The Potential For The Exploitation Of Geothermal

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The Potential For The Exploitation Of Geothermal Energy In The United Kingdom Essay, Research Paper Whether the World Population stabilises at 8 Billion or 10 Billion, both developing and developed nations will call for increasing amounts of energy as they strive to achieve ?higher? standards of living.The oil crises twenty years ago gave rise to a debate about the availability of energy, adequacy of supply and the hunt for alternatives.? Today, there is no shortage of energy, the question is how can we generate and deliver more of it with less environmental impact.? Hence, the quest for increased use of renewable energy supplies. Wind, wave, solar, hydro, the renewables that are, increasingly viable, variable in output and much vaunted.? All of these energy sources focus

primarily on the generation and delivery of electricity.? While electricity is probably the most advanced and flexible form of energy devised by man, transport and the heating and cooling of buildings are two equally large consumers of energy.? Hidden away, beneath our feet, is another, vast, renewable energy resource.?? At depths of several kilometres there is a thermal resource available to mankind.? In fact 99% of the Earth?s volume is at temperatures in excess of 1000°C (Appendix 1).? This vast resource can be exploited for both electricity production and direct use applications.? This report investigates whether there is a potential to exploit geothermal energy resources in the United Kingdom.HistoryThe exploitation of geothermal resources dates back to Roman times where

hot water was used for mechanical, domestic and leisure applications.? Roman Spa towns in Britain sought to exploit natural warm water springs with simple plumbing technology.? Today, more than 30 countries worldwide are involved with direct uses of warm groundwater resources. Space heating, bathing, fish farming and greenhouses represent 75% of the applications, giving a total installed capacity of 10,000 MW thermal (see Boyle, G10 p359).Geothermal energy was first used for power generation in 1904, when a 5KWe prototype unit was developed at Larderello, Italy.? Today the Larderello power station complex (Appendix 2) has a capacity exceeding 400MW and a rebuilding programme in progress that will take the capacity to 885MW (see Batchelor, A5 p39).Another 20 countries now produce

power with natural geothermal steam rising from deep wells drilled into hot permeable aquifers. The capacity of all the geothermal power plants amounts to 8,000 MW electric (See IGA2 p3).What is geothermal energy?In order to evaluate the potential in the UK, I have used a variety of resources to research into the origins, distribution and geographicalrequirements for the different applications of geothermal energy.Geothermal energy is derived from the earth?s natural heat flow, which has been estimated at some 2.75×1016cal/h (thermally equivalent to 30,000 million KW) (see Laughton8 p61).Heat flows out of the earth because of the massive temperature difference between the surface and the interior: the temperature at the centre is around 7000°C.? This heat and therefore the

source of geothermal energy exists for two reasons: first, when the earth formed from particles around 4,600 million years ago the interior heated rapidly, largely because the kinetic energy of accreting material was converted into heat; second, the earth contains tiny quantities of radioactive isotopes, principally thorium 232, uranium 238 and potassium 40, all of which release heat as they decay (See Boyle, G10 p357).? The distribution of heat flow over the surface of the globe is related to ?plate tectonics? illustrated in (Appendix 3).? In the zones of active tectonism and volcanism along the ?plate? boundaries, the heat flow peaks at values of 2-3W/m2 as a result of actively convecting molten rock (magma).? Variations in the vertical thermal gradient are also considerable,