Would this work to get free energy....?

Question

...was thinking of a 'gravity harvester', if you dropped water far enough into a hole then at some point you would 'harvest' enough potential energy through hydro-electric means to convert that same water into hydrogen and oxygen. This hydrogen could then naturally rise back to the top through displacement to be converted back into water to start the cycle again. The conversion would be your free energy. Although in reality I'm wanting somebody to point out the flaw in the idea as it must be complete balls or we would be doing it.

...was thinking of a 'gravity harvester', if you dropped water far enough into a hole then at some point you would 'harvest' enough potential energy through hydro-electric means to convert that same water into hydrogen and oxygen. This hydrogen could then naturally rise back to the top through displacement to be converted back into water to start the cycle again. The conversion would be your free energy. Although in reality I'm wanting somebody to point out the flaw in the idea as it must be complete balls or we would be doing it.

Add.
The depth of the required hole is something i'm hoping a smart person out there will calulate

I know you're right in saying 'there's no such thing as a free lunch' and I posted the question only so someone would point out the flaw that i can't see but your answer hasn't explained that fully. If Hydrogen is lighter than everything else then would it not rise without the input of energy because other elements displaces it. Is that not the 'free' energy?

Congratulations to the person who has figured out it would take a hole to the centre of the earth for exposing the practical failures of the system, as it stands I will award the best answer to that person. Some of the other answers miss the point, yes you can use hydroelectric but you have to have a water source (dependent on rain) and be prepared to disrupt natural river flows. What I was proposing was a closed system that could in theory but put anywhere and left to run. To the most recent posting I’d like to point out that the ‘free’ energy is obtained when the hydrogen is recombined back at the top of the system into water in a fuel cell, I thought that was obvious? However if somebody can point out the theoretical failures that explain why, even if put on a really big planet, in a really big hole, this does not work I will give them the best answer. Good luck.

Answer 1

Okay, so you dig your huge hole to the centre of the earth and pour water down it. I assume the water then turns a turbine, which produces the electricity to split your water molecules. Maybe you could even make your hole slightly deeper than you've calculated, to get more energy necessary in order to overcome energy losses in this system, right? And the deeper you make this hole, the more energy you can make with your water - for free! Good luck with that infinite hole...

However, there are some problems nobody seems to have mentioned. Like, what's in your hole? Air? This causes resistance so your water will have a terminal velocity, thus there is a maximum amount of energy you can get out at the bottom. A vacuum? Then you have the added energy expense of keeping your hole evacuated. Plus, how do you get your hydrogen out? Yes, it rises above other gases, but if you're in a vacuum this won't work - you'll have to use yet more energy to pump it to the surface. You have to keep the hydrogen apart from the oxygen, or the slightest thing will cause a huge explosion, until you can recombine them safely at the top of your hole, so maybe you fill it with a heavy inert gas, that both oxygen and hydrogen will rise above, but you'll have your work cut out to find enough of it! Then, you must be converting energy somewhere as your gases rise back up to the top - it's being converted into heat, and either pressure is building in your hole, or your inert gas is becoming less dense - still sure your hydrogen and oxygen will rise?

Perpetual motion machines simply do not work! You have to think about energy losses at every stage of the process, and the energy losses of the ideas you come up with to prevent them - you'll always find the numbers won't add up!

Answer 2

Based on information in the source plus the fact that potential energy is mass * height * acceleration of gravity (pe=mgh), I calculate you would need a hole at least 1,345 kilometers deep. That is over 800 miles. That is, the potential energy of one mole of water (18 grams) 1,374 kilometers up is the same as the electrical energy required to split one mole of water into hydrogen and oxygen. I made all sorts of simplifying assumptions, like gravity is constant over the distance, 100% efficient processes and so on. In reality, you would probably need a hole deeper than the distance to the center of the Earth.

And of course as others have pointed out, there is no free lunch. The energy would have to come from somewhere. It doesn't come from gravity because the force of gravity isn't getting smaller as you run the process. Just because I can't say where it would come from is no reason to think you have found a way to violate conservation of energy.

Answer 3

I like it, you could use math to see if this will work, calculating how far the water must fall, how much electricity you could generate from that fall using hydro -electric means. It is of course possible to do this, I have also had ideas along this line of thinking. My idea is to harvest the energy in weight and gravity. (short description I know, but I am still working on it, good luck.

Update: Upon calculating your answer to how deep the hole must be I also had to calculated the diameter of the hole also. As Follows:

The diameter of the hole would be 1.3 miles across, and the depth would be 8,000 feet deep. At this point you could hypothetically do this.

Answer 4

Like there ain't no such thing as a free lunch, there ain't no such thing as free energy. Throughout your posit, you are overlooking energy losses due to friction, heat, drag, etc.

Each and every time, in your scheme, you convert one form of energy (water fall) to another (chemical...the H and O from water), you lose useful energy to entropy. Thus, you need to replace those losses with useful energy (enthalpy) to keep your cycle going. And that replaced energy is not free.

I'll give you a quick example if energy conversion inefficiencies. Your H and O bubbling up, for example, takes work, which is just another name for energy. The work force function is W = Fd; where, in the bubbling up case, F is the force of buoyancy to lift those bubbles to the surface. That work (W) is lost to any further work or useful energy; so, to keep your cycle going, it has to be replaced by outside energy.

And that, inefficiencies (the no free lunch), is the fatal flaw in your free energy concept.

PS: Even a closed system (and I dare you to find a true closed system) would eventually run down. Why? Because its enthalpic energy would convert to entropic energy. And once it becomes entropic, it is useless for work. There's still no free lunch.

Answer 5

Well done, you've made a perpetual motion machine.

However its impossible due to the most fundamental laws of physics - thermodynamics. which is a guide to the movement of heat (thats what thermodynamics means).

The main problem here is that converting water in to hydrogen and oxygen separately would use up much more energy than you'd get from pouring them down the hole. In fact - think about rockets - they burn oxygen with hydrogen - think about the power that comes out, and yet you're left with water - to get water back in to the two gases you have to provide all that energy right back!

I recommend a book called 'voodoo science' which in large part talks about perpetual motion machines.

Answer 6

The other flaw I see is this-- you could either build some complicated apparatus using high voltages, deep holes, and explosive gases, or you could just use the heat of the sun to evaporate water, let it fall as rain, and use the energy of that rain running through a big dam to produce energy. It's needlessly complicated. It uses multiple steps to do what is already done in one-- water runs through dam, turns turbine, people are happy.

Answer 7

Sadly, no, it's not going to work. The conversion from kinetic to electrical energy can't be 100% efficient, so you'll never turn all the water into hydrogen and oxygen. You'll end up with a very deep puddle!

Answer 8

P.E of water - to -
Electrical energy - to-
Production of hydrogen and oxygen - to -
P.E of water.
Cycle is completed. Confirms conservation of energy.

But in this cycle nowhere out put work is extracted for useful work.

Once you take even small amount of energy for out side work the cycle will not work.

But nature is doing the above work, evaporation of water- rain and evaporation of water.

The work energy we harness from the cycle is made good by Sun.

Actual process of life in this earth, or the method of getting energy is what you have said.

WE get electrical energy using hydro static power.

Now if we use all such electrical energy to convert water to hydrogen and oxygen to get the same amount of water, how to get energy for our day to day life?

Answer 9

they kind of already do it... but it isn't free... hydro electric energy is produced when water passes through a dam and as it does it turns a turbine which turns a rotor or field inside of an armature or generator stator. as the magnetic lines of flux produced by the rotor pass across the copper coils in the armature electricity is produced. The electricity is the sold into the grid. some of the produced electricity is used to power large pumps that pump water back up into the upper reservoir to be reused.

Answer 10

Given its high volatility, hydrogen gas would make for a very dangerous system. Also I'm wondering if the conversion processes themselves would offset any financial gain realized by the overall system.