Geothermal Energy and Its Effects on Environment - Essay Example

Running Head: History of Geothermal Energy and its Effects on Environment History of Geothermal Energy and its Effects on Environment [Institute’s Name] History of Geothermal Energy and its Effects on Environment Introduction One of the clean and sustainable energy sources is geothermal energy; however, environment is being affected by its development since decades. In this regard, it is very imperative to consider the positive, as well as, negative aspects of the impact before the development of a geothermal field. Particularly, surface commotions and fluid withdrawal’s physical effects are some of the major effects on the environment by the geothermal development. Moreover, discharge of chemicals during the geothermal development also effects the environment at a greater extent. It has been observed that biological environment is also affected largely by the abovementioned factors due to the geothermal energy. Moreover, socio-economic effects of the geothermal energy have also been observed by the experts. In Iceland, development of geothermal resources was considered for a study by the launching of an enforcement program in the year 1995. Geothermal plants in Iceland were studied, in order to understand the impact of high-heat fields of geothermal energy in the country. Since the year 1997, a number of projects are under way according to the regulations of Geothermal Implement Agreement by the International Energy Association. History Historically, R&D programs of various governments have included geothermal energy as one of the renewable sources of energy along with the options of solar, biomass, wind, etc. One of the major characteristics that have been studied and found by the experts since years is its low emissions of greenhouse gases that make it one of the environmental friendly sources of energy. However, certain limits can be observed in the friendly nature of geothermal energy, as an entire industry could be discredited due to any attempts of obscuring production of this energy. The Bruntland Commission was the first one to derive the proper sustainability of geothermal environment in terms of the environment. According to this commission, production levels of geothermal energy can be sustained for a long period by the production systems of this source of energy. 1 Due to such efficient sustainability of geothermal energy, economic goals and objectives are also being considered by the investors due to its capability of quick payback. Such energy has also been considered for the production of various equipments, which are providing huge revenues to the investors. One of the most significant examples is the geysers, which is providing enormous profits to the investors with the utilization of geothermal energy resource. 2 Since ages, it has been observed that engineering and building activity is required in almost every kind of processes that involves production of energy. In the result, environment and economy are two of the major factors that are affected by such production. Although the title of a clean energy source has been provided to the geothermal energy, some emission of gases is performed by its development, which results in the disposal of effluent water. However, role of a benign energy source is played by the geothermal energy, as compared with the other sources of energy, such as nuclear, fossil fuels, etc. 3 Only a fraction of the amounts from fossil fuel is emitted by the electricity of geothermal resource. In order to understand the economic benefits of the geothermal energy, experts have observed that 12.5 million tons of fossil fuel is saved due to the production of geothermal electricity on annual basis. In addition, savings of 12.1 Mt is achieved by the direct use of geothermal heat annually. One of the major beneficial of geothermal energy is Iceland, where geothermal energy contributes more than fifty percent of consumption of the total energy of the country. On the other hand, greenhouse gas emissions are added by only five percent due to this energy. Since a long time, different forms of energy are being studied and compared with the geothermal energy, in order to evaluate it according to features of the environment. In this regard, compilation of the first Environmental Impact Assessment was done in the year 1970 in the United States, which has been followed by the setting up of different procedures by various countries around the globe. In the year 1987, the World Commission on Environment and Development was formed, which was followed by the United Nations Conference on Environment and Development in the year 1992. It has been observed that geothermal project and plant planning has been contributed effectively by the process of EIA, in order to safeguard environmental features. In the process of studying geothermal energy, different types of reservoir play a crucial role in providing insight into different characteristics of geothermal energy. Impact on Environment One of the most imperative obligations during the development of geothermal energy is the protection of environment and its different features. In the year 1991, the United Nations Summit defined various goals and objectives of plants and projects related to the development of geothermal energy, which are being implemented and followed by various countries around the world. It has been observed that utilization of different technologies affects the impact on environment, which has been discussed in following section of the paper. Power Generation and Direct Use Exploration, production tests, and construction are some of the foremost phases of development of geothermal energy, which are not changed with the changes of the applied technology. Some of the major temporary, as well as, irreversible effects on the environment are changes in the landscape, utilization of land, low emissions of greenhouse gases, noise, land subsidence, solid waste, seismicity, physical effects, chemical pollution, and some of the thermal and biological effects. A much lower emission of greenhouse gases is created by the power generation of geothermal energy, as compared with the utilization of other technologies. In this regard, all phases of development of the geothermal energy have been studied and considered for comparing the production cycle with the other technologies. It has been observed that low carbon dioxide emissions are created by the power plants of geothermal energy, as compared with the plants of other energy sources. However, geothermal power generation also affect the environment, which cannot be ignored during the study. As earlier mentioned in the paper, drill site, reservoir, and location of power plant play a vital and crucial role in the impact on environment. Theoretically, power generation and direct use share the environmental impacts, however, correspondingly smaller impacts of direct uses on the environment have been observed due to its production of geothermal energy on the smaller scale, as compared with the power generation. 4 Case Studies Icelandic Environmental Project In the year 1991, the National Energy Authority of Iceland launched a cooperative project with the collaboration of a number of developers of geothermal energy in the country. In particular, different geothermal fields of Krafla, Namafjall, Svartsengi, and Rekjanes were utilized for such purpose. In that year, remedies were being suggested to resolve environmental issues and establishment of an environmental law was under preparation. During this project, development of geothermal fields was considered for the assessment, and researchers recommended a number of alternative options for the evaluation of such development. 5In particular, exploited geothermal fields were surveyed for observing gas emissions from the development of geothermal energy on this project. Moreover, steam pillows in these fields were investigated, especially their formation and pervasion. In addition, gravity measurements and ground leveling were also included in the project, which was followed by the monitoring of geothermal activity with the help of aerial thermography. Furthermore, natural steam discharges were measured, and different methods for its measurement were searched by the experts. In this project, all the geothermal fields carried out measurements of gravity and ground level, and monitoring of future trends were also considered with the help of a network. Moreover, high-quality thermal images were acquired by the installation of thermal scanner on an aircraft, which was referred as the aerial thermal scanning project in this Icelandic environmental project. The Wairakei Geothermal Plant, New Zealand The North Island of New Zealand has the volcanic belt near the Lake Taupo, where the Wairakei geothermal plant has been formed. West bank of the river has been chosen for the construction of power station of the plant. Bore field is equipped with sixty odd-wells. Mixture of steam and water by the ratio of 1:4 has been formed as a geothermal fluid. The study of Wairakei geothermal plant was quite easy, as compared with the Icelandic Environmental Project due to the proper documentation of this plant. Typically, 0.9 is the annual load factor of the abovementioned plant of New Zealand. During this project, assessment and research was carried out related to the development of geothermal fields, and a number of alternative options for such development was studied after the selection of case study. Particularly, surveying of exploited geothermal was done for the observation of gas emissions from the development of geothermal energy on the New Zealand plant. 6 Almost similar impacts on the environment were observed in the abovementioned two geothermal case studies, which will be discussed in following section of the paper. Air Pollution Air pollution may be caused by the release of geothermal gases in the condensation. The major lawbreakers are carbon dioxide and hydrogen sulfide, although problems can be caused by some of the gases like methane, mercury, radon, ammonia, etc. One of the major greenhouse gases is carbon dioxide that requires great attention during the development of geothermal energy. However, such attention is also required by gas methane, which is also one of the major constituent of geothermal development. In this regard, production of such greenhouse gases is being reduced by a number of countries that are involved in the development of geothermal energy, such as Iceland, New Zealand, the United States, etc. The abovementioned two case studies have shown low emissions of carbon dioxide as an industrial by-product after the project. Moreover, these case studies found out that power generation was not the cause of emission of carbon dioxide in these projects, but the land was the cause of venting out carbon dioxide gradually. Both projects also found out the moderate concentrations of toxic and unpleasant hydrogen sulfide that was also emitted in the atmosphere.7 Thermal Effects Thermal effects will usually escort creation from geothermal fields. Low efficiency of heat has been observed during the power production in the projects, therefore, waste of a considerable amount of energy was observed. It has been found out during the studying of the abovementioned projects that the local weather is changed and cloud formation is affected by the formation of a steam due to the excess emission of heat during the projects. Moreover, ecological and biological systems near the geothermal fields are also affected seriously by the discharge of wastewater in the near lakes, rivers, ground water, etc. In this regard, environment was benefited by the achievement of pond cooling after this process. Particularly, the project of Iceland implemented this strategy to cool out the environment. On the other hand, such cooling resulted in the creation of different chemical pollution in the environment, which affected a number of cattle fields in the near locations. In cold regions like Iceland, snow melting is done by the generation of electricity with the help of geothermal energy that saves millions of dollars, as compared with the generation of electricity with the help of fossil fuels. Therefore, generation of electricity in these two projects was done by geothermal utilization that provided economic benefits. On the other hand, the project of New Zealand used the excess heat from the geothermal energy production to cool the house heat, which was another economic benefit of the project. 8 Chemical Pollution In the abovementioned two case studies, it has been observed that steam of chemicals is discharged into the atmosphere, which results in the pollution chemically. Environment is also harmed potentially by the spent liquid. Moreover, surrounding areas have also been damaged in terms of its vegetation due to the testing spray during the project.9 Natural Features Most of the projects of geothermal energy are located in the places that have outstanding beauty, and therefore, the survey has shown results that touristic importance of such places should be considered important during the operation and construction of the project. However, tourism is also affected beneficially by the utilization of geothermal development, which adds an attraction to the places. In the case study of Icelandic project, the Svartsengi geothermal field’s Blue Lagoon is one of the most striking beneficial attractions of the geothermal utilization.10 Groundwater Table Subordination of groundwater table may result in the combination of fluids between aquifers and inflow of acidic water. The springs and fumaroles may also disappear due to such mixing. It has been observed in the New Zealand project that a steam pillow is grown at an accelerated pace due to the lowering of the groundwater table, which is followed by the consequent boiling and degassing of the geothermal field. Major explosions may be persuaded by such a development. Particularly in the New Zealand project, historical facts have shown that a number of people have been killed by the abovementioned development. In this regard, the spent fluid can be injected back into the reservoir, in order to overcome the effects of fluid withdrawal. 11 Seismicity As more frequency is observed in the reinjection, a new issue results in the project that has been referred as seismicity. In the process of reinjection, injection of spent geothermal fluids is done in large volumes into the subsurface, which results in the modification of local stress field. Statistical reports of the abovementioned projects have shown that larger earthquakes are not led by the increasing volumes of fluids; however, frequency of such events causes the devastation. In particular, the Hot Dry Rock technology is very much relevant to the induced seismicity, where hydraulic fracturing has created the artificial reservoirs, which can cause earthquakes at a larger extent. It is necessary that a seismometer system should be set up to observe limited seismicity before the beginning of process of reinjection and fracturing.12 Noise Geothermal utilization involves a number of noises that affect the environment. Drilling noise is the foremost noise that is observed in the utilization of geothermal resources. Such noise is temporary, but affects the environment in some manner. Subsequently, boreholes are discharged after the drilling noise, which is between 2 to 4000 Hz that is considered as the pain threshold in these projects. Once the operations are started in the plant, the environmental noise can be kept down with the help of a noise muffer, which has been regulated by the Geological Survey of the United States. The abovementioned two case studies have shown little effects of noise of geothermal utilization, but the organizations are trying their best to resolve this issue with the help of innovated technologies. 13 Land Slides Some places have shown events of land sliding near the geothermal fields. It has been observed that the site that is chose for the purpose of construction of geothermal fields should be located in such a place that should have limited chances of landslides. As volcanic rocks are often near the location of geothermal fields, as in the Icelandic project, thermal alteration is observed in such fields, which results in the acceleration of land sliding chances, which should be monitored during the geothermal projects, as both case studies have formed a committee for the monitoring of land sliding. In other words, monitoring of landslides is one of the major responsibilities of geothermal plant management, as historical facts have shown a number of examples of worse devastation due to landslides at the installation of geothermal projects.14 Subsidence When the natural inflow of fluid withdrawal is exceeded, subsidence takes place in the project. Almost every utilized area has shown evidence of subsidence, although great variation has been observed in the magnitude of such phenomenon. In Wairakei, New Zealand, 400 mm has been the maximum subsidence on annual basis, however, approximately 25 cm of subsidence has been observed in the Svartsengi field of Iceland project.15 Surface Disturbances During the process of drilling, surface disturbances occur, however, it has been observed that such disturbances are disappeared due to the removal of drill rigs after the completion of drilling. In addition, draining of ponds and reshaping of landscape are also responsible for the disappearing of surface disturbances. Statistical facts have shown that excavation and construction of new roads are some of the causes of surface disturbances. Usually, 200 to 2500 meter of area is covered by a drill site. As the normal utilization of source is performed near the drill site, long pipelines are not needed in such places. 16 Fluid Withdrawal Lastly, modifications of surface manifestations can be affected by fluid withdrawal, which results in the creation of fumaroles by the disappearing of geysers or hot springs. This effect has been observed in the project of New Zealand, which is being studied by the experts and professionals associated with the plant. Conclusion The paper discussed that one of the clean and sustainable energy sources is geothermal energy; however, environment is being affected by its development since decades. In this regard, it is very imperative to consider the positive, as well as, negative aspects of the impact before the development of a geothermal field. Moreover, two projects were considered as case studies, which are the Icelandic Environmental Project, and the . Furthermore, different environmental and economic effects of geothermal energy were discussed and analyzed in this paper. It is hoped that this paper will help the students, professionals, and experts in the better understanding of the topic. References American Society for Testing & Materials. (2004). Nuclear, Solar, and Geothermal Energy. American Society for Testing & Materials. Axtmann, Robert C. (1975). Environmental Impact of a Geothermal Power Plant. Science New Series 187. Gesell, Thomas F. (1975). Geothermal Power Plants: Environmental Impact. Science New Series 189. Harsh K. Gupta. (2006). Geothermal Energy. Elsevier Science & Technology. Kenneth Wohletz. (1992). Volcanology and Geothermal Energy. Library Incorporated. Kristmannsdottir, Hrefna, and Halldor Armannsson. (2003). Environmental Aspects of Geothermal Energy Utilization. Geothermics 32. Mary H. Dickson. (2005). Geothermal Energy: Utilization and Technology. Earthscan. Rybach, Ladislaus. (2003). Geothermal Energy: Sustainability and the Environment. Geothermics 32. Read More