Hang weights from reels, underneath, for energy storage: reel them out to generate, reel them back up to store excess for later. Gang dozens of reels on each motor/generator, for economy. (Using just one reel per motor/generator is what makes mineshaft energy storage uneconomical.) Make the weights out of peridotite rock, which is very cheap and 60% denser than most.
Certain places are better for this than others. Offshore of Rhodes, eastern South Korea, Monaco, the Philippines have very deep water not far off shore.
Certain places are better for this than others. Offshore of Rhodes, eastern South Korea, Monaco, the Philippines have very deep water not far off shore.