Gravitational Vortex Power is Renewable Energy

Why is the focus for renewables only on solar and wind, why is the discussion not gravitating toward (no pun intended) Gravitational Vortex Power. 

A three foot water drop and one cubic meter per second constant flow you can get 57 MW out of a single unit that does not dam the water, just spins it for a few seconds to push blades and releases downward. Rethink Renewable