river current brainstorm

[trevorjohnson83]

without using water wheels, how could you gain energy from the flow of a river?

its so very hard because something has to flow with the water and be drawn back to its original position, If you are trying to use the sheer torque of the current flow its similar to trying to gain the energy of a rock on a spring, but at the same time the two are different. I would mention surface area as a resistance that can be altered to gain energy....