Does this violate the Law of conservation of energy?

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Discussion Overview

The discussion revolves around the concept of energy conservation in the context of pumping water and generating electricity from a turbine. Participants explore whether the energy generated from the water flow can offset the energy required to re-pressurize a water tank, touching on mechanical and electrical energy interactions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions if the current generated from the tap water is negated by the energy needed to re-pressurize the tank.
  • Another participant asserts that nothing in the scenario violates the Law of Conservation of Energy, suggesting that mechanical activities do not lead to energy violations.
  • A different participant indicates that the current generated would be completely used up in the process of pumping water back into the tank, and due to inefficiencies, more energy would be required than what was generated.
  • A practical example is provided regarding the energy dynamics of pumping water into a reservoir during low usage times and releasing it during high usage, emphasizing that more energy is needed to pump than is recovered.

Areas of Agreement / Disagreement

Participants generally agree that the Law of Conservation of Energy is not violated in this scenario, but there are differing views on the specifics of energy usage and recovery, particularly regarding the efficiency of the processes involved.

Contextual Notes

Participants mention inefficiencies in energy conversion and the timing of energy recovery, but do not resolve the specific energy calculations or assumptions about the system's efficiency.

DLindahl
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If I were to pump water from my well (at my house) into the pressure tank that we have, it would require a certain amount of work. If I then turned on my faucet and had a small turbine generating an electric current, would that electric current (which I realize would be small, this is more for myself to understand the concept) just be required then when the pressure tank is re-pressurized...does that make sense?

Basically, if I generate a current from the tap, does that current then get negated by an extra amount needed to re-pressurize the tank?

Thanks in advance!
 
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1. Re-Read what you write before you post, that makes no sense.
2. What is violating the law?

The fact that everything in your question relates to mechanical activities I can say without understanding your description-- nothing violates the Law of Conservation of Energy (to answer your "subject" question).
 
I think you are asking if the current generated by the tap water is completely used up when pumping water back into the tank. If so, then yes, that current would be completely used up, and due to inefficiencies you would actually require more energy than you created to pump water back into the tank.
 
A practical example relating to your question is pumping water into a reservoir during periods of low electrical usage and then releasing the water later during a period of high electrical usage.

It takes more energy to pump the water up than is later produced when it is released, but because energy is recovered during peak usage it is a practical compromise. So it it NOT getting 'something for nothing', but the timing of the pumping and subsequent recovery can make it useful.
 

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