Geothermal Energy as a Renewable Energy Source - Essay Example

Geothermal Energy as a Renewable Energy Source Understanding the Essence of Geothermal Energy Heat derived from the Earth by means of a natural geologic process has been widely attributed to 'geothermal energy' (with Greek words geo meaning earth and therm for heat) treated as a remarkable alternative to fossil fuels or other non-renewable energy resources. The latter collectively being the typical origin of carbon in high percentages normally brings about global warming and pollution due to heat content and incomplete combustion, respectively, hence to address this concern of reducing such risks and hazards to public health and other relevant aspects of living, harnessing potentials with geothermal energy is thereby proposed to abolish or at least minimize dependence on the traditional use of fossil fuels at low cost, promote lack of pollution, large supply of energy, and reliablility. Unlike the conventional method of burning fuels to produce the heat required, optimizing earth's energy from deep within the ground is by nature sustainable and would not take additional chemical process to be transformed to a useful form. Moreover, geothermal energy is never likely to contribute to greenhouse effect as fossil fuels are and once put up, the power plant would be self-sustaining or not necessitating external energies aside from the power it yields. Roughly 33,000 feet beneath the earth's surface lies heat that contains about fifty thousand times more energy compared to the combined presence of natural gas and oil currently processed by men. This inevitably fluid heat experiences high temperatures in various zones where layers upon layers of molten rock commonly known as 'magma' are continuously formed as a consequence of naturally occurring radioactive elements that undergo intense decomposition on a subatomic level for several years. Because magma is less dense than the rocks surrounding it, it rises to the surface. Sometimes magma escapes through cracks in the Earth's crust, erupting out of volcanoes as part of lava. But most of the time magma stays beneath the surface, heating surrounding rocks and the water that has become trapped within those rocks. Sometimes that water escapes through cracks in the Earth to form pools of hot water (hot springs) or bursts of hot water and steam (geysers). The rest of the heated water remains in pools under the Earth's surface, called geothermal reservoirs. By the Earth’s crust shifting and allowing water to mix into natural hot-spots water is superheated and then vented through holes in the Earth’s surface with tremendous power. The superheated water generated at these locations can naturally reach temperatures of up to 200°C (430°F). Earth's core is nearly 6000°C - hot enough to melt a rock. Even a few kilometers down, the temperature can be over 250 °C given that the Earth's crust is thin. Temperature generally rises a degree Celsius for every 30 - 50 meters you go down, but this alters with respect to location. Among the hotspots from which geothermal energy may be obtained are certain states of America as Oregon, California, Alaska, and Nevada which possesses a significant number of volcanoes comprising the Pacific Rim or the Pacific 'Ring of Fire'. Hotspots are typically close to fault lines or young volcanoes were the Earth’s crust is thin enough to allow internal heat to escape and be accessed by as little drilling is possible. It may be a surprising fact to discover that besides these seismically active regions, any other location on earth ranging from a depth of 10 to a few hundred feet through the crust is capable of heating objects even at lower degrees. The capacity to generate electricity by extracting heat out of these places would of course depend on the quantity of drawn heat which can be converted to electrical energy. Landrello, in Italy is the first to own a geothermal power station, followed by Wairekei in New Zealand and a few others were built in Iceland, Japan, Indonesia, Philippines, and the United States which shows evidence of geothermal energy effect through geysers like Old Faithful in Yellowstone Park. Superheated water is formed at such locations when the earth's crust shift and let water mix into natural hot-spots then vented through holes in the Earth’s surface with huge power with temperatures of up to 200°C (430°F). How Geothermal Energy Works The basic concept of utilizing geothermal energy is by heating liquid water until it vaporizes as a steam so that heat is released and this mechanism is the sole role magma is needed for. Pressure results with the heat in the steam and becomes the chief component of work in running engines that create electricity. Basically, a geothermal power plant has several of the same components namely turbines, generators, transformers, and other standard power-generating equipment. Tapping into systems with 'hydrothermal convection' is the most prevalent means of capturing the energy from geothermal sources as springs where the water input made to seep through the hot crust absorbs in heat and the output steam would operate electric generators in turn. Drilling holes into the rocks can be rendered in a variety of ways as to efficiently allow steam capture and this is one major investment for geothermal plants to come up with an optimum design. Each setup design may take into account certain types of customization and a simple design considers turbine to which the steam goes directly for rotary motion prior to condenser where the steam undergoes condensation back into the state of liquid water in a cycle. As such, geothermal power plants may employ such process by drilling into geographic hotspots in order to gain direct access to the natural source of heat and establish a water circulation system in which cold water is pumped into the drilled hole and the superheated steam is vented out of a secondary channel to supply turbines the anticipated amount of power. Pressurized geothermal fluid or a secondary working fluid, is allowed to expand rapidly and provide rotational or mechanical energy to turn the turbine blades on a shaft. Direct usage of geothermal heat is said to be feasible anywhere in the world, it may be limited however by the requirements set for temperature or physical rock properties which are less stringent than for electric power generation. Extremely hot water can be depressurized as well or 'flashed' into steam which enables the turbine to adopt a binary system that makes hot water pass through a heat exchanger in order to transfer heat to another liquid component which boils at a temperature lower than that of water but has acquired sufficient amount of heat in the process to function like a steam. Design options vary according to the source and flash systems are usually applicable to water temperature relative to that of the steam for instance whereas using heat exchangers are found most beneficial for water at moderate temperatures as the one coming out of a well. Besides the aforementioned customs, geothermal springs can also be used for direct heating purposes and for one, hot spring water can facilitate heating of greenhouses, oil recovery, ice removal along roads, fish drying, as well as relaxing atmosphere for spas. Geothermal heat pumps like ground-source heat pumps on the other hand may serve buildings with both heating and cooling systems interchangeably with the use either of air or antifreeze liquid which is pumped through pipes that are buried underground and connected to a pipe framework in a building by which hot or cold liquid is circulated for the desired effect. The U.S. Department of Energy found that heat pumps can save a typical home hundreds of dollars in energy costs each year, with the system typically paying for itself eight to twelve years. In enhanced geothermal systems (EGS), heat is derived from dry areas as hot rock reservoirs frequently designated at greater depths, far down the conventional sources. These reservoirs are broken up by pumping high-pressure water through them to draw out fresh hot water of higher temperature back on the surface to power turbines for electricity generation after which the used water is returned to the reservoirs to complete the circulation loop with the help of injection wells. Binary cycles in closed loops as such are conducive for plants especially that it can satisfy the aim of cooling after vapors are released with no heat trapped during emissions so that heat transfer can be maximized, as in systems of air conditioning. Furthermore, a closed loop is one in which both ends of the loop's piping are closed and the water or other fluid is recirculated over and over and no new water is introduced to the loop. The heat is transferred thru the walls of the piping to or from the source, which could be ground, ground water, or surface water. As heat is extracted from the water in the loop the temperature of the loop falls and the heat from the source flows toward the loop. With the approach of pumping cool water into the earth and collecting the steam back into pressurized system which can be depressurized over time creating the necessary driving force for the turbine to transform geothermal energy to electrical energy can find better worth for moderate geothermal spots despite their slightly less heat production capability. EGS has been carefully analyzed with sensitive regard for any induced seismic activity that might possibly take place with drilling and developing of 'hot dry rock'.  Risks associated with an induced EGS-related seismic event that can be felt by the neighboring population appears to project a serious concern in the long run like the threat posed by carbon dioxide capture and storage in deep saline aquifers due to drilling of gas and oil by still growing implementation 'hydraulic fracturing'. To address this issue, projects must be monitored properly and located at an appropriate distance away from major fault lines. Open communication with local communities would greatly help also aside from selecting and monitoring rock fracturing and seismic activity at the same time. Economic Aspect of Geothermal Technology While the distance to reach the magma layer differs from place to place, the cost of reaching the geothermal energy source is equivalently a function mostly of 'how thick' the Earth's crust could get in the attempt to arrive at the magma layer since areas of interfacing Earth plates make good spots for collecting heat. Different economical aspects may suit any such condition and different types of geothermal power production, depending on whether they are natural or engineered systems with regard to either dry or wet system and the technology used whether ORC or Kalina Cycle. One advantage of geothermal power plants is that they can be built economically in much smaller units, not taking up much room unlike hydropower stations. Like other types of non-fossil, low carbon dioxide renewable energy sources, energy in geothermal form has been predicted by experts to supply a greater and even more principal share of the future global electric power and heat demand only if it can be offered at a reasonable, if not competitive price. Such degree of competitiveness is perceived with reference to the energy prices based on fossil fuels as the standard. As an extremely volatile quantity, it would be prone to adjust itself not only to the demand and supply as it turns out in a free market but also to the country's political state of affairs. Average trend in the past had demonstrated variation of competitiveness with geothermal energy, attracting as many buyers as those who would maintain oil for steady option. Through current heat providers in well-developed heat markets as in the industrial sphere, cheap excess heat is often available with fossil and nuclear power derivatives and may only pull themselves out of tight competition if geothermal heat is offered at an affordability that majority in the market would feel truly financially wise or rewarding. Thus, in such an economic environment, selling of geothermal heat is undeniably difficult and is highly determined by the prices on fuels, specifically gas and oil. On the contrary nevertheless, since geothermal heat possesses unlimited availability despite time and weather conditions, it proves to be a prominent choice for providing large base loads and less attractive for more transient systems requiring high peak loads. In effect, geothermal heat attains being economically attractive if, in addition to space heating of apartments and houses, it can be used to provide significant base load to the benefit of major clients of space heating or commercial and industrial process heat. Geothermal projects are more closely linked to the specific site than oil and gas projects since geothermal fluids are normally used at or near the producing field and this is due to the cost of insulation for minimizing heat losses from pipelines which makes pumping fluids over long distances uneconomical, as indicated in the more than ten-fold larger enthalpy of oil, 41, 800 kJ kg-1, compared to that of high-enthalpy geothermal steam, 3000 kJ kg-1 or hot water, 209 kJ kg-1 for a production and injection temperature of 80°C and 30°C, correspondingly. Geothermal energy compared to other renewable resources, has proven record of reliability and minimal environmental impact both for direct use and production of electricity dating back 100 years over. Experience with it and its pertinent technology may then take pride in the capacity to operate geothermal fields under fit economy with water and vapor altogether for over a century with careful re-injection of spent fluids to help constrain the decline of reservoir pressure and thus flow rate and the associated subsidence of land. The most important economic aspect of geothermal energy use is that it's homegrown — using geothermal energy reduces our dependence on foreign oil, creates jobs here in the United States, and more favorably balances our global trading position.  Policy Recommendations and Grounds for Recommendations As one policy recommendation, all natural resources inclusive of geothermal energy must be kept from being wasted. The prevention shall cover associated resources which make possible the transfer, production, exploration, development, or even maintenance of such form of energy. This is to be implemented in strict compliance by the states that have relied on using geothermal energy on the average as a result of construction or ongoing progress of geothermal power plant and preference of the majority over oil and gas alternatives. With the stated recommendation, geothermal energy may be well conserved upon conservation of certain materials that can be recycled in its production such as water or some other liquids in place of vapors which would be made capable of exchanging heat at a certain value. It may also be recommended for petroleum companies to acquire grant of lease over additional lands governed by state jurisdiction provided they would establish plants that manufacture geothermal energy regardless of schemes made for the currently existing or future refineries. This way, potentials with geothermal source of power is further harnessed and examined in the process for comparative studies. Curiosity can be deflected towards consideration of renewable energy which is clean, naturally sustainable, and less sophisticated in design. Sufficient funds must be allocated for extensive research on technological possibilities with geothermal energy. Since the reality of using Earth's own heat has already been experienced with present system designs, scientists and engineers conducting the research may further exhaust other possibilities to better construct facilities that manufacture geothermal energy whether direct or indirect. Funding a research can raise probability of deeper awareness for people when insights are shared through reading materials. This might as well inspire future scientists of the same field to carry out their own study of the matter and figure how else it may be enhanced in different aspects. Protection of potent geothermal energy sources as hot springs or wells and locations hereof from commercialization is another commendable policy aimed at both preserving the beauty of nature and securing areas prone to seismic activities. Encouragement of this act must be deemed necessary as commercializing with all its related tasks could endanger and denature such place which would eventually lessen good energy source. Financial issues may further be brought up through forums in order to determine wise financial act on funding geothermal energy projects which may involve proper solicitations or campaigns that encourage people to participate and share in the goal of supporting the widespread application of renewable energy. The relevant policy must see to it that each organized forum contains a group of individuals headed towards a common solid interest and inclination of developing similar fields of specialization to come up with a fruitful discussion of ways to plan available monetary resources with the intended design either on process or on equipment. Works Cited “How Geothermal Energy Works.” 2010. http://www.ucsusa.org/clean_energy/technology_and_impacts/energy_technologies/how- geothermal-energy-works.html. 12 May 2011. “Energy Resources: Geothermal Power.” 2011. http://www.darvill.clara.net/altenerg/geothermal.htm. 14 May 2011. Clauser, C., 2006. Geothermal Energy, In: K. Heinloth (Ed), Landolt-Bornstein, Group VIII: “Advanced Materials and Technologies”, Vol. 3 “Energy Technologies”, Subvol. C “Renewable Energies”, 480 – 595, Springer Verlag, Heidelberg-Berlin. “How Geothermal Energy Works.” 2011. http://science.howstuffworks.com/environmental/energy/geothermal-energy.htm. 15 May 2011. Read More