I wrote about the power coefficient Cp of the Savonius wind turbine.
I stand by it as well as the characterization of the Savonius rotor that I indicated.
You use the expression “generation efficiency”, while I used the expression “power coefficient Cp”, which is not the same. Then you move on to the “capacity factor of conventional wind turbine”. Capacity factor and power coefficient are two different things, even if they can be included in “generation efficiency” in the broad sense.
How does requiring a larger swept area constitute an improvement, knowing that more equipment would need to be used?