Bwuh? The details are the interesting bit.
Come on people. It’s so simple! Forget the windmills. We are going to be generating the electricity from the Generator at the bottom of the water pipe or chain. Yeah, we’ll have to get this thing started, but we could use a car battery for that :).
The power comes from the billions of tons of oxygen that’s up high, that we’re now going to bring downward. Nature carries this oxygen back up using winds and what not. (Who cares?)
We let the hydrogen float up in an **open **pipe or balloon and it costs us nothing. Who’s to say this pipe should be closed? Why? We just leave it open and let our hydrogen drift into it at the bottom. This will create a draft. Wonderful.
We then burn it to get power. We then drop the water to get power. Some power is used to get new hydrogen and the rest is Happy Power. Plus, we have superclean Happy Water.
And it is powered by nature, who supplies us with billions of tons of oxygen to drop from however high we can get our installation. There’s no limit, and all we need is a couple of pipes and 3 installations: Electrolysis, H2 burn generator and H2O flow/pressure generator.
The billions of tons of oxygen over a large gravitational potential should be able to overcome the minor problem of inefficiency. Even if we were only to break even, we’d still get lot’s of Yummy Happy Water. And that turns out to be hard to come by…
The good part: We can use gravity and natrure, without having to wait for rainfall, a very limiting factor in hydropower today. We could create as many of these installations as we feel like. But, of course, we do need lots of oxygen, and, even though people have said that this oxygen and it’s depletion would not be present, I believe that this would certainly turn out to be a limiting factor. If you can’t find the oxygen up on the mountain, because of overharvesting, your plant will stop (or slow down).
All in all, a fabulous idea. Who’s ready to get a grant?
The more I’ve thought about this, the less concerned I am with the efficiency of the whole thing, and the more curious I am about where the energy comes from in that liquid water.
some relevant values:
hydrogen higher heating value: 141.9 MJ/kg
STP hydrogen density: 0.08988 g/l
STP oxygen density: 1.429 g/l
STP air density: 1.2 g/l
Begin:
Electrolysis
The oceanside windmill electrolyzes 1 kg of water. The result is 0.1111 kg (1.236 m[sup]3[/sup]) of hydrogen, and 0.8889 kg (0.622 m[sup]3[/sup]) of oxygen. In breaking those molecular bonds, the electrolysis process has stored 15.767 MJ in the hydrogen. It has also done 0.1252 MJ of work pushing the atmosphere back to make room for the hydrogen balloon, and 0.063 MJ of work for the oxygen balloon. The balloons are unstretched gas envelopes; no energy is stored in tensile strain of the balloon skin. Assume the electrolysis process is arbitarily efficient; if 100%, then the total energy input from the windmill is 15.955 MJ.
Buoyancy
Now we take our buoyant hydrogen balloon attach it to Mangetout’s balloon-conveyor-belt rig, and let it drive the conveyor as it rises. Assume the conveyor belt has frictionless bearings and moves arbitarily slowly so as to avoid inducing aero drag on the balloon. It was shown earlier that if we let this balloon rise to the top of the atmosphere it will do 0.1252 MJ of mechanical work on the conveyor; by 4000 meters altitude we can recover 40% of the energy we put into making that balloon of hydrogen. In this particular scenario, we will let our hydrogen balloon float up to an altitude of 100,000 meters (the edge of space), by which point our conveyer has recovered 99.4% of the energy, or 0.1244 MJ.
Thermal Power Plant
Up there at our high-altitude power plant, we burn the hydrogen using local air as the oxygen source. In burning the hydrogen, we release 15.767 MJ of thermal energy. Since our plant runs on a steam cycle our conversion of heat to mechanical work is limited to Carnot efficiencies; large power plants can be as efficient as 50%. Again though, this is beside the point: with the waste heat and mechanical work taken together, we have recovered 15.767 MJ of the energy that our windmill provided in the electrolysis step. Since the electrolysis step extracted hydrogen from 1 kg of water, when our power plant burns the hydrogen, we develop 1 kg of steam.
Hydroelectricity
The flue gas is a blend of steam and nitrogen. We run this flue gas through massive heat exchangers, condensing the steam into 1 kg of liquid water. Up at this altitude (100,000 m) the liquid water has a gravitational potential energy of 0.981 MJ. So we take this liquid water and feed it into a pipe that runs back down to a Pelton wheel at sea level, which converts the gravitational potential energy of the water into mechanical work. There’s no theoretical restriction on the efficiency of a Pelton wheel, and in fact large-scale hydro-power Pelton wheels have efficiencies of over 90%. For the sake of this discussion, we can assume our Pelton wheel is 100% efficient; we therefore recover 0.981 MJ of work from the water before dumping it back back into the ocean.
Accounting
In the Electrolysis step, our windmill provided 15.955 MJ.
In the Buoyancy machine, we recovered 0.1244 MJ of mechanical work.
In the Thermal Power Plant, we recovered 15.767 MJ of combined mechanical work and waste heat.
In the Hydroelectricity step, we recovered 0.981 MJ of mechanical work.
The sum of the three recovery terms is 16.87 MJ, which is greater than our windmill input by 0.9174 MJ. This is in spite of simply discarding the 0.063 MJ we invested in producing the oxygen balloon during Electrolysis.
Where is this extra 0.9174 MJ coming from? I’d like to avoid any magical hand-waving; I want to understand the source of the energy and how the energy gets delivered/transported to the liquid water up at the power plant.
Actually electrolysis creates oxygen and burning it makes it back equal - no shortage there. NaOH in brine - is it good?
One source is the gravitational potential of the oxygen, which comes from the sun. The gravitational potential of the oxygen component of the water is 0.872 MJ.
This is a start. But can you explain how it comes from the sun to the oxygen molecules?
In buckets. Think of each little photon as a bucket of energy. There’s more energy that wasn’t accounted for as well. The buoyancy energy isn’t a closed box, it’s an exchange. An equal volume of gas at altitude was exchanged for the gas at sea level. You’ve got to count that as a source.
What if you skip the windmills, electrolisis, and buoyancy machine? Just condense atmospheric water vapor at 100,000 feet. You still get 0.981 MJ of work, pretty close to, and more than enough to account for, your extra energy.
I did explain this.
The process is convection. It carries the Oxygen produced at the bottom, to the burner at the top. Of course, it doesn’t literally carry the same Oxygen from electrolysis to the top of the mountain. It just constantly mixes the atmosphere so that on the whole the Oxygen concentration in the atmosphere does not change. Most of the energy for these currents comes from the sun.
You would need power to operate the condenser.
The OP has suggested it may be possible to recover two (three?) times the the work produced by the windmills. I trust we have shown now that it’s not possible in theory (owing primarily to the Carnot efficiency limit at the combustion power plant), and that we wouldn’t even come close in practice due to:
-inefficient electrolysis
-the need to pump the hydrogen up to the mountains instead of relying on buoyancy
-the combustion power plant operating at something less than the Carnot efficiency limit
-the limited height of the mountains, which restricts the amount of gravitational potential energy available for hydroelectric power generation
-the limited efficiency of hydroelectric generation (Pelton wheel is pretty good, but not perfect, and there is flow friction as you bring the water to the wheel, etc.)
The 50% efficiency at the combustion power plant is a major problem. So is the actual efficiency of electrolysis; we can assume that would probably be about 50%. So for every joule your windmills generate and dump into electrolysis, your power plant would crank out maybe a quarter of a joule; the rest would be discarded as waste heat at the electrolysis plant and at the combustion power plant’s chimney. And the hydroelectric generation - especially from a real 4000 meters instead of a theoretical 100,000 - is small potatoes in the scheme of things here. I haven’t bothered to calculate the power requirement for pumping the hydrogen 200 miles up the pipe into the mountains; that would make things even worse.
If your goal is electrical power, it will cost far less - and deliver far more energy - to just get it straight from a windmill.
Did you consider lighting the gas? Cos’ O2 is up there H2 must go up and so does H20. Don’t calculate - think.
If I’ve learned one thing from my physics classes, it’s that things that I think are possible often aren’t.
Calculating is an essential part of thinking. Without calculation, you’re not thinking, you’re daydreaming at best, or engaging in mental masturbation at worst.
think then calculate to see if you thunk correctly.
There isn’t enough oxygen at 4000 meters to support open combustion.
Could you explain in more detail what you’re proposing?
Sorry about my last comment (I was drunk).
Burning H2 at the top creates drift that can be used to create more energy. If it was an open pipe it would propably collapse because of the forces, but using a valve everything happens peacefully. So we need electricity for electrolysis. We gain energy
- drift (wind turbine)
- burning gas (steam turbine)
- mass of water at 3000 meters (hydroelectricity)
Now, I believe that the system is efficent enough, because there is eight times mass on the top - that is oxygen waiting to react with H2.
I think I see what’s causing all this misunderstanding. The First Law of thermodynamics states that energy cannot be created or destroyed. The sea-level windmills stored wind energy in hydrogen gas; if you burn that hydrogen in/at the top of the pipe and use that energy to create high-velocity jet to power a windmill up there, you are not creating energy. You are simply using the energy that was stored in that hydrogen gas, and after that, the energy will not be available to run the combustion power plant.
One should not drink while brainstorming world-saving ideas; it generally doesn’t turn out well. 
There’s a sig in the making.
I don’t think that’s the problem here - I’m pretty sure the OP is just using ‘create’ as a (misleading) synonym for ‘generate’.
The problem in this discussion is not denial of the laws of thermodynamics, it’s difficulty in seeing exactly how and where they restrict the theoretical operation of this complex, yet sketchy system.