The Power of Gravity - You might find this interesting.

[ResinRat2]

In a thought experiment of building a mechanical battery I found the following calculation very sobering.

In order to simply store the equivalent of One Kilowatt-Hour of energy the following is required:

One Kilogram of water falling one meter produces:

(1 kg water)(9.8 m/s2)(1 meter) =  9.8 kg-m2/s2 which is equivalent to

9.8 Joules of energy

                       ------------------------------

1000J/s for one hour is One Kilowatt-hr of energy

(1000J/s)(60sec/min)(60min/hour)  =  3.6 million Joules .

In order to store this much energy by raising a weight to a height of  3 meters we would need a total weight of:

(3600000 kg-m2/s2)/ ((9.8 m/s2)(3 m))  =  122000 kg. raised to a height of 3 meters.

For those of us in the United States it is equivalent to approximately 134 Tons raised to a height of approximately 10 Feet.
                                  -----------------------------

Wet sand weighs approximately 2.3g/cm3 or 19.19 lbs/ gal

A single ton of this heavy stuff would require 53 cubic meters of volume. Multiply this by 134 and you can see why energy is never stored by raising a weight, and why a gravity-based battery has never been economically developed.

For the first time in my life, my old sore knees being now ignored, I am looking at the reality that the force of gravity is a very weak force indeed.

[spoondini]

Resinrat,
   On another post somebody had a very clever idea to perform electrolysis, take advantage of the natural buoyancy of hydrogen and let it rise in a tower, react with oxygen from the atmosphere (burn) at altitude and capture that energy, the capture the hydro power as the water fell back down.  A perpetual water fall if you will.  Sounded great to me.  I did the math and after taking into account efficiency losses, I calculated the tower would need to be really freeking tall, like stratospheric to even break even.

Are knees certainly don't perceive gravity as a weak force, bu math sure as hell does.

[sm0ky2]

or using water instead of sand, 1 gallon weights 3.787 Kg

so,  1 KW-Hr is roughly 32,220 gallons per hour, or approx. 550 gallons per minute through an hydroelectric generator.
with a drop height of 9.8 ft.

size = its about a 20-ft by 40-ft / 5 ft deep swimming pool.
completely dumped in 1 hour.

[ResinRat2]

Yes, the math does show what a pittance of energy gravity potentially can store; but doesn't this also hint at the fact that even if a perpetual motion wheel could possibly be invented, it would require such a large number of them to produce even a small amount of energy from gravity that it would be a waste of energy even building them?

I originally thought of digging downward and building the mechanical battery with a shaft in the ground a hundred feet deep. Even this would require such a large weight (over 13 tons) that it was ridiculous to even consider it.

[TechStuf]

Yes, but consider that such an eventuality is not really about gravity wheels at all....

But instead, certain tangential possibilities.

From there, a single great leap is possible.


TS