This is the publication I was looking for, and which could explain one of the reasons why inflatable blades are not used for wind turbines, as are inflatable wings for airplanes with some exceptions. The explanations are logical and easily understandable, and give a negative view to the whole topic.
From Abstract:
As the flow speed is increased the aerofoil deforms significantly around its trailing edge, resulting in a negative camber and a loss of lift. The loss of lift is ameliorated by increasing the inflation pressure but at the expense of an increase in drag as the aerofoil bulges into a less aerodynamic shape.
Page 11 (and figures 3 and 4):
This loss in lift remains relatively small for low flow speeds U∞, while for U∞ > 10 a more severe loss of lift occurs, with the aerofoil achieving less than half of the lift of the corresponding rigid aerofoil.
While this value is relatively high for a simple elastic material, the stiffness is increased for aerofoils constructed with composite materials [3] or inflatable panels [7].
That said, the problem of deformation would tend to decrease as the profile size increases. We can assume that for considerable dimensions, and with a relatively low tip speed ratio (TSR), the deformation would be limited, and the efficiency closer to that of an equivalent rigid profile.