Could you make a dyson fan work backwards as a generator and avoid the blade problem?
Its an interesting idea. You would definitely create an uplift if air was blown through the fan and that could drive a turbine, and that turbine would be experiencing a much higher air speed, so you might be able to avoid the mechanical gearing. You'd have less moving parts, but probably lower efficiency.
You could also combine the fans with ducting and use a single generator. Ducting also has significant losses when compared with wiring, but if the generator is your biggest expense maybe its worth it?