Energy Storage Thread

Discussion in 'Architecture & Engineering' started by Facial, Jun 25, 2009.

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  1. Facial Valued Senior Member

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    Due to the explosive growth of wind turbines, essentially a periodic source of power, people are trying to find new ways of storing energy at lower costs.

    I have two ideas.

    1. A collection of massive springs, which stores as strain energy.
    2. A fluid stored atop a hill, which stores as gravitational potential energy.

    For #2, this is already a fairly well-known storage mechanism (at least discussed). The fact is, you have to find a large reservoir, if water is the fluid of choice, and a lot of space to put it in at both elevations. So, I was thinking it should be possible to use mercury as the fluid, which will either decrease the required amount of fluid by 13 times, or decrease the height req'd by 13 times, or a product of the two. That means for any leak-proof design for water energy storage, you can store 169 times more energy if mercury was used instead. Of course there are environmental concerns with using so much mercury so I'd recommend it over a deep mine shaft such that in case a spill/flood ever occurs all the mercury will sit deep inside the crust where it should belong. But this might be impractical too, due to the cost of mercury. But who knows - with so much pollution going on people might be able to extract mercury from pollutants.

    I'm debating myself whether #1 is practical. After all, if the springs are to be aligned vertically, why not just substitute them for masses in a potential energy system? This is something which I recently reversed my mind on, thinking that yes, you can store megawatt-hours of electricity in springs. Before that, for the previous three years or so, I thought it was infeasible. And even before that, when I first thought of the idea, I thought it was feasible. So now I've switched my mind twice. In posts which I hope to post soon, I will at least attempt to demonstrate why a spring system might work.
     
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  3. kmguru Staff Member

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    With wind turbine, a better system would be a flywheel arrangement. Flywheels have been used since the dawn of industrialization. Recent development of composite materials that is more safe in case it explodes would work.

    Spring system would work too, but you need a massive system. How about electrolysis of water to oxygen and hydrogen and then use a fuel cell to generate power?

    Large scale but cheap power storage has been a difficult issue for quite sometime.
     
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  5. krokah Registered Senior Member

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    It's to bad earthlings haven't found a way to harness the energy given off by lightning strikes. What a waste huh? If we could it would do away with our need of more energy resources...
     
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  7. kmguru Staff Member

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    It is like harnessing energy after a nuclear explosion...erthlings do not know how to...not yet...
     
  8. Nasor Valued Senior Member

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    A lightening strike has a few billion joules of energy. That's about the same amount of energy as what a large power plant might produce every second. So you would need to capture one lightening bolt every second just to equal the output of a single normal power plant.
     
  9. kmguru Staff Member

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  10. Nasor Valued Senior Member

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    A great many pages say that the energy is in the billions of joules, or hundreds of kw hours (not mw hours). If a lightening bolt actually had 500 mw hours of energy, I would expect each bolt to be incredibly destructive (as in "oh shit, that lightening bolt just blew up my house and left a 30-foot crater in the ground...").
     
  11. PieAreSquared Woo is resistant to reason Registered Senior Member

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  12. Facial Valued Senior Member

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    Ok, I'll do a quick back-of-the-envelope calculation soon to demonstrate the spring-type system. Now, this assumes people can manufacture hollow springs made from 1090 carbon steel, with a wire diameter in excess of 1 inch.

    I mean this is really huge.
     
  13. Facial Valued Senior Member

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    First, however, I think I need to do a preliminary on the ideal spring dimensions to use.
     
  14. mugaliens Registered Member

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    We have, actually - just shunt the strike through molten salt and store it as heat. The problem is that even in Florida, lightening capital of the world, the frequency per unit of ground area makes it very inefficient.
     
  15. Facial Valued Senior Member

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    Most of the energy in a lightning bolt is spent on exciting and ionizing air molecules, ie, the dielectric breakdown of insulation.

    A very small percentage of it can melt the salt, that is, unless you have a salt rod about mile long, and then come up with the cost to insulate the heat.
     
  16. Facial Valued Senior Member

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    I was obviously stupid in not considering the extraordinary cost of mercury for the fluid reservoir. That makes it dead.

    But I haven't given up on the spring idea. The fact is that even though springs utilize shear deformations in a very clever way such that it allows large displacements, the shear strength of solids is always less than the tensile and compressive strengths.

    Probably, a giant rotational spring can store energy more efficiently.
     
  17. Westy Registered Member

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    Good idea for sure. Any way of turning electricity into a stable storeable resource would be awesome way of storage. I think the conversion rate would be very low for electrolysis as I believe the energy requirement is high from what I remember from Organic Chem classes from college.

    This could also solve problems of transmission losses which is the main restrictive factor in the placement of Wind and Solar plants, as they usually need to be near population centers for them to be economically viable, and the quality of the resource is usually not so great near population centers.
     
  18. scifes heckle the snobs Valued Senior Member

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    use to electrocute water for hydrogen and oxygen, store, and burn later.
     
  19. Kernl Sandrs Registered Senior Member

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  20. Bifoot08 Registered Member

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    I'm just guessing here, but I was under the impression that stored energy needs to be released in order for it to be useful. So in order for storing water in an elevated tank as potential energy to be useful you would have to release the energy say by dumping the water. In which case you've just made yourself a fancy version of a hydroelectric damn, right? Otherwise I don't see any other way of harnessing potential energy. :shrug:
     
  21. Kernl Sandrs Registered Senior Member

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    http://en.wikipedia.org/wiki/Potential_energy#Chemical_potential_energy
     
  22. Bifoot08 Registered Member

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    I guess I should've been more specific. I don't see any other way of harnessing gravitational potential energy. :shrug:
     
  23. hypewaders Save Changes Moderator

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