Wind Energy Technology

ELTR 1223Survey of Renewable

Energy Technology

Wind Energy Technology

Unit 8

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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.

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Author, Editors/Reviewers Author: Timothy J. Wilhelm, P.E.,

Kankakee Community College Editors/Reviewers / Modifier: Chris Miller Heartland Community

College

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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:

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.

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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.

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One of the Earliest Applications of Wind Power

Source: http://tonto.eia.doe.gov/energyexplained/images/WINDENERGY1.gif

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

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.

Driving a Mill

Horse-Powered vs. Wind-Powered

Source: http://www.tvnet.lv/men/images/upload/04.jpg

The Term “Mill” Stuck…Wind “Mill” pumps have been used for

centuries in the Netherlands.

Windmills to Drive Generators Charles Bruch – GE, Cleveland, OH Brush Windmill – 1888

50’ diameter

144 cedar blades

12KW generator Battery charger

Source: http://ecoinventos.files.wordpress.com/2007/05/220237i1.jpg

Source: http://centros5.pntic.mec.es/ies.victoria.kent/Rincon-C/Curiosid/rc-74/image006.jpg

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

Drag vs. Lift

Linear wind PUSHES against angled surface and resulting force vectors create torque.

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

Machine Types – VA va HA

Source: http://www.redriven.net/skin1/images/wtconfig.gif

Vertical vs. Horizontal Axis

Vertical axis machines do not care which direction the wind is from.

Simple, but inefficient.

Unless shrouded, they fight themselves.

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

Savonius – Vertical Axis, Drag

Source: http://www.reuk.co.uk/Savonius-Wind-Turbines.htm

Darius – Vertical Axis, Lift

Source: http://www.reuk.co.uk/OtherImages/darrieus-rotor.jpg

Midwest Windpumper -- Drag

Modern Windgennie -- Lift

Source: http://i.treehugger.com/files/airx.jpg

Upwind vs Downwind

Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/sotovento.jpg

Source: http://hensonelectric.com/Excel.Color.jpg

2-Blade vs. 3-Blade (vs. 1Blade?)

Source: http://3.bp.blogspot.com/_PpVQS40h-MA/R5j4vqOuD9I/AAAAAAAAAKA/F3sOpAGsZdc/s320/aerogerador%2Bmoinho%2Bvento.jpg

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

Modern Wind Generators Horizontal axis 3-bladed True airfoil Loss-of-load protection

Modern electronics High Wind protection

Yaw control Pitch control

Modern Wind Generators

Source: http://www.testek.com/images/diagram.gif

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.

Pitch Control – relies on “Stall”

PLC Control maintains constant rpm needed for AC grid-tie machines.

Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/stallmov.gif

Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/pitchmo.gif

Wind Siting – Wind Speed is CRITICAL Power is proportional to the cube of

the wind speed…(wind speed)3 !

Wind Turbine Siting – Wind Speed

Estimates

Source: http://www.seps.sk/zp/fond/2002/vietor/enq2.jpg

Wind Turbine Siting – Wind Maps

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

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.

Speed up effect Hill effect

Speed up effects Tunnel effect

Sizes and Applications Small wind – residential

10KW and less

Small wind – commercial 100KW and less

Large wind – commercial wind farms, industrial applications

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

Tower types

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

Commercial wind siting Same as small wind, plus…

Sufficient participating land owners Proper zoning ordinance Special Use Permit Application County Planning Commission County Zoning Board of Appeals County Board Special Use Permit Granted Building Permit Application and Approval

Commercial Wind issues

Shadow Flicker Blade Glimmer Amplitude Modulation Noise Infrasound Disturbance of the natural vista Vibro-Acoustic Disease/Wind Turbine

Syndrome TV and Communications Interference

Interesting Experiences

Future? Maglev Wind Turbine

Source: http://www.technogeek.ro/images/turbina_maglev.jpg