Wind Turbine

12 Key excerpts on "Wind Turbine"

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  eBook - PDF

  Wind Turbine Technology

  • Ph.D., A. R. Jha(Authors)
  • 2010(Publication Date)
  • CRC Press

    (Publisher)

  1 Chapter 1 Chronological History of Wind Turbine Technology 1.1 Introduction This chapter describes the history of Wind Turbine technology development and its potential applications. Wind Turbine technology offers cost-effective solutions to eliminate the dependence on costly foreign oil and gas now used to generate electricity. Additionally, this technology provides electrical energy without green-house effects or deadly pollution releases. Furthermore, Wind Turbine installation and electricity generating costs are lower compared to other electrical energy gen-eration schemes involving coal fired steam turbo-alternators, tidal wave turbines, geothermal-, hydrothermal-, biofuel-, and biodiesel-based electrical energy sources and nuclear reactor-based generators. Wind Turbine technology offers a cost-effective alternate renewal energy source. It is important to mention that a Wind Turbine is capable of generating greater amounts of electrical energy with zero greenhouse effects compared to other energy generating schemes including solar cell, tidal wave, biofuel, hydrogen, biodiesel, and biomass technologies. A Wind Turbine is the reverse of an electrical fan. A Wind Turbine uses wind energy to generate the electricity; a fan uses electricity to gener-ate wind. In more sophisticated terminology, a Wind Turbine converts the kinetic energy of the wind into electrical energy. Wind Turbines come in different sizes and types, depending on power generating capacity and the rotor design deployed. Small Wind Turbines with output capacities below 10 kW are used primarily for residences, telecommunications dishes, and irrigation water pumping applications. A Wind Turbine advertisement states that 2 ◾ Wind Turbine Technology a prototype 5-kW system can be built for $200, using inexpensive off-the shelf components and excluding labor costs. Utility-scale Wind Turbines have high power ratings ranging from 100 kW to 5 MW—sufficient to power 10 to 500 homes.

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  Wind Energy Explained

  Theory, Design and Application

  • James F. Manwell, Jon G. McGowan, Anthony L. Rogers(Authors)
  • 2010(Publication Date)
  • Wiley

    (Publisher)

  This is in contrast to a ‘windmill’, which is a machine which converts the wind ’ s power into mechanical power. As electricity generators, Wind Turbines are connected to some electrical network. These networks include battery-charging circuits, residential scale power systems, isolated or island networks, and large utility grids. In terms of total numbers, the most frequently found Wind Turbines are actually quite small – on the order of 10 kWor less. In terms of total generating capacity, the turbines that make up the majority of the capacity are, in general, rather large – in the range of 1.5 to 5 MW. These larger turbines are used primarily in large utility grids, at first mostly in Europe and the United States and more recently in China and India. A typical modern Wind Turbine, in a wind farm configuration, connected to a utility network, is illustrated in Figure 1.1. The turbine shown is a General Electric 1.5 MW and this manufacturer had delivered over 10 000 units of this model at the time of writing of this text. To understand how Wind Turbines are used, it is useful to briefly consider some of the fundamental facts underlying their operation. In modern Wind Turbines, the actual conversion process uses the basic aerodynamic force of lift to produce a net positive torque on a rotating shaft, resulting first in the production of mechanical power and then in its transformation to electricity in a generator. Wind Turbines, unlike most other generators, can produce energy only in response to the resource that is immediately available. It is not possible to store the wind and Figure 1.1 Modern utility-scale Wind Turbine. Reproduced by permission of General Electric 2 Wind Energy Explained: Theory, Design and Application use it at a later time. The output of a Wind Turbine is thus inherently fluctuating and non-dispatchable.

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  Wind Energy in the 21st Century

  Economics, Policy, Technology and the Changing Electricity Industry

  • R. Redlinger, P. Andersen, P. Morthorst(Authors)
  • 2016(Publication Date)
  • Palgrave Macmillan

    (Publisher)

  41 3 Wind Turbine Technology and Industry This chapter provides an introduction to Wind Turbine technology, a discussion of technological development and grid interaction issues, and an overview of the Wind Turbine industry. We begin with a brief introduction to the history of wind power use, followed by an intro- duction to the physical principles of extracting energy from the wind. A brief history of wind power utilisation People have used technology to transform the power of the wind into useful mechanical energy since antiquity. Along with the use of water power through water wheels, wind energy represents one of the world’s oldest forms of mechanised energy. Though solid histor- ical evidence of wind power use does not extend much beyond the last thousand years, anecdotal evidence suggests that the harnessing of mechanised wind energy pre-dates the Christian era. The use of wind power is said to have its origin in the Asian civil- isations of China, Tibet, India, Afghanistan and Persia. The first written evidence of the use of Wind Turbines is from Hero of Alexandria, who in the third or second century BC described a simple horizontal-axis Wind Turbine. It was described as powering an organ, but it has been debated as to whether it was of any practical use other than as a kind of toy. More solid evidence indicates that the Persians were harnessing wind power using a vertical-axis machine in the seventh century AD (Shephard, 1990). From Asia the use of wind power spread to Europe. Historical accounts date the use of windmills in England to the eleventh or 42 Wind Energy in the 21 st Century twelth century. Witnesses also spoke of the German crusaders bring- ing their windmill-making skills to Syria around AD 1190. From this, one can assume that windmill technologies were generally known around Europe from the Middle Ages on.

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  The Science of Renewable Energy

  • Frank R. Spellman(Author)
  • 2016(Publication Date)
  • CRC Press

    (Publisher)

  Tower—The tower is made from tubular steel, concrete, or steel lattice. Wind speed increases with height, so turbines on taller towers capture more energy and generate more electricity.

  Wind direction—An upWind Turbine operates facing into the wind; other turbines are designed to run downwind, facing away from the wind.

  Wind vane—The wind vane measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind.

  Yaw drive—The yaw drive of upWind Turbines is used to keep the entire nacelle and thus the rotor facing into the wind as the wind direction changes. DownWind Turbines do not require a yaw drive, as the wind blows the rotor downwind.

  Yaw motor—The yaw motor powers the yaw drive.

  WIND ENERGY AND POWER CALCULATIONS

  A Wind Turbine is a machine that converts the kinetic energy of wind into the mechanical energy of a shaft. Calculating the energy and power available in the wind relies on a knowledge of basic physics and geometry. The kinetic energy of an object is the extra energy it possesses because of its motion. It is defined as the work necessary to accelerate a body of a given mass from rest to its current velocity. Once in motion, a body maintains it kinetic energy unless its speed changes. The kinetic energy of a body is given by

  Kinetic energy = 0 .5   ×   m   ×   v 2

  (5.1)

  where

  m = Mass.

  v = Velocity.

  ⬛ EXAMPLE 5.1. DETERMINING POWER IN THE WIND

  For the purpose of determining the kinetic energy of moving air (wind), let’s say we have a large packet of wind (i.e., a geometrical package of air passing through the plane of a Wind Turbine’s blades, which sweep out at cross-sectional area A and have thickness D), passing through the plane over a given time. (See Figure 5.6 .)

  FIGURE 5.6  A packet of air passing through the plane of a Wind Turbine’s blades, with thickness D, passing through the plane over a given time.

  Step 1. To determine the power in the wind, we must first consider the kinetic energy of this packet of air, along with its mass (m) and velocity (v

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  Introduction to Energy Systems

  • Ibrahim Dinçer, Dogan Erdemir, Ibrahim Dincer(Authors)
  • 2023(Publication Date)
  • Wiley

    (Publisher)

  Major landforms can accelerate wind, resulting in some regions being very windy while others remain relatively calm. By converting wind power into electricity, wind power can be transported over long distances, serving the needs of urban centers with large populations. One of the fastest-growing renewable energy sources in the world is wind energy. Technology developments, environmental concerns, and the continuous increase in conventional energy use have led to a reduction in relative wind energy costs in many locations to economically acceptable levels as a result of concerns over fossil fuel demand. As a result, many jurisdictions are considering wind energy farms as an alternative energy source because they have been installed and operating for more than 25 years. Electricity is produced by Wind Turbines by converting the kinetic energy of the wind to shaft power. The shaft power is transmitted to the generator by transmission. Figure 7.7 demonstrates the wind power generation mechanism. Modern large-scale Wind Turbines convert wind kinetic energy into rotational motion by mounting a rotor on which the device to catch the wind is mounted. Wind Turbines usually have a three-bladed assembly at the front, but other geometries and types are also available. Wind Turbines have a rotor that spins a shaft, which transfers motion to the nacelle. A gearbox inside the nacelle increases the rotational speed of the slowly rotating shaft. Several hundred volts of electricity are generated by converting the rotational motion of the output shaft into electricity at a medium voltage. A transformer (a few thousand volts) increases the voltage of the electric power to a level more appropriate for distribution (a few thousand volts) by passing it through heavy electric cables inside the tower. By using higher voltage electricity, fewer power losses and less heat will be generated through electric lines as a result of fewer resistances

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  Advanced Renewable Energy Sources

  • Gopal Nath Tiwari, Rajeev Kumar Mishra(Authors)
  • 2015(Publication Date)
  • Royal Society of Chemistry

    (Publisher)

  wind energy-conversion system (WECS) .

  Generated electricity from wind has been used in three modes namely (a) small wind electric generators below 4 kW capacity for battery chargers; (b) wind electric generators in the range of 20 to 100 kW in standalone model supplemented by power from diesel generator sets and (c) wind electric generators in the range of 50 to 300 kW capacities have been used in grid-connected wind farms.

  Being a clean and ecofriendly, wind energy has the limitation of its intermittent nature, like solar energy. Wind potential is a localised concept in comparison with solar energy. Power fluctuations due to uncertainty of wind, variations in magnitude and directions of wind velocities, structural instability due to heavy gusts and cyclonic storms are also some of the problems associated with wind energy-conversion systems. It can be harnessed in a clean and inexhaustible manner through the application of technically advanced and efficient systems.

  7.2 HISTORICAL DEVELOPMENT

  The wind has played a long and important role in the history of human civilisation. Wind power has been harnessed by mankind for thousands of years. Since the earliest recorded history, wind power has been used to move ships, grind grain and pump water. There is evidence that wind energy was used to propel boats along the Nile River as early as 5000 B.C. The first true windmill, a machine with vanes attached to an axis to produce circular motion, may have been built as early as 2000 B.C. in ancient Babylon. By the 10th century A.D., windmills with wind-catching surfaces as long as 16 feet and as high as 30 feet were grinding grain in the area now known as eastern Iran and Afghanistan. The western world discovered the windmill much later. The earliest written references to working wind machines date from the 12th century. These were used for milling grain. It was not until a few hundred years later that windmills were modified to pump water and reclaim much of Holland from the sea. The first horizontal-axis windmill appeared in England around 1150, in France 1180, in Flanders 1190, in Germany 1222 and in Denmark 1259. This fast development was most likely influenced by the Crusaders, taking the knowledge about windmills from Persia to many places in Europe. The people of Holland improved the basic design of the windmill. They gave it propeller-type blades made of fabric sails and invented ways for it to change direction so that it could continually face the wind. Windmills helped Holland become one of the world’s most industrialised countries by the 17th century. The first person, who generated in 1891 electricity from wind speed, was the Dane Poul LaCour, who lived in Denmark. He had also received meteorology education and used the wind tunnel for the first time in order to obtain some theoretical formulations. Danish engineers improved the technology during World Wars I and II and used the technology to overcome energy shortages.

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  eBook - ePub

  Wind Turbines and Aerodynamics Energy Harvesters

  • Dan Zhao, Nuomin Han, Ernest Goh, John Cater, Arne Reinecke(Authors)
  • 2019(Publication Date)
  • Academic Press

    (Publisher)

  available in the blade swept area is determined as the rate of change of the wind kinetic energy:

  w ̇

  available

  =

  d

  m

  V 2

  / 2

  dt

  =

  ρA

  V 3

  2

  =

  Air density

  Disk / swept area

  Wind speed 3

  2

    (1.1)

  It is apparent that the available wind power is proportional to the swept/disk area and also proportional to the cube of the wind speed. Doubling the wind speed (for example choosing a region where the turbine can be exposed to higher-speed wind) or the turbine blade diameter will lead to 8 or 4 times as much available wind power.

  Additionally, wind power density is another comprehensive index to evaluate various Wind Turbines at different locations for comparison. It is the available wind power in moving air through a unit area of perpendicular cross-sectional plane within a period [8] as defined in Eq. (1.2) with a unit of W/m2 . It can be used to evaluate the effectiveness of wind energy harvester in utilisation of space.

  Wind power density =

  ẇ available

  / A =

  Air density

  Wind speed 3

  2

    (1.2)

  Eq. (1.2) reveals that

  1. (1)  
     The wind power density is linearly proportional to the air density. Colder air has a larger wind power density than warmer air blowing at the same speed. However, this density effect is typically insignificant.
  2. (2)  
     The wind power density is proportional to the cube of the wind speed. Doubling the wind speed increases the wind power density by a factor of 800%. This is the main reason why wind farms are located where wind speed is high!

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  Wind Power in America's Future

  20% Wind Energy by 2030

  • U.S. Department of Energy(Author)
  • 2013(Publication Date)
  • Dover Publications

    (Publisher)

  Chapter 2.

  Wind Turbine Technology

  Today’s wind technology has enabled wind to enter the electric power mainstream. Continued technological advancement would be required under the 20% Wind Scenario.

  2.1 INTRODUCTION

  Current turbine technology has enabled wind energy to become a viable power source in today’s energy market. Even so, wind energy provides approximately 1% of total U.S. electricity generation. Advancements in turbine technology that have the potential to increase wind energy’s presence are currently being explored. These areas of study include reducing capital costs, increasing capacity factors, and mitigating risk through enhanced system reliability. With sufficient research, development, and demonstration (RD&D), these new advances could potentially have a significant impact on commercial product lines in the next 10 years.

   

  A good parallel to wind energy evolution can be derived from the history of the automotive industry in the United States. The large-scale production of cars began with the first Model T production run in 1910. By 1940, after 30 years of making cars and trucks in large numbers, manufacturers had produced vehicles that could reliably move people and goods across the country. Not only had the technology of the vehicle improved, but the infrastructure investment in roads and service stations made their use practical. Yet 30 years later, in 1970, one would hardly recognize the vehicles or infrastructure as the same as those in 1940. Looking at the changes in automobiles produced over that 30-year span, we see how RD&D led to the continuous infusion of modern electronics; improved combustion and manufacturing processes; and ultimately, safer, more reliable cars with higher fuel efficiency. In a functional sense, Wind Turbines now stand roughly where the U.S. automotive fleet stood in 1940. Gradual improvements have been made in the past 30 years over several generations of wind energy products. These technology advances enable today’s turbines to reliably deliver electricity to the grid at a reasonable cost.

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  Wind Energy

  An Introduction

  • Mohamed A. El-Sharkawi(Author)
  • 2015(Publication Date)
  • CRC Press

    (Publisher)

  59 4 Overview of Wind Turbines Until the middle of the twentieth century, Wind Turbine designs failed to provide the reliability and efficiency needed for serious consideration as electric power producers. However, as with any technology, Wind Turbines have evolved over the years and the major innovations were made from 1990s. With the advancement in material, structure, power electronics, and control, we have now Wind Turbines that are proven reliable, effi-cient, and worthy of grid integration. These turbines are also cost effective and can pro-duce electricity at rates comparable to conventional thermal generation. The present size of Wind Turbines ranges from just a few kW to 8 MW. The size is continuously increasing and we should expect 10–15 MW within a decade or two. Wind Turbines come in a plethora of designs with different generators, configurations, and control strategies. The most common generators used in Wind Turbines are the squirrel- cage induction generator (SCIG), slip-ring induction generator (SRIG), synchronous gen-erator (SG), and permanent magnet SG (PMSG). The basic system, called “type 1,” has little or no control on its generator. The other systems, types 2–4, use power electronic to provide various control actions. In this chapter, the configurations of the most common types of wind energy system are discussed. 4.1 Classification of Wind Turbines Nowadays, Wind Turbines have several designs with a plethora of features. To classify Wind Turbines, engineers use features such as the alignment of the rotating axis, type of electrical generator, speed of rotation, power conversion, and control actions. For utility size turbines, the industry has established a type system to describe the general design and features of Wind Turbines. In this section, the classification based on features is dis-cussed, and in Section 4.2, the types of Wind Turbines are given.

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  Sustainable Fuel Technologies Handbook

  • Suman Dutta, Chaudhery Mustansar Hussain(Authors)
  • 2020(Publication Date)
  • Academic Press

    (Publisher)

  The present chapter is conceived to describe the rudiments of wind power and includes most of the major aspects of wind energy and various relatable issues for development of wind power technology. The contents are organized in a cohesive manner for an uncomplicated comprehension of stakeholders. The chapter is initi-ated with a discussion of historical background of wind power technology. Subsequently, the principle of aerodynamic forces behind the working of modern Wind Turbines are explained and various wind energy conversion devices (wind tur-bines) are introduced with a focus on most popular contemporary horizontal axis Wind Turbine. Basics of wind energy and power, power output and efficiency con-siderations, extractable limits of wind power, axial thrust and torque on blades, con-cepts of tip speed ratio, and various operational characteristics are made clear in the chapter. The chapter also discusses on wind resource assessment, wind measure-ment techniques, evaluation of suitable sites, and wind tower spacing for develop-ment of wind power projects. Besides, different types of wind electric generators, constant speed and variable speed operation, and speed control strategies of wind power plant have been put in plain words. In addition, the chapter focuses on envi-ronmental impact and public perception on wind power technology and also con-tains the topics like wind energy applications, offshore wind energy, and Wind Turbine economics. References [1] Wind generation. , https://nptel.ac.in/content/storage2/courses/108108078/pdf/chap6/ teach_slides06.pdf . (accessed 27.10.19). [2] M.A. El-Sharkawi, Electric Energy: An Introduction, second ed., Taylor & Francis, Boca Raton, FL, 2009. [3] Renewable energy, facts and information. , https://www.nationalgeographic.com/envi-ronment/energy/reference/renewable-energy/ . (accessed 15.08.19). [4] U. Rathore, Energy Management, second ed., S.K.

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  Renewable Energy

  Sustainable Energy Concepts for the Future

  • Roland Wengenmayr, Thomas Bührke, Roland Wengenmayr, Thomas Bührke(Authors)
  • 2011(Publication Date)
  • Wiley-VCH

    (Publisher)

  Wind Energy A Tailwind for Sustainable Technology BY MARTIN KÜHN

  The use of wind energy has experienced a rapid increase in the past fifteen years. What technologies, economic and political factors have fostered this development? Will further increases be compatible with the present system of energy supplies?

  By mid-year of 2007, there were more than 19 000 Wind Turbines with a total capacity of nearly 21 GW installed in Germany - and the trend is for this number to increase. Assuming an average wind year, these installations together can generate 6.9 % of the total net electricity consumption, and thus exceed the power generated in Germany today from every other renewable energy form. More than a quarter of the worldwide wind power is at present installed in Germany, but the international markets are also growing. Within the last five years, the annual newly-installed capacity increased by 17 % on average, especially in other European countries, the USA and in Asia (Figure 1 ). The German wind energy sector currently provides 74 000 jobs and exports 74 % of the turbine equipment produced; it is profiting effectively from the continuing international boom.

  From the Drag Device to the High Tip Speed Turbine

  Humans have made use of wind power for around 4000 years. Besides sailing ships, wind-driven pumps and mills were developed long ago. Early forms of windmills used a rotor with a vertical axis which was driven by the drag force exerted by the air flow passing the rotor blades. This design concept, known as a drag device, has a low efficiency, at most about one fourth of that of the lift devices described in the following [1]. Today, it is therefore used practically only in the form of the cup anemometers that measure wind speed. From around the 12th century on, new windmill types were developed, such as the post mill or Dutch windmill, which operated on the basis of a different and more effective principle. The decisive advance was not the generally horizontal orientation of the rotor axis, but rather the fact that the flowing air drives the rotor blades via the aerodynamic lift force. For a drag device, which is moving with the flow, the relative velocity at the rotor blades is always smaller than the wind speed. Lift devices, in contrast, can achieve higher apparent wind speeds by superposition of the wind speed and the circumferential velocity of the rotor. Only in this way can the forces necessary for an optimal deceleration of the wind be generated, and the aerodynamic efficiency approaches its theoretical maximum of 59 % calculated by Albert Betz and F.W. Lancaster.

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  Operation and Control of Renewable Energy Systems

  • Mukhtar Ahmad(Author)
  • 2017(Publication Date)
  • Wiley

    (Publisher)

  Chapter 7 Wind Energy

  7.1 Wind as Source of Energy

  The wind power is basically nothing but another form of solar energy. Approximately 1% of the total solar energy absorbed by the Earth is converted to kinetic energy in the atmosphere, in the form of wind. Since early recorded history, people have realized the potential of wind energy and utilized it for various applications. It was used to propel boats along the Nile River as early as 5000 BC, and it was used to pump water and grind grain between 500 and 900 BC. By the 11th century, windmills were used in food production in the Middle East. The windmills were further improved by the Dutch and others and were adapted for industrial applications such as sawing wood, making paper and draining lakes and marshes. In the late 19th century, the wind power was used in windmills to pump water for farms and ranches. However, due to industrialization and rural electrification, in the 20th century, there was gradual decline in the use of windmills for mechanical applications.

  First large-sized automatically operating Wind Turbine for generation of electricity was built by Charles Brush of the United States in 1888. From 1920 to 1940, propeller-type horizontal-axis Wind Turbines (HAWTs) with two or three blades were used to supply electricity in rural areas where supply of electricity from the grid was not available. However, the use of Wind Turbines to generate electricity at a commercial scale started in the 1970s as a result of technical advances in the field of turbine and mainly due to escalating oil prices because of OPEC crisis in 1971. During the last few years, the three-blade upwind horizontal-axis large turbines on monopole tower have become the standard. In terms of total number of Wind Turbines in use at present, they are of small capacity of the order of 10 kW or less. But in terms of total generating capacity, the turbines that are used in large wind farms have capacity in the range of 1.5–5 MW.

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