Technical Report

Letter of transmittal

February 27, 2019 Yazan Shakfa [email protected]

Dear Yazan Shakfa,

This report investigates The Sustainability of Wind Turbines, and methods of further advancements in the field. This report would be published on February 27th, 2019. The report was assigned on February 14th, 2019. This report is split into two major areas of concern renewable energy production, and the conservation of energy. It discusses current employed technologies, and future projects and ideas, and the results that would be reached if those implementations are to be made. Wind turbine design and efficiency will be areas of interest in renewable energy sector. Energy consumption, storage, and reusability will be further analyzed and discussed. Thank you in advance for reviewing this report. I look forward to receive your feedback, and would be more than happy to address any inquiries.

Sincerely, Abdallah Alshantaf

Enclosed: technical report

The Sustainability of Wind Turbines Abdallah Alshantaf (214999007)

Contents 1.

Introduction and Background............................................................................................................ 4

2.

Description of Wind Turbines ........................................................................................................... 5 2.1Turbine Components........................................................................................................................ 6 2.1

Horizontal axis wind turbines: ............................................................................................... 6

2.2

Vertical axis wind turbines: ................................................................................................... 7

3.Discussion: ................................................................................................................................................. 8 Environmental impact ........................................................................................................................ 8 Parameters that affect Turbine design: ........................................................................................... 8 4.Conclusion:............................................................................................................................................... 10 5. References: ............................................................................................................................................. 11

Figure 1:emissions from a power plant credit (iStockphoto) ............................................................... 4 Figure 2:VAWT-left HAWT-right............................................................................................................... 5 Figure 3: HAWT types [2] .......................................................................................................................... 7 Figure 4: types of VAWT design[2] .......................................................................................................... 8 Figure 6:Bahrain World Trade Center [sh-architecture] Figure 5: turbine design in urban areas source [New Wind] 10

1. Introduction and Background The most commonly used source for electricity production today is coal; 41% of all electricity is produced from coal, according to the World Coal Association. Due to its high level of pollution (water and air pollution during mining and air pollution during burning) and often miserable circumstances for miners, we can conclude that this is not a sustainable source for electricity. [1] As cities are expanding and population of people is increasing exponentially, energy is being consumed at a faster rate than ever. With this increase in energy demand, researchers are looking for ways to produce energy that is renewable (found in abundance in nature) , efficient (produces energy with least amount of losses), pollutionfree, etc. Examples of renewable energy sources are wind, solar, tidal, geothermal, hydro. Renewable energy would help solve many problems that face big and old cities, and open new doors for uprising cities. Engineers are hoping that the increase development in renewable energy system would allow mankind to shift their reliance of energy sources towards more eco-friendly ones. As climate change is affecting our planet and many ecosystems worldwide, people are learning more about alternative methods of energy production and are becoming more aware of the impact that the burning of fossil fuels is having on our planet. Humans have been using wind power to perform certain tasks that were labor demanding to make tasks simpler. For examples they were using windmills to grind corn into flour. They used water wheels to elevate water from a low elevation to a higher elevation. Renewable energy sources have been available at Earth as long as man has known, but extraction methods were not efficient, or the technology was simply not there yet.

Figure 1:emissions from a power plant credit (iStockphoto)

2. Description of Wind Turbines Wind turbines are devices that harness energy from wind blowing over them. There are two main types for turbines, horizontal axis wind turbines (HAWT), and vertical axis wind turbines (VAWT). Either type have its advantages and disadvantages which relates to the size of energy required and the mounting location of the turbines. Both types consist of blades, a mountable tower, gearbox, brakes, generator, and transformers. When the blades of a wind turbine turn, they rotate the axis which feeds into a generator. This creates a DC current which can then be passed through an inverter that changes it to AC, suitable for powering your home.

Figure 2:VAWT-left HAWT-right

2.1Turbine Components

Figure 3:turbine components

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Blades: Part of the turbine that rotates caused by wind, the faster the winds, the faster these blades would rotate. Gearbox: A system component that transmits high speed rotation to great power by changing speeds. Just like how cars shift gears, and speeds. Generator: Changes the rotation energy to electrical energy. Computer system: regulates the power output, voltage, current. Tower: Holds all the components at an optimum height.

2.1 Horizontal axis wind turbines: Horizontal axis wind turbines are the most common type used. All of the components (blades, shaft, generator) are on top of a tall tower, and the blades face into the wind. The shaft is horizontal to the ground. The wind hits the blades of the turbine that are connected to a shaft causing rotation. The shaft has a gear on the end which turns a generator. The generator produces electricity and sends the electricity into the power grid. The wind turbine also has some key elements that adds to efficiency. Inside the Nacelle (or head) is an anemometer, wind vane, and controller that read the speed and direction of the wind. As the wind changes direction, a motor (yaw motor) turns the nacelle so the blades are always facing the wind. The power source also comes with a safety feature. In case of extreme winds the turbine has a break that can slow the shaft speed. This is to inhibit any damage to the turbine in extreme conditions.

Figure 4: HAWT types [2] Advantages • Blades are to the side of the turbines center of gravity, helping stability • Ability to wing warp, which gives the turbine blades the best angle of attack • Ability to pitch the rotor blades in a storm to minimize damage • Tall tower allows access to stronger wind in sites with wind shear • Tall tower allows placement on uneven land or in offshore locations • Can be sited in forest above tree-line • Most are self-starting Disadvantages • Difficulty operating in near ground winds • Difficult to transport (20% of equipment costs) • Difficult to install (require tall cranes and skilled operators) • Effect radar in proximity • Local opposition to aesthetics • Difficult maintenance 2.2 Vertical axis wind turbines: In vertical axis turbines the shaft the blades are connected to is vertical to the ground All of the main components are close to the ground. Also, the wind turbine itself is near the ground, unlike horizontal where everything is on a tower. There are two types of vertical axis wind turbines; lift based and drag based. Lift based designs are generally much more efficient than drag, or ‘paddle’ designs. [2]

Figure 5: types of VAWT design[2] Wind turbines that have a vertical axis are starting to become more popular as a way for generating localised electricity particularly for new constructions. Because the axis is vertical, with the blades arranged around it, the array doesn’t need to be positioned directly into the wind as with horizontal axis turbines. The benefit of vertical axis turbines is that they can be placed much closer to the ground and are ideal for roof top arrays. They are also lighter and more easily introduced into a domestic, town or inner-city environment. [3] Vertical axis wind turbines are categorized into two sections depending on their blade designs: drag dependant or lift dependant. In general, drag dependant are less efficient than lift dependant because they result in less torque applied to shaft. Advantages • Easy to maintain • Lower construction and transportation costs • Not directional • Most effective at mesas, hilltops, ridgelines and passes Disadvantages • Blades constantly spinning back into the wind causing drag • Less efficient • Operate in lower, more turbulent wind • Low starting torque and may require energy to start turning

3.Discussion: Environmental impact Wind provided more than half of renewables growth, while solar contributed more than a third despite accounting for just 21% of the total. [4] Parameters that affect Turbine design: Energy from the wind to electrical energy that is used to power the grid or store energy. The turbines operate on abundant resource, wind, that is intermittently occurring in nature, which is the reason behind different types of blades, and turbine structure.

Researchers design most largescale turbines after gathering information about the geographical mounting location. Turbine designs depend on the type of turbine (vertical, horizontal), sweeping area, tip speed ratio (TSR) , Reynold’s no., drag and lift coefficients. When it comes to wind turbines, height means everything. The ideal place for a free-standing turbine is on top of a hill with a smooth top that is free from turbulence and obstructions such as buildings. The benefit of free-standing turbines is that they produce a greater power output and are therefore more likely to realise a profit with options such as the Feed in Tariff. Cut-in speed: The minimum wind speed at which useful power can be generated. Rated speed: The wind speed that delivers the rated power, usually the maximum power. Cut-out speed: The maximum wind speed at which the wind turbine is designed to produce power. At wind speeds greater than the cut-out speed, the turbine blades are stopped by some type of braking mechanism to avoid damage and for safety issues. The short section of dashed blue line indicates the power that would be produced if cut-out were not implemented. [6]

4.Conclusion: Nowadays, technology allows us to get energy from even the least expected sources. i.e. potatoes to power lights or other devices. Technology has come a long way in terms of looking for energy extraction and storage methods. Turbines are now becoming cheaper in terms of production and accessibility, and more people are installing them in their households and new and uprising buildings. They will be used even if it would be on a small scale to power low power consuming electronics in open areas like bus stops or subway stations. They will be used to charge phones or power routers that supply internet.

Figure 6:Bahrain World Trade Center [sh-architecture]

Figure 7: turbine design in urban areas source [New Wind]

5. References: [1] M. Helder, “Renewable energy is not enough: it needs to be sustainable,” World Economic Forum. [Online]. Available: https://www.weforum.org/agenda/2015/09/renewable-energy-is-not-enough-it-needs-tobe-sustainable/. [Accessed: 28-Feb-2019]. [2] Murat, Aydin” Wind turbines”, [accessed: 27-Feb-2019} [3] “Types of Wind Turbines,” Improving the Efficiency of Solar Panels | The Renewable Energy Hub. [Online]. Available: https://www.renewableenergyhub.co.uk/windturbines/types-of-wind-turbines.html. [Accessed: 28-Feb-2019]. [4] “Thermal Systems,” Types Of Wind Turbines And Associated Advantages - Thermal Systems. [Online]. Available: http://me1065.wikidot.com/types-of-wind-turbines-andassociated-advantages. [Accessed: 28-Feb-2019]. [5] “Types of Wind Turbines,” Improving the Efficiency of Solar Panels | The Renewable Energy Hub. [Online]. Available: https://www.renewableenergyhub.co.uk/windturbines/types-of-wind-turbines.html. [Accessed: 28-Feb-2019].