Harnessing energy from gravity

In summary: It's really frustrating when I can't understand what's being said because you are not outputting anything. Just summarize the content.
  • #1
Erazman
66
0
Theres already methods of harnessing energy from gravity (like from the flow of water), but not in very massive amounts. What if we drilled a very deep hole into the ocean (down to the extremely hot farthest reaches of the crust where water will evaporate easily) and set up a generator at the bottom? Have a massive pipe connected from the ocean water to the bottom of the pit. The hole won't fill up with water if ventilate the steam to the air above the ocean (driven by the difference in pressure). Mineral Insulated cables could be run down to the generator. I'm talking extremely hot conditions here to allow the massive amount of water flow to evaporate ASAP.. we would actually be using the Earth's heat as a driving force to return the water...

Law of Convservation remains unbroken.. because the steam that rises back up the hole has lost its potential energy from the deep pressures of the ocean and the gravity of the hole... and has given it to us.

There's already a thread on here that talks about harnessing energy from the bottom of the ocean, but not from BENEATH the bottom of the ocean.
 
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  • #2
Sounds pretty good to me. The main problem is drilling the hole and setting up a generator miles under the ocean floor.
 
  • #3
Originally posted by russ_watters
Sounds pretty good to me. The main problem is drilling the hole and setting up a generator miles under the ocean floor.

okay, now putting aside the problems that come with it (such as disturbing ocean life, the costs of deep ocean floor drilling, etc), can we figure out, theoretically, how much KW/hr we could produce?

Variables:

crust beneath the ocean: 6.5 miles
(lets set it up short of 6 miles) = 30,000 FEET
That should give us plenty of heat to evaporate the water reservoir fast enough so our operation doesn't flood.

Ocean depth of 15,000 feet
(a TREMENDOUS amount of downward pressure)

10 ft diameter pipe (wide open) blasting a large turbine.

Assuming the generator/pipes can withstand this force, and won't overheat.. how much power could we harness?
 
  • #4
Ultimately, the peak power you can get depends on the flow rate you have.

Since this is a heat engine, you can approximate the peak efficiency at [tex]1-\frac{T_{min}}{T_{max}}[/tex]
Let's say that the temperature of the lava is 10000 degress Kelvin, and the temperature of the water is about 300 degress kelvin, so the peak efficiency is quite high.

Now, assuming that water has a specific heat of four joules per degree per gram, we can figure that you'll get about 39000 joules of work per gram of water at peak efficiency. That translates to a peak power of roughly 40 gigawatts per ton of water per second.

Since water has a specific density of 1 ton per cubic meter, that's a lot of energy even with a relatively small pipe.

Of course, thermodynamic efficiency is not likely to break 10%, so you're looking at a much smaller amount of power.

On the other hand, the technical challenges associated with actually creating and maintaining that kind of pipeline are very hard.

Geothermal power systems on the Megawatt scale are in use at several locations. You can google for more information.

Effectively, the peak power is equal to the peak heat transportation.
 
  • #5
Emmmm. Hmmm!

Let's say we drilled a whole under the north and south pole, and revealed the Earth's core; a water stream toroid would form around the hole, since the high speach of gravity drags the water to the pole, and the hot water bursts out of the hole like a geiser. If you managed to tame the energy, you would perhaps gain a bit from doing this! besides, the poles magnetic fields would also become stronger, and its differing position could perhaps be used as an energysource etcetera.
 
  • #6
There might be an easier way, if the aether theorists are right and gravity propogates through the aether medium like sound through air then an aether vacuum might work better, gravity could supposedly be switched on and off like a light switch, but experimenting with it I haven't tried, somehow magnetism would be needed to pump out the negative and positive aether in a chamber that was designed to make a barrier to both positive and negative aether. If you strongly doubt Tesla's aether theories take a look at tesla lines and ask yourself what a superimposed + and - foam would act like near a magnet?
 
  • #7
You do know that aether doesn't exist?
 
  • #8
If there were magnetic ether particles you could make a pretty advanced telescope.
I'm sure you could create ether fusion, though the fact that you cannot use ether as a battery, since the particles to small might and perhaps already have lead to other conclusions.
 
  • #9
Sariaht and jammieg,

Please keep your posts about non-mainstream science out of the general forums. They are welcome only in the Theory Development forum.

- Warren
 
  • #10
I gues s this is the same sort of thing as geothermal power plants except being at the bottom of a ocean is closeer to the Earth's core thus more heat, I hav always thought this kind of energy transfer could be profitable compared to say deep drilled oil wells in the ocean, don't really know much about it, btw: for the post about aether look up michleson - morley experiments in google, mind u that was a long time ago.
 
  • #11
As the steam rose up your pipe vent it would cool and recondense and fall back into the pipe filling it up with water, clogging the system. The water entering the system would cool the lava rock and would stop the system unless you were continually drilling or scraping off the crust.
 
  • #12
Erazman said:
okay, now putting aside the problems that come with it (such as disturbing ocean life, the costs of deep ocean floor drilling, etc), can we figure out, theoretically, how much KW/hr we could produce?

Variables:

crust beneath the ocean: 6.5 miles
(lets set it up short of 6 miles) = 30,000 FEET
That should give us plenty of heat to evaporate the water reservoir fast enough so our operation doesn't flood.

Ocean depth of 15,000 feet
(a TREMENDOUS amount of downward pressure)

10 ft diameter pipe (wide open) blasting a large turbine.

Assuming the generator/pipes can withstand this force, and won't overheat.. how much power could we harness?


youre going to want something A LOT bigger than 10 foot. As in a 50 foot diameter pump.
 
  • #13
sheldon said:
As the steam rose up your pipe vent it would cool and recondense and fall back into the pipe filling it up with water, clogging the system. The water entering the system would cool the lava rock and would stop the system unless you were continually drilling or scraping off the crust.

Itll only cool if it hits something cooler. I suspect the steam would be going very, very fast under all the pressure so in an insulated system (esp surrounded by much much hotter rock) it not only won't have time to cool off, it won't have anywhere to cool off to

the advantage to that is you won't drain the ocean, as soon as it blasts to the surface, itll condense very quickly :p
 
  • #14
why not simply make a machine above the surface, weighted with magenets so it rotates?
 
  • #15
Atrius said:
why not simply make a machine above the surface, weighted with magenets so it rotates?
Weighted with magnets? What would that do? Could you elaborate?
 
  • #16
i think he's thinking a wheel basically.. with like tank track treds all around it. each side of the treds would have an opposing charge. basically the same idea as that little solar glass thingy with the white n black sided diamonds. except instead of dark n light it would be + & -. and instead of solar energy it would be magnetism.
 
  • #17
One problem is just as with existing geothermal plants, your hot water cools the underneath hot rock or lava so after a while power output decreases and you would need it to regenerate a couple of years. Drilling holes in the ocean floor is also not exactly the cheapest and easiest thing.
 
  • #18
Addressing the problem of cooling steam.

There is no problem. All of the various steam driven power plants in use today utilize a closed system. As the steam leaves the turbine it goes through cooling coils surrounded by water pumped from a nearby river or lake. Once it is cooled it is pumped back into the boiler tubes. This is possible, and doesn't use up all of the energy gained, because, though the pressure is just as high at this end as at the turbine end, the volume to be introduced is much lower than the volume escaping. (This is the reason a jet engine even works.) The steam generated at the bottom of the system can be cooled VERY effieciently by the water at the ocean floor (which is actualy closer to 275 degrees k), and allowed to simply fall back down to the boiler. For best efficiency, however, the generator needs so be as close to the heat source as possible, for obvious reasons.
 
  • #19
Can of worms?

Am I missing something here? Assuming that the prodigious engineering feat of drilling, temperature and pressure control,etc. can be handled; let's ignore the action of the water above, and consider that of the magma when it suddenly finds a hole above it. It sounds like instant volcano to me. Why not consider something infinitely simpler (but still not easy), like pressure capping Kilauea (while somehow still allowing the lava to escape) and pumping water up into it's bowl. This will be an incredibly difficult and expensive project, but still a lot easier and cheaper than the sea floor exercise.
 
  • #20
May I remind the readers of this post, that in France and Germany, artificial thermal energy pits are already being tested? They're just very deep holes through which water is pumped, which gets heated and then travels back up. One in France (500 metres deep) created half a megawatt continuously. In Germany they're building several of around 2000 metres deep.

So this idea is a bit baked.

You don't need to go offshore for this. Just drill a hole onshore, and divert water into it. That's all you need.
 
Last edited:
  • #21
shonagon53 said:
You don't need to go offshore for this. Just drill a hole onshore, and divert water into it. That's all you need.
Well, that and a geothermal source.
 
  • #22
russ_watters said:
Well, that and a geothermal source.

We have one. It's called the Yellowstone Caldera, and I wouldn't touch it! It's potentially the largest supervolcano in the world, and it's probably due to erupt on its own. If so, we're all toast. Maybe this is an opportunity we should just sit out.
 
  • #23
Drilling holes like the 30k feet desribed earlier is impossible.
And will remain to be for quite a long time.
If only because you can't spin a pipe 30k foot long, it wouldn't hold out.
Appart from the fact that ould you get close you'll start warming up you bit it would get to weak to keep chewing ground.

This completely besides tha fact that its damn near impossible to drill at 15k feet depth.

Just keep it onland, then it'll work.
Drilling that deep ill never work.
But cool idea.
 
  • #24
Kenneth Mann said:
Am I missing something here? Assuming that the prodigious engineering feat of drilling, temperature and pressure control,etc. can be handled; let's ignore the action of the water above, and consider that of the magma when it suddenly finds a hole above it. It sounds like instant volcano to me. Why not consider something infinitely simpler (but still not easy), like pressure capping Kilauea (while somehow still allowing the lava to escape) and pumping water up into it's bowl. This will be an incredibly difficult and expensive project, but still a lot easier and cheaper than the sea floor exercise.

What you could probably do is pump tons and tons of water into the bowl of a volcano, and just let it boil off. A localized weather pattern should be created by the evaporation/condensation cycle. Once that weather pattern is established, you oughta be able to surround the cone with a mess of wind-powered electric generators. Yes?
 
  • #25
Hmmm, ok.
Assuming this works.
Pumping in tons of water into a vulcano (generally an elevated object in relation to sealevel) would take so much power that your "generator" wouldn't become profitable (in supplied energy) for years, if ever.
Besides, putting up a lot of wind generators on a surface that has volcanic activity?
Even if it doesn't errupt it will still probably be subject to minor quakes, not a really stable ground.

And i seriously doubt the fact that it would work.
It probably would be easier to create a dome over the lower part of the bowl and using the steam created, thus in fact making a giant steam engine.

2 problems:
#1 the shear size of the project in $$
#2 a biatch of a place to do construction work.
If it can boil water, it certainly will be the toughest place to work for construction workers ever.

In other words, no go either.

The french and german solutions will prove the better ones in this type of powergeneration.
 
  • #26
Tether system

There is an article in scientific american about using Earth's, or any other planets gravity to generate electricity. Its the august 2004 issuet called "fly by wire", it proposes a terther system which build electricity in the tether that connects two objects in space (satelites) .

This isn't thermodinamics+gravity... but it's a way...

Question, is there a way to transmit electricity from space to earth? i alsways wondered about wireless electricity transmission... ( i think lightning are not an option tho' ;)
 
  • #27
siliconhype,

Sure, you could use a microwave beam to trasmit the energy. Just make sure the pointing apparatus is fail-safe, or the beam could become a major hazard.

- Warren
 
  • #28
As to the space tether, let's call O the planet, and ---T the tether.

If it looks like: O----T

so long as the tether itself is a conductor, which is grounded on earth, it shouldn't be any trouble to just use conventional methods to collect the energy.


As to the hole in the ground generator, I've got a few thoughts.

For one, can we dig down deep enough to boil water, without exposing lava? If you dug two shafts, one a drop point for the water, which turned generators via the water falling towards the Earth's core, and at the bottom the water was heated into steam, which returned up the second tube.

Could you not also turn turbines on the escape tube via the steam? As was mentioned, the hot environment would not allow it to condense back into water, so you could get a double effect.

I guess you could test this with two hoses and a glass or metal container. Hose A would be the water input, and turns a generator before it falls into the container. Hose B would be a steam vent for the boiled water. The container would be completely sealed, aside from the two hoses. The steam shouldn't be able to escape through hose a because of the constant input of water.

The only challenges I see to setting this up would be ensuring you are boiling off the water quicker then it is building up.
 
  • #29
The Scientific American article on tethered satellites

siliconhype said:
There is an article in scientific american about using Earth's, or any other planets gravity to generate electricity. Its the august 2004 issuet called "fly by wire", it proposes a terther system which build electricity in the tether that connects two objects in space (satelites) .

Question, is there a way to transmit electricity from space to earth?
Gravity is a static force. Neither energy nor power can be generated from it. The Scientific American article admits as much:


  • Of course, conservation of energy demands that there is no "free lunch." For instance, power is generated only at the expense of the satellite's altitude, which was originally achieved by expending energy in rocket engines. So it may seem at first glance as if EDTs merely exchange one kind of energy for another in a rather pointless exercise. In drawing power from the tether, the satellite would descend and require reboosting... So why bother? The answer is that the tether system is potentially more efficient...
(Electrodynamic Tethers in Space, By: Lorenzini, Enrico, Sanmartín, Juan, Scientific American, 00368733, Aug2004, Vol. 291, Issue 2)
 
  • #30
Hydro-electric plants get power from gravity all the time!

To answer the original question, there is no practical way to "transmit" energy. There is some theory about transmitting energy by micro-waves but with any large amount, you run into problems with the atmosphere disrupting it. There are also those who point to serious problems if an antenna transmitting large amounts of energy gets pointed slightly wrong! (Where is all that energy going to go if the transmitting wave hits your house instead of a receiver?)
 
  • #31
In the game "sid meir's alpha centauri" one can play with what they call "bore holes" and play with geothermal energy in this way. These are holes that go down to where the rock is hot and produce power in this way much like what people are talking about here.
 
  • #32
There a e already methods of harnessing energy from gravity (like from the flow of water), but not in very massive amounts. What if we drilled a very deep hole into the ocean (down to the extremely hot farthest reaches of the crust where water will evaporate easily) and set up a generator at the bottom?

cinci: Some of the heat at the center of the Earth was caused by gravity, but that would have cooled long ago. The heat we get now is primarily from decay of radioactive materials.

Have a massive pipe connected from the ocean water to the bottom of the pit. The hole won't fill up with water if ventilate the steam to the air above the ocean (driven by the difference in pressure). Mineral Insulated cables could be run down to the generator. I'm talking extremely hot conditions here to allow the massive amount of water flow to evaporate ASAP.. we would actually be using the Earth's heat as a driving force to return the water...

Law of Convservation remains unbroken.. because the steam that rises back up the hole has lost its potential energy from the deep pressures of the ocean and the gravity of the hole... and has given it to us.

There's already a thread on here that talks about harnessing energy from the bottom of the ocean, but not from BENEATH the bottom of the ocean.

cinci: Harnessing the tides is possible. They are gravity driven.
 
  • #33
HallsofIvy said:
Hydro-electric plants get power from gravity all the time!



Sorry to bring back an old post, but no they do not get the power from gravity. They get the power from the Sun, which brought the water up to a higher level than previously.
 
  • #34
physical1 said:
Sorry to bring back an old post, but no they do not get the power from gravity. They get the power from the Sun, which brought the water up to a higher level than previously.

Er... what?
 
  • #35
xxChrisxx said:
Er... what?

The Sun converts nuclear bonds into energy through nuclear fusion. The energy then travels to Earth where some of it warms water and causes it to evaporate. The warmed water vapor rises and gains gravitational potential energy. Eventually the water falls as rain and ends up at a higher elevation than it was at the start. As the water flows downstream to a lower elevation we force it to turn turbines to capture some of its energy.

Thus, the energy we get in hydroelectric plants comes from nuclear fusion in the Sun. Energy is conserved, at no point is it created or destroyed. Energy never comes from gravity, it is a force not a source of energy.
 
<h2>1. How does harnessing energy from gravity work?</h2><p>Harnessing energy from gravity involves using the force of gravity to generate power. This can be done in various ways, such as using water flow to turn turbines, using weights or pendulums to create motion, or using the gravitational pull of celestial bodies to generate electricity.</p><h2>2. What are the benefits of harnessing energy from gravity?</h2><p>Harnessing energy from gravity is a renewable and sustainable source of energy. It does not produce harmful emissions and does not deplete natural resources. It also has the potential to provide a constant and reliable source of energy, as gravity is always present.</p><h2>3. What are the limitations of harnessing energy from gravity?</h2><p>One limitation of harnessing energy from gravity is that it requires specific geographical conditions, such as access to flowing water or steep hillsides. It also requires significant infrastructure and technology, which can be expensive to implement. Additionally, the amount of energy that can be harnessed from gravity is limited by the force of gravity itself.</p><h2>4. How is harnessing energy from gravity being used currently?</h2><p>Currently, harnessing energy from gravity is primarily used in hydropower plants, where the force of falling water is used to turn turbines and generate electricity. It is also being explored in other forms, such as using tidal energy or gravitational potential energy from weights.</p><h2>5. What are the potential future developments in harnessing energy from gravity?</h2><p>There is ongoing research and development in harnessing energy from gravity, with the goal of making it more efficient and accessible. Some potential developments include using new materials and technologies to improve the efficiency of turbines and exploring new methods of harnessing energy from gravity, such as using the Earth's rotation or harnessing the gravitational pull between two objects in space.</p>

1. How does harnessing energy from gravity work?

Harnessing energy from gravity involves using the force of gravity to generate power. This can be done in various ways, such as using water flow to turn turbines, using weights or pendulums to create motion, or using the gravitational pull of celestial bodies to generate electricity.

2. What are the benefits of harnessing energy from gravity?

Harnessing energy from gravity is a renewable and sustainable source of energy. It does not produce harmful emissions and does not deplete natural resources. It also has the potential to provide a constant and reliable source of energy, as gravity is always present.

3. What are the limitations of harnessing energy from gravity?

One limitation of harnessing energy from gravity is that it requires specific geographical conditions, such as access to flowing water or steep hillsides. It also requires significant infrastructure and technology, which can be expensive to implement. Additionally, the amount of energy that can be harnessed from gravity is limited by the force of gravity itself.

4. How is harnessing energy from gravity being used currently?

Currently, harnessing energy from gravity is primarily used in hydropower plants, where the force of falling water is used to turn turbines and generate electricity. It is also being explored in other forms, such as using tidal energy or gravitational potential energy from weights.

5. What are the potential future developments in harnessing energy from gravity?

There is ongoing research and development in harnessing energy from gravity, with the goal of making it more efficient and accessible. Some potential developments include using new materials and technologies to improve the efficiency of turbines and exploring new methods of harnessing energy from gravity, such as using the Earth's rotation or harnessing the gravitational pull between two objects in space.

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