Presentation on theme: "Wind Energy in the Classroom The Kidwind Project and WindWise."— Presentation transcript:
Wind Energy in the Classroom The Kidwind Project and WindWise
KidWind Project | www.kidwind.org What is KidWind? The KidWind 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.
Holland & Colonial America First documented windmill: Afghanistan (900AD) Greece Yesterday & Today Wind Pumper
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 10 kW 50 kW 400 W 900 W (Not to scale) Downwind Rotor Upwind Rotors
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 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) Windspire 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
KidWind Project | www.kidwind.org Wind Energy is a Growing Industry US total installed wind energy capacity now over 43,635 MW as of Sept 2011 per WindPoweringAmerica.com Enough electricity to power the equivalent of over 7 million households!
Where do we get our electricity? KidWind Project | www.kidwind.org
Fighting windmills has a long history! Don Quixote fighting “Giants”
Accidents & Troubles KidWind Project | www.kidwind.org “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
Impacts of Wind Power: Noise Modern turbines are relatively quiet Rule of thumb – stay about 3x 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.
1980’s California Wind Farm Older Technology + Higher RPMs + Lower Elevations + Lattice Towers + Poorly Sited = Bad News! Prospecting the Right Site: Lessons Learned
Prospecting the Right Site: Off-Shore On the Farm On a Mountain
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? The Transmission Challenge
KidWind Project | www.kidwind.org Where is the Wind?
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 – V X V X V 20% increase in wind speed means 73% more power Doubling wind speed means 8 times more power
Calculation of Wind Power Power in the wind Power in the wind – 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 ). Power in the Wind = ½ρAV 3 R
KidWind 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!!
KidWind Project | www.kidwind.org Pitch Control Mechanisms
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 Fast Faster Fastest
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 V TSR = 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 Solidity is the ratio of total rotor planform area to total swept area Low solidity (0.10) = high speed, low torque High solidity (>0.80) = low speed, high torque A R a Solidity = 3a/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 KidWind Project | www.kidwind.org
Wind Energy in the Classroom
Many Topics Addressed KidWind Project | www.kidwind.org 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
Scientific & Engineering Practices New National Frameworks 1.Asking questions & defining problems 2.Developing & using models 3.Planning & carrying out investigations 4.Analyzing & interpreting data 5.Using mathematics & computational thinking 6.Developing explanations & designing solutions 7.Engaging in argument from evidence 8.Obtaining, evaluating & communicating information
Upper Elementary/Middle Building Wind Turbines Assessing Wind Resource Mathematics balloon streamers Kite or balloon string ~3m
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!
KidWind Project | www.kidwind.org
KidWind Opportunities & Resources KidWind and Wind Wise Web Sites Free Downloads -- Wind Wise – Math Lessons NEW On-Line Turbine Design Competition KidWind store – good prices: great stuff KidWind Competitions For Utica area, contact Raymond Pitcher at firstname.lastname@example.org
KidWind Project | www.kidwind.org
The KidWind Project www.kidwind.org Susan Reyes Science & Sustainability Educator KidWind Wind Senator KidWind Western Mass Area Event Coordinator email@example.com Presenters: Raymond Pitcher Technology Education Specialist KidWind Senator KidWind Challenge Utica Area Event Coordinator firstname.lastname@example.org