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Wanderer posted:https://www.youtube.com/watch?v=u-fbBRAxJNk New tokamak design. Not a sustainable reactor, but its supposed to handle the plasma better than a standard torroid. Its called a stellarator.
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Oct 27, 2015 19:58
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CommieGIR posted:New tokamak design. Not a sustainable reactor, but its supposed to handle the plasma better than a standard torroid. The prime difference between a stellarator and tokamak design is that a tokamak has stronger magnetic fields on the inside of the torus, and weaker on the outside. This creates unbalances within the plasma that is contained, and has a bunch of knock on effects that can be difficult to deal with*. With a stellarator design, the plasma is twisted around as it travels though the device, swapping 'inside' and 'outside' parts of the plasma. The hope is that this smooths out plasma flow, and allows for easier management of the plasma itself. the downside is the magnet design grows horribly complex, and in fact this reactor at Wendelstein has been in the design phase for nearly 20 years. It's only recently that supercomputer simulation has become fine grained enough to allow testing and optimization of the magnet shape and position. If it works, however, it switches many of tokamaks ongoing operating issues to a one time design and manufacturing cost, which is very attractive in power plant construction. * Temperature gradients, uneven flow rates, variable expansion, containment weaknesses, etc
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Oct 27, 2015 20:13
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EoRaptor posted:The prime difference between a stellarator and tokamak design is that a tokamak has stronger magnetic fields on the inside of the torus, and weaker on the outside. This creates unbalances within the plasma that is contained, and has a bunch of knock on effects that can be difficult to deal with*. With a stellarator design, the plasma is twisted around as it travels though the device, swapping 'inside' and 'outside' parts of the plasma. The hope is that this smooths out plasma flow, and allows for easier management of the plasma itself. the downside is the magnet design grows horribly complex, and in fact this reactor at Wendelstein has been in the design phase for nearly 20 years. It's only recently that supercomputer simulation has become fine grained enough to allow testing and optimization of the magnet shape and position. Much better write up, thanks.
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Oct 27, 2015 20:38
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EoRaptor posted:The prime difference between a stellarator and tokamak design is that a tokamak has stronger magnetic fields on the inside of the torus, and weaker on the outside. This creates unbalances within the plasma that is contained, and has a bunch of knock on effects that can be difficult to deal with*. With a stellarator design, the plasma is twisted around as it travels though the device, swapping 'inside' and 'outside' parts of the plasma. The hope is that this smooths out plasma flow, and allows for easier management of the plasma itself. the downside is the magnet design grows horribly complex, and in fact this reactor at Wendelstein has been in the design phase for nearly 20 years. It's only recently that supercomputer simulation has become fine grained enough to allow testing and optimization of the magnet shape and position. Would this just be a prototype test reactor? Would it even have a positive net output? Is the idea that if this works it could be scaled up for positive net energy output, or does scaling make things even more horrendously complex?
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Oct 29, 2015 10:23
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Boten Anna posted:Would this just be a prototype test reactor? Yes. quote:Would it even have a positive net output? Who knows. So far no fusion reactor has done more than breakeven ( and I don't know if any has even truly done that). JET-60 achieved a theoretical Q of 1.25, but that doesn't really count because it was using D:D fusion; if it were using D:T it would theoretically have reached 1.25 but it didn't actually do that. For actual commercial fusion power you'd need a gain factor of around 20. quote:Is the idea that if this works it could be scaled up for positive net energy output, or does scaling make things even more horrendously complex? Yes to both.
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Oct 29, 2015 14:04
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Phanatic posted:Yes. NIF supposedly had a net positive output, but it was never meant to generate power, only that they got more power out of the reaction than was put in.
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Oct 29, 2015 14:07
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CommieGIR posted:NIF supposedly had a net positive output, but it was never meant to generate power, only that they got more power out of the reaction than was put in. No, they didn't, they weren't even loving close. It was only positive output if you count only the input energy absorbed by the fuel, which is only a *tiny fraction* of the actual input energy. Gonna quote myself from way the hell earlier in the thread when this utterly marginal advance was trumpeted by the press as a major breakthrough: quote:First, if you read the article you'll see that this "breakeven" isn't really breakeven, it's just breakeven if you only consider the energy absorbed by the fuel. Which is only the tinest fraction of the actual input energy. First they have to turn electricity into 3 megajoules of infrared laser beam, which they then throw away half of converting it into 1.5 megajoules of ultraviolet laser beam, which they then throw away some of converting it into x-rays at the hohlraum, and about 15% of those x-rays actually impact the target. These are flashlamp-pumped lasers, which are very inefficient; the *input energy is 422 megajoules.* NIF is a jobs program for nuclear weapons engineers who'd otherwise be out of work. It will never, ever, ever generate commercial fusion power, and it has never approached within several light years of breakeven.
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Oct 29, 2015 14:36
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Phanatic posted:No, they didn't, they weren't even loving close. It was only positive output if you count only the input energy absorbed by the fuel, which is only a *tiny fraction* of the actual input energy. Gonna quote myself from way the hell earlier in the thread when this utterly marginal advance was trumpeted by the press as a major breakthrough: Oh, drat, I missed that post. Good write up. Phanatic posted:NIF is a jobs program for nuclear weapons engineers who'd otherwise be out of work. It will never, ever, ever generate commercial fusion power, and it has never approached within several light years of breakeven.  Yeah, I know what it is.
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Oct 29, 2015 14:37
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CommieGIR posted:Oh, drat, I missed that post. Good write up. They're making big strides! They'll have it all figured out in another 20 years.
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Oct 29, 2015 15:20
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Deteriorata posted:They're making big strides! They'll have it all figured out in another 20 years. Even if the NIF was making any progress on fusion, I've still got my money on the Tokamak teams and the new Stellarator.
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Oct 29, 2015 15:38
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CommieGIR posted:Even if the NIF was making any progress on fusion, I've still got my money on the Tokamak teams and the new Stellarator. Bussard inertial confinement fo' life. 
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Oct 29, 2015 20:11
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EoRaptor posted:Bussard inertial confinement fo' life. Well, unlike Lockheed and their announcement, Tokamaks at least generate public data
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Oct 29, 2015 21:00
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Maybe we should focus on nuclear development until fusion some how becomes needed??
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Oct 29, 2015 21:51
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There are already lots of people focusing on nuclear development. It's not like there's some limited supply of science points that has to go to one or the other.
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Oct 29, 2015 21:54
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Baronjutter posted:Maybe we should focus on nuclear development until fusion some how becomes needed?? Even if we never deploy fusion at some massive scale on the grid, the research is still valuable. We shouldn't spend our R&D money on infrastructure. But yeah, I do agree we should be focusing on installing the most zero-carbon emissions power sources that will come on line as fast as we can as soon as we can rather than waiting for some mythical technology change in the future.
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Oct 29, 2015 21:56
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-Troika- posted:There are already lots of people focusing on nuclear development. It's not like there's some limited supply of science points that has to go to one or the other. However, there is a limited supply of scientists and engineers that have the expertise to do such. This is happening to the Salt Reactor expiriment in Oak Ridge, most of the people who ran/designed/planned it are aging and dying.
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Oct 29, 2015 22:05
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CommieGIR posted:However, there is a limited supply of scientists and engineers that have the expertise to do such. You fix that by training a new generation of nuclear engineers and scientists, not by telling people working in other fields that they need to be working on fission now. And you train that new generation of nuclear engineers and scientists by deciding to put down some cash to fund R&D in fission and to build new reactors (at this point I'd even go out on a limb and say "gently caress it, if the private sector won't step up then let's just build some government-owned fission reactors"). You can accomplish all of this without sacrificing any of the priorities in nuclear fusion QuarkJets fucked around with this message at 21:36 on Oct 31, 2015 |
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Oct 31, 2015 21:34
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QuarkJets posted:You fix that by training a new generation of nuclear engineers and scientists, not by telling people working in other fields that they need to be working on fission now. And you train that new generation of nuclear engineers and scientists by deciding to put down some cash to fund R&D in fission and to build new reactors (at this point I'd even go out on a limb and say "gently caress it, if the private sector won't step up then let's just build some government-owned fission reactors"). You can accomplish all of this without sacrificing any of the priorities in nuclear fusion Agreed. Fusion is a very different discipline to study. Fission plant design, construction, and operation have almost nothing in common with fusion research. You can argue about R&D dollar allotments between fusion and fission, but having very educated people swap fields is VERY inefficient and silly to boot.
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Oct 31, 2015 21:45
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QuarkJets posted:You fix that by training a new generation of nuclear engineers and scientists, not by telling people working in other fields that they need to be working on fission now. And you train that new generation of nuclear engineers and scientists by deciding to put down some cash to fund R&D in fission and to build new reactors (at this point I'd even go out on a limb and say "gently caress it, if the private sector won't step up then let's just build some government-owned fission reactors"). You can accomplish all of this without sacrificing any of the priorities in nuclear fusion Oh, I totally agree.
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Oct 31, 2015 21:47
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Too bad there's no poltical will to do that. I'm hopeing China has some break throughs before the poo poo really get bad and we have the Science Race 2 : Race for Fusion
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Oct 31, 2015 22:39
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QuarkJets posted:You fix that by training a new generation of nuclear engineers and scientists, not by telling people working in other fields that they need to be working on fission now. And you train that new generation of nuclear engineers and scientists by deciding to put down some cash to fund R&D in fission and to build new reactors (at this point I'd even go out on a limb and say "gently caress it, if the private sector won't step up then let's just build some government-owned fission reactors"). You can accomplish all of this without sacrificing any of the priorities in nuclear fusion See e.g.: The UK: heavily subsidising the initial restart of reactor building and having a bunch of specific nuclear development and operation courses, despite having a retarded right wing government at the moment.
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Nov 1, 2015 09:42
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I CANNOT EJACULATE WITHOUT SEEING NATIVE AMERICANS BRUTALISED!
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QuarkJets posted:You fix that by training a new generation of nuclear engineers and scientists, not by telling people working in other fields that they need to be working on fission now. And you train that new generation of nuclear engineers and scientists by deciding to put down some cash to fund R&D in fission and to build new reactors (at this point I'd even go out on a limb and say "gently caress it, if the private sector won't step up then let's just build some government-owned fission reactors"). You can accomplish all of this without sacrificing any of the priorities in nuclear fusion Since new fission reactors are currently being built, presumably there's R&D going on for conventional fission, to say nothing of all that's going into thorium development in India. I do not think we need to worry about losing the knowledge of fission development.
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Nov 1, 2015 16:02
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Hi guys, Do you guys have particular resources for energy storage? I'm talking large scale sorts of things that help intermittent sources like wind and solar be viable over night, in poor weather etc. I'm sure you've covered this extensively in the past, sorry for not reading the whole thread. Batteries are getting more common so I'm sure that's a thing, most especially Tesla's home batteries. But I've heard of some pretty wacky schemes. Like pumping water piston-style into old mine shafts, using I think the gravitational potential energy in a floater? It sounds dumb just to say, but what I read wasn't too far off from my spotty memory. I'd like to know about these things, whats good, whats dumb, and where its likely to go in the future.
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Nov 16, 2015 17:20
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Count Roland posted:Hi guys, Basically there are a few main approaches. * Some sort of pumped hydro: Good: low tech with a pump and generator plus concrete walls for an arbitrarily sized reservoir, just add more generators to increase peak power output. Can be very efficient. Energy can be stored for a long time. Bad: takes up tons of space. * Some mechanical solution like flywheels Good: another low tech solution that can run on dumb (if finely machined) steel structures with a motor/generator. Can spin up/be spun down quickly. Bad: bleeds off energy very quickly, so you don't want to run the things for more than a few hours * Compressed air Good: low tech once built Bad: giant pressure containers that don't leak are somewhat harder to build than the average spray can * Hydrolysing water/Synthetic fuels Good: Made from readily available atmospheric elements. Easily stored synthetic fuel. Can be burned in a typical combustion engine. Very energy dense and therefore takes up little space and is light. Energy can be transported around and stored for a long time. Bad: Synthetic fuel production doesn't seem to be quite there yet for large scale applications. Hydrogen is not quite as easily stored as hydrocarbons. Internal combustion engines produce dirty exhaust (though hydrogen/oxygen is clean). Not terribly efficient because physics. * Batteries Good: Moderately energy dense. Energy can be transported around by lugging a battery, though not as easily as by a can of gas, and can be stored for a moderate amount of time. Electric engines are common and making them larger is feasible. Bad: The entire energy storage medium is a mix of substances many of which need to be mined, processed and/or shipped before being assembled into a battery. Currently developed batteries with useful energy density for transport are expensive and use rare earths so you might not be able to build enough to power mankind for generations. Batteries don't last very long before wearing out. * Comedy option world wide smart grid
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Nov 16, 2015 18:11
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blowfish posted:Basically there are a few main approaches. Another mechanical solution I've seen installed is a electric rail system that pushes concrete blocks uphill and then generates power by riding the blocks back down (there's an automatic block loading/unloading mechanism). +80% efficiency.  Also, most of the grid scale compressed air storage I've heard about have used underground storage in salt domes or w/e rather than just a pressure vessel.
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Nov 16, 2015 18:20
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Trabisnikof posted:Another mechanical solution I've seen installed is a electric rail system that pushes concrete blocks uphill and then generates power by riding the blocks back down (there's an automatic block loading/unloading mechanism). +80% efficiency. That's hilarious. "So, pumped hydro works, right? What if we... pumped something denser?"
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Nov 16, 2015 18:34
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GreyjoyBastard posted:That's hilarious. "So, pumped hydro works, right? What if we... pumped something denser?" If we fill the water with algae and leave it pumped it will take carbon from the air and naturally increase its own density while in storage.  ?
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Nov 16, 2015 20:59
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Trabisnikof posted:Another mechanical solution I've seen installed is a electric rail system that pushes concrete blocks uphill and then generates power by riding the blocks back down (there's an automatic block loading/unloading mechanism). +80% efficiency. That's kinda neat. I like the idea of a Sisyphus machine. The other Con that wasn't covered about this and pumped hydro is the elevation difference required. You can't do it for most of America (as an example), because there aren't many 100+ meter elevation changes over relatively short horizontal distances apart from the Rockies/Appalachians. I'd argue almost none near large urban centers.
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Nov 16, 2015 21:31
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Also concrete is like 2t/m³, so you'd need to haul about half a water reservoir's volume of concrete to replace an equivalent reservoir, which is not terribly resource efficient. Well, in a desert it might make sense.
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Nov 16, 2015 21:42
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And pretty much all the sites good for hydroelectric storage have already been used for hydroelectric dams.
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Nov 16, 2015 21:54
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GreyjoyBastard posted:That's hilarious. "So, pumped hydro works, right? What if we... pumped something denser?" Pumped mercury storage. I want a silvery lake of mercury, shining in the sun and I will build a cabin on its shores. I will sit and stare at what we have done and as it sparkles, weighty on the earth, every day enjoy my growing madness. ductonius fucked around with this message at 04:56 on Nov 17, 2015 |
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Nov 17, 2015 04:49
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ductonius posted:Pumped mercury storage. I want a silvery lake of mercury, shining in the sun and I will build a cabin on its shores. I will sit and stare at what we have done and as it sparkles, weighty on the earth, every day enjoy my growing madness. You are Qin Shi Huang and I claim my five pounds.
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Nov 17, 2015 05:45
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blowfish posted:* Batteries Do batteries actually require rare earth elements, or is this like when you tried to claim that solar cells require rare earth elements earlier in this thread, i.e. you are pulling this out of your rear end? Also lol at your "they don't grow on trees" argument.
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Nov 17, 2015 14:29
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silence_kit posted:Do batteries actually require rare earth elements, or is this like when you tried to claim that solar cells require rare earth elements earlier in this thread, i.e. you are pulling this out of your rear end? Also lol at your "they don't grow on trees" argument. You can probably make designs that don't require them, but currently (or so the assertion says) those designs don't exist/aren't used. Also mining is a pretty major (in terms of volume anyway; it's actually pretty stupid) argument against fission so I don't see why it wouldn't apply here.
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Nov 17, 2015 14:31
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Trabisnikof posted:Another mechanical solution I've seen installed is a electric rail system that pushes concrete blocks uphill and then generates power by riding the blocks back down (there's an automatic block loading/unloading mechanism). +80% efficiency. edit: nevermind this is an energy storage system, yes? I just said something real dumb but edited it out. I bet you can guess what it was.
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Nov 17, 2015 14:35
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computer parts posted:You can probably make designs that don't require them, but currently (or so the assertion says) those designs don't exist/aren't used. Rare earths refer to 17 elements and there's plenty of battery chemistries that don't involve any of them such as zinc-air or lead-acid. What he means - I'm guessing - is that batteries with a reasonable energy density require expensive and rare elements such as the lithium batteries in Teslas powerwall. Personally I find it odd to pay a premium for energy density on the utility scale so I don't think lithium will really be used there - it'll probably be flow batteries and other chemistries to optimize for cost rather than size.
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Nov 17, 2015 14:42
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computer parts posted:You can probably make designs that don't require them, but currently (or so the assertion says) those designs don't exist/aren't used. If he's misusing the term rare-earth element and is trying to claim that lithium is scarce, I'd be interested in reading about that. People are usually hysterical about the scarcity of resources, so I take those claims with a grain of salt. Still, I'd like to read about it. computer parts posted:Also mining is a pretty major (in terms of volume anyway; it's actually pretty stupid) argument against fission so I don't see why it wouldn't apply here. It's not only the mining, but the "they have to be manufactured" argument I find hilarious. You can make a detailed argument about the cost of the manufacturing, but complaining that batteries don't grow on trees is pretty funny.
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Nov 17, 2015 14:43
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Anosmoman posted:What he means - I'm guessing - is that batteries with a reasonable energy density require expensive and rare elements such as the lithium batteries in Teslas powerwall. Yeah, that was actually explicitly stated: quote:Currently developed batteries with useful energy density for transport are expensive and use rare earths(...)
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Nov 17, 2015 14:44
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computer parts posted:Yeah, that was actually explicitly stated: Rare earth elements and elements that are rare are different things, is what I'm saying.
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Nov 17, 2015 14:53
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Oberleutnant posted:edit: nevermind this is an energy storage system, yes? Did you go off on one about scam power companies fiddling the taxpayer by pumping water back into hydro dams? For a qualified civil engineer my stepdad can be a bit dim sometimes.
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Nov 17, 2015 14:58
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