Wind Turbines

in the Classroom

Hands-On Alternative Energy Engineering

Matt Hardy matth@edenpr.org Grade 3 Teacher, Eden Prairie SchoolsJoe Rand joe@kidwind.org KidWind Project kidwind.org

Agenda

• Project Background• Current state of wind energy (U.S. & Globally)– Joe Rand, Kidwind.org

• Classroom Activities– Build the Tower– Engineer the Blades– Turbines in Tandem (Wind Farm)

My Background

• BA, Computer Science, U of M, Morris• Web Development• M. Ed., U of M, Twin Cities• 3rd Grade, Eden Prairie (6 yrs.)

Project Background

• Go Green/Impact Project– “High-Tech Environmental Engineering” – 2-3 Weeks– Hands-on, inquiry based, highly motivational– Funded by a generous grant from the

Foundation for Eden Prairie School (FEPS)• Tied to Magnets and Electricity curriculum• “Alternative” energy is becoming mainstream

Wind Energy Today

• Joe Rand– Kidwind Project– kidwind.org

Energy

Energy

• What is energy?• Where does energy come from?– Coal, Natural Gas, Solar, Wind– Sun (primary source)– Nuclear, geothermal

• We can harness this energy • We can transform it so it’s useful to people

Electricity

• Where does electricity come from?• Capture/release energy to make electrons move

Electricity Production:Wind Turbines

• How to “catch” the wind? Blades!– Spin a turbine– Push electrons– Generate electricity!

Daily PlanBuild the base (tower)Free inquiry: cut/glue/test – does it spin?Controlled design: independent variableDiscuss “ideal” designs“Turbines 2.0 ” • Redesign, with advice from peers• Other testing devices

Day 1:Day 2:

Day 3-5:Day 6:

Day 7-10:

Part 1: Build a Tower

• (1) Generator• (1) Hub• (5) 90° Fitting • (3) T-Fitting (1 Drilled!) • (1) 24” Pipe • (6) 6” Pipe • (1) Coupler • (1) 2” Pipe

Part 2: Blade Design

• Students design blades out of various materials• Try to make their rotor turn

Measuring Performance

• Multimeters (volts = speed)• LEDs - “The Squid” (volts)• Water Pump (power: volts x amps)– The true test of a turbine’s utility

Test Your Blades• Always uncrimp/recrimp hub– Don’t press/pull dowels too hard

• Danger zone = sideways

• Wear safety goggles when testing

• Use multimeter to quantify speed

Improve Your Blades• SHORTEN THE BLADES - No bigger than fan

• CHANGE THE PITCH - Try flatter (Twist?)

• USE FEWER BLADES - 2, 3 or 4 blades.

• USE LIGHTER MATERIAL - balsa wood rules!

• SMOOTH SURFACES - watch tape & rough edges

• FIND MORE WIND - Use a utility fan

• BLADE SHAPE - Narrow tips

Don’tBeA

Drag

Part 3: Wind Farms

Polarity

• Determine positive/negative wires• Red/Black don’t matter!• Test turbine with multimeter: Red-Red Black-Black• If the voltage reading is positive (no “-” sign),

then the red wire is positive• Otherwise, the black wire is positive• Put a piece of tape on the “+” wire to remember• DO NOT CHANGE THE PITCH OF THE BLADES

Wait for the Wind

• Watch the weather forecast for a windy way

• Head out to the field!

• Hold onto those blades (hand on the hub)!

• Arrange the turbines in a line, facing the wind

Line Them Up…

Connect the Turbines

• Place a “jumper wire” between each turbine.• Start at one end of the line• Clip + to - , + to - , + to - , + to - …

until you reach the last turbine.• Connect a LONG wire from the last turbine’s free

wire back toward the first turbine.• Connect a multimeter to the first turbine’s free

wire and the long wire from the last turbine.• Release the hubs. Stand back and admire them!

Resources

• kidwind.org• Detailed PVC Turbine Assembly Instructions• Blade Design Lesson Plans