It's motionless in the sense that it doesn't rotate like traditional turbines or vertical axis turbines. The structure vibrates and somehow they capture the energy from it. Kinda like comparing a circular saw to an oscillating saw but for generating power.

Ok NVM I went and read the article (shame on me) and there is a turbine it's just hidden from the surface.

I thought this was a different type that does exactly what my explanation was suggesting.

Here is what I thought we were talking about: https://vortexbladeless.com/technology/