I have some experience with SketchUp Pro. I'd say it's the easiest 3D modeling software available but I think the best use out of it may just be the ability to import several types of 3D models of fan blades that could be available from open sourced turbine projects or even literature research often provides some 3D CAD files for public use. But to do any type of simulation for optimization based on your own local wind conditions and analysis I'd try to use some other simulation software because some of the Sketchup plug ins to try to do any physics simulations are really buggy and crash all the time.