Wind Energy in the Classroom The Kidwind Project

Wind Energy in the Classroom The Kidwind Project and Wind. Wise

What is Kid. Wind? The Kid. Wind Project is a team of teachers, students, engineers and practitioners exploring the science behind wind energy in classrooms around the US. Our goal is to introduce as many people as possible to the elegance of wind power through hands-on science activities which are challenging, engaging and teach basic science principles. Kid. Wind Project || www. kidwind. org Kid. Wind www. kidwind. org

Yesterday & Today First documented windmill: Afghanistan (900 AD) Wind Pumper Greece Holland & Colonial America

Wind Energy Technology in the World Today: Modern Small Wind Turbines: Horizontal Axis • Technically Advanced • Minimal Moving Parts • Very Low Maintenance Requirements • Proven: ~ 5, 000 On-Grid • American Companies are the Market and Technology Leaders Downwind Rotor 10 k. W 400 W 50 k. W Upwind Rotors 900 W (Not to scale)

Vertical Axis Wind Turbines? Advantages • Omnidirectional – Accepts wind from any angle • Components can be mounted at ground level – Ease of service – Lighter weight towers • Can theoretically use less materials to capture the same amount of wind Disadvantages • Rotors generally near ground where wind poorer • Centrifugal force stresses blades & components • Poor self-starting capabilities Windspire • Requires support at top of turbine rotor • Requires entire rotor to be removed to replace bearings • Overall poor performance and reliability/less efficient • Have never been commercially successful (large scale) Savonious

Large Wind Turbines • • 450’ base to blade Each blade 112’ Span greater than 747 163+ tons total Foundation 20+ feet deep Rated at 1. 5 – 5 megawatt Supply at least 350 homes Upwind rotors

Wind Energy is a Growing Industry • US total installed wind energy capacity now over 43, 635 MW as of Sept 2011 per Wind. Powering. America. com • Enough electricity to power the equivalent of over 7 million households! Kid. Wind Project | www. kidwind. org

US Capacity is Growing in fits and starts

Costs are Decreasing 1979: 40 cents/k. Wh 2000: 4 -6 cents/k. Wh • Increased Turbine Size • R&D Advances • Manufacturing Improvements NSP 107 MW Lake Benton wind farm 4 cents/k. Wh (unsubsidized) 2004: 3 – 4. 5 cents/k. Wh

Issues Today: Costs & Benefits

Where do we get our electricity? Kid. Wind Project | www. kidwind. org

Fighting windmills has a long history! Don Quixote fighting “Giants”

Accidents & Troubles “So far no evacuation zone has been declared. There are no threats to sea life, and the fallout from the disaster was not detectable thousands of miles away. Cleanup efforts are in progress, and will not include covering the area in a giant concrete dome. No workers have been asked to give their lives in order to save their countrymen from the menace of this fallen wind turbine. ” – Christopher Mims Kid. Wind Project | www. kidwind. org

Impacts of Wind Power: Noise • Modern turbines are relatively quiet • Rule of thumb – stay about 3 x hub-height away from houses

Impacts of Wind Power: Wildlife

• In the November-December Audubon Magazine, John Flicker, President of National Audubon Society, wrote a column stating that Audubon "strongly supports wind power as a clean alternative energy source, " pointing to the link between global warming and the birds and other wildlife that scientist say it will kill.

Prospecting the Right Site: Lessons Learned 1980’s California Wind Farm Older Technology + Higher RPMs + Lower Elevations + Lattice Towers + Poorly Sited = Bad News!

Prospecting the Right Site: Off-Shore On the Farm On a Mountain

The Transmission Challenge • Where is the wind? • Where are the population centers? • Where are the wind farms? • How do we get wind energy from the wind farms to the population centers?

Where is the Wind? Kid. Wind Project | www. kidwind. org

Get more local details at http: //nyswe. awstruepower. com/

Importance of Wind Speed • No other factor is more important to the amount of power available in the wind than the speed of the wind • Power is a cubic function of wind speed – VXVXV • 20% increase in wind speed means 73% more power • Doubling wind speed means 8 times more power

Calculation of Wind Power • Power the=wind Power in thein. Wind ½ρAV 3 – Effect of swept area, A – Effect of wind speed, V – Effect of air density, Swept Area: A = πR 2 Area of the circle swept by the rotor (m 2). R

Technology

Kid. Wind Project | www. kidwind. org

How does a generator generate electricity?

Airfoil Shape Just like the wings of an airplane, wind turbine blades use the airfoil shape to create lift and maximize efficiency. The Bernoulli Effect

Lift & Drag Forces • The Lift Force is perpendicular to the direction of motion. We want to make this force BIG. • The Drag Force is parallel to the direction of motion. We want to make this force small. α = low α = medium <10 degrees α = High Stall!!

Pitch Control Mechanisms Kid. Wind Project | www. kidwind. org

Twist & Taper • Speed through the air of a point on the blade changes with distance from hub • To optimize angle of attack all along blade, it must twist from root to tip Fastest Faster Fast

Tip-Speed Ratio Tip-speed ratio is the ratio of the speed of the rotating blade tip to the speed of the free stream wind. There is an optimum angle of attack which creates the highest lift to drag ratio. Because angle of attack is dependant on wind speed, there is an optimum tip-speed ratio ΩR TSR = V Where, Ω = rotational speed in radians /sec R = Rotor Radius V = Wind “Free Stream” Velocity ΩR R

Performance Over Range of Tip Speed Ratios • Power Coefficient Varies with Tip Speed Ratio • Characterized by Cp vs Tip Speed Ratio Curve

Betz Limit All wind power cannot be captured by rotor or air would be completely still behind rotor and not allow more wind to pass through. Theoretical limit of rotor efficiency is 59% Most modern wind turbines are in the 35 – 45% range

Rotor Solidity is the ratio of total rotor planform area to total swept area Low solidity (0. 10) = high speed, low torque R a A High solidity (>0. 80) = low speed, high torque Solidity = 3 a/A

Over-Speed Protection During High Winds Upward Furling: The rotor tilts back during high winds Angle Governor: The rotor turns up and to one side

Yawing – Facing the Wind • Active Yaw (all medium & large turbines produced today, & some small turbines from Europe) • Anemometer on nacelle tells controller which way to point rotor into the wind • Yaw drive turns gears to point rotor into wind • Passive Yaw (Most small turbines) • Wind forces alone direct rotor • Tail vanes • Downwind turbines

Maintenance Kid. Wind Project | www. kidwind. org

Wind Energy in the Classroom

Many Topics Addressed §Use of Simple Tools & Equipment §Applied Mathematical Relationships §Practices of Engineering & Science §Forces and Change §Energy Transformations (Forms of Energy) §Circuits/Electricity/Magnetism §Properties of Air §Weather Patterns §Impacts on ecosystems, wildlife & humans §Renewable – Non Renewable Energy Kid. Wind Project | www. kidwind. org

Scientific & Engineering Practices New National Frameworks 1. 2. 3. 4. 5. 6. 7. 8. Asking questions & defining problems Developing & using models Planning & carrying out investigations Analyzing & interpreting data Using mathematics & computational thinking Developing explanations & designing solutions Engaging in argument from evidence Obtaining, evaluating & communicating information

Upper Elementary/Middle balloon ~3 m streamers Kite or balloon string • Building Wind Turbines • Assessing Wind Resource • Mathematics

Secondary • • • Advanced Blade Design School Siting Projects Data Analysis Mathematics Download lessons

Wind Turbine Blade Challenge • Students perform experiments and design different wind turbine blades • Use simple wind turbine models • Test one variable while holding others constant • Record performance with a multimeter or other load device • Goals: Produce the most voltage, pump the most water, lift the most weight – Minimize Drag – Maximize LIFT – Harness the POWER of the wind!

Kid. Wind Project | www. kidwind. org

Kid. Wind Opportunities & Resources Kid. Wind and Wise Web Sites Free Downloads -- Wind Wise – Math Lessons NEW On-Line Turbine Design Competition Kid. Wind store – good prices: great stuff Kid. Wind Competitions For Utica area, contact Raymond Pitcher at rpitcher 1@twcny. rr. com Kid. Wind Project | www. kidwind. org

Kid. Wind Project | www. kidwind. org

Presenters: The Kid. Wind Project www. kidwind. org Susan Reyes Science & Sustainability Educator Kid. Wind Senator Kid. Wind Western Mass Area Event Coordinator sreyes 7@mac. com Raymond Pitcher Technology Education Specialist Kid. Wind Senator Kid. Wind Challenge Utica Area Event Coordinator rpitcher 1@twcny. rr. com