Geothermal Energy

Question: Describe about the Geothermal Energy? Answer: Introduction Today, most of the countries rely heavily on natural gas, oil and coal for its energy usage. But, the days are not far away that non-renewable energy gets extinct, considering the volume in which we are spending. Hence, to cope up with the need of the situation, countries are looking forward to find out the alternatives. We have already found out some alternatives (renewable energy) which are already in use and giving great result throughout the world. There are various types of renewable energy which have the potential and are already providing exceptional results; namely, Solar energy, Wind Energy, Geothermal Energy, Ocean Energy and Wave Energy. Most of the renewable energies are directly or indirectly related to the solar energy, except the geothermal energy. The Energy Resource Geothermal Energy uses the heat energy from the core of the earth and taps it down for various purposes, which includes heating and cooling of the buildings and the electric power generation. The various resources of geothermal energy are the hot rock found just around 10 feet from the earth surface and when we go even deeper the high temperatures of the molten rock (magma) does the work (Kubik, 2006). Mostly, the upper 10 feet of the earth surface comes into use as the constant temperature of around these regions nearly lies between 50 to 60 degree Fahrenheit. This helps the geothermal heat pumps to suck out the heat from these regions and to be used for the heating and cooling purpose of the buildings. The United States is the global leader when we compare the installed geothermal capacity within the countries. When we talk about numbers, the US produces around 3300 MW in eight different states out of which 8% of the capacity comes from California (Tester, 2008). In most of the homes and building, a geothermal heat pump are inbuilt and uses the steady temperature of the earth just below the building to heat and cool the same building, inexpensively and very cleanly (Huddlestones, 2011). Conversion Process There are various methods to capture the geothermal energy from the earth and the most common of it is to use the natural occurring hydrothermal convection systems. In this process, the cooler water enters into the earth crust and is heated up and then is again risen up to the surface. When this heated water rises up the surface of the earth, this heated steam can be used in to drive the electric generators. To capture the steam in the most effective manner, the geothermal power plant drills their own holes into the rock (Bromley, 2011). The geothermal power plants works basically on three different models. But, all of these models pulls the hot steam and water from the ground, uses it to heat or cool the building and then again refuels it back to the ground. The different models are dry steam system, flashed or depressurized system and the binary cycle system. Figure 2: The three basic design of Geothermal Power Station In the dry steam power plant, these is a regular flow of the steam into the turbine and then to the condenser where it is condensed back to water. In the flash steam power plant, the steam is pumped into the steam only when there is a requirement of the electrical or the heat energy to be produced (Blodgett, 2014). And, the third one is the binary cycle power plant which uses a heat exchanger in addition to the condenser and turbine. The water is not used directly into the turbine rather the water heats up the second liquid which further runs the turbine (Kagel, 2007). The purpose of using two fluids is to increase the efficiency of the plant. The second fluid used in this cycle is always a fluid with low boiling point such that it is easily converted into steam to run the turbine. The choice of the design depends majorly on the location on which the plant is to be placed. If the water comes out as a steam directly from the well, then it can be directly used and the first system is perfect for it (Green, 2003). If the water doesnt have that much high temperature then either the flashed system is used or the binary system (incorporation of heat exchanger) is used. The largest geothermal plant in operation today is in California and is called as Geysers. This plant is a steam driven plant and the heat that is used in the plants comes all from the steam, not hot water. Pros and Cons of Geothermal Energy There are various pros and cons of the geothermal energy which needed to be discussed so that to get a clear picture of whether it benefits us or not. The pros of the geothermal energy are as follows: The production of the geothermal energy have become of low cost considering the recent advancement in the technology which have made the resources more exploitable (Wendell, 2004). There are no limitation to the resource, the geothermal energy is available almost everywhere. There are no any uses of fuels in the extraction of the geothermal energy, which means a very stable electricity production with minimum fluctuation in the cost. It is excellent for heating and cooling of the building, almost every small household can be benefited. Unlike any other source of renewable energy such as wind or solar energy, geothermal energy proves to be excellent in meeting the base load energy demands. The potential of the geothermal energy is massive. An estimate shows the potential of around 2 Terawatt. Last but not the least, the geothermal energy reservoirs are naturally replenished and are considered to be eco-friendly (pollution free). Coming to the cons of the Geothermal Energy The geothermal reservoirs can only sustain if it is properly taken care of. Although the geothermal energy is available everywhere, but most of the location are uneconomical when it comes to build a power plant at that particular location. The initial cost of setting up of the plant and as well as the geothermal system is quite high Some minor environmental issues can take place with the geothermal power, in the most extreme cases it can lead to earthquakes. Conclusion It is easily understandable that the geothermal energy has the potential to play a significant role in meeting the energy demands in the coming future. Unlike any other thermal and nuclear power plants, the geothermal binary cycle can be used to help the variable supply of the wind and the solar energy. The wind or the solar plants can be used with the geothermal power plant as a binary power plant and provide a continuous flow of energy. Moreover, the costs of the geothermal energy power plant are becoming increasingly competitive day by the day by the advancement of the technology. We can expect the geothermal energy to be one of the major sources of energy in the coming future. References Tester, J W 2008, The future of geothermal energy as a major global energy supplier, in H Gurgenci AR Budd (eds), Proceedings of the Sir Mark Oliphant International frontiers of science and technology Australian geothermal energy conference, Geoscience Australia, Canberra, viewed 5 January 2010, https://www.ga.gov.au/image_cache/GA11825.pdf Blodgett, L 2014, Geothermal Energy, viewed on 13 March 2016, https://geo-energy.org/Basics.aspx Bertani, R Bromley, C 2011, Geothermal Energy, Cambridge, New York, USA. Green, B 2003, Geothermal Energy, Elsevier, Sydney. Kubik, M 2006, The future of geothermal energy, Idaho National Laboratory, Massachusetts. Duffield, A Wendell 2004, Geothermal energy- clean power from the earths heat, U.S Department of the interior, US. Kagel, A 2007, A guide to the geothermal energy and the environment, Pennsylvania Enclave SE, Washington D.C. Huddlestones, H 2011, Potential of geothermal energy, Kenmore, Queensland.