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I Fusion power, still the king of power?

  1. Nov 8, 2017 #1
    Is fusion power still considered to be the most powerful energy source possibly achievable of technology by mankind, or there is any other type of fuel that has passed it? I'm not looking for anything outrageous like a hurricane engine or a black hole engine, but some kind of reaction scientists speculate may be a good source of energy for a power-plant or engine that mankind could realistically use if everything worked out. For example, horsepower yields to coal steam engines yields to gas engines yields to nuclear fission power yields to fusion power (not yet, but the next thing) yields to (fill in the blank) maybe later with better technology. If fusion is still king of achievable high power and there is nothing foreseeable to supercede it right now, that is fine, too. This is mostly a status check.
     
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  3. Nov 8, 2017 #2

    mfb

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    Define "most powerful".
    Energy released per fuel? Sure - but there are electricity production methods that don't use any fuel.
    Power we could get if we build as many power plants as possible? Yes, but we don't have the possibility (or the demand) to cover the surface with power plants of any type anyway.
    Possible size of power plants? Big dams produce more electricity per installation than a fusion power plant would probably do.
    Price? Unclear.
     
  4. Nov 8, 2017 #3
    I think I was thinking of energy per fuel. I was only thinking of the next type of energy that would be within a single installation, like a power plant--but that doesn't cover the size of a whole country or something outrageous or that would need a million of them. I know hydroelectric dams, wind power, and solar power can produce a lot of electricity but need a ton of real estate--a hydroelectric dam by its size and wind or solar power for how many you need. None of these three basic methods would fit too neatly in a city block or would ever be used to power any kind of vehicle, whether an oil tanker or down to some kind of automobile. The price is no concern--I would assume that whatever would replace fusion would be would be commercially available after its research phase. If there is not anything more powerful than fusion within these kinds of limits, I am fine with thinking of "fusion as king" for right now. I just wasn't sure if something had surpassed fusion on the drawing board, theoretically achievable in a generation but not science fiction outright.
     
  5. Nov 8, 2017 #4
    Well everything you've mentioned with the exception of fission and fusion is energy collected in some way from the Sun. Oil, Water, Wind etc are all mainly generated by sun light.
    Fusion is how the sun generates energy. So in a way fusion power is a step change. Its the first time we are producing energy independent from any sun. (Fission is kind of undoing the Fusion that has already happened a while before, in some larger sun or super nova. So lets leave that to one side.) In fusion we can convert more mass into energy than before so that's good, and H is very common so that's good.
    Geothermal power is actually from energy from our planet left over from the formation of the solar system. The newish geothermal power plant in Iceland is really quite incredible it produces enough electrical energy to make hydroponics cost effective as a food source and also so much that they are thinking of exporting the electricity to the UK. However the difficulty is transporting the energy. The other problem with this power source is it only works in (shall I say) geologically special places on earth.
    Going back to fusion the future might be that after fusion you have fusion-fusion-fusion. With larger and larger elements being fused.
    However with both geothermal and fusion power you have the problem of transporting the energy. So smart new battery designs and interesting chemical methods of storing electricity may be the future. It is also presently a very interesting field.
     
    Last edited: Nov 8, 2017
  6. Nov 8, 2017 #5

    mfb

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    Fusion (especially fusion of hydrogen) releases the most energy per fuel for everything that is around in relevant quantities. Antimatter-matter annihilation would beat it, but there are no relevant amounts of antimatter in nature, and there is no known way to produce it without putting as much energy in as you get out again (or, practically, orders of magnitude more due to low efficiencies).
    Antimatter-matter annihilation could still become interesting for spacecraft as ultra compact energy storage.

    Annihilation has the highest possible energy density - 100%.
    Hydrogen to helium fusion releases about 0.4%, hydrogen to iron fusion would give 0.7%.
    Fission releases 0.1%.
    Chemical reactions release something of the order of 0.00000005% or 5*10-10 (oxygen not included)
    A hydro power plant with 100 meter height difference gives 10-14.
     
  7. Nov 8, 2017 #6
    What mfb just posted is exactly what I was looking for. Matter/Antimatter is a real reaction in science with a lot more power/energy that feels like the next step after fusion (if ever achieved) but isn't feasible for a long time in civilization; but that it would power large vehicles or compact power plants in the future. I feel my question is answered and appreciate your help.
     
  8. Nov 9, 2017 #7

    russ_watters

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    Just to expand on @mfb 's point about availability; matter-antimatter will never be a primary power source on which civilization can be run, unlike fusion (or fission, solar, coal, etc.). It will only ever be an energy carrier like a battery. But if you are only asking about space travel, then it fits, since we mostly use energy carriers in our chemical rockets, not primary energy sources. You might say all of our rockets are in effect battery powered.
     
  9. Nov 9, 2017 #8
    @russ_watters That's a good point and clarifies something I had not thought of. Excellent.
     
  10. Nov 9, 2017 #9

    sophiecentaur

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    Something that is often ignored here. Humans do not actually use H atoms, they use heavy isotopes of Hydrogen in any reactor because the yield of Deuterium and Tritium by fusion of Hydrogen is so very slow - we wouldn't have time to wait. So we have to 'cheat' and extract Deuterium and Tritium etc. from the available mix of isotopes before we can make a Fusion Reactor of any practical kind. The idea that the whole of the Oceans is available for a Hydrogen reactor is an overstatement. The situation in a Star is that there is all the time in the world to wait for the first step in the fusion process. Humans are in too much of a hurry.
     
  11. Nov 9, 2017 #10

    mfb

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    To be fair, 1/7000 of the oceans (fraction of deuterium in the hydrogen) is still a humongous amount. With DD and DT fusion (using tritium produced in DD fusion) it would release about 1*1031 J, sufficient to satisfy today's worldwide energy demand for 10-20 billion years.
     
  12. Nov 10, 2017 #11

    sophiecentaur

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    Oh yes. But we don’t do what a star does.
    The supply would still be limitless in human terms, as you say.
     
  13. Nov 10, 2017 #12
    Its also possible, if we have working DD and DT fusion power plants and energy is no longer a problem, that in the future we could use particle accelerators to artificially make more Deuterium and Tritium from other elemental isotopes. This would take a lot of energy, however we would, potentially, make more energy back when we fused the Deuterium or Tritium.
     
  14. Nov 10, 2017 #13
    Thorium reactors can become the king of energy sources for a few centuries. Chances are, thorium and solar will just be more compact reliable and simple. Places like Africa can deploy solar easier than fusion perhaps for all the millenium. Only fusion and fission are energies that can be seen in the observable universe. quantum fusion for example quarks can't make runaway reactions that are known or seen.
     
  15. Nov 11, 2017 #14

    mfb

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    Most reactions would cost more energy than you get out even at 100% efficiency, and I don't see any reaction that would work with more realistic efficiency values.
    A prediction for 1000 years in advance? I wonder how this would have worked out in 1017...
    I see wind, burning biomass, geothermal energy, flowing water, sunshine and so on around me. All these things don't naturally produce electricity but neither do fusion or fission. And natural fission processes are extremely rare.
    That statement doesn't make sense.
     
  16. Nov 11, 2017 #15

    tech99

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    The trend seems to be that alternative energy continues to fall in price. Offshore wind is now coming in cheaper than nuclear in the UK. On top of this, battery technology is falling in price and is becoming practical for both homes and solar farms. The previous peaks in demand which occurred due to TV commercials have gone away, as people no longer watch broadcast TV. There are opportunities for smoothing peaks by switching things off, such as car charging and commercial freezers. The grid is becoming smart, and needs to change its design to suit local generation. We are now seeing occasional days where countries are running entirely on renewables.
     
  17. Nov 11, 2017 #16

    russ_watters

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    Both of those have serious issues with energy density that will make continued price/power drops difficult....even if I were to agree with the current practicality of batteries, which I don't.
    Huh? What does that mean? Are you saying TV commercials cause peaks in energy use? I can't fathom where you might have gotten such an idea.
    And days when intermittent renewables provide nothing at all. That isn't going to change and no amount of "smart" grid adjustment is going to be able to deal with that. We'll need massive storage or backup capacity.
     
  18. Nov 11, 2017 #17

    DrGreg

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    During commercial breaks, people may go into another room, turn on lights and kettles, use water (causing electric pumps in the water supply system to operate), etc, all of which increases electricity demand. The effect is greater in Europe than in the US because of tighter ad regulation. Commercial breaks tend to be less frequent, but longer in duration, than in the US. For example here in the UK we get only 4 commercial breaks per hour, and, until a couple of decades ago, there were only two UK commercial TV stations with significant viewing figures (one -- ITV -- with much more than the other -- Channel 4) so the extra demand during ITV commercial breaks was significant. The National Grid supplying electricity consulted TV schedules to predict when peak demands would occur.

    In recent years this is somewhat less of a problem to due decreases in viewing figures, both for TV as a whole and for any one channel, as the number of channels has increased, although ITV still dominates in the commercial TV sector.
     
  19. Nov 11, 2017 #18

    russ_watters

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    Do you have a reference for this? It seems very hard to believe considering how little a few lights and a little bit of water use compared to an air conditioner.
     
  20. Nov 11, 2017 #19

    ISamson

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    I think that annihilation will be someday used in rockets.
     
  21. Nov 11, 2017 #20

    mfb

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