I'll show you where to get the energy- you show me how.

[APPLE314]

1. Go to the beach and take out your shot put ( 16 lbs ) and hold it a shoulder height, say 5 feet from ground. It has 80 foot/pounds of potential energy, ready to be captured. At 1.355 watt/second per foot pound this would give you 108.4 Watt/Second.

2. Same shot put ( 16 pounds ) but you drop it over the side of a ship just over Nero's Deep, off the island of Guam. The ocean depth is 36,198 feet. Potential energy is (16 * 36198) or 579,168 foot pounds. At 1.355 watt/second per foot pound this would give you 784,772.64 Watts/Second. Almost a MegaWatt just from 16 pounds with absolutely no pollution.

3. Using a standard 15 barge tow of 55,000,000 pounds and dropped into Nero's Deep you would be able to capture
(55,000,000 * 36,198 * 1.355) or 2,697,655,950,000 Watts/second of power. That's right--- over 2 trillion watts of power.

4, Come on people--- rise to the challenge and save the earth.



note: my math sucks but the energy is there and it's relatively free.

[amitten]

1. Well, it takes energy to lift it up in the first place.

How does that figure in?

[Warren DeMontague]

2. I think the point is, it starts at Sea level.

Interesting idea.

[ret5hd]

3. it didn't...

and the laws of thermodynamics tells us that it will take more energy to lift than can be recovered by dropping...a net energy loser.

[amitten]

5. Well whaddya know? I gots me a brain!!!

And here I thought I was just a lowly creative type. :toast:

[skids]

14. It never ceases to amaze me...

How the Laws of Thermodynamics are consistantly trotted out by those who don't even bother to read and comprehend a proposal, as if the mere incantation of their name is enough to instantly solve any problem.

As to the OP, yes your math is horrible :-) You could conceivably get energy this way, however not nearly as much power as you calculated -- it would work better if you payed more attention to the amount of time the weight falls, and also reasonable speeds for underwater descent given friction.

Such an operation would be a lot less convenient than merely harvesting tide and wave in a stationary installation, however.

[GOPBasher]

15. Well it falls farther down into the

water. You're only lifting from sea level, and it falls farther than you lift it, so it's different in this case. Plus, who cares anyway, if in this case the energy comes from our own muscle power? Most Americans (including myself) can stand to burn some calories. For my own body, I want to be a net energy loser. :-)

As for this proposal, however, it wouldn't work. Falling through the ocean would lose way more energy than you'd get.

[TheMadMonk]

4. Terminal Velocity. Next perpetual motion candidate please.

[ArbustoBuster]

6. This is (in essence) how hydroelectric dams work.

Water falls from a higher point to a lower one and we take some energy from the movement to transform into electricity. We get the "lifting" for free in the form of rainfall from the sky onto the mountains or plateaus. However, dropping rocks into the sea isn't going to help much with energy generation for the reasons given above by others.

[HysteryDiagnosis]

8. After shrub gets done, all we may have left to drop on

one another is a bunch of rocks.

[neoblues]

7. What do we do when we've filled Nero's Deep?

Is that a good thing? Would it raise sea level (by an inch?)? Where do we get the millions of pounds of what? Collecting and moving all that mass into position would eat up much of the energy. Alas, we couldn't collect that energy.

I know, I know, it was just an example--we need to get to thinking and find some new ways...

[amitten]

9. I still don't see why we can't do A LOT more with solar. Right now,

the way it's harnessed, it seems like you get precious little from it.

Good God people, it's the SUN. It's giving out ENORMOUS amounts of energy. Like more than enough to run...everything! Forever!

But whenever I read articles about it, it goes something like this:

"The company, hoping to save on future energy costs, installed three acres worth of solar panels. The cost was four million dollars. Within a week, the new system had provided enough energy to keep the shift manager's reading light running for over an hour." :wtf:

We can't do better than this? It's THE SUN, for cryin' out loud! You will NEVER find another free, more powerful energy source.

[TransitJohn]

22. Limiting technology

has been and continues to be batteries.

[Canuckistanian]

24. Ultimately, almost all of our power come from the sun

Photosynthesis makes plants, plants decay and are compressed to become petroleum, coal and natural gas.

Hydroelectric plants work because the sun evaporates water and moves it to higher ground.

So, gravity and sunlight already provide almost all of our power.

[Dead_Parrot]

10. Paging Sisyphus... nt

[gristy]

11. There's the loss due to friction as the weight falls through the water,

the energy needed to get all that rock from a mountain somewhere over to Guam, and surely many other things that will reduce the conversion efficiency of the potential energy to useful electric energy.

Lots more calculations needed, but there's no doubt you are starting with some substantial positive potential energy.

[TransitJohn]

21. And let's not forget bouyancy

rho*g*h my good friends.

[NNadir]

12. I have an idea.

Let's get a big spaceship, a really, really really big spaceship, and tow the planet Jupiter to our vicinity. Then let's get really, really big lead balls and attach them to cam shafts so that whenever Jupiter goes by in its orbit the big lead balls are pulled up, and when the planet passes to the other side of the earth, the balls are pulled down. With appropriate gearing, we should be able to power all the world's generators by this means.

This program should, I think, have wide appeal to Americans. They often think creatively like this.

[XemaSab]

13. It would be a helluva lot easier

to tow Earth over THERE than to tow Jupiter over HERE. :bounce:

[NNadir]

16. This is the problem! You come up with a perfectly reasonable energy

idea, and everybody else says they have a better idea!

:hi:

[phantom power]

20. You need to think bigger.

Consider the kinetic energy available from the orbit of the Magellanic clouds about the center of the Milky Way...

[Dead_Parrot]

23. too small

Now, let's start by calculating the mass of the Virgo cluster...

[jwtravel]

17. Your math doesn't suck but your assumptions aren't correct

I looked all over the place to find definitions of Potential Energy, mostly to remind myself of the assumptions involved. Being a garden variety mechanical engineer, the definition "mgh" suffices for my purposes. However, when the "h" (height above a "zero" datum) involves 2 different fluids, in this case sea water and air, things change. I found one definition of Potential Energy that doesn't involve recovery of the Potential Energy as it falls through "h", but defines it in terms of how much energy it takes to put something of mass "m" in a given position "h" with respect to the "zero" datum. Assuming that the deep ocean floor (36,198 ft below sea level)is your "zero", the highest amount of potential energy that could be recovered from the shot put is the energy it takes to lift it from 36,198 feet deep to sea level IN SEA WATER plus the energy it takes to lift the shot put from sea level to X height "h" above sea level. Additionally, as "h" below sea level increases, the "ambient" water pressure increases. To be honest, I don't know the answer as to how much energy could really be recovered, but my engineering "spider sense" (developed by 4 years of professors pounding me with homework problems) tells me that it would be a net energy loser. If I had more time, I could really dig into this and provide a rigorous solution to back up my answer.
I just thought of another way of looking at Potential Energy; the maximum obtainable Potential Energy of something with mass "m" depends on how much Kinetic Energy that mass could possibly obtain, which depends on its velocity. Realization of Potential Energy involves "stepping in" and instantaneously harvesting the Kinetic Energy. Your shot put will not obtain much velocity as it sinks in the sea water, so that limits the realization of Potential Energy. One or 2 folks mentioned this "viscous loss" in previous posts. I guess that's why it's called Potential Energy. Sorry for the rambling, but I have the day off work, my back is hurting thus rendering me in a chair and useless, and I love getting to think about stuff like this since I rarely use it at work. It keeps my brain sharp, re-sharpens it, or in some cases gives me a new knife.

[Dogmudgeon]

18. Let's not be too harsh on him

At least he's begun to think about the problem. To most people, energy is even more mysterious than the proverbial "Black Box" that anything technological is.

I myself started thinking about energy in just this way, only my sixth-grade proposal was to use massive carts on rails going down mountains at high velocity. The carts would be braked by electronic generators, and part of that electricity would be used to transport the carts back up the mountain.

Yes, it was a perpetual motion scheme, and I quickly found out about its long and inglorious history. But the principle is also used in hybrid automobiles to recover a part of the energy the same way as centrifugal force -- or at least sufficiently rapid rotation -- can be used to decrease stresses on wheels and disks, which incidentally make up another genre of PM machines.

One cheer for the lad ... the "wheels" have begun to turn in yet another head. A little education, and we'll have another mind with sufficient might to pull an inert world in the direction of hope and survival, rather than despair and death.

--p!

[muriel_volestrangler]

19. It's not perpetual motion if you're transporting rocks

or shot putts, from the top to the bottom - their potential energy at the top is converted to kinetic energy on the way down, and you could set up a loop with buckets that drop the load at the bottom, and drive a generator off it. However, it would have to move slower than the 'terminal veloicty' of the loaded bucket (in water or air), and practically, you might not get much out of it. In the meantime, you're filling up the deep, and having to excavate rocks at the top (which will take some energy itself). Unlike hydroelectric power, you don't get the load taken back up again for you by energy from the sun.

Overall, we're probably better off developing generators that run off wave power - they would be sustainable (and probably more constant than wind power).

[Canuckistanian]

25. That's some of the big problems - brakes and radiators

What do brakes do? They stop rotational motion. How do they do it? By converting all that kinetic energy to heat and then letting it get away.

Radiators? They're another way of getting rid of heat from an inefficient process.

We should find a way to harness this heat or recover all this "lost energy".