Its difficult and non-intuitive to imagine a wind turbine without blades but Vortex Blades. a Spanish company, has gone ahead and proved it possible. It does not work on the conventional notion of the blades rotating and converting the kinetic energy of the wind into electrical energy. Instead it uses the principle of vorticity to oscillate and generate electricity in the process. If this were to become commercially available, then I guess a wind farm would look like a field of vibrating tubes sticking out of the ground! To read more check out https://www.wired.com/2015/05/future-wind-turbines-no-blades/.