1 / 89

Wind Energy

Wind Energy. Dr Jehad Yamin. Ancient Resource Meets 21 st Century. Wind Turbines Power for a House or City. History and Context. Wind Energy History. 1 A.D. Hero of Alexandria uses a wind machine to power an organ ~ 400 A.D. Wind driven Buddhist prayer wheels 1200 to 1850

idona-armstrong
Télécharger la présentation

Wind Energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Wind Energy Dr Jehad Yamin

  2. Ancient Resource Meets 21st Century

  3. Wind TurbinesPower for a House or City

  4. History and Context

  5. Wind Energy History • 1 A.D. • Hero of Alexandria uses a wind machine to power an organ • ~ 400 A.D. • Wind driven Buddhist prayer wheels • 1200 to 1850 • Golden era of windmills in western Europe – 50,000 • 9,000 in Holland; 10,000 in England; 18,000 in Germany • 1850’s • Multiblade turbines for water pumping made and marketed in U.S. • 1882 • Thomas Edison commissions first commercial electric generating stations in NYC and London • 1900 • Competition from alternative energy sources reduces windmill population to fewer than 10,000 • 1850 – 1930 • Heyday of the small multiblade turbines in the US midwast • As many as 6,000,000 units installed • 1936+ • US Rural Electrification Administration extends the grid to most formerly isolated rural sites • Grid electricity rapidly displaces multiblade turbine uses

  6. Manufacturing Market Share Source: American Wind Energy Association

  7. Wind Power Advantages

  8. Advantages of Wind Power • Environmental • Economic Development • Fuel Diversity & Conservation • Cost Stability

  9. Environmental Benefits • No air pollution • No greenhouse gasses • Does not pollute water with mercury • No water needed for operations

  10. Pollution from Electric Power Source: Northwest Foundation, 12/97 Electric power is a primary source of industrial air pollution

  11. Economic Development Benefits • Expanding Wind Power development brings jobs to rural communities • Increased tax revenue • Purchase of goods & services

  12. Economic Development Example Case Study: Lake Benton, MN $2,000 per 750-kW turbine in revenue to farmers Up to 150 construction, 28 ongoing O&M jobs Added $700,000 to local tax base

  13. Fuel Diversity Benefits • Domestic energy source • Inexhaustible supply • Small, dispersed design • reduces supply risk

  14. Cost Stability Benefits • Flat-rate pricing • hedge against fuel price volatility risk • Wind electricity is inflation-proof

  15. Modern Wind Energy and Origin • The re-emergence of the wind as a significant source of the world's energy must rank as one • of the significant developments of the late 20th century. • The advent of the steam engine, followed by the appearance of other technologies for converting fossil fuels to useful energy, would seem to have forever relegated to insignificance the role of the wind in energy generation. • In fact, by the mid 1950s that appeared to be what had already happened. • By the late 1960s, however, the first signs of a reversal could be discerned, and by the early • 1990s it was becoming apparent that a fundamental reversal was underway.

  16. To understand what was happening, it is necessary to consider five main factors. • Need • An emerging awareness of the finiteness of the earth's fossil fuel reserves as well as of the adverse effects of burning those fuels for energy had caused many people to look for alternatives • Potential (Availability) • Wind exists everywhere on the earth, and in some places with considerable energy density. Wind had been widely used in the past, for mechanical power as well as transportation. • Technological Capacity • In particular, there had been developments in other fields, which, when applied to wind turbines, could revolutionize they way they could be used. • Political Will • Vision of new way of utilization

  17. Wind Power DesignandConstruction

  18. A wind turbine, is a machine which converts the power in the wind into electricity. • 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.

  19. How it Works

  20. HAWT • Today, the most common design of wind turbine, is the horizontal axis wind turbine (HAWT). • That is, the axis of rotation is parallel to the ground. • HAWT rotors are usually classified according to • The rotor orientation (upwind or downwind of the tower), • Hub design (rigid or teetering), • Rotor control (pitch vs. stall), • Number of blades (usually two or thee blades), and • How they are aligned with the wind (free yaw or active yaw).

  21. The principal subsystems of a typical horizontal axis wind turbine include: • The rotor, consisting of the blades and the supporting hub • The drive train, which includes the rotating parts of the wind turbine (exclusive of the rotor); it usually consists of shafts, gearbox, coupling, a mechanical brake, and the generator • The nacelle and main frame, including wind turbine housing, bedplate, and the yaw system • The tower and the foundation • The machine controls • The balance of the electrical system, including cables, switchgear, transformers, and possibly electronic power converters

  22. A wind turbine usually has the following components: • Rotor consisting of the hub and blades of the turbine. Most turbines have rotors with three blades and a few designs with two blades. • Nacelle that houses the main components of the wind turbine, such as the controller, gearbox, generator, and shafts. • Shafts including the low speed and high speed shafts connected to the rotating components. • Gear box to convert the low rotational speed of the rotor into a higher speed for the electric generator.

  23. Generator that converts the mechanical energy from the wind turbine’s rotation into electrical energy. • Yaw system responsible for the orientation of the wind turbine rotor towards the wind. • Mechanical brake used to hold the turbine at rest for maintenance.. • Anemometer for measuring the wind speed. • Tower usually made of tubular steel and is 60 to 100 meters high. • Power electronic converter used to adjust the electrical output of the wind turbine (must be used with grid connected WECS).

  24. Power output prediction • The power output of a wind turbine varies with wind speed and every wind turbine has a characteristic power performance curve. • With such a curve it is possible to predict the energy production of a wind turbine without considering the technical details of its various components. • The power curve gives the electrical power output as a function of the hub height wind speed.

  25. Typical wind turbine power curve

  26. The performance of a given wind turbine generator can be related to three key points on the velocity scale: • Cut-in speed: the minimum wind speed at which the machine will deliver useful power • Rated wind speed: the wind speed at which the rated power (generally the maximum power output of the electrical generator) is reached • Cut-out speed: the maximum wind speed at which the turbine is allowed to deliver power (usually limited by engineering design and safety constraints)

  27. = 1/2 x air density x swept rotor area x (wind speed)3 A V3  Power in the Wind (W/m2) Density = P/(RxT) P - pressure (Pa) R - specific gas constant (287 J/kgK) T - air temperature (K) Area =  r2 Instantaneous Speed (not mean speed) kg/m3 m2 m/s

  28. Wind Energy Natural Characteristics • Wind Speed • Wind energy increases with the cube of the wind speed • 10% increase in wind speed translates into 30% more electricity • 2X the wind speed translates into 8X the electricity • Height • Wind energy increases with height to the 1/7 power • 2X the height translates into 10.4% more electricity

  29. Wind Energy Natural Characteristics • Air density • Wind energy increases proportionally with air density • Humid climates have greater air density than dry climates • Lower elevations have greater air density than higher elevations • Wind energy in Denver about 6% less than at sea level • Blade swept area • Wind energy increases proportionally with swept area of the blades • Blades are shaped like airplane wings • 10% increase in swept diameter translates into 21% greater swept area • Longest blades up to 413 feet in diameter • Resulting in 600 foot total height

  30. Betz Limit • Theoretical maximum energy extraction from wind = 16/27 = 59.3% • Undisturbed wind velocity reduced by 1/3 • Albert Betz (1928)

  31. How Big is a 2.0 MW Wind Turbine? This picture shows a Vestas V-80 2.0-MW wind turbine superimposed on a Boeing 747 JUMBO JET

  32. 2003 1.8 MW 350’ 2000 850 kW 265’ Recent Capacity Enhancements 2006 5 MW 600’

  33. Nacelle Components • Hub controller 11. Blade bearing • Pitch cylinder 12. Blade • Main shaft 13. Rotor lock system • Oil cooler 14. Hydraulic unit • Gearbox 15. Machine foundation • Top Controller 16. Yaw gears • Parking Break 17. Generator • Service crane 18. Ultra-sonic sensors • Transformer 19. Meteorological gauges • Blade Hub

  34. Larger turbines Specialized blade design Power electronics Computer modeling produces more efficient design Manufacturing improvements Turbines Constantly Improving

  35. 100 80 60 % Available 40 20 0 Year 1981 '83 '85 '90 '98 Improving Reliability • Drastic improvements since mid-80’s • Manufacturers report availability data of over 95%

  36. Wind Project Siting

  37. Wind Power Classes Wind speed is for standard sea-level conditions. To maintain the same power density, speed increases 3%/1000 m (5%/5000 ft) elevation.

  38. Siting a Wind Farm • Winds • Minimum class 4 desired for utility-scale wind farm (>7 m/s at hub height) • Transmission • Distance, voltage excess capacity • Permit approval • Land-use compatibility • Public acceptance • Visual, noise, and bird impacts are biggest concern • Land area • Economies of scale in construction • Number of landowners

  39. Wind Disadvantages

More Related