ELTR 1223
Survey of Renewable
Energy Technology
Wind Energy Technology
Unit 8
Source:
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:
Author, Editors/Reviewers
Author: Timothy J. Wilhelm, P.E., Kankakee
Community College
 Editors/Reviewers / Modifier:
 Chris Miller Heartland Community College

Source:
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.

Source:
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:
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
Source: http://www.tvnet.lv/men/images/upload/04.jpg
Horse-Powered vs. Wind-Powered
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

Source:
http://centros5.pntic.mec.es
/ies.victoria.kent/RinconC/Curiosid/rc74/image006.jpg
Battery charger
Source:
http://ecoinventos.files.wordpress.com/2007/05/220237i1.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.
Source: http://thales.cica.es/rd/Recursos/rd99/ed99-0226-01/liftmovi.gif

Single-sided vs. true airfoil
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/ed990226-01/sotovento.jpg
Source: http://hensonelectric.com/Excel.Color.jpg
2-Blade vs. 3-Blade (vs. 1Blade?)
Source: http://3.bp.blogspot.com/_PpVQS40hMA/R5j4vqOuD9I/AAAAAAAAAKA/F3sOpAGsZdc/s320/aerogerador%
2Bmoinho%2Bvento.jpg
Wind-Driven Electrical Generators

PM Field DC Generators



PM Field AC Alternators



Smaller machines
Battery charging and inversion
“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”
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/ed990226-01/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


Small wind – commercial


10KW and less
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_m
ed.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