The Shams Power Generation - Case Study Example

Name Course Tutor Date The Shams Power Generation Located in Madinat Zayed city South West of Abu Dhabi, United Arab Emirates, Shams power generation located in is the biggest concentrated solar system (CSP) worldwide. The plant produces enough electric power (net rated power output of 100MW) to supply power to thousands of citizens of the Middle East. Shams Power Company which is a partnership of Masdar, Total and Abengoa Solar owns and operates the power generating project. Initially it was Abu Dhabi-based Masdar that provided the entire Middle East with renewable energy (Quick 1). Shams therefore was registered with the UN as the Company’s second project. Clean development mechanism (CDM) approved Shams as the first CSP plant. The plant was given carbon credit by the UN's CDM. The Abu Dhabi government in Green Power agreement made an approval to the project for a solar incentive programme. The Shams CSP covers an area about 2.5km² of desert and has several parabolic trough collectors in about 6,300,000ft² of land (Quick 1). Concentrated Solar Power Mechanism (CSP) CSP power systems concentrate thermal energy from large surface areas to a confined area thereby generating solar power using lenses or mirrors. The mirrors or lenses have tracking systems that focuses on areas receiving direct sunlight and directs it on a small surface. Energy in form of electricity is generated immediately when the concentrated light is converted to energy. At this stage, the CSP system works under the principle of the first law of thermodynamics which states that ‘energy cannot be created nor destroyed but can be transformed into other forms (Waele de 3),’ Light energy from the sun is converted to electric energy. Heat engine connected to an electrical power generator is thus driven or it powers a thermal reaction (Harsha 5). The convectional power plant can, therefore, use the concentrated light as a heat source or used in solar air conditioning (heating/cooling). This technology that involves concentrated light occurs in various forms including parabolic troughs, enclosed troughs, Stirling dish system, Fresnel reflector and a solar power tower (Blundell and Blundell 98). Parabolic trough: This involves concentrating light on the receiver that is positioned along the focal line of the reflector. A linear parabolic reflector is used. A tube (receiver) is filled with the working fluid and is directly placed above the parabolic mirror. The reflector proceeds to the direction of the sun during the day as it tracks along single axis working fluid (Harsha 8). Molten salt at a higher temperature of 540oC is effective as heat transfer fluid or as a medium for storing thermal energy (Harsha 8). Molten salt is stable at 540oC and is able to store more thermal energy. The stability of molten salt is due to the third law of thermodynamics which states that the entropy of a perfect crystal is zero when its temperature is equal to absolute zero (Waele de 10),. The molten salt at 540oC is like a perfect without thermal motion and is thus stable causing no disorder to the system. Absorber tubes are heated to extreme temperatures after they have circulated with molten salts then directed to a system that stores heat. Enclosed trough: This works such that it encapsulates within a glasshouse the solar thermal system. A protected environment is therefore created by the glasshouse so that it can tolerate any element that can have a negative impact that may alter proper functioning of the solar system. Light-weight and curved solar-reflecting mirrors are often suspended by wires from the glasshouse ceiling. These mirrors are positioned by one axis tracking system to receive enough sunlight. The sunlight is then focused on a network once concentrated (Harsha 7). Frensel reflectors: These are made of tiny flat mirror strips which concentrate light from the sub and direct it to the tubes having the working fluid. When the mirrors are flat, there is more reflective surface than in a parabolic reflector, therefore, more sunlight is captured (Harsha 10). Dish Stirling: Made up of independent parabolic reflector concentrating light onto a receiver located at the focal point of the reflector. To ensure that the concentrators to proceed to the sun’s direction, they are mounted on a structure having a two-axis tracking system. The heat engine uses the collected heat directly as the dish structure rotates with the receiver (Harsha 12). Power tower: They utilise sun-tracking mirrors to focus light from the sun and direct it to the receiver present on the top tower. The receiver has fluid capable of transferring heat and is capable of producing steam necessary in the production of electricity by in convectional turbine generator (Harsha 9). In CSP plant, the quality of Direct Normal Irradiation (DNI) must be detected because the rate by which electric auxiliaries are consumed and thermal losses made by the receiver are often constant (Roldan, 13). Therefore, a null total energy output when DNI rate falls below a certain level is realised. To determine this, the concentration ratio of the solar collectors is calculated by dividing the concentrator aperture area (m2) by the receiver area (m2) (Roldan, 13. The second law of thermodynamics is applied to determine the ratio of maximum concentration by determining the radiative exchanged between the receiver and the sun. This is because in the exchange process, more energy is wasted and only a few reaches the receiver. This is in accordance with the second law of thermodynamics which states that more and more energy is wasted in its transfer process (Waele de 4). However, the heat loss can be minimised by connecting each receiver with a generator to store the heat thereby modifying this law. How CSP and Photovoltaic Cells Differs Photovoltaic (PV) solar panel is different from solar thermal systems because it uses sunlight via the’ photovoltaic effect’ to produce direct electric current (DC) in a direct process releasing electricity (Green et al., 14). This is different with CSP that uses heat from the sun to generate power (Chu 44). With PVs, inverters are used to convert DC to AC in order to ensure current distribution on the power network. Semiconductors allow the photovoltaic effect to take place. The semiconductors are after a specific chemical procedure that allows electric current to be generated upon light exposure.The shape of the semiconductors is organised in layers conforming to the solar cells able to generate direct current. The solar cells are found within the solar panels where a given amount of voltage and current can be obtained (Chu 7). Concentrated solar power system not much sophisticated though it is important in generating consumable energy like the photovoltaic effect. It is, however, dependent on the direct heat from the sun that heats the water. This conversion of energy occurs on different devices. This depends on the temperature ranges at which the working fluid is being heated (Chu 27). In terms of how the two technologies retain energy and how efficient they are, CSP systems have the capability to retain energy using Thermal Energy Storage technologies (TES). It then uses the stored energy when there is no sunlight. PV systems are not able to store or produce thermal energy because they generate electricity directly. It is impossible to store electricity in large power plants. CSP is thus more efficient power generation plant. Energy market players have also demonstrated that PV systems technology is easier to set up due to the low cost and little time required. CSP plants require a lot of space for large-scale uses and it has greater risks including cooling and storage of thermal energy. Environmental Impact of Shams Power Plant Shams power plant has enabled the displacement of almost 175,000t of carbon dioxide. This has helped get rid of carbon dioxide that 1.5 million estimated numbers of trees could remove (Shamspower 1). This has really aided in environmental conservation from excess Carbon dioxide level which causes global warming. The United Arab Emirates is mainly a desert that cannot support the growth of sufficient trees to eliminate high levels of carbon dioxide gas released into the environment from industries. The plant has local impacts on flora and fauna which includes ecosystem disturbance and loss of their function as the construction can cause indirect mortality to the local fauna (Wang 1). Some vertebrate especially birds collide with concentrated light beams or are killed by heat shock. Emissions released by the plant include Nitrous oxide derived when nitrous salts are used are used as heat transfer fluids but the quantities are negligible. This CSP plant, therefore, has the much better performance to the environment because it doesn’t use extractable fuels. The materials used in the construction are mainly steel, glass and concrete which have high potential to be recycled (Abutayeh et al.417, 421). Shams Power Plant Current Output Sham power generation plant currently produces sufficient electricity that can provide power to about 62000 homes. The sham power generation plant system consists of 125 MW capacity steam turbine supported by Turbo and MAN diesel engine. It uses parabolic trough technology to release steam of pressure about 120 Pascal and temperature of 540oC and the exhaust steam is cooled by the availability of limited water in that region (Shamspower, 1). The power plant release power output at a constant rate obove100MWe which is taken as renewable electric power. The sham system it saves approximately 175000 emissions of carbon IV oxide compares to thermal power station per year. Shams Power Generation Plant Future Plans The power generation plant future plans are to enhance the capability of electric generation to meet the resource needs for 2017 to 2026 period of time. Focuses of the power generation system are based on supply side additions and the sites of these additions. First, the project plan is to utilise new cost-effective solar generation. This is due to large declining cost of equipment of photovoltaic equipments. There is need to project additional 2,086 MW of photovoltaic by 2023. Second is the plan to modernise fleets of fossil fuelled generating units of the power generating system. The already existing Lauderdale power system which has two 442MW combined cycle units are modernised then replaced with modern 2 x 1 combined cycle unit by end of 2022. This will save the cost of customers and it may improve system fuel efficiency (Wang 1). The third is the upgrading of the CT component in its combined cycle units which is planned to continue through the year 2020. The construction of these units will be completed at the end of the year 2021. Shams Power plans to partition the project in two phases with Phase-1 producing 1.2MW and Phase-2 producing 48.8MW.The company has plans of installing small-scale solar generation facilities. It has linked with the National Electric Power Regulatory Authority (Nepra) in order to generate 50MW gross combined capacity power. This will be achieved by a gradual increase in the generation facilities to the prospective buyers using Solar PV Modules. The sale of electricity would then occur within the same premises without the use of distribution or transmission lines (The Government of Abu Dhabi 1). Personal Reflection I was able to learn that even when it is cloudy or post sunset, storage systems can be integrated to CSP power plants that store heat involved in power generation (Harsha 6). A fluid with high thermal capacity stores the heat from the concentration when there is the sun. The capacity factor of CSP plant is thus improved. This is mainly achieved by increasing the size of heat collectors and mirrors (solar field) in relation to the plant’s nominal capacity of electricity (MW). It also came to my attention that photovoltaic panels also can work when it is cloudy because of their ability to collect irradiation, both diffuse and direct (Harsha 6). A good example is a photovoltaic solar plant located in California which can achieve a peak capacity of 10% when it is rainy. I also noted that apart from using synthetic oils as heat transfer fluids in parabolic troughs because of their stability at 400oC, molten salt at a higher temperature of 540oC is effective as heat transfer fluid or as a medium for storing thermal energy (Harsha 8). Molten salt is more efficient due to its capability to store more thermal energy (Harsha 8). The fact that Stirling dish systems used in CSP plants are highly efficient than the other systems including frensel reflectors, enclosed and parabolic troughs were knew to my knowledge (Harsh 12). The Stirling dish systems use air cooling mechanism instead of water, this making their implementation on slopes or terrains that are uneven more effective. Each receiver has a generator located on the dish minimising heat loss (Harsha 12). I found it interesting having noted the use of solar position algorithm in directing the reflectors to the exact position of the sun tracking the heat during the day. This automatic tracking system involves the use of simulation and calculating software that are programmed to detect the suns position (Harsha 15, 16). Work Cited Abutayeh, M., Goswami, Y. D. and Stefanakos, E. K., 2013, “Solar thermal power plant simulation. Environ. Prog. Sustainable Energy, 32, pp. 417-424. Blundell, Katherine and Blundell, Stephen.Concepts in Thermal Physics, 2009 Chu, Yinghao. Review and Comparison of Different Solar Energy Technologies. Global Energy Network Institute.August 2011 Green, Martin, A., Emery, Keith. Hishikawa, Yoshihiro, Warta, Wilhelm, Dunlop, Ewan, D. Solar Cell Efficiency Tables (Version 38), Progress in Photovoltaics, 2011 Quick, Darren, 2010, “100MW concentrated solar power plant to be built in the UAE.” from http://www.gizmag.com/shams-1-concentrated-solar-power-plant/1538 Harsha, Vardhan. Operation and Monitoring of Parabolic Trough Concentrated Solar Power Plant. Scholar Commons, November 2015. Roldan Serrano, M.I. Concentrating Solar Thermal Technologies Analysis and Optimisation by CFD Modelling.2017, IX, 88 p. 25 Shamspower, Press releases issues since June 2010. The Government of Abu Dhabi, “The Abu Dhabi Economic Vision 2030.2009, from http://gsec.abudhabi.ae/Sites/GSEC/Content/EN/PDF/Publications/economic-vision-2030-executive-summary-mandate2,property=pdf.pdf Waele de, A.T.A.M. The First, Second, and Third Law of Thermodynamics (ThLaws05.tex). September 3, 2009. Wang, Ucilia, "The Rise of Concentrating Solar Thermal Power", Renewable Energy World, July 6, 2011. Read More

The reflector proceeds to the direction of the sun during the day as it tracks along single axis working fluid (Harsha 8). Molten salt at a higher temperature of 540oC is effective as heat transfer fluid or as a medium for storing thermal energy (Harsha 8). Molten salt is stable at 540oC and is able to store more thermal energy. The stability of molten salt is due to the third law of thermodynamics which states that the entropy of a perfect crystal is zero when its temperature is equal to absolute zero (Waele de 10),.

The molten salt at 540oC is like a perfect without thermal motion and is thus stable causing no disorder to the system. Absorber tubes are heated to extreme temperatures after they have circulated with molten salts then directed to a system that stores heat. Enclosed trough: This works such that it encapsulates within a glasshouse the solar thermal system. A protected environment is therefore created by the glasshouse so that it can tolerate any element that can have a negative impact that may alter proper functioning of the solar system.

Light-weight and curved solar-reflecting mirrors are often suspended by wires from the glasshouse ceiling. These mirrors are positioned by one axis tracking system to receive enough sunlight. The sunlight is then focused on a network once concentrated (Harsha 7). Frensel reflectors: These are made of tiny flat mirror strips which concentrate light from the sub and direct it to the tubes having the working fluid. When the mirrors are flat, there is more reflective surface than in a parabolic reflector, therefore, more sunlight is captured (Harsha 10).

Dish Stirling: Made up of independent parabolic reflector concentrating light onto a receiver located at the focal point of the reflector. To ensure that the concentrators to proceed to the sun’s direction, they are mounted on a structure having a two-axis tracking system. The heat engine uses the collected heat directly as the dish structure rotates with the receiver (Harsha 12). Power tower: They utilise sun-tracking mirrors to focus light from the sun and direct it to the receiver present on the top tower.

The receiver has fluid capable of transferring heat and is capable of producing steam necessary in the production of electricity by in convectional turbine generator (Harsha 9). In CSP plant, the quality of Direct Normal Irradiation (DNI) must be detected because the rate by which electric auxiliaries are consumed and thermal losses made by the receiver are often constant (Roldan, 13). Therefore, a null total energy output when DNI rate falls below a certain level is realised. To determine this, the concentration ratio of the solar collectors is calculated by dividing the concentrator aperture area (m2) by the receiver area (m2) (Roldan, 13.

The second law of thermodynamics is applied to determine the ratio of maximum concentration by determining the radiative exchanged between the receiver and the sun. This is because in the exchange process, more energy is wasted and only a few reaches the receiver. This is in accordance with the second law of thermodynamics which states that more and more energy is wasted in its transfer process (Waele de 4). However, the heat loss can be minimised by connecting each receiver with a generator to store the heat thereby modifying this law.

How CSP and Photovoltaic Cells Differs Photovoltaic (PV) solar panel is different from solar thermal systems because it uses sunlight via the’ photovoltaic effect’ to produce direct electric current (DC) in a direct process releasing electricity (Green et al., 14). This is different with CSP that uses heat from the sun to generate power (Chu 44). With PVs, inverters are used to convert DC to AC in order to ensure current distribution on the power network. Semiconductors allow the photovoltaic effect to take place.

The semiconductors are after a specific chemical procedure that allows electric current to be generated upon light exposure.The shape of the semiconductors is organised in layers conforming to the solar cells able to generate direct current.

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