I think I've found Maxwell's Demon, however the demon is quite large...

[triffid]

I think this is an interesting project.If the temp difference can be made great enought it could drive a miter wheel which could in turn, turn a generator to make electricity.The tank could absorb the heat during the day and then release it at night thus turning the wheel nearly 24 hours around the clock.It would be a solar heating project of sorts since most heat on earth comes from the sun except for that which comes from the earth's core.Triffid

[Nabo00o]

Yes those are really handy to have, and I see water will actually increase its volume with around 4.3% if heated from 4 up to 100 degrees.
This is in contrast to gases which will increase their volume by 33% when heated from 0 to 100 degrees.

One thing which might influence these figures is the static increase of water pressure as you go down in meters, in your case it was about 24 meters.
I checked a converter in Opera and it seem 10.4 meters will give you one bar of pressure, and 24 meters will give about 2.34 bars. A change in pressure will give some change in temperature so it is worth taking into account.

Also here is a useful link about air pressure and the gas laws.
http://galileo.phys.virginia.edu/classes/152.mf1i.spring02/ThermProps.htm

[Nabo00o]

I think this is an interesting project.If the temp difference can be made great enought it could drive a miter wheel which could in turn, turn a generator to make electricity.The tank could absorb the heat during the day and then release it at night thus turning the wheel nearly 24 hours around the clock.It would be a solar heating project of sorts since most heat on earth comes from the sun except for that which comes from the earth's core.Triffid

I haven't heard of the miter wheel before, but yes, if it could generate enough heat all common machinery should be able to be powered. One idea is, that if you could maybe make the pvc tubes generate up to 70 degrees Celsius in temperature, you could connect the last tube to a more powerful steel tube which could safely bring the water up to 100 degrees without risking to melt or blow up.

Also as there is some similarities with this tread and the heat pump tread, in both I do not believe that I am using either solar heat or any heat source to make the potentials. The total temperature of this system and its surroundings will be the same at all time, but inside there will appear a potential difference of temperature.

This means that no heat is "used up", in fact I believe there exists almost no machinery that can actually convert heat into mechanical motion, what we most commonly use is difference of pressure and temperature, not the actual heat itself, and so the total temperature of Earth would absolutely not have decreased if its entire population had used this or the heat pump technology to make extra energy.

I am not saying that the energy appears out of nowhere, but I don't believe that its source is a physical one.

Naboo

[lumen]

You can use a sterling heat engine or even some high tech peltier devices to convert the heat to electric directly.
The best part is both these devices need a heat sink or cool side also, so you can just put the heat back into the first tank!

You would only need some ambient heat to get up to working temperature, then it would just recycle the heat and keep producing electricity. It would be a true gravity machine!

[Nabo00o]

You can use a sterling heat engine or even some high tech peltier devices to convert the heat to electric directly.
The best part is both these devices need a heat sink or cool side also, so you can just put the heat back into the first tank!

You would only need some ambient heat to get up to working temperature, then it would just recycle the heat and keep producing electricity. It would be a true gravity machine!

Yes that was exactly my thought, this is why you could put the entire "power plant" into a "box", isolate it from the environment and have a wire coming out, giving you free electricity. In the heat pump scenario you would have two wires, one input and one output, with the out wire giving more than you put in because of the heat pump's extreme efficiency of separating heat into temperature potential.

Of course we do not need to put it in a box, but it would prove the point that once some environmental heat has been absorbed and placed in the loop inside, it would work much more like a medium for energy production than the source of energy itself.
So I guess the first thing to test now is to measure how well heat can be separated in a pipe isolated at the top, and absorbing at the bottom. If we could just get a few degrees of difference top-to-bottom, and before waiting too many hours, this could really spark the beginning of whole new way to heat homes and and buildings, and eventually even fuel todays power hungry home electrical needs.

Well, maybe..... We should always dream. And never say anything is impossible, at least not before we try it. Naboo