Water Recirculation Power Generation Systems

On to global warming:

I had another interesting thought. What about generating limitless hydroelectric power through an encapsulated water system. I can’t draw a diagram at the moment but the idea is for very large tubes (industrial) tapered from top to bottom to let gravity push water through a generator at the bottom under natural pressure with the water falling into a sump. This water is then pumped up to the top again and poured back in.

The system, if it works, could run 24/7 365 days a year producing limitless greenhouse gas free electricity anywhere in the world for next to no cost.