Comprehensive Study Of The Wind Energy Engineering Essay

Wind energy is a form of solar energy, created by the circulation patterns in the Earth's atmosphere that are driven from the sun. People have made use of wind energy for thousands of years, fashioning sails and attaching them to boats for transportation or wind mills to grind grain. The energy that the wind contains can either be used directly, as in these examples, or it can be converted into that high-value, highly flexible and useful form of energy we call electricity As the air flows past the rotor of a wind turbine (a rotor that looks a lot like an airplane propeller), the rotor spins and drives the shaft of an electric generator produces electricity.

CHAPTER 2

LITERATURE REVIEW

Wind Energy:

In reality, wind energy is a converted form of solar energy. The sun's radiation heats different parts of the earth at different rates-most notably during the day and night, but also when different surfaces (for example, water and land) absorb or reflect at different rates. This in turn causes portions of the atmosphere to warm differently. Hot air rises, reducing the atmospheric pressure at the earth's surface, and cooler air is drawn in to replace it. The result is wind.

Air has mass, and when it is in motion, it contains the energy of that motion ("kinetic energy"). Some portion of that energy can converted into other forms mechanical force or electricity that we can use to perform work.

Wind turbine

A wind energy system transforms the kinetic energy of the wind into mechanical or electrical energy that can be harnessed for practical use. Mechanical energy is most commonly used for pumping water in rural or remote locations- the "farm windmill" still seen in many rural areas of the U.S. is a mechanical wind pumper - but it can also be used for many other purposes (grinding grain, sawing, pushing a sailboat, etc.). Wind electric turbines generate electricity for homes and businesses and for sale to utilities.

There are two basic designs of wind electric turbines: vertical-axis, or "egg-beater" style, and horizontal-axis (propeller-style) machines. Horizontal-axis wind turbines are most common today, constituting nearly all of the "utility-scale" (100 kilowatts, kW, capacity and larger) turbines in the global market.

TOP

Turbine subsystems include:

a rotor, or blades, which convert the wind's energy into rotational shaft energy;

a nacelle (enclosure) containing a drive train, usually including a gearbox* and a generator;

a tower, to support the rotor and drive train; and

electronic equipment such as controls, electrical cables, ground support equipment, and interconnection equipment.

*Some turbines do not require a gearbox

Wind turbines vary in size. This chart depicts a variety of historical turbine sizes and the amount of electricity they are each capable of generating (the turbine's capacity, or power rating).

1981

1985

1990

1996

1999

2000

Rotor (meters)

Rating (KW)

100

225

550

750

1,650

Annual MWh

220

550

1,480

2,200

5,600

The electricity generated by a utility-scale wind turbine is normally collected and fed into utility power lines, where it is mixed with electricity from other power plants and delivered to utility customers. Today (August 2005), turbines with capacities as large as 5,000 kW (5 MW) are being tested.

Potential of wind energy:

Utilities must maintain enough power plant capacity to meet expected customer electricity demand at all times, plus an additional reserve margin. All other things being equal, utilities generally prefer plants that can generate as needed (that is, conventional plants) to plants that cannot (such as wind plants).

However, despite the fact that the wind is variable and sometimes does not blow at all, wind plants do increase the overall statistical probability that a utility system will be able to meet demand requirements. A rough rule of thumb is that the capacity value of adding a wind plant to a utility system is about the same as the wind plant's capacity factor multiplied by its capacity. Thus, a 100-megawatt wind plant with a capacity factor of 35% would be similar in capacity value to a 35-MW conventional generator. For example, in 2001 the Colorado Public Utility Commission found the capacity value of a proposed 162-MW wind plant in eastern Colorado (with a 30% capacity factor) to be approximately 48 MW.

The exact amount of capacity value that a given wind project provides depends on a number of factors, including average wind speeds at the site and the match between wind patterns and utility load (demand) requirements. It also depends on how dispersed geographically wind plants on a utility system are, and how well-connected the utility is with neighboring systems that may also have wind generators. The broader the wind plants are scattered geographically, the greater the chance that some of them will be producing power at any given time.

Latest Technology:

The increase in usage of wind energy across the globe, making the companies to push forward to develop the latest technology. The latest technology not only increases the production but also the efficiency and the cost incurred in the manufacturing, establishment and maintenance.

Chapter 3

State of art of Wind Energy

Electricity can be generated from a large array of sources that can be classified into fossil fuels (oil, coal and natural gas), nuclear power, and renewable sources such as hydro power, wind energy, solar energy, biomass energy, geothermal energy, and wave and tide power. Wind power forms a very small part of the total power consumed at the global level, when compared to fossil fuel and hydro power.

After the oil crisis in the 1970s, many countries tried to reduce their reliance on oil imports from the Middle East, which meets a significant part of the global oil demand. Fossil fuel combustion - for various end use applications such as power generation and transportation - has also contributed to global warming, depletion of the ozone layer, rise in ocean temperature, and melting of icebergs in the polar region, which in turn leads to a rise in sea level.

Taking these factors into consideration, the world is turning toward renewable energy sources such as wind for power generation...

Wind power all starts with the sun. When the sun heats up a certain area of land, the air around that land mass absorbs some of that heat. At a certain temperature, that hotter air begins to rise very quickly because a given volume of hot air is lighter than an equal volume of cooler air. Faster-moving (hotter) air particles exert more pressure than slower-moving particles, so it takes fewer of them to maintain the normal air pressure at a given elevation (seeHow Hot Air Balloons Work to learn more about air temperature and pressure). When that lighter hot air suddenly rises, cooler air flows quickly in to fill the gap the hot air leaves behind. That air rushing in to fill the gap is wind.

If you place an object like a rotor blade in the path of that wind, the wind will push on it, transferring some of its own energy of motion to the blade. This is how a wind turbine captures energy from the wind. The same thing happens with a sail boat. When moving air pushes on the barrier of the sail, it causes the boat to move. The wind has transferred its own energy of motion to the sailboat

History of Wind Energy

As early as 3000 B.C., people used wind energy for the first time in the form of sail boats in Egypt. Sails captured the energy in wind to pull a boat across the water. The earliest windmills, used to grind grain, came about either in 2000 B.C. in ancient Babylon or 200 B.C. in ancient Persia, depending on who you ask. These early devices consisted of one or more vertically-mounted wooden beams, on the bottom of which was a grindstone, attached to a rotating shaft that turned with the wind. The concept of using wind energy for grinding grain spread rapidly through the Middle East and was in wide use long before the first windmill appeared in Europe. Starting in the 11th century A.D., European Crusaders brought the concept home with them, and the Dutch-type windmill most of us are familiar with was born.

Modern development of wind-energy technology and applications was well underway by the 1930s, when an estimated 600,000 windmills supplied rural areas with electricity and water-pumping services. Once broad-scale electricity distribution spread to farms and country towns, use of wind energy in the United States started to subside, but it picked up again after the U.S. oil shortage in the early 1970s. Over the past 30 years, research and development has fluctuated with federal government interest and tax incentives. In the mid-'80s, wind turbines had a typical maximum power rating of 150 kW. In 2006, commercial, utility-scale turbines are commonly rated at over 1 MW and are available in up to 4 MW capacity.

The simplest possible wind-energy turbine consists of three crucial parts:

Rotor blades - The blades are basically the sails of the system; in their simplest form, they act as barriers to the wind (more modern blade designs go beyond the barrier method). When the wind forces the blades to move, it has transferred some of its energy to the rotor.

Shaft - The wind-turbine shaft is connected to the center of the rotor. When the rotor spins, the shaft spins as well. In this way, the rotor transfers its mechanical, rotational energy to the shaft, which enters an electrical generator on the other end.

Generator - At its most basic, a generator is a pretty simple device. It uses the properties of electromagnetic induction to produce electrical voltage - a difference in electrical charge. Voltage is essentially electrical pressure - it is the force that moves electricity, or electrical current, from one point to another. So generating voltage is in effect generating current. A simple generator consists of magnets and a conductor. The conductor is typically a coiled wire. Inside the generator, the shaft connects to an assembly of permanent magnets that surrounds the coil of wire. In electromagnetic induction, if you have a conductor surrounded by magnets, and one of those parts is rotating relative to the other, it induces voltage in the conductor. When the rotor spins the shaft, the shaft spins the assembly of magnets, generating voltage in the coil of wire. That voltage drives electrical current (typically alternating current, or AC power) out through power lines for distribution. (See How Electromagnets Work to learn more about electromagnetic induction, and see How Hydropower Plants Work to learn more about turbine-driven generators.)

Now that we've looked at a simplified system, we'll move on to the modern technology you see in wind farms and rural backyards today. It's a bit more complex, but the underlying principles are the same.

Modern Wind-power Technology

When you talk about modern wind turbines, you're looking at two primary designs: horizontal-axis and vertical-axis. Vertical-axis wind turbines (VAWTs) are pretty rare. The only one currently in commercial production is the Darrieus turbine, which looks kind of like an egg beater.

Photo courtesy NREL (left) and Solwind Ltd

Vertical-axis wind turbines (left: Darrieus turbine)

In a VAWT, the shaft is mounted on a vertical axis, perpendicular to the ground. VAWTs are always aligned with the wind, unlike their horizontal-axis counterparts, so there's no adjustment necessary when the wind direction changes; but a VAWT can't start moving all by itself -- it needs a boost from its electrical system to get started. Instead of a tower, it typically uses guy wires for support, so the rotor elevation is lower. Lower elevation means slower wind due to ground interference, so VAWTs are generally less efficient than HAWTs. On the upside, all equipment is at ground level for easy installation and servicing; but that means a larger footprint for the turbine, which is a big negative in farming areas.

Darrieus-design VAWT

VAWTs may be used for small-scale turbines and for pumping water in rural areas, but all commercially produced, utility-scale wind turbines are horizontal-axis wind turbines (HAWTs).

Photo courtesy GNU; Photographer: Kit Conn

Wind farm in California

As implied by the name, the HAWT shaft is mounted horizontally, parallel to the ground. HAWTs need to constantly align themselves with the wind using a yaw-adjustment mechanism. The yaw system typically consists of electric motors and gearboxes that move the entire rotor left or right in small increments. The turbine's electronic controller reads the position of a wind vane device (either mechanical or electronic) and adjusts the position of the rotor to capture the most wind energy available. HAWTs use a tower to lift the turbine components to an optimum elevation for wind speed (and so the blades can clear the ground) and take up very little ground space since almost all of the components are up to 260 feet (80 meters) in the air.

Large HAWT components:

rotor blades - capture wind's energy and convert it to rotational energy of shaft

shaft - transfers rotational energy into generator

nacelle - casing that holds:

gearbox - increases speed of shaft between rotor hub and generator

generator - uses rotational energy of shaft to generate electricity usingelectromagnetism

electronic control unit (not shown) - monitors system, shuts down turbine in case of malfunction and controls yaw mechanism

yaw controller (not shown) - moves rotor to align with direction of wind

brakes - stop rotation of shaft in case of power overload or system failure

tower - supports rotor and nacelle and lifts entire setup to higher elevation where blades can safely clear the ground

electrical equipment - carries electricity from generator down through tower and controls many safety elements of turbine

Turbine Aerodynamics

Unlike the old-fashioned Dutch windmill design, which relied mostly on the wind's force to push the blades into motion, modern turbines use more sophisticatedaerodynamic principles to capture the wind's energy most effectively. The two primary aerodynamic forces at work in wind-turbine rotors are lift, which acts perpendicular to the direction of wind flow; and drag, which acts parallel to the direction of wind flow.

Turbine blades are shaped a lot like airplane wings -- they use anairfoil design. In an airfoil, one surface of the blade is somewhat rounded, while the other is relatively flat. Lift is a pretty complex phenomenon and may in fact require a Ph.D. in math or physics to fully grasp. But in one simplified explanation of lift, when wind travels over the rounded, downwind face of the blade, it has to move faster to reach the end of the blade in time to meet the wind travelling over the flat, upwind face of the blade (facing the direction from which the wind is blowing). Since faster moving air tends to rise in the atmosphere, the downwind, curved surface ends up with a low-pressure pocket just above it. The low-pressure area sucks the blade in the downwind direction, an effect known as "lift." On the upwind side of the blade, the wind is moving slower and creating an area of higher pressure that pushes on the blade, trying to slow it down. Like in the design of an airplane wing, a high lift-to-drag ratio is essential in designing an efficient turbine blade. Turbine blades are twisted so they can always present an angle that takes advantage of the ideal lift-to-drag force ratio. See How Airplanes Work to learn more about lift, drag and the aerodynamics of an airfoil.

Aerodynamics is not the only design consideration at play in creating an effective wind turbine. Sizematters -- the longer the turbine blades (and therefore the greater the diameter of the rotor), the more energy a turbine can capture from the wind and the greater the electricity-generating capacity. Generally speaking, doubling the rotor diameter produces a four-fold increase in energy output. In some cases, however, in a lower-wind-speed area, a smaller-diameter rotor can end up producing more energy than a larger rotor because with a smaller setup, it takes less wind power to spin the smaller generator, so the turbine can be running at full capacity almost all the time. Tower height is a major factor in production capacity, as well. The higher the turbine, the more energy it can capture because wind speeds increase with elevation increase -- ground friction and ground-level objects interrupt the flow of the wind. Scientists estimate a 12 percent increase in wind speed with each doubling of elevation.

Calculating Power

To calculate the amount of power a turbine can actually generate from the wind, you need to know the wind speed at the turbine site and the turbine power rating. Most large turbines produce their maximum power at wind speeds around 15 meters per second (33 mph). Considering steady wind speeds, it's the diameter of the rotor that determines how much energy a turbine can generate. Keep in mind that as a rotor diameter increases, the height of the tower increases as well, which means more access to faster winds.

Rotor Size and Maximum Power Output

Rotor Diameter (meters)

Power Output (kW)

100

225

300

500

600

750

1000

1500

2000

2500

Sources: Danish Wind Industry Association, American Wind Energy Association

At 33 mph, most large turbines generate their rated power capacity, and at 45 mph (20 meters per second), most large turbines shut down. There are a number of safety systems that can turn off a turbine if wind speeds threaten the structure, including a remarkably simple vibration sensor used in some turbines that basically consists of a metal ball attached to a chain, poised on a tiny pedestal. If the turbine starts vibrating above a certain threshold, the ball falls off the pedestal, pulling on the chain and triggering a shut down.

Probably the most commonly activated safety system in a turbine is the "braking" system, which is triggered by above-threshold wind speeds. These setups use a power-control system that essentially hits the brakes when wind speeds get too high and then "release the brakes" when the wind is back below 45 mph. Modern large-turbine designs use several different types of braking systems:

Pitch control - The turbine's electronic controller monitors the turbine's power output. At wind speeds over 45 mph, the power output will be too high, at which point the controller tells the blades to alter their pitch so that they become unaligned with the wind. This slows the blades' rotation. Pitch-controlled systems require the blades' mounting angle (on the rotor) to be adjustable.

Passive stall control - The blades are mounted to the rotor at a fixed angle but are designed so that the twists in the blades themselves will apply the brakes once the wind becomes too fast. The blades are angled so that winds above a certain speed will cause turbulence on the upwind side of the blade, inducing stall. Simply stated, aerodynamic stall occurs when the blade's angle facing the oncoming wind becomes so steep that it starts to eliminate the force of lift, decreasing the speed of the blades.

Active stall control - The blades in this type of power-control system are pitchable, like the blades in a pitch-controlled system. An active stall system reads the power output the way a pitch-controlled system does, but instead of pitching the blades out of alignment with the wind, it pitches them to produce stall.

(See Petester's Basic Aerodynamics for a nice explanation of both lift and still.)

Globally, at least 50,000 wind turbines are producing a total of 50 billion kilowatt-hours (kWh) annually. In the next section, we'll examine the availability of wind resources and how much electricity wind turbines can actually produce.

On a global scale, wind turbines are currently generating about as much electricity as eight largenuclear power plants. That includes not only utility-scale turbines, but also small turbines generating electricity for individual homes or businesses (sometimes used in conjunction with photovoltaic solar energy). A small, 10-kW-capacity turbine can generate up to 16,000 kWh per year, and a typical U.S. household consumes about 10,000 kWh in a year.

A typical large wind turbine can generate up to 1.8 MW of electricity, or 5.2 million KWh annually, under ideal conditions -- enough to power nearly 600 households. Still, nuclear and coal power plants can produce electricity cheaper than wind turbines can. So why use wind energy? The two biggest reasons for using wind to generate electricity are the most obvious ones: Wind power is clean, and it's renewable. It doesn't release harmful gases like CO2 and nitrogen oxides into the atmosphere the way coal does (see How Global Warming Works), and we are in no danger of running out of wind anytime soon. There is also the independence associated with wind energy, as any country can generate it at home with no foreign support. And a wind turbine can bring electricity to remote areas not served by the central power grid.

But there are downsides, too. Wind turbines can't always run at 100 percent power like many other types of power plants, since wind speeds fluctuate. Wind turbines can be noisy if you live close to a wind plant, they can be hazardous to birds and bats, and in hard-packed desert areas there is a risk of land erosion if you dig up the ground to install turbines. Also, since wind is a relatively unreliable source of energy, operators of wind-power plants have to back up the system with a small amount of reliable, non-renewable energy for times when wind speeds die down. Some argue that the use of unclean energy to support the production of clean energy cancels out the benefits, but the wind industry claims that the amount of unclean energy that's necessary to maintain a steady supply of electricity in a wind system is far too small to defeat the benefits of generating wind power.

Taking these factors into consideration, the world is turning toward renewable energy sources such as wind for power generation...

Electricity generation

Typical components of a wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position

In a wind farm, individual turbines are interconnected with a medium voltage (often 34.5 kV), power collection system and communications network. At a substation, this medium-voltage electric current is increased in voltage with a transformer for connection to the high voltage electric power transmission system.

The surplus power produced by domestic microgenerators can, in some jurisdictions, be fed into the network and sold to the utility company, producing a retail credit for the microgenerators' owners to offset their energy costs.[14

Potential of Wind Energy

It was estimated by the Energy Information Administration that in 2007 primary sources of energy consisted of petroleum 36.0%, coal 27.4%, natural gas 23.0%, amounting to an 86.4% share for fossil fuels in primary energy consumption in the world.[4] Non-fossil sources in 2006 included hydroelectric 6.3%, nuclear 8.5%, and (geothermal, solar, tide, wind, wood, waste) amounting 0.9 percent.[5] World energy consumption was growing about 2.3% per year.

Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being made. The production and use of fossil fuels raise environmental concerns. A global movement toward the generation of renewable energy is therefore under way to help meet increased energy needs.

The burning of fossil fuels produces around 21.3 billion tonnes (21.3 gigatonnes) of carbon dioxide (CO2) per year, but it is estimated that natural processes can only absorb about half of that amount, so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year (one tonne of atmospheric carbon is equivalent to 44/12 or 3.7 tonnes of carbon dioxide).[6] Carbon dioxide is one of the greenhouse gases that enhances radiative forcing and contributes to global warming, causing the average surface temperature of the Earth to rise in response, which most climate scientists agree will cause major adverse effects.

So, the disadvantages of fossil fuels lead to the development of wind energy technology which will help the world to produce energy with cleaner and less problems associated with it.

The Earth is unevenly heated by the sun, such that the poles receive less energy from the sun than the equator; along with this, dry land heats up (and cools down) more quickly than the seas do. The differential heating drives a global atmospheric convection system reaching from the Earth's surface to the stratosphere which acts as a virtual ceiling. Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160 km/h (99 mph) occur. Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth's surface and the atmosphere.

The total amount of economically extractable power available from the wind is considerably more than present human power use from all sources.[10] An estimated 72 terawatt (TW) of wind power on the Earth potentially can be commercially viable,[11] compared to about 15 TW average global power consumption from all sources in 2005.

Distribution of wind speed

The strength of wind varies, and an average value for a given location does not alone indicate the amount of energy a wind turbine could produce there. To assess the frequency of wind speeds at a particular location, a probability distribution function is often fit to the observed data. Different locations will have different wind speed distributions. The Weibull model closely mirrors the actual distribution of hourly wind speeds at many locations. The Weibull factor is often close to 2 and therefore a Rayleigh distribution can be used as a less accurate, but simpler model.

Because so much power is generated by higher wind speed, much of the energy comes in short bursts. The 2002 Lee Ranch sample is telling;[12] half of the energy available arrived in just 15% of the operating time. The consequence is that wind energy from a particular turbine or wind farm does not have as consistent an output as fuel-fired power plants; utilities that use wind power provide power from starting existing generation for times when the wind is weak thus wind power is primarily a fuel saver rather than a capacity saver. Making wind power more consistent requires that various existing technologies and methods be extended, in particular the use of stronger inter-regional transmission lines to link widely distributed wind farms. Problems of variability are addressed by grid energy storage, batteries, pumped-storage hydroelectricity and energy demand management.[13]

Wind power usage

There are now many thousands of wind turbines operating, with a total nameplate capacity of 157,899 MW of which wind power in Europe accounts for 48% (2009). World wind generation capacity more than quadrupled between 2000 and 2006, doubling about every three years. 81% of wind power installations are in the US and Europe. The share of the top five countries in terms of new installations fell from 71% in 2004 to 62% in 2006, but climbed to 73% by 2008 as those countries - the United States, Germany, Spain, China, and India - have seen substantial capacity growth in the past two years (see chart).

The World Wind Energy Association forecast that, by 2010, over 200 GW of capacity would have been installed worldwide,[54] up from 73.9 GW at the end of 2006, implying an anticipated net growth rate of more than 28% per year.

Wind accounts for nearly one-fifth of electricity generated in Denmark - the highest percentage of any country - and it is tenth in the world in total wind power generation. Denmark is prominent in the manufacturing and use of wind turbines, with a commitment made in the 1970s to eventually produce half of the country's power by wind.[citation needed]

In recent years, the US has added substantial amounts of wind power generation capacity, growing from just over 6 GW at the end of 2004 to over 35 GW at the end of 2009.[4] The U.S. is currently the world's leader in wind power generation capacity. The country as a whole generates just 2.4% of its electrical power from wind, but several states generate substantial amounts of wind power.[4] Texas is the state with the largest amount of generation capacity with 9,410 MW installed.[4] This would have ranked sixth in the world, were Texas a separate country. Iowa is the state with the highest percentage of wind generation, at 14.2% in 2009.[55] California was one of the incubators of the modern wind power industry, and led the U.S. in installed capacity for many years. As of mid-2010, fourteen U..S. states had wind power generation capacities in excess of 1000 MW.[4] U.S. Department of Energy studies have concluded that wind from the Great Plains states of Texas, Kansas, and North Dakota could provide enough electricity to power the entire nation, and that offshore wind farms could do the same job.[56][57]

China had originally set a generating target of 30,000 MW by 2020 from renewable energy sources, but reached 22,500 MW by end of 2009 and could easily surpass 30,000 MW by end of 2010. Indigenous wind power could generate up to 253,000 MW.[58] A Chinese renewable energy law was adopted in November 2004, following the World Wind Energy Conference organized by the Chinese and the World Wind Energy Association. By 2008, wind power was growing faster in China than the government had planned, and indeed faster in percentage terms than in any other large country, having more than doubled each year since 2005. Policymakers doubled their wind power prediction for 2010, after the wind industry reached the original goal of 5 GW three years ahead of schedule.[59] Current trends suggest an actual installed capacity near 20 GW by 2010, with China shortly thereafter pursuing the United States for the world wind power lead.[59]

India ranks 5th in the world with a total wind power capacity of 10,925 MW in 2009,[1] or 3% of all electricity produced in India. The World Wind Energy Conference in New Delhi in November 2006 has given additional impetus to the Indian wind industry.[60] Muppandal village in Tamil Nadu state, India, has several wind turbine farms in its vicinity, and is one of the major wind energy harnessing centres in India led by majors like Suzlon, Vestas, Micon among others.[61][62]

Mexico recently opened La Venta II wind power project as a step toward reducing Mexico's consumption of fossil fuels. The 88 MW project is the first of its kind in Mexico, and will provide 13 percent of the electricity needs of the state of Oaxaca. By 2012 the project will have a capacity of 3,500 MW. In May 2010, Sempra Energy announced it would build a wind farm in Baja California, with a capacity of at least 1,000 MW, at a cost of $5.5 billion.[63]

Another growing market is Brazil, with a wind potential of 143 GW.[64]

South Africa has a proposed station situated on the West Coast north of the Olifants River mouth near the town of Koekenaap, east of Vredendal in the Western Cape province. The station is proposed to have a total output of 100 MW although there are negotiations to double this capacity. The plant could be operational by 2010.

France has announced a target of 12,500 MW installed by 2010, though their installation trends over the past few years suggest they'll fall well short of their goal.

Canada experienced rapid growth of wind capacity between 2000 and 2006, with total installed capacity increasing from 137 MW to 1,451 MW, and showing an annual growth rate of 38%.[65] Particularly rapid growth was seen in 2006, with total capacity doubling from the 684 MW at end-2005.[66] This growth was fed by measures including installation targets, economic incentives and political support. For example, the Ontario government announced that it will introduce a feed-in tariff for wind power, referred to as 'Standard Offer Contracts', which may boost the wind industry across the province.[67] In Quebec, the provincially owned electric utility plans to purchase an additional 2000 MW by 2013.[68] By 2025, Canada will reach its capacity of 55,000 MW of wind energy, or 20% of the country's energy needs.

Finding potential of an area

CHAPTER 4

METHODOLOGY

Wind energy is produced by windmills. Windmills are essentially a type of generator that converts kinetic energy (motion energy) into electrical energy. Wind energy comes from the motion of the air. According to the Department of Energy, air over land heats up faster than air over water. When the warm air over land rises, the cooler air over water rushes in to replace it. This creates wind.

The blades on a windmill catch the wind and the windmill turns. The windmill has an internal shaft that turns inside a generator to produce electricity. The generator produces electricity by spinning a magnet inside a coil of wires. When the magnet turns, it forces electrons through the wires and thus electricity is generated.

The electricity that is generated travels out through wires. A small wind turbine that produces less than 100 kilowatts of electricity can be used to power a single home. Or a large group of wind turbines together make up a "wind farm" that can send electricity out into a power grid and provide electricity for a whole city or even multiple cities.

CHAPTER 5

CONCLUSION

To make sure we have plenty of energy in the future, it's up to all of us to use energy wisely. We must all conserve energy and use it efficiently. It's also up to those who will create the new energy technologies of the future. All energy sources have an impact on the environment. Concerns about the greenhouse effect and global warming, air pollution, and energy security have led to increasing interest and more development in renewable energy sources such as solar, wind, geothermal, wave power and hydrogen. But we'll need to continue to use fossil fuels and nuclear energy until new, cleaner technologies can replace them. One of you who is reading this might be another Albert Einstein or Marie Curie and find a new source of energy. Until then, it's up to all of us. The future is ours, but we need energy to get there.

Comprehensive Study Of The Wind Energy Engineering Essay

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