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The KidWind Project introduces students to the science and engineering behind wind energy through engaging, hands-on activities. Our goal is to improve understanding of wind power, debunk myths, and inspire interest in science and math.
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Wind Energy Educators Workshop Michael Arquin The Kidwind Project St. Paul, MN michael@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. KidWind Project | www.kidwind.org KidWind Project | www.kidwind.org
Why Wind Education in K-12 ? • Students learn science/math standards • Lessons are completely scalable from elementary through college level • Addresses myths regarding wind energy • Improves the local understanding of wind energy • Provides a bulwark against misunderstandings and fictional problems with wind energy • Encourages higher interest in Science and Math • Science/Math activities with “larger social purpose” • Students learn about jobs/careers in wind industry, as well as opportunities for further training
Expensive Wind Kits… $200 !! $99 ?? $800 !! $200 ?? $300 “Complete Renewable Energy Set” Demonstration – little experimental value
Typical Wind Lessons - Not Technical • Beaufort Scale • Pinwheels • Student Reports • Demonstrations • Discussion Activity All very interesting but very little of the science and technology related to the current wind industry is presented. In fact most text books are pretty negative about the future of wind and misrepresent the technology miserably.
This is strange because…Wind Energy is the Fastest Growing Energy Source in the World!! US installed capacity grew 45%in 2007 and 50% in 2008!!!
2008: 8,358 megawatts (MW) of new wind energy capacity installed • 50% growth rate! • Brings US total installed wind energy capacity to 25,170 MW • Enough electricity to power the equivalent of close to 7 million households! • 2009 was a slower year due to the economy
Why such growth…costs! 1979: 40 cents/kWh 2000: 4 - 6 cents/kWh NSP 107 MW Lake Benton wind farm 4 cents/kWh (unsubsidized) • Increased Turbine Size • R&D Advances • Manufacturing Improvements 2004: 3 – 4.5 cents/kWh
Other Reason to teach… Elegant Power Source
Wind Power • History • Technology • The Wind Resource • Wind in the Classroom KidWind Project | www.kidwind.org
Jacobs Turbine – 1920 - 1960 WinCharger – 1930s – 40s
Smith-Putnam Turbine Vermont, 1940's
Orientation Turbines can be categorized into two overarching classes based on the orientation of the rotor Vertical AxisHorizontal Axis
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 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 Have never been commercially successful (large scale) Vertical Axis Turbines
Horizontal Axis Wind Turbines • Rotors are usually Up-wind of tower • Some machines have down-wind rotors, but only commercially available ones are small turbines • Proven, viable technology
50 kW 10 kW 900 W 400 W Modern Small Wind Turbines:High Tech, High Reliability, Low Maintenance • Technically Advanced • Only 2-3 Moving Parts • Very Low Maintenance Requirements • Proven: ~ 5,000 On-Grid • American Companies are the Market and Technology Leaders (Not to scale)
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
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
Workers Blade 112’ long Nacelle 56 tons Tower 3 sections Wind Turbine Perspective
Maintenance KidWind Project | www.kidwind.org
Calculation of Wind Power • Power in the wind • Effect of swept area, A • Effect of wind speed, V • Effect of air density, Power in the Wind = ½ρAV3 R Swept Area: A = πR2 Area of the circle swept by the rotor (m2).
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
