• EleventhHour@lemmy.world
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    1 month ago

    Hey, at least we have actually accomplished (edit: net-positive) fusion. 10-20 years before the first commercial plant comes online, but fusion is a technology which now exists. This is extremely awesome. Honestly, I never thought I’d see it. But, it’s here, it exists, and now the distance between today and when the first power plant comes online is just a matter of scaling the tech upwards.

    Full, autonomous self-driving cabs - especially from Tesla - on a massive scale… not so much.

    • Badabinski@kbin.earth
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      1 month ago

      Question for you, when you say that we’ve accomplished fusion, do you mean fusion that produces more power than took to generate it? Or simply the act of fusing atoms together in a reactor (vs the uncontained fusion present in thermonuclear bombs)? If it’s the former, then like, holy shit, that’s actually been accomplished‽ Like, I know NIF had their whole thing with breakeven fusion a couple of years ago, but that was only counting the energy that made it to the hohlraum, not all the energy that was lost powering the lasers and shit. When you factor all of that in (like you’d need to for realistic power generation) then it’s very far away from breakeven generation. It’s still an incredible breakthrough and will help us figure out fusion energy, but it’s not a practical means of energy generation at this time. Did something else happen that I missed‽

      If it’s the latter, then we’ve actually been fusing atoms together in reactors since the 1950s. In fact, there’s a community of people who build small fusion reactors as a hobby! I learned about this a few years ago when a 16 year old made the news by being the youngest person to build their own reactor. The main site I know of is https://www.fusor.net/

        • Badabinski@kbin.earth
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          1 month ago

          Ah, okay, that’s what I was referring to with NIF. They absolutely have generated more power than they put in, but only in a way that is scientifically interesting. If you only consider the energy flowing into the hohlraum, then more energy was produced, which is crazy cool! They also achieved true ignition which is great. We’ve never been able to get things hot enough and squozed enough for long enough to be able to directly observe that in a controlled setting. The fact that they can now just do that means they can experimentally probe where the boundaries are and find the cheapest way for us to get to ignition.

          However, they got the energy to the hohlraum using lasers. Those lasers (and all of the equipment around them) required (I think) three orders of magnitude more power to generate the laser impulse that triggered fusion. A productive fusion reaction did occur, but it absolutely wasn’t productive enough to make up for all the power required to generate the laser pulse. Making lasers that can output at the required power levels and frequencies without all of the waste (i.e. 2.5 MJ of electricity to laser results in 2 MJ laser output) is a Hard Problem™ and is probably impossible with our current understanding of physics.

          When you made your comment, I wondered if someone had achieved breakeven using a tokamak or some other form of magnetic confinement setup. Inertial confinement fusion is great for research but not practical for power generation, whereas magnetic confinement fusion is probably where the future is.

          ICF is really good at putting the squoze on stuff, because the things you want to fuse are all stuffed in a tiny hohlraum and you’re zorching it with a shitload of giant friggin lasers. Magnetic confinement fusion used in tokamaks occurs much more gradually by magnetically heating and containing plasmas. The nice thing about tokamaks is that they just constantly generate heat. With modern superconducting magnets, the infrastructure efficiency is also pretty decent, giving them a chance at truly generating more power than they use when you take the entire reactor into consideration.

          Jesus that’s a lot of words. I should go do my damn job instead of distracting myself talking about fusion. Sorry for the brain dump.

            • Badabinski@kbin.earth
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              1 month ago

              No worries, I didn’t think you were trying to mislead! I’m also very hopeful for fusion and I like to read about it. I don’t know if magnetic confinement systems will be able to reach the temperatures and pressures required for ignition (versus those just for fusion) soon, but technological progress certainly has a tendency towards jumping forwards unexpectedly!

              • EleventhHour@lemmy.world
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                1 month ago

                “Magnetic confinement”… just hearing the term in real-world use get me all excited that Star Trek and real life are finally starting to cross over.

                Although Star Trek also predicted that the next 30-50 years are gonna suck the hard one.

                Edit: at least we’re not trying to screw around with matter/antimatter power production. There was an entire episode of Star Trek: Voyager about how that is an absurdly, ridiculously dangerous technology for power production on a planetary scale, even in the 24th century.

    • CarbonIceDragon@pawb.social
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      1 month ago

      Er, not really with fusion actually, unless you just mean “have made atoms fuse regardless of if it generates net energy or not” in which case we’ve had it for decades. We have managed net energy production if you compare the output of a very powerful laser used to compress the fuel to the energy of the resulting reaction, but crucially, the laser in question isn’t perfectly efficient, and only a fraction of the electrical energy put in is turned into laser energy in the beam. This means that we still don’t have net electricity production, and even once we finally get that, getting the tech efficient enough to produce enough electricity to be cost competitive will be a tough ask, especially as electricity from solar in particular has been going down in price of late.

        • CarbonIceDragon@pawb.social
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          1 month ago

          That’s what I was talking about regarding the lasers. As far I understand that result, it’s net energy in a physics sense, as in the reaction itself produced more energy than put in, but because the energy put in isn’t electricity itself, and the conversion process between electricity and energy in the laser is inefficient, the entire machine as a whole isn’t energy positive, just the reaction. It can’t yet be used as an electric generator, unless the reporting I saw on this at the time was inaccurate

          • EleventhHour@lemmy.world
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            1 month ago

            I get what you’re saying, and you’re right on many ways (especially wrt the energy conversion), but the barrier to producing net-positive fusion has been overcome. And it’s just a matter of scaling it up at this point— which includes overcoming many new hurdles such as (more) efficient energy conversion.

            But none will be so insurmountable as the initial creating of net-positive reactions. That was the big one, and we did it.

            • CarbonIceDragon@pawb.social
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              1 month ago

              I guess my objection then is that I tend to take “just scale it up” to imply “all the tech development hurdles are done, we have a working prototype of the machine we want to build, we just need to construct a physically larger one”, and so was taking the process of improving the efficiency of the reaction to useful levels and figuring out how to make a significantly more efficient laser as “we don’t have this technology done yet, because we still have these milestones left”. In other words, we’re just arguing from confusion over different definitions of a word rather than the reality of what those words are referring to

              • EleventhHour@lemmy.world
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                1 month ago

                I never claimed that all of the development hurdles were done. Far from it. But if you wish to object to my phrase, “just scale it up“, then you can certainly criticize me for oversimplifying the matter.

    • deegeese@sopuli.xyz
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      1 month ago

      We’ve accomplished fusion for 70 years. Problem is it’s always been 20 years away from being viable for general use.

    • hobovision@lemm.ee
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      1 month ago

      I’d argue that it wasn’t really “net-positive”. Certainly it was a positive energy gain, but it took way more energy to create the fusion than just the input energy. There is a ton of efficiency losses to create the input energy, which is defined by the energy in the laser beam that triggers the fusion. A lot of energy is also used to maintain confinement during the reaction.

      I would like the term net positive to be more inclusive of all of the recurring energy used to support the fusion. It’s fair to not include the energy used to construct the machines, but anything that would need to be put in to a fusion plant each reaction to get out energy should be considered.