermal resources to produce electricity” (48). Applications of Geothermal Energy Thermal energies have varying temperatures; and an operational definition is formulated for low temperatures: temperatures that are less than 149 degree Celsius. While they are not normally used for large-scale production of geothermal power, they are commonly utilized for heating, industrial applications, and fisheries among others. Nevertheless, "some low-temperature resources can be harnessed to generate electricity using binary cycle electricity generating technology" (DOE, "Low Temperature and Co-produced Geothermal Resources"). In 2004, about 70 countries from around the world took advantage of direct heating, which is used primarily in resorts, pools, and space heating, while the rest are used for agriculture and manufacturing. In the year 2000, non-electric applications of geothermal energy accounted to more than 15,000 Megawatts worldwide (Dickson and Fanelli 7). In addition, 58 countries stated direct uses of geothermal energy, which is approximately 41% to 48% increase on the number of countries that reported direct uses of geothermal energy: there were only 28 countries in 1995 and 24 countries in 1985 who reported direct uses (7). The number of geothermal energy capacities worldwide has increased together with the upsurge in reported direct uses of geothermal energy (8). The most common non-electric applications used around the world are the following: (1) heat pumps (2) bathing (3) space-heating (4) greenhouses (5) aquaculture, and (6) industrial processes (8). District heating is also widely used in heating buildings, especially during winter. The largest direct heating capacity in the world is found in Reykjavik, Iceland, that is likewise considered as the tidiest city in the globe with the aid of geothermal energy. How is Geothermal Energy Captured? At the innermost center of the Earth lies a layer of molten rocks called magma. The constantly decaying radioactive materials such as Uranium and Potassium continually heat up the Earth’s core (Union of Concerned Scientists, “How Geothermal Energy Works”). The energy contained within the first 10 kilometers of the earth’s surface is “50, 000 times more energy than all the oil and natural gas resources in the world (“How Geothermal Energy Works”). Geothermal energy is mostly found at regions where there are active volcanoes. These regions are located near the edge of a tectonic plate wherein an easier passage is provided for the innermost heat to flow through. Natural heat flows out to the earth’s surface through the movements of the magma, which as it breaks up rock covering, allows the circulation of water, and eventually rises to the surface (“How Geothermal Energy Works”). There are several methods used in capturing geothermal energy such as geothermal heat pumps, hydraulic fracturing, and enhanced geothermal systems (EGS). Geothermal heat pumps unearth heat from low grounds. This type of approach is feasible anywhere in the world; although, it does not suit much to most industrial applications as they require heat with higher temperatures, which can only be extracted from deeper grounds (Lund 5). Hydraulic fracturing injects water, sometimes chemicals, to the rock layers. This is particularly applicable to regions with heavy rock formations. Lastly, enhanced geothermal systems, as it is famously known in North America, create thermal energies in dry rocks by hydraulic simulation. Environmental Impacts Materials extracted from beneath the earth’s surface are in fluidic form. It carries different types of gaseous elements such as carbon dioxide (CO2) and hydrogen sulfide (H2S) (Bertani 1). At smaller amount, geothermal fluids also contain methane gas (CH4) and ammonia (NH3). Today’s geothermal power plants release 122 kWh (kilowatt per hour); although, large power plants have technologies that subdue the amount of the pernicious emitted gases. Geothermal fluids, if not controlled, are potential contributors to global warming. Further, the toxicity level of gases extracted from underground such as ammonia and methane gases could become so volatile that they are rather quick to explosion. That is why most, if not all, of the geothermal power plants today are armed with emission-control systems that prevent excessive emission of these gases. Works Cited Bertani, Ruggero and Ian Thain. "Geothermal Power Generating Plant CO2 Emission Survey". International Geothermal Association News 49 (2002): 1–3. Web. 3 November 2012. Dickson, Mary and Mario Fanelli. "What is Geothermal Energy?" Pisa: Istituto di Geoscienze e Georisorse, 2004. Web. 3 November 2012. Glassley, William.Geothermal Energy: Renewable Energy and the Environment. CRC Press, 2010. Print. Holm, Alison. "Geothermal Energy:International Market Update." Geotermal Energy Association. Geothermal Energy Association, 2010. Web. 3 November 2012. "How Geothermal Energy Works." ucsusa. Union of Concerned Scientists, 2009. Web. 3 November 2012. "Low Temperature and Co-produced Geothermal Resources." energy. US Department of Energy, 2012. Web. 3 November 2012. Lund, John."Characteristics, Development and utilization of geothermal resources." Geo-Heat Centre Quarterly Bulletin 28.2 (2007): 1–9. Web. 3 November 2012. "Magma." Merriam-Webter's Dictionary Online. Merriam-Webter's, Inc., 2012. Web. 3 November 2012. Nemzer, J. "Geothermal heating and cooling." Geothermal Education Office. Geothermal Education Office, n.d. Web. 3 November 2012. Turcotte, Donald and Gerald Schubert.Geodynamics. 2nd ed. Cambridge: Cambridge University Press, 2002. Print. "U.S. Geothermal Power Production and Development Update." geo-energy. Geothermal Energy Association, 2009. Web. 3 November 2012. Read More