Energy & Environment · Renewable energy / Principles and inquiry
Wind power and the cube of wind speed experiment guide
Vary wind speed and blade radius to compare power with the Betz limit.
How does it work?
At fixed radius and power coefficient, doubling wind speed multiplies power by eight.
Key relationship
P = ½ρπr²v³Cp · Cp ≤ 16/27
Try this investigation
- Vary wind speed and blade radius to compare power with the Betz limit.
- Run and record each of the three reference settings.
- Change one variable in each comparison and compare its energy results with the baseline.
Interpreting your results
At fixed wind speed, doubling blade radius multiplies power by what factor?
4 · At fixed radius and power coefficient, doubling wind speed multiplies power by eight.
Assumptions and limitations
This rotor model assumes steady uniform wind. Cut-in, rated-power limits, shutdown and generator losses are omitted. Real turbine curves differ.