1. Wind Power
Kelly Farmer

2. How it Works

3. Optimizing Power Output
Adjustable rotor blade pitch
Yaw system rotates the blades about the tower
The yaw system rotates the rotor blades about the tower

4. Limitations Betz Limit establishes a maximum power efficiency of 59%
Operates in wind speeds between 4 m/s and 25 m/s
Most Wind Turbine have an actual efficiency of 35%-45%
Wind turbines extract energy by slowing down the wind. For a wind turbine to be 100% efficient it would need to stop 100% of the wind - but then the rotor would have to be a solid disk and it would not turn and no kinetic energy would be converted. On the other extreme, if you had a wind turbine with just one rotor blade, most of the wind passing through the area swept by the turbine blade would miss the blade completely and so the kinetic energy would be kept by the wind.

5. Pros Renewable resource Fewer greenhouse gas emissions
Cost per kWh: Coal: 4.5 cent; Nuclear 4.6 cent: Wind 7.5 cent

6. Cons Inconsistent power generation
Limited availability of wind resource
Expensive source of energy

7. QUESTIONS?