Generating power through displacement.

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SUMMARY

The discussion centers on the feasibility of generating renewable energy through water displacement using a large cylinder. The proposed method involves utilizing pressure differences at a depth of 100 meters, where the pressure reaches approximately 145.304 psi, to drive a turbine. However, participants unanimously conclude that the energy produced will never exceed the energy required to remove the water from the cylinder due to the law of conservation of energy. Practical efficiencies of turbines, generators, motors, and pumps lead to an overall efficiency of around 38%, meaning output energy is only 20-30% of input work.

PREREQUISITES
  • Understanding of the law of conservation of energy
  • Knowledge of fluid dynamics and pressure differentials
  • Familiarity with turbine and pump efficiency metrics
  • Basic principles of renewable energy generation
NEXT STEPS
  • Research turbine efficiency calculations and improvements
  • Explore advanced fluid dynamics principles in energy systems
  • Investigate alternative renewable energy generation methods
  • Study the impact of mechanical efficiencies on energy systems
USEFUL FOR

Engineers, renewable energy researchers, and students interested in energy efficiency and fluid mechanics will benefit from this discussion.

Mulith
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Hi there.

I've been looking at whether it's possible to create renewable energy though the use of diplacement and taking advantage of pressure differences. Let me explain.

Lets say you had a cylinder 100m x 50m. At the bottom of this cylinder you had multiple inlet pipes. The cylinder is then dragged down into the water using a weight of some kind so as to displace the water. The pressure at that depth, if I'm not mistaken would be 145.304 psi. The water is then allowed to pass through the inlet pipes to drive a turbine which then pumps the water out and over the edge of the cylinder. What I want to know is whether the energy created is likely to be greater than the energy required to remove the water from the cylinder?
 
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I think you may already know the answer to the question: The law of conservation of energy applies.
 
Mulith said:
What I want to know is whether the energy created is likely to be greater than the energy required to remove the water from the cylinder?

No it definitely won't be greater. At the very best, it would be the same if the machine had an efficiency of unity.

CS
 
Energy Can Neither Be Created Nor Destroyed; Can Just Be Transferred From One Form To Another.
This Idea Is An Illusion Like Perpetual Motion Machines.
 
i remember when i used to get out of the box ideas in school and i thought i was a genious ;))
 
Mulith said:
What I want to know is whether the energy created is likely to be greater than the energy required to remove the water from the cylinder?

No. In theory and an idealistic situation, it will be exactly equal. In practice, it will always be less.. less by around 20-30%.
 
It's much, much less than that. You might get a turbine efficiency of 65%, then a generator efficiency of 95%, then a motor efficiency of 95%, then a pump efficiency of 65%. That's an overall efficiency of 38%.
 
russ_watters said:
It's much, much less than that. You might get a turbine efficiency of 65%, then a generator efficiency of 95%, then a motor efficiency of 95%, then a pump efficiency of 65%. That's an overall efficiency of 38%.

oops.. i stated it wrong.. What i was meaning to say is, "Output energy is 20-30% of input work".
 

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