University of East Anglia are researching storing gas underwater as an energy dense cheap energy storage means....
They have however not mentioned how they would get the gas there in the first place... pumping gas underwater is very expensive.
Electrolysis of water is more efficient at pressure.
Why not generate Hydrogen and Oxygen deep underwater so that they are at industrial application pressures when you pipe them to the surface?
Hmmm. For processes that best function at inhuman conditions, there ARE inhhuman environments available on Earth.
The question is whether the complications arising from operating a remote plant in a corrosive environment that must be maintained by robots (remember the BP spill?) is less or more expensive than steel pressure vessels on land.
I think I know the answer, but it is still possible. The gas storage application could be MUCH simpler to implement; a hose and a balloon might be all one needed.
Deep water is easy to find close to land, Or even make. so the effects of tides, waves, wind can be largely controlled for this application... if need be.
There was a whole load of thick plastic pipe washed up on the shore here last year... (I ran some through my loft for future ducting) but yes, That and a strong bag are two main components.. I have some sketches on sites.google.com/site/kitepowerresearch/