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Rotor diameter - 270mm Height - 456mm
Rotor type - 3-Blade savonious
Blade material - Aluminium
Rated output - 10 W at 12 m/s (26 mph)
A quick calculation: area is 0.123 m², air density is assumed to be 1.2.
1/2 x 1.2 x 0.123 x 12³ = 127 W.
The rated output is specified at 10 W.
So the Cp (power coefficient) is only 0.0787, less than 0.1. It is not too much.
Another model on
In technical specifications:
- Rotor diameter: 270mm
- Rotor height: 918mm
- Rotor type: 3-Blade Savonious
- Blade material: Stainless Steel
- Rated output: 24W at 8m/s (17.8mph)
Area 0.248 m².
1/2 x 1.2 x 0.248 x 8³ = 76 W.
The Cp (power coefficient) is 0.315, which is a good value, comparable to that of very good VAWT Darrieus-type.
And yet these two turbines seem to be of the same brand, the second being higher.
And as Savonius turbines are known to be very good in very strong winds (see the curve of the 1st model), if we have a Cp of 0.3, then this can be an AWE option (with rope drive transmission), using for example shapewave® technology to ensure better rigidity ([hence efficiency] as well as lightness.
Lift by Magnus effect when the Savonius rotor is horizontal, flying like a rotating kite:
