Pressure Harvesting - from ocean depths

Discussion in 'General Science & Technology' started by Quantum Quack, Mar 8, 2020.

  1. Quantum Quack Life's a tease... Valued Senior Member

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    In other words it is simply a novel hydro electric generator that works in the deep ocean...

    No dams or river needed etc...location can be any where in the ocean... and so on...
     
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  3. Write4U Valued Senior Member

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    Well, yes, where there is sufficient deep water pressure. The ocean itself is the natural headwater, the turbine generates electricity, the empty tailwater tanks allow for thousands of gallons to flow from high pressure ocean to low-pressur tanks until the pressure in the tailwater tanks equals the outside ocean pressure and inflow stops. The tanks get pumped out and the system is ready for next inflow of naturally pressurized deep ocean water and creating direct electricity in the process. No storage, unless you want to add batteries to the system but that just makes it more complicated and I detect a desire to keep it very simple.

    It's a self-contained deep water direct high pressure to low pressure system which drives a reversible turbine to generate direct electricity, simple.
     
    Last edited: Mar 16, 2020
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  5. exchemist Valued Senior Member

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    Well done for finding that out.

    But, depressingly, I see from post 521 that you still seem to be thinking this can be an energy source, like hydroelectric power. You can use subsea tanks pressurised by the ocean as an energy storage device (i.e. you put 100MWh into it by pumping and get out maybe 80 MWh later, by running the pump as an engine or turbine), but there is no way you can use it as a net source of electricity.
     
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  7. Quantum Quack Life's a tease... Valued Senior Member

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    I do believe it can but haven't really considered it that thoroughly.
    I do believe that they are yet to resolve key issues such as the ones you are suggesting are present.
    Given the amount of energy required to pump out the water to create the inflow. I fail to see how the 80% efficiency claim can be justified.
    However the system uses deep water pressure to create that inflow via the turbines and as such capitalizes on deep ocean pressure to do so..it is highly debatable as to whether it is economically viable... I simply haven't looked at it close enough to form an opinion.
    Personally I wouldn't write it off too quickly... as a lot of investment has been spent on it...apparently. ( Sophisticated scams can be so hard to detect when it comes to new energy systems.)
    I have been too busy researching the VVSS idea and watching Netflix, playing video games and drinking a lot of coffee...lol

    Maybe I will have a closer look at it later... especially regarding any requests for investment capital.
     
    Last edited: Mar 16, 2020
  8. exchemist Valued Senior Member

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    Zero investment has been spent on this as a source of energy, for reasons we have rehearsed at great length.

    As a medium for storage of energy it may attract some backers.

    I have not done the maths on the energy losses for this as a storage system, but they won't be trivial, since when you compress a gas it gets hot and this heat will be lost to the ocean. It may well be that 80% recovery is too high, in which case this storage idea may struggle to compete with batteries or pumped hydro storage, neither of which suffers from this snag.
     
  9. Quantum Quack Life's a tease... Valued Senior Member

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    ok... I felt like doing a little clicking (5 minutes) and discovered that:
    • The original articles predate 2013 (>17 years ago)
    • The corporate web site is a pretty water image with out any links and zero content. http://subhydro.com/
    • The web site is unsecured like sciforums is. ( no SSL )
    • I couldn't find it in the wiki list of new energy projects. ( but I only skimmed)
    • Discrepancy as to nationality of research firm. Are they Norwegian or German?
    My tentative conclusion:
    • If it was as claimed in 2013 there would be more recent developments after all 80 % efficiency is a big deal isn't it.
    • No corporate web site just a domain name parked with a single web page and no links, no redirection, no contact details nor information.
    • Extremely unprofessional at the very least.
    • Not a serious proposition ...
    However when it comes to working out energy cycles and conservation of energy factors it could be a useful thought experiment and be good practice for a budding fluid mechanics student.
     
    Last edited: Mar 16, 2020
  10. exchemist Valued Senior Member

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    No, 80% efficiency for a storage system is pretty crap.

    80% efficiency for a heat engine , as used in many types of generator, would be sensational.

    But that is not what we have here.
     
  11. billvon Valued Senior Member

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    You can't generate any net power, which is what dozens of people have been telling for hundreds of posts. You can generate TEMPORARY power, which is why both pumped storage and this thing might be useful.
    That's what this system does.
    And the pressure already exists in pumped storage, too.
    And that takes more energy than you get back by letting the water flow back in.
    The article says they want to store energy. The INVENTOR says it is to store energy. We are telling you that it's to store energy.

    How many times do we have to go around before you understand this very simple concept?
     
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  12. Write4U Valued Senior Member

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    20,069
    Are you telling me that a river cannot generate any net electric power? I am not claiming that doing this underwater will yield a net surplus power.

    I am saying nothing gets stored for later use. The illustration shows a direct system without any pressurized storage in the tanks. Look at the passive airvents . These tanks are not desiged to store anything . You pump out water to create tailwater space. That's how that passive airvent to the surface is used , merely to equalize pressure by filling empty tanks with air which will be replaced by the inflow of naturally pressurized ocean water.

    Nothing gets ever pumped IN, water is always only pumped out to create empty tailwater storage for inflowing (not in-pumping) . I am only describing the way it works from the illustration and I make no claim as to its efficiency.

    Your hundreds of times telling me that you cannot create net stored energy with this system is not even in context of the illustration. And I agree IF you would try to use this system for storage which if physically impossible to begin with as illustrated, it just wouldn't even work as illustrated.
    But, IMO, you are not looking at this correctly. Again, I make no claim as to its efficiency, I merely am describing the system as illustrated and you keep telling me I am not doing this correctly because you are focused on a completely different energy storage system, which this is not.

    How can you create surplus water pressure in a passively vented tank unless you want to create a fountain at the surface?

    You can create an empty tank by pumping water out and have the passive airvent replace the water with air to prevent the creation of a real vacuum in the tanks.

    The inventor does not speak at all, his words are translated and clearly incorrectly at that, if the illustration is correct.
     
    Last edited: Mar 16, 2020
  13. exchemist Valued Senior Member

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    This has become one of those "Mit der Dummheit kämpfen Götter selbst vergebens" threads.

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  14. billvon Valued Senior Member

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    A river can generate quite a bit of power - because the water is moving. When you dam a river, you generate a head, or a distance from a high reservoir to a low one. That represents potential energy that you can use.

    If you did not have a river, and just built a dam to put water behind, you could not generate any net power - because that water would not be returned to the upper reservoir.

    This is grade school stuff.

    They are storing head, just like a pumped storage plant does. This system stores the head at the bottom instead of at the top of the system, by creating a void at the bottom instead of creating a reservoir at the top. They work on EXACTLY THE SAME basic principles. EXACTLY THE SAME.
    Yes. And that takes more energy than you get from allowing the water to flow in. Again, just like pumping water to the top of a pumped storage facility.
    The illustration is correct. The inventor is correct. The only person who is wrong here is you, due to your ignorance of basic physical principles of hydropower.
     
  15. billvon Valued Senior Member

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    Why thank you! Although I am hardly that big an authority . . . .
     
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  16. Write4U Valued Senior Member

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    Right and that is what we have here. Instead of high to low reservoir, we are using high to low pressure.

    The bottom of 800 feet of water creates as much pressure as a flowing stream . The illustration clearly indicates that fact by using an oversized downward pointing arrow. Lots of pressure given a small inlet (remember the inlet valve) provides plenty of kinetic power to drive a turbine/generator to generate instant electricity.

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    Ocean pressure-->inlet valve-->turbine/generator-->electricity--> tailwater storage. That is the pressure driven kinetic system as illustrated, just like any other pressure driven kinetic system, except this is an underwater system, which requires an underwater storage facility to allow for water flow through the system

    You just want to refer to the narrative, fine do so, but don't tell me I'm wrong. The narrative does not match the illustration.

    I see a functional model in the illustration and I am right. If it is efficient is another question, which no one has addressed because the counter is always about pumping and storing energy, which is not what I am talking about at all.

    The potential energy is already contained in the pressurized deep ocean water. The system as illustrated converts this potential energy into electricity.

    I am the only one who is adddressing the question in the OP title! Everyone else is beating around the bush, with introducing pumping to replace ocean pressure. Pumping is not "pressure harvesting from ocean depths".
     
    Last edited: Mar 16, 2020
  17. billvon Valued Senior Member

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    You are a fool. A flowing stream creates almost zero pressure.
    Yep. And lots of pressure through that same small inlet requires even more kinetic energy to pump out the water. The pressure doesn't just go away when you want it to.
    You are wrong. Your intentional ignorance has led you to believe in a fairy tale. If you had even high school math you'd be able to understand why that is.
     
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  18. Write4U Valued Senior Member

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    A high pressure flowing stream through a small orifice (like a turbine) creates no kinetic energy? You cannot be that stubborn. A simple garden hose is a high pressure flowing stream that can be used to generate electricity.
    And stop with the ad hominem, please.
     
  19. billvon Valued Senior Member

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    I didn't say that. Try again.
     
  20. exchemist Valued Senior Member

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    For any interested readers, the pressure in a garden hose is due to the pressure in the water main, not the rate of flow of the water. This becomes obvious if you turn off the nozzle on the end and after a while a connection pops off, due to not being firmly attached. Nothing is flowing. It is the mains pressure that does it.

    A flowing stream can exert pressure on the blades of a water wheel, due to the momentum it has (d (mv)/dt =F ). But there is little or no static pressure in it.
     
  21. Write4U Valued Senior Member

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    Right, and I have addressed that problem in my question of net electricity . You keep insisting that I somehow am claiming a cure-all. You cannot point to any statement I made that this is a satisfactory solution to the OP question.

    I merely said it is functional, not it is profitable.
     
  22. Write4U Valued Senior Member

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    Yes you inferred it. If you didn't then why offer it as an argument. We are not talking about a mere flowing stream. We're talking about a a high pressure flowing stream. Stay in the established context please.
     
  23. billvon Valued Senior Member

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    No, I didn't. Your crazy-straw logic might have made you think I did - but I did not.
    Then why did you make a comparison to it?

    Let's get away from what you imagine and use math.

    Let's say one of these systems has been installed in 500 meters of water. The tank has a volume of 100 cubic meters. The turbine has an efficiency of 80% when used as a water turbine and an efficiency of 80% when used as a pump.

    How much energy will you get when you let the tank fill? How much energy will you need to pump the tank out?
     

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