Working with Wind Energy
24 September 2010
Moshe Kam
24 - 25 SEP 2010
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Activity Goal
• Build a wind turbine with simple materials
• The wind turbine must withstand the wind
generated by a fan or hair dryer and rotate for up
to 1 minute to lift a small object
24 - 25 SEP 2010
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Activity Objectives
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Learn about wind energy conversion
Design a wind turbine
Construct the wind turbine
Test the wind turbine
Evaluate Performance
24 - 25 SEP 2010
3
Why is this experiment useful to
teachers and students?
• Learn about wind energy and wind turbines
• Learn about the concepts of forces and motion
• Learn about engineering design
• Learn how engineering can help solve societal challenges
• Learn about teamwork and problem solving
24 - 25 SEP 2010
4
Principles & Standards
for School Mathematics
• Geometry:
– Use visualization, spatial reasoning, and geometric modeling to
solve problems
– Analyze characteristics and properties of two- and threedimensional geometric shapes and develop mathematical
arguments about geometric relationships
• Problem Solving:
– Recognize and apply geometric ideas in areas outside of the
mathematics classroom
– Apply and adapt a variety of appropriate strategies
• Communication:
– Communicate mathematical thinking coherently and clearly to
peers, teachers, and others
24 - 25 SEP 2010
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What is Wind?
• Wind is a form of Solar Energy
• The sun heats the
Earth’s surface at varying rates
• The air above the warmer areas heats up,
becomes less dense and rises
• Cooler air from adjacent higher-pressure areas
moves to the lower-pressure areas
• That movement = wind
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Where in the World is Wind?
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What is Wind Energy?
• The process by which the wind is
used to generate mechanical
energy or electricity
• Wind turbines convert
the kinetic energy in the wind into
mechanical and electrical energy
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24 - 25 SEP 2010
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A Wind Turbine
• The wind hits the blades…
• Shaft leads to a gearbox
whose output leads to a
generator to make
electricity
• Usually has 2 or 3 blades
24 - 25 SEP 2010
WIND
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The Turbine Blade
• Operates much like
an airplane wing
• Low-pressure air
forms on the
downwind side of
the blade
• The low-pressure air
pocket then pulls the
blade toward it,
causing the rotor
to turn
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Many blade designs
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Your Challenge
• Design, construct and test your own wind
turbine design
• Wind up weight 15 cm
as quickly as possible
• Maximum 1 minute
• No human interaction!
• Blowdryer at least
30cm away from turbine
24 - 25 SEP 2010
> 1ft, 30cm
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Turbine Requirements
• Must have a rotor shaft
around which to wind
up given weight
• Must be freestanding
(no human interaction)
• Must use only
materials provided
24 - 25 SEP 2010
> 1ft, 30cm
14
Test Procedure
• Blowdryer at least 30 cm
away from turbine
• No human interaction with
turbine
• Attach weight around rotor
• Up to 1 minute to wind up
weight
• Record time to wind up
weight
24 - 25 SEP 2010
> 1ft,
30cm
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Materials
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wooden sticks, spoons
bendable wire
string
paperclips
rubber bands
toothpicks
aluminum foil, plastic wrap
tape, glue
wooden dowels
paper, cardboard
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Procedure
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Teams of 2
Develop and sketch your design
Construct initial design
Preliminary test
Modify design, if necessary
Final test
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Evaluate Your Design
• Efficiency of design may depend on
– Cost of materials
– Speed (rotations per minute)
– Power (time to wind weight)
• Possible measure of efficiency:
– Eff. = (Cost of materals) / (time [sec] to wind weight)
• Are two designs that have the same rotational
speed equally as “good”?
24 - 25 SEP 2010
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