WIND ENERGY Presented By omkar nath yadav 0916521034

WIND ENERGY Presented By: omkar nath yadav 0916521034 EN III year

CONTENTS 1. INTRODUCTION 1. 1 HISTORY 2. WHY WIND ENERGY IS REQUIRED? 3. POWER IN THE WIND 4. PRINCIPLE OF OPERATION 5. THE TECHNICAL ANALYSIS 5. 1 INDUCTION GENERATOR 5. 2 SYNCHRONOUS GENERARATOR 5. 3 SYNCHRONOUS MACHINE WITHOUT GEAR 5. 4 WIND TURBINES 6. 1 ADVANTAGES 6. 2 DISADVANTAGES 7. CONCLUSION

INTRODUCTION • Wind or air in motion contains the “kinetic energy”, which is converted into mechanical power by means of a wind turbine. • wind strikes in wind turbine blade as shown the fig-1. • The wind turbine is connected to a generator for producing electricity. • The potential for wind energy is immense, and experts suggest wind power can supply up to 20% of world electricity • Betz’ law

HISTORY l l l l Wind power has been used as long as humans have put sails into the wind. For more than two millennia wind-powered machines have ground grain and pumped water. Wind power was widely available and not confined to the banks of fast -flowing streams, or later, requiring sources of fuel. Wind-powered pumps drained the polders of the Netherlands, and in arid regions such as the American mid-west or the Australian outback, wind pumps provided water for live stock and steam engines. With the development of electric power, wind power found new applications in lighting buildings remote from centrally-generated power. Throughout the 20 th century parallel paths developed distributed small wind plants suitable for farms or residences, and larger utility-scale wind generators that could be connected to electricity grids for remote use of power. Today wind powered generators operate in every size range between tiny plants for battery charging at isolated residences, up to neargigawatt sized offshore wind farms that provide electricity to national electrical networks.

WIND ENERGY - What is it? l All renewable energy (except tidal and geothermal power), ultimately comes from the sun l The earth receives 1. 74 x 1017 watts of power (per hour) from the sun l About one or 2 percent of this energy is converted to wind energy (which is about 50 -100 times more than the energy converted to biomass by all plants on earth l Differential heating of the earth’s surface and atmosphere induces vertical and horizontal air currents that are affected by the earth’s rotation and contours of the land WIND. ~ e. g. : Land Sea Breeze Cycle

WHY WIND ENERGY IS REQUIRED? 1. The Cheapest source of electrical energy 2. Wind Turbine Technology is available which is technically feasible. 3. No marketing risks, as the product is Electrical energy. 4. Wind Energy is considered as an important input for the economic development of any country. 5. This led to a search for environmental friendly renewable Energy sources. 6. Wind mill can be constructed near the load centre. 7. Wind mill can be immediately erected with in one month. 8. Can supply up to 20% of electricity demand.

P/m^2 = 6. 1 x 10^-4 v^3 *The power in wind is proportional to the cubic wind speed ( v^3 ). WHY? ~ Kinetic energy of an air mass is proportional to v^2 ~ Amount of air mass moving past a given point is proportional to wind velocity (v)

PRINCIPLE OF OPERATION

TECHNICAL ANALYSIS AND APPLICATIONS A Windmill captures wind energy and then uses a generator to convert it to electrical energy. l The design of a windmill is an integral part of how efficient it will be. l When designing a windmill, one must decide on the size of the turbine, and the size of the generator. l

LARGE TURBINES: • Able to deliver electricity at lower cost than smaller turbines, because foundation costs, planning costs, etc. are independent of size. • Well-suited for offshore wind plants. • In areas where it is difficult to find sites, one large turbine on a tall tower uses the wind extremely efficiently.

SMALL TURBINES: § Local electrical grids may not be able to handle the large electrical output from a large turbine, so smaller turbines may be more suitable. § High costs for foundations for large turbines may not be economical in some areas. § Landscape considerations

TYPES OF WIND TURBINE 1. Horizontal Turbine Horizontal-axis wind turbines (HAWT) have the main rotor shaft and electrical generator at the top of a tower, and must be pointed into the wind. 2. Vertical Turbine Vertical-axis wind turbines (VAWTs) are a type of wind turbine where the main rotor shaft is set vertically and the main components are located at the base of the turbine.

Wind Turbines: Number of Blades q Most common design is the three-bladed turbine. The most important reason is the stability of the turbine. A rotor with an odd number of rotor blades (and at least three blades) can be considered to be similar to a disc when calculating the dynamic properties of the machine. q A rotor with an even number of blades will give stability problems for a machine with a stiff structure. The reason is that at the very moment when the uppermost blade bends backwards, because it gets the maximum power from the wind, the lowermost blade passes into the wind shade in front of the tower.

WORLD’S LARGEST TURBINE The German Re. Power turbines have a power output of 5 Megawatts. l It has rotor blade diameter of 126 metres sweeping an area of over 12, 000 square metres. l Maximum power output is achieved at around 30 mph, but a couple of MW are generated even in a fresh breeze. l Rotors start turning at around 7 mph, and are automatically braked at 70 mph. l

• The generator is attached at one end to the wind turbine, which provides the mechanical energy. • At the other end, the generator is connected to the electrical grid. • Wind power generators convert wind energy (mechanical energy) to electrical energy. • The generator needs to have a cooling system to make sure there is no overheating.

SMALL GENERATORS: § Require less force to turn than a larger ones, but give much lower power output. § Less efficient i. e. . If you fit a large wind turbine rotor with a small generator it will be producing electricity during many hours of the year, but it will capture only a small part of the energy content of the wind at high wind speeds. LARGE GENERATORS: § Very efficient at high wind speeds, but unable to turn at low wind speeds. i. e. . If the generator has larger coils, and/or a stronger internal magnet, it will require more force (mechanical) to start in motion.

Induction Generator: l The electrical power by the induction generator and is transmitted to l l l grid by the stator winding. The stator winding is connected to the grid by the wind turbine. The pitch angle is controlled in order to limit the generator out power to its nominal value for high wind speeds. But the speed variation is typically so small that the wind turbine induction generator is considered to be a fixed speed wind generator. The reactive power absorbed by the induction generator is provided by the grid or by the some devices like capacitor banks, SUC, STATCOM or synchronous condenser. It acts like load of its rated power at time of starting the flow this energy conversion

Working principle of induction Generator • When wind changes its direction wind wane senses direction of wind and sends the signal to controller. Then it sends signal to the yaw motor. Yaw motor will bring the wind turbine blades perpendicular to the flow of wind. Output of turbine is connected to high speed generator through the low speed shaft and gear mechanism. • When wind velocity is less than minimum velocity required to run the turbine and greater than maximum permissible velocity, then pitch control turns the blades parallel to the wind direction, then wind turbine will shutdown.

SYNCHRONOUS MACHINE WITHOUT GEAR 1. Rotor blade 2. Wind measurement device 3. Synchronous Generator 4. Winch 5. Nacelle control cabinet 6. Yaw drives 7. Blade adapter 8. Pitch drive

Single-line diagram of Synchronous machine connected to grid

Wind machine with a gear system Figure: Wind machine with a gear system

COST OF WIND TURBINE 1. Installation costs are typically $125, 000. Therefore, the total costs will be about $575, 000. 2. The average price for large, modern wind farms around $1, 000 per kilowatt electrical power installed. is 3. Modern wind turbines are designed to work for some 120, 000 hours of operation throughout their design lifetime of 20 years. ( 13. 7 years non-stop) 4. A typical 600 k. W turbine costs about $450, 000. Maintenance costs are about 1. 5 -2. 0 percent of the original cost, per year.

• Winds are influenced by the ground surface at altitudes up to 100 meters. • Wind is slowed by the surface roughness and obstacles. • When dealing with wind energy, we are concerned with surface winds. • A wind turbine obtains its power input by converting the force of the wind into a torque (turning force) acting on the rotor blades. • The amount of energy which the wind transfers to the rotor depends on the density of the air, the rotor area, and the wind speed. • The kinetic energy of a moving body is proportional to its mass (or weight). The kinetic energy in the wind thus depends on the density of the air, i. e. its mass per unit of volume. In other words, the "heavier" the air, the more energy is received by the turbine. • at 15° Celsius air weighs about 1. 225 kg per cubic meter, but the density decreases slightly with increasing humidity.

v The U. S. currently has more than 1, 600 MW of installed capacity and produces about 3 billion KWh of electricity each year. v This is enough to meet the annual residential needs of 1 million people. v More than 90 percent of this power is produced by three wind farms in California (Altamont Pass, Tehachapi and Palm Springs).

• The U. S. contains enough useable wind resource to produce more electricity than the nation currently uses. • The majority of this usable resource is in the Great Plains region. North Dakota alone has enough suitable wind resource to supply 36 percent of the electricity consumed in the U. S. • In addition, development of major global wind energy markets could significantly impact jobs—recent studies show that each billion kilowatt-hours of annual wind energy generation creates between 440 to 460 jobs.

Advantages of Wind Energy • The wind blows day and night, which allows windmills to produce electricity throughout the day. (Faster during the day) • Energy output from a wind turbine will vary as the wind varies, although the most rapid variations will to some extent be compensated for by the inertia of the wind turbine rotor. • Wind turbines take up less space than the average power station. Windmills only have to occupy a few square meters for the base, this allows the land around the turbine to be used for many purposes, for example agriculture. • The decreasing cost of wind power and the growing interest in renewable energy sources should ensure that wind power will become a viable energy source in the United States and worldwide. • Wind turbines are a great resource to generate energy in remote locations, such as mountain communities and remote countryside. Wind turbines can be a range of different sizes in order to support varying population levels.

Disadvantages Of Wind Energy l l l The main disadvantage regarding wind power is down to the winds unreliability factor. In many areas, the winds strength is too low to support a wind turbine or wind farm, and this is where the use of solar power or geothermal power could be great alternatives. Wind turbines generally produce allot less electricity than the average fossil fuelled power station, requiring multiple wind turbines to be built in order to make an impact. Wind turbine construction can be very expensive and costly to surrounding wildlife during the build process. The noise pollution from commercial wind turbines is sometimes similar to a small jet engine. This is fine if you live miles away, where you will hardly notice the noise, but what if you live within a few hundred meters of a turbine? This is a major disadvantage. Protests and/or petitions usually confront any proposed wind farm development. People feel the countryside should be left in tact for everyone to enjoy it's beauty.

THE END

WIND POWER HISTORY FIRST ELECTRICITY GENERATING WIND TURBINE WAS BULIT IN DENMARK BY POUL LACOUR IN 1891 Ø Ø TILL 1950 WIND ENERGY WAS USED IN INDIA TO PUMP WATER FOR DOMESTIC USE AND IRRIGATION ØMAJOR TECHNOLGY UPGRADATION HAS TAKEN PLACE IN LAST 20 YEARS

ANY QUESTION ?

INDIRECT CONNECTION WIND TURBINES

LAST TO SAY CLEAN POWER GREEN POWER WIND POWER