Proposal to Build an Underground Turbine - Term Paper Example

Proposal to Build an Underground Turbine The proposed project is to build an underground turbine that will act as an alternative source of power and thus supplement the much-needed power needs in society. The entire project proposal is going to provide a guided manner of building an underground turbine, together with explaining the expected output from its completion. Abstract A tidal energy generator is a kind of machine that is able to extract from energy resulting from the moving masses of water. The intention here is to use the underground water tides to run the turbine, which eventually generates energy. The underground turbine system of electricity generation has been a technology under operation since 2003 from the East Atlantic Ocean, but such project have not yet hit the mainstream. While the wind power technology continues gaining more popularity, underwater power technology remains off the radar since it still has limited appeal to the residential customer. Upon conducting some research, it is apparent that strong tides have the potential of producing up to 10 knots or more of the electricity, thus calling for the implementation of special procedures that would help in generating an accurate and reliable map of using these strong ocean currents (Meyers 27). The paper thus provides the guidelines and the basics to consider into completing a project that could produce electricity from the tidal waves. Introduction The fact is that in the present generation, people are living in conditions of which more than 80% of the energy is subject to furnish by sources like natural gas, coal, or oil. These sources of energy are becoming subject to depletion at an alarming rate, combined with the fact that they are environmentally unfriendly. The generation has also gone to the advances of producing destructive technologies, such as nuclear power plants, which eventually end up causing more harm to the human life. Lucky enough, the same human generation has been able to realize the significance of making some enormous changes in life procedures and the manner of using energy. In this regard, the idea of building renewable sources of energy as a substitute for the current sources of energy came into being. Tidal power is thus subject to consider as being a renewable source of energy. The tides result from the solar system’s orbital mechanics, thus becoming subject to consider as being inexhaustible through the human timeframe. According to Meyers (2012), tidal energy is a kind of energy obtained from tidal power is a pollution free energy that has a lot of potential for supplementing the present sources of power. Even though the measure of this potential has not become a subject to complete realization, it is hard for anyone to deny the advantage of which this kind of renewable energy might pose to the human life. Therefore, this research proposal provides some basics of the introduction to the tidal power, going ahead to provide the basic principles of its operations, while it focuses towards the development of tidal power energy to the entire world. Electricity generation with the aid of underground turbines through areas with strong tidal currents may aid in providing dependable and predictable source of energy that is absolutely clean and renewable. Literature Review Scientific studies indicate that more than 70% of the total solar radiation that reaches the earth’s surface falls into the ocean, thus heating on the upper layers of the water bodies. Combining this thermal energy with the wind alongside forces of the solar system ends up causing currents, waves, and the tides. Altogether, these mechanical and thermal forces combine into making a huge energy resource. There is a similarity in the manner of which the tidal system generator will draw energy from the moving water currents when compared to the manner of which wind turbines operate (DeGennaro 38). However, the potential of power quantity that one may generate from a single turbine may be greater than that of the similarly rated wind energy turbine. Since water has relatively higher density than air, it implies that a single turbine generator may be able to provide significant amount of power even at the lowest tidal velocities. Since power varies relative to the density of medium together with the cube of velocity, the amount of water speeds that reaches nearly one-tenth of the wind speed provides the same quantity of power similar to that produced by wind turbines, which is at least 2 knots (1 m/s) of energy. Consequently, cases where there is higher speed of water movements, such as between 2 to 3 meters per second will result to the tidal turbine being able to achieve accessing four times of much energy per every rotor swept area (Mohan 19). There are various mechanisms and models applicable in generating energy from tides. The first method may involve the use of tidal basins. The tidal energy generation is a process that involves the erection of a barrage across the tidal basin, whereby a sluice is subject to use by directing the water into the basin. As the ocean level begins to drop, the water then flows back to the ocean. This is similar to the way the traditional hydroelectric technologies use through redirected water into producing electricity. The image of this technique is as shown below; Source: http://energy.gov/sites/prod/files/2014/06/f16/ocean_power Other means of capturing tidal energy may include using floats and pitching devices. This technique can be useful to the floating structure or the anchored structure deep at the floor of the sea. Largely known for the public, electricity and heat energy remains to be essential commodities in the human life. Extraction of energy using traditional sources like coal, oil, gas and nuclear power causes environmental problems, which may include changes in the climate, depletion of ozone layer and many other impacts. Developing an energy policy that enhances a sustainable future bases on the high level of energy efficiency, combined with the greater use of renewable energy sources. Tidal power energy source becomes the primary target of producing renewable energy as it may help in solving numerous problems. Tidal energy generation does not produce any waste and pollution and is very free to use (DeGennaro 47). There is an absolute possibility of tidal power becoming the most popular power sources in the near future and thus end up becoming one of the most attractive options for the power company that engages on renewable sources of energy. China remains to be the only country that has been able to build ideal tidal stations. The success of which the country has achieved in supplementing its other normal power sources makes tidal energy generation to be an ideal source of renewable energy. In this case, there is no doubt in regards to tidal power playing an important role in supplementing the energy needs of the human race in the modern society. The production of electricity with the technology of underground turbines from strategic areas that experience tidal currents may be effective at providing the human race with a renewable energy that is also predictable and clean (Mohammadian et al. 13). Production Methodology Source: http://energy.gov/sites/prod/files/2014/06/f16/ocean_power The underwater turbine performs in the same manner of which the rest of above ground turbines work. In this model, three bladed rotors are subject to place on a vertical stack so that they can move by any presence of water motion. The rotating rotor then turns the magnetic coil generator built inside the shaft housing thus creating the electric current. The assumption is that when there are higher speeds in the moving water near the turbine, more and more electricity is subject to generate. The underground turbine is subject to make in a design that water flow in any direction, be it front or backwards, allows the turbine to move and hence generate energy. This design allows the advantage of using the back and forth motion that tidal waves produced by generating electric energy (Mohan 31). An added advantage of the underwater turbine is that there is room for predictability. In the scenario where water flow rates remain relatively stable through the whole day and night, it makes it easy for the system engineers to predict the actual amount of electricity that the system will generate basing on the already available flow chart. Underwater turbines are subject to a place deep inside a river or in an ocean. The turbine will function best whenever the coastal currents are running between 3.6 and 4.9 knots. At the situation where currents are of this speed, a turbine constructed of a 15-meter (49.2-feet) diameter of a tidal turbine will end up generating as much energy that a 60-meter in diameter of a wind turbine will generate. The ideal area to place an underground turbine is somewhere close to the shore in water depths ranging from 20-30 meters. The movement of the tides will eventually cause the loss of the mechanical energy within the system. It is all a result of the pumping of water based on the natural restrictions in turbines (Reza 29). Analysis and calculations A tidal generator is able to convert the energy of the tidal flow in producing electricity. With the presence of greater tidal current velocities, there is a relative dramatic increase on the amount of electricity generated. The figure below shows the distribution of tidal phases below the seabed; Source: http://tethys.pnnl.gov/blog/admiralty-inlet-pilot-tidal-project The tidal energy converters normally vary on the modes of their operation and in the same capacity have varying power output. In the case where the power coefficient of the device “Cp” is well known, the power equation below can be useful in determining the amount of power output that the hydroelectric system is able to generate (Reza 43). The energy power generated from the kinetic system is subject to express as; P = (ρ AV3)/2 * Cp Where Cp = the turbine power coefficient p = the power generated (in watts) ρ = water density (whereby seawater is 1027 kg/m3) A = area of which the turbine sweeps (in m2) V = velocity of tidal flow When relative to the open turbine that is in free stream, ducted turbines have the capacity of producing as much as 3 to 4 more times of the power when compared to the same turbine rotor available in the open-air flow. While conducting resource assessment of the available energy available in a channel, there is need to focus on calculations with aid of kinetic energy flux model. However, in this calculation, the limitations of tidal power that is subject to generate have significant complications. Water in motion has the kinetic energy with similar characteristics to the wind. The amount of energy intercepted in each second through a device of frontal area A0 (m2) through water containing density of ρ and the current velocity of V (m/s) is thus subject to express as; Pe (t) = 0.5ρ A0 V3 (t) The maximum power possible to convert to forming a useable mechanical form is thus limited only for a device that is in the open water flow through the following formula; Pm (t) = 0.5Cp ρ A0 V3 (t) Whereby Cp is the power coefficient The total value of the computed Cp for the turbine exposed directly towards the flow of an incompressible liquid has the limitation of a theoretical maximum value that is approximately 0.593 in accordance to the Betz law. For the underground turbine, the power coefficient is entirely a function occurring at the tip speed ratio, which is entirely dependent on the form of blade or also dependent on the number of blades. Upon making the assumption that the gearbox transmission efficiency is η1together with the generator efficiency of η2, then the electric power output is subject to calculate as; P (t) = η1η2 0.5 Cp ρ A0 V3 (t) The fact remains is that tidal currents are not constant. They are just a combination of the quasi-steady marine currents and flows that are subject to induce by the tides. In this situation, the estimation of energy capture ends up becoming a complex procedure. According to Reza (2010) most sites that are possible to extract tidal flows, it makes it easy to parameterize on the tidal currents as being a series of simple sinusoids. Taking the assumption that current velocity V (t) will follow a cyclic pattern then; V (t) = V max sin ω t ω = 2π/T Where V max is maximum amount of current speed occurring at the surface ω refers to the angular velocity of tide while T is the period of entire cycle, typically taking 12 hours and 25 minutes. Results and Discussion The below graph is an indication of power available together with the predicted power output from using a marine current turbine over a single typical cycle. The coefficient of turbine power takes the assumption of being approximately 0.4 units, with a cut speed of 0.7 m/s (14 kW) imposed, together with the rated speed of about 2.4 m/s, which thus limits the maximum power rated at a value of 500 kW. Basing on the predictability of the tidal flows, it should be unnecessary in setting a cut-out condition for the turbine at the time it is under normal operation. The time of which the cut-in together with the rated power will occur as indicated in the T1 and T2 in the graph below; Source: http://www.esru.strath.ac.uk/EandE/Web_sites/03-04/marine/energy_theory.htm A tidal current will be able to generate power from both directions of water flow (flood and ebb), thus making its power characteristic appear as a function of time that is most similar to the half cycle. According to Mohammadian (2014) the speed of which the tides flow become generally higher than that of the ebb flow. The energy that becomes subject to capture in this situation relative to the covered area occurs under the power curve. Therefore, the total energy that is subject to capture during the single half of each cycle of each half-tidal cycle is subject to compute by the following formula; ∫ P (t) = ∫ (η1η2 0.5 Cp ρ A0 V max 3 sin3 ω t) ∂t + P rated (Tm – T2) from initial time T1 to final time T2 The positive results of the project Engaging in tidal energy production has many positive outcomes in relation to its successful production. The first positive outcome is that there will be a production of the renewable resource, which requires no fuel for maintenance and that it is free of charge. The second positive outcome is that there is no pollution of any kind. The characteristic is different from other fuel sources that normally end up producing greenhouse gases or other forms of waste (Blass 51). Another positive outcome is the energy source will be predictable, implying that it will be independent of weather and the changes in climate, thus following predictable relationship. Consequently, the resulting energy output will be more efficient than wind energy all resulting from the density of water. Finally, the other positive result of the output is that it offers large protection to the stretch of the coastline against the form of damage that may result from high storm tides. The negative results of the project Utilizing on this technology presently remains a costly affair, which is very expensive to build and maintain. Another negative outcome is that erecting a barrage has its related environmental effects, such as fish and plant migration, results into silt and mud deposits, and causes waste and sewage blocks. Consequently, this kind of technology remains under shadows as it is not yet fully developed. According to Blass (2008), another negative outcome of the result is that this kind of project only provides power that last for about 10 hours each day, which is the time tide is actually involved in the in and outward movement in the underground turbine. Conclusion Upon doing comparison of tidal power with wind and solar power, it is apparent that tidal power remains unpopular among these renewable sources of energy production. However, it is also clear that this technology is gaining more popularity for the recent decades. By this rate of growth, there is absolute bright future of using tidal power in fixing several power problems that many states encounter with the challenge of fulfilling the ever-increasing demand for power supply. In this regard, I recommend that many governments and respective organizations should support such projects as they offer permanent solutions to the present energy problems. The turbine technology is more effective if it achieves the set target. Finally, the point to note with tidal energy production is that its environmental impacts should not be subject to neglect as measures are subject to device for solving current problems. Works Cited Blass, Tom. A Decade of Discovery. Arlington, VA?: Published by Altio Media for the U.S. Dept. of Energy, 2008. Print. DeGennaro, Sean. Design, Construction, and Testing of a Model Hydrokinetic Prototype. , 2012. Internet resource. Meyers, Robert A. Encyclopedia of Sustainability Science and Technology. New York: Springer, 2012. Internet resource. Mohammadian, Abolfazl, Konstadinos G. Goulias, Elif Cicek, Jieh-Jiuh Wang, and Chrysanthos Maraveas. Civil Engineering and Urban Planning Iii: Proceedings of the 3rd International Conference on Civil Engineering and Urban Planning (ceup 2014), Wuhan, China, 20-22 June 2014. , 2014. Internet resource. Mohan, Ned. Electric Power Systems: A First Course. Hoboken, N.J: John Wiley & Sons, 2012. Print. Reza, Zaqie. Dissipation and Eddy Mixing Associated with Flow Past an Underwater Turbine. , 2010. Print. Read More