I would like to put the following idea into the public domain in the hopes that someone can improve upon it or use it. I have found one recent patent which covers the underlying primary concept (so I guess I was not the first to think of it and thus have no hope of making money off of it, but I DO feel that I have improved on the original concept significantly) but I want the world to have the benefit of it. Not surprising someone has thought of it as it is a fairly simple concept. It may not be free energy per se, but even if it steps up the efficiency of the system it would be worthwhile.

  While watching a show on TV one evening about generating Hydrogen gas for use in future upcoming hydrogen powered cars, it suddenly dawned upon me, why not put that gas to some other use in the process... like by generating some or ALL of the electricity used to make it. The idea is simply this. When hydrogen is generated via electrolysis, it rises in the water. Why not put that buoyancy effect to work by lifting a lever attached to an inverted scoop which in turn is connected to a turbine? There used to be a child's toy in the 60's containing water and a series of staggered inverted scoops. You would push a button to generate bubbles and they would rise, raising the scoops alternately with them and passing the scoop-full of bubbles on to the next scoop which in turn rises as the last one drops back for more. Of course you catch the hydrogen near the surface after it has done the work. So we gain a little extra energy and recycle it. But here is the beautiful part. I see no reason it should not be HIGHLY scale-able. In other words, put the electrolysis, say a mile or more under the ocean (saltwater already a free electrolyte) and have the rising bubbles buoy nearly any number of scoops all the way to the surface generating more and more electricity all along the way, theoretically generating enough electricity to entirely run the electrolysis or more. Physics says electrolysis under pressure is more efficient and in this manner we can also save some energy by collecting the H2 under pressure before it reaches the surface, thus not having to compress it as much. One reason I think it would work is because it costs us nothing (cable resistance?) to "pump" the electricity a mile under the ocean, but we generate a lot of buoyancy force in return which can be used over and over until it reaches the surface.

  I welcome comments and criticisms from the learned out there. Please point out anything I am missing. And if it works and solves all our energy problems, I just want my name mentioned on it (unless you make billions, then I want a tiny percent :-) ).

  Yes, this appears to be a common misconception, of unknown origin. And YES, my calculations confirm that if you are talking about HOH gas non-boyancy would likely be a real problem at any significat depth since the molal weight (2 Hydrogen and 1 Oxygen) would be the same as for water. However the design (perhaps not made clear in the original description - my apology) was for generating Hydrogen gas, not HOH. Therefore, the H2 and O would be released up separate "stacks" using  DC current and thus would each have a MUCH lower molal weight than the surrounding water and thus retain significant buoyancy to well over 1 mile (per my calculations posted on another similar website, but which I will repost here if desired).
  Fans do not capture the buoyancy factor in this scenario nearly as well as levered scoops and based on my calculations would probably be at best 10% as efficient as scoops. Think overturned row boats or grain scoops.

I'm pretty sure Tesla has talked about a similar process of performing electrolysis at the bottom of a lake and using the buoyancy of the gas to produce electricity to close the loop, just can't find the paper.

The problem with such ideas is that not everyone has a sea, lake or a huge water column in their backyard.