Can a Vacuum Generate Energy?

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Discussion Overview

The discussion revolves around the feasibility of using a vacuum to generate energy by lifting water through a tube, akin to siphoning. Participants explore the mechanics of capillary action, vacuum generation, and the principles of siphoning in the context of energy production.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant suggests using capillary action to power a generator but later realizes it may not be viable.
  • Another participant argues that producing a vacuum requires more energy than could be recovered, questioning the overall efficiency of the idea.
  • Concerns are raised about the need for a control system to manage the vacuum in an on/off pattern, which could introduce energy losses.
  • A participant proposes a loop system where water is drawn up through a tube and deposited into a reservoir, questioning if this could work without a control system.
  • Another participant challenges the feasibility of the proposed system, pointing out that if the reservoir is under vacuum, water would not flow out unless the vacuum is released.
  • Participants are encouraged to conduct a simple siphoning experiment to observe the principles in action, noting that flow will stop if the output is higher than the input.

Areas of Agreement / Disagreement

Participants generally agree that producing a vacuum is energy-intensive, but there is disagreement regarding the mechanics of siphoning and whether a vacuum could effectively lift water without a control system. The discussion remains unresolved on the practicality of the proposed ideas.

Contextual Notes

Participants express uncertainty about the mechanics of siphoning and the implications of maintaining a vacuum, highlighting potential limitations in understanding the system's behavior under different conditions.

CuriouslyDumb
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I recently thought about using capillary action to power a generator (capillary action lifts water, right?) then researched it and learned that 1) I'm not the first one to think of it and 2) it wouldn't work anyways. Then I thought, why can't you use a vacuum to lift the water through a tube, like siphoning gas (though maybe I'm just missing something, and siphoning doesn't actually work or something). Any ideas? Could you use a vacuum to siphon water up a tube, let it fall and turn a generator?
 
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1) You need to produce a vacuum - that takes more energy than you'd get back.

2) You'd have to apply the vacuum in a on / off pattern (lift / drop) which would mean a control system = losses.

3) Siphoning works using gravity so the reservoir has to be lower than the source.
 
ok so I agree with #1, it would take a lot of energy to make a vacuum, and I know nothing about siphoning so I'll take your word for #3, but for #2 I was thinking that water is drawn up through the tube, the tube curves down at the top and deposits the water into a resevoir, and the water in the resevoir then falls to a source pool which feeds the tubes, like a loop. Giving up any ideas of power production, if you have a vacuum would it work? No control system is needed from what I can tell.
 
CuriouslyDumb said:
ok so I agree with #1, it would take a lot of energy to make a vacuum, and I know nothing about siphoning so I'll take your word for #3, but for #2 I was thinking that water is drawn up through the tube, the tube curves down at the top and deposits the water into a resevoir, and the water in the resevoir then falls to a source pool which feeds the tubes, like a loop. Giving up any ideas of power production, if you have a vacuum would it work? No control system is needed from what I can tell.

No, it wouldn't work.

The "tube curves down at the top"? So the whole reservoir is under vacuum? If that's the case, how would water flow out?

The water will be drawn into the vacuum and remain there, unless you 'release' the vacuum to allow it to drop. (Think about the vacuum system they use for internal mail in some companies).

For siphoning, take a piece of tube and try it out. Simple experiment. Once the output is higher than the input the flow will stop / reverse.
 

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