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[–] 86 points 7 months ago (4 children)

Can't find it for the life of me... Describing a web comic vs actually posting it always feels like a flop, but...

Aliens abduct a physicist, who doesn't seem to give much of a damn about the abduction but is instead enthused to learn about the alien tech on board, so they give him a tour of the ship. They get to the power reactor and start dropping a bunch of sci-fi jumbo about "We harness dark matter to... (sci-fi Ruth Goldberg machine) ...and finally, we use the heat it generates to boil water and crank a turbine!!"

*Physicist drops to his knees in despair and let's out a dramatic 'noooooo!'

 

Paraphrasing heavily due to having shit memory. I thought it was a SMBC comic, but... /shrug.

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  • [–] 6 points 7 months ago

    "And then, the power generated is used to heat water and generate steam!"

    "No...."

    "That steam is used to turn a wheel!"

    "No! NOOOOOOO!!!!!"

    "Hey dude, calm down."

    -Actual exchange during first contact.

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  • [–] 73 points 7 months ago (23 children)

    still waiting for someone to demonstrate a more efficient power transfer solution

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  • [–] 78 points 7 months ago (11 children)

    You're in luck. Supercritical CO2 turbines are a thing now, and they're way more efficient because they don't involve a phase change.

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  • [–] 24 points 7 months ago (3 children)

    Got any sources on that? I would love to learn about some new tech in electricity generation.

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  • [–] 6 points 7 months ago (3 children)

    It’s funny (in a sad and sardonic sense) - I pay attention to the energy industry and the outcry over data centers has got me watching these generators closely. If they deliver on their promises, they could represent a great way to deliver on mirror-based solar reactors in areas with limited water resources. (And to recapture and use waste heat from the servers of data centers.)

    Society is on the precipice of investing a lot into increasing energy generation for data centers that have to be near the same sorts of resources that people need - fresh water, environs conductive to generating power, stable (enough) climates. But this technology is arriving/set to reach adoption just in time for this boom-bust cycle. All those data centers in populated areas already have a timer ticking for when the shell corps have their rugs pulled.

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  • [–] 3 points 7 months ago (2 children)

    Unfortunately, there's no way to get energy out of waste heat that won't be spent pushing that heat a little harder. Already a significant amount of energy is spent cooling data centers, any attempts at energy recapture will just make that cooling harder.

    The best we can do is something like district heating, because heat pumps can get over 100% effective efficiency.

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  • [–] 2 points 7 months ago (1 child)

    The energy needed for phase change for supercritical CO2 is substantially lower than steam.

    There’s more wiggle room. My understanding is that similar to heat pumps, they can build systems with different optimal temperatures, and even daisy chain them together. They’ll never make a perpetual motion machine, but they can waste less energy.

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  • [–] 1 point 7 months ago (2 children)

    At some point you are going to need steam to spin a turbine to generate enough energy to compress the CO2.

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  • [–] 19 points 7 months ago (7 children)

    Solar cells, technically.

    boiling water systems have a thermal efficiency of ~40% Solar cells are closer to 45% efficient

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  • [–] 6 points 7 months ago (2 children)

    So line a nuclear fusion containment chamber with photovoltaic cells?

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  • [+] -6 points 7 months ago (3 children)

    Doesn't seem particularly efficient to me... The sun burns hundreds of millions of tons of hydrogen every second. The amount of released energy we actually put to use is indistinguishable from zero, not 45%.

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  • [–] 11 points 7 months ago (1 child)

    If we put it like that, every other energy source on earth begins that way and adds at least one conversion step.

    ... except for fusion of course.

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  • [–] 1 point 7 months ago

    Exactly.

    Nuclear plants are probably the least efficient, because they required all that fusion energy inside earlier stars to build hydrogen into uranium, and we can only extract a tiny portion of that trapped fusion energy through fission.

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  • [–] 3 points 7 months ago (2 children)

    Helion is trying to build a fusion reactor that harvests the energy through electro magnetic induction.

    https://youtu.be/HlNfP3iywvI

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  • [–] 34 points 7 months ago (1 child)

    Even wind power still turns a generator, but solar is just completely different than everything else

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  • [–] 6 points 7 months ago

    They’re actually quite similar to thermoelectric generators. But the potential difference between two semi conductors is created by a heat differential rather than by photon excitation.

    Thermoelectric generators have been used on various rovers and deep space probes as well as in remote lighthouses.

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  • [–] 26 points 7 months ago (1 child)
  • [–] 23 points 7 months ago

    Man... can you imagine? Someone could shut down the whole power grid just by watching all that water.

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  • [–] 17 points 7 months ago (7 children)

    Didn't China recently use super conducting CO2 instead of water?

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  • [–] 22 points 7 months ago

    Supercritical CO2 has been looked at a lot for the Brayton cycle which can get 50% efficiency compared to steam that generally caps out around 34%

    The US and china both published studies talking about a brayton turbine but to my knowledge no commercial plants running off of it have been built yet

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  • [–] 7 points 7 months ago (3 children)

    idk but you can also use molten salt

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  • [–] 35 points 7 months ago (3 children)

    fission. aside from the fact physicists didn’t invent either, we’ve yet to boil any water with fusion.

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  • [–] 23 points 7 months ago* (last edited 7 months ago) (1 child)

    * Looks up *

    * Ahem *

    Nuclear fusion existed well before physicists.

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  • physicists looove hot showers! they're the best! so comfy ☺️

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  • [–] 4 points 7 months ago
    [–] 4 points 7 months ago

    Iirc one of the theoretical ways of generating power with fusion is magnetohydrodynamic generators which use the magnetic field created by the plasma to generate an electrical current directly. Still theoretical though...

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  • [–] 1 point 7 months ago

    Mofos just reinvented the steam engine

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  • [–] 1 point 7 months ago

    The idea that using steam loop to turn a turbine is mind blowing to some.

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