Wind energy is one of the more efficient alternatives to fossil fuel energy. Wind power gives a significant Return On Investment (ROI) since it’s free energy that also has an endless renewable power source. 59% efficiency is the BEST a conventional wind turbine can do in extracting power from the wind.
Wind Power depends on:
• amount of air (volume)
• speed of air (velocity)
• mass of air (density)
flowing through the area of interest (flux)
Kinetic Energy definition:
- KE = ½ * m * v 2
Power is KE per unit time:
Fluid mechanics gives mass flow rate
(density * volume flux):
- dm/dt = ρ* A * v
Thus:
P = ½ * ρ * A * v 3
Betz Limit & Power Coefficient:
- Power Coefficient, Cp, is the ratio of power extracted by the turbine to the total contained in the wind resource Cp = PT/PW
- Turbine power output
- PT = ½ * ρ * A * v 3 * Cp
- The Betz Limit is the maximal possible Cp = 16/27
- 59% efficiency is the BEST a conventional wind turbine can do inextracting power from the wind
