Wind Energy Technology

1. Wind Energy Technology Unit 8 Source:

2. Use Policy • This material was developed by Timothy J. Wilhelm, P.E., Kankakee Community College, with funding from the National Science Foundation as part of ATE Grant No. 0802786. • All materials in this presentation are designed and intended for educational use, only. They may not be used for any publication or commercial purposes. Source:

3. Author, Editors/Reviewers • Author: Timothy J. Wilhelm, P.E., Kankakee Community College • Editors/Reviewers / Modifier: • Chris Miller Heartland Community College Source:

4. Objectives • Students will be able to describe, in very simple terms, at least three different styles of “prime mover” used to convert linear air movement (wind) into rotational shaft movement. • Students will be able to briefly describe, in very simple terms, at least two of the basic criteria for properly siting a modern wind turbine. Source:

5. Objectives • Students will be able to describe, in very simple terms, how change in wind speed affects the output of a modern wind-driven generator. • Students will be able to describe, in very simple terms, three different size-groups of modern wind turbines and their typical applications. Source:

6. Objectives • Students will be able to describe, in very simple terms, at least three advantages and three disadvantages, to a local community, relative to the local construction of a commercial wind farm. Source:

7. One of the Earliest Applications of Wind Power Source: http://tonto.eia.doe.gov/energyexplained/images/WINDENERGY1.gif

8. Wind Energy History • 5000 BC – Wind-driven sail boats were moving on the Nile River • 200 BC – Wind-powered pumps were moving water in China; • and, sail-wing windmills (with woven-reed sails) were used in Persia and the Middle East

9. What is a mill? • Mill (noun): • a. A building equipped with machinery for grinding grain into flour or meal. • b. A device or mechanism that grinds grain. • Mill (verb): • a. To grind, pulverize, or break down into smaller particles.

10. Driving a Mill Source: http://www.tvnet.lv/men/images/upload/04.jpg Horse-Powered vs. Wind-Powered

11. The Term “Mill” Stuck… Wind “Mill” pumps have been used for centuries in the Netherlands.

12. Windmills to Drive Generators • Charles Bruch – GE, Cleveland, OH • Brush Windmill – 1888 • 50’ diameter • 144 cedar blades • 12KW generator • Battery charger Source: http://centros5.pntic.mec.es/ies.victoria.kent/Rincon-C/Curiosid/rc-74/image006.jpg Source: http://ecoinventos.files.wordpress.com/2007/05/220237i1.jpg

13. How to Divert Wind Energy • Vertical Axis Machines • Simplest • Least efficient • Horizontal Axis Machines • Requires “yaw” control – face the wind • Can be “upwind” or “downwind” • Drag-type blades – applies to both V and H • Lift-type airfoils – applies to both V and H

14. Drag vs. Lift Linear wind PUSHES against angled surface and resulting force vectors create torque.

15. Drag vs. Lift • Lift-type airfoils use the Bournelli Effect. • Single-sided vs. true airfoil Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/liftmovi.gif

16. Machine Types – VA va HA Source: http://www.redriven.net/skin1/images/wtconfig.gif

17. Vertical vs. Horizontal Axis • Vertical axis machines do not care which direction the wind is from. • Simple, but inefficient. • Unless shrouded, they fight themselves.

18. Vertical vs. Horizontal Axis • Vertical requires yaw control and often a mechanical power transmission. • More complex. • More efficient. Source: http://www.acsaeolica.com/img/productos_torre06.jpg

19. Savonius – Vertical Axis, Drag Source: http://www.reuk.co.uk/Savonius-Wind-Turbines.htm

20. Darius – Vertical Axis, Lift Source: http://www.reuk.co.uk/OtherImages/darrieus-rotor.jpg

21. Midwest Windpumper -- Drag

22. Modern Windgennie -- Lift Source: http://i.treehugger.com/files/airx.jpg

23. Upwind vs Downwind Source: http://hensonelectric.com/Excel.Color.jpg Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/sotovento.jpg

24. 2-Blade vs. 3-Blade (vs. 1Blade?) Source: http://3.bp.blogspot.com/_PpVQS40h-MA/R5j4vqOuD9I/AAAAAAAAAKA/F3sOpAGsZdc/s320/aerogerador%2Bmoinho%2Bvento.jpg

25. Wind-Driven Electrical Generators • PM Field DC Generators • Smaller machines • Battery charging and inversion • PM Field AC Alternators • “Wild” AC • Rectified for battery charging and inversion • Synchronous Alternators • Larger machines • Often 3-phase • Grid-tied, only

26. Modern Wind Generators • Horizontal axis • 3-bladed • True airfoil • Loss-of-load protection • Modern electronics • High Wind protection • Yaw control • Pitch control

27. Modern Wind Generators Source: http://www.testek.com/images/diagram.gif

28. High-Wind Yaw Control • High winds mechanically force the face of the turbine away from the direct force of the wind. • Some machines rotate face sideways. • Some machines tilt face back toward the sky.

29. Pitch Control – relies on “Stall” Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/stallmov.gif PLC Control maintains constant rpm needed for AC grid-tie machines. Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/pitchmo.gif

30. Wind Siting – Wind Speed is CRITICAL • Power is proportional to the cube of the wind speed…(wind speed)3!

31. Wind Turbine Siting – Wind Speed Estimates Source: http://www.seps.sk/zp/fond/2002/vietor/enq2.jpg

32. Wind Turbine Siting – Wind Maps

33. Wind Turbine Siting – Wind Rose • Wide wedges gives the relative frequency of each of the 12 wind directions. • 2nd wedge tells how much each sector contributes to the average wind speed. • Red wedge how much each sector contributes to the energy content of the wind. Source: www.windpower.org

34. Wind Turbine Siting – Terrain Effects • Laminar flow vs turbulent flow • Roughness and obstacles • Laminar flow (straight-line) winds are available aloft. • Rule of Thumb: • Bottom of turbine’s swept area should be 30’ to 50’ above anything within a 300’ horizontal radius. • Power-cubed – wind-speed relationship…taller tower is cheaper than heavier machine with heavier tower.

35. Speed up effect • Hill effect

36. Speed up effects • Tunnel effect

37. Sizes and Applications • Small wind – residential • 10KW and less • Small wind – commercial • 100KW and less • Large wind – commercial wind farms, industrial applications

38. Small wind issues • Suitable wind resource • Sufficient property/space • Allowed by zoning • Accepted by neighbors • Technical ability of the owner to maintain the machine • Tower types – monopole, lattice, guyed, tilt-up

39. Tower types Source: http://www.northerntool.com/images/product/images/339987_med.gif