wind energy for students the kidwind project copyright 2008
TRANSCRIPT
Wind Energyfor Students
The Kidwind ProjectThe Kidwind Projectwww.kidwind.orgwww.kidwind.org
Copyright 2008Copyright 2008
Electricity!
• How much would it cost to run this 100 Watt bulb for a full day (24 hrs)?
• 100 Watts x 24 hours = 2400 Watt Hours (2400 Watt Hours = 2.4 Kilowatt Hours)
• 2.4 kWh x $0.08/kWh = $0.19
• What about this 25 Watt CFL light bulb, which produces the same amount of light?
• 25 Watts x 24 hours = 600 Watt Hours (600 Watt Hours = 0.6 Kilowatt Hours)
• 0.6 kWh x $0.08/kWh = $0.05
More efficient light bulbs are great, but what is the BEST way to conserve electricity and reduce our consumption of fossil fuels???
TURN IT OFF!!!Be conscious of your energy choices!
Where do we get our electricity?Where do we get our electricity?
Types of Electricity Generating Windmills
Small (10 kW)•Homes•Farms•Remote Applications (e.g. water
pumping, telecom sites, icemaking)
Large (250 kW - 2+MW)
•Central Station Wind Farms
•Distributed Power
Intermediate (10-250 kW)•Village Power•Hybrid Systems•Distributed
Power
150 m2
250 m2
800 m2
1,800 m2
3,700 m2
19801985
1990
19952000
A= 12,000 m2
2005 How big will wind turbines be?
2010
Slide courtesy NREL
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
Yawing – Facing the WindYawing – 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
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 Effect of air density,
– Effect of swept area, A– Effect of wind speed, V
R
Swept Area: A = πR2 Area of the circle swept by the rotor (m2).
Power in the Wind = ½ρAV3