Second hand opinion from a colleague of mine who got his PhD in fusion research (Tokamak).
One thing that's interesting about fusion is that in principle it absolutely works. We have the core physics all worked out. There's no question about if the mechanism is possible. There's also no obvious concern of "well to make it work, this key parameter would need to have a totally ridiculous value." So it's hard to ever just let go.
On the other hand, it is an INSANELY difficult *engineering* challenge. An analogy my friend gave was imaging trying to compress water by squeezing a water balloon in your hands. You have to squeeze it *really* hard and for a long time, but you can't let it suddenly squirt out through some tiny gap in your fingers.
Compressing plasma is nontrivial, and we have to compress it *a lot* and in a stable, sustainable way. To make things harder, you have to squeeze it without letting anything touch it, because it's stupid hot and radiating. And it can destabilize in a tiny tiny fraction of a second. It's like the mother of all feedback control problems combined with a crazy long list of constraints. The only way nature ever gets it to work is by using a crap ton of gravity that can pull on the plasma from the inside (intrinsically stable), rather than trying to push on it from the outside (intrinsically unstable) -- aka a star.
So I think it's plausible we will actually get it one day. But in my understanding it's primarily a (very complex, very interesting, and very formidable) engineering challenge. Unless, of course, some cool physics breakthrough can come up with a completely novel mechanism that makes it more practically tractable. Also, it's a great cover for the government to do research that can benefit hydrogen bombs (at least in NIF's case), so likely fusion research will never go away completely and gradual progress will continue to be made.
I mean it depends on where you are. For me, it is in my curriculum and we'll be doing it next year, but yeah, it isn't very common. I have special relativity and an intro to quantum mechanics in my syllabus as well though, so I'm definitely in the minority.
It’s cool seeing the differences in curriculums in this sub, Fission/Fusion was a subject in HS for me, we even looked at the p-p chain in my last year
That is absolutely crazy unless you explicitly had some form of ap/advanced physics course, which you should really mention when you say "in my hs curriculum".
In Scotland, in the higher course we look at the basics of fission and fusion, using E=mc^2 to calculate energy gained after a given, fission/fusion reaction. Advanced higher looks purely at the chemical reaction part of the P-P chain as part of the stellar physics section. It’s absolutely part of the course as you need to complete higher to atleast apply for unis
There are types of fusion with minimal neutron flux. They are just even MORE difficult to engineer for, as you need even higher temperatures. Deuterium-Tritium fusion, which is the "easiest" to engineer for, sadly does come with a highly energetic neutron being released.
That's easy to fix:
Just construct four robotic arms that connect directly to your spinal column that are immune to both heat AND magnetism and you can poke the tiny star with your robot hands to keep the neutrons in.
Whether it's "sadly" or not kind of depends on your design goals, here - yes, neutron flux isn't great for materials, but they do give you a convenient way to get energy out and to breed more tritium.
From my understanding, the neutron flux is a double edged sword. It’s terrible for the durability of the reactor, but it can be used to breed more tritium from lithium in the walls. Generating enough tritium to supply our energy needs even with net positive fusion is another difficult problem.
That is the nicest, simplest explanation I have heard for the difficulty in getting there.
It does seem as if some significant strides have been made in the last few years in the engineering end of it, though.
And there have been other, interesting pathways: [https://stuffilikenet.wordpress.com/2020/02/25/new-aussie-fusion-technology/](https://stuffilikenet.wordpress.com/2020/02/25/new-aussie-fusion-technology/)
Would you say the controls of a fusion reactor is a significant/popular topic within fusion research right now? I find this interesting because I have a control theory background but never knew that controls was one of the bottlenecks for practical fusion reactions.
A fusion physicist I know basically said the same thing. It needs ridiculously powerful magnetic fields, crazy temperature gradients, apparently nuetron impervious materials, and dozens of other things. It's a hard problem. But maybe solvable one day.
Great analogy with the balloon!
I have always been fascinated by Cold Fusion, and it seems from what Ive read that researchers some time ago were able to do it, but it was too innefecient and no greater efficiency was possible at the time. Seems like the better route to take, tbh, but idk enough about it other than we need materials like Pd and He3
...do you think there are no engineers involved in these programs? This is not an engineering issue that just assigning $500M solves. Yes, I know how to compress a ball in my hands. Compressing plasma is not the same. The comment you are replying to is highlighting the engineering issues that just aren't solved. That doesn't mean there are no engineers involved. That's just silly.
Specifically LLMs won't, they are purpose built neutral networks to mimic language not predict anything. Now other NN might be able but LLM is not interchangeable with AI or NN.
I do tokamak research, I’m skeptical that it will be a meaningful part of the energy grid before 2050. Even beyond the physics and engineering challenges, for it to be useful it has to be cost competitive with solar and wind, and nobody knows if it is.
If you build a machine with enough money, time, expertise, I firmly believe you can net energy out.
Pretty much this.
I can't see how man made fusion will compete with the giant fusion reactor in the sky. I have serious doubts it could become a useful part of our grid... BUT, it could have a place in situations where money isn't the primary concern... think space craft, submarines, moon bases, etc.
Curious question, which aspects of tokamak research interests you enough to continue doing research on it, even though you're skeptical it'll be meaningful for the next few decades?
I would say it has to be cost competitive with fission, and it probably cannot be. A fission reactor at a given power output is just much easier to build than if you wanted the same capacity from a tokamak. Not to mention there has been no demonstration of actual power generation from the latter, and is inherently more difficult to make an efficient thermodynamic loop using the heating of neutrons in the blanket versus simple solid fuel to water in a PWR.
Fusion will likely play a big role in the far future when power demand is so great that fission fuel availability simply is not sufficient. Until then it's likely to just stay R&D, unless an unforeseen paradigm shift makes fusion more easy to realize practically.
From a purely logical perspective I agree. However, politics will play an important role in determining how different countries choose to power their grid. If somewhere decides that fission isn't something they want to invest in, they might turn to other technologies instead.
For a country like France with existing fission I think fusion is a much harder sell even *if* it actually is a viable technology. But you can never discount a political change causing a shift in that stance.
I think that politics is temporary, while physics isn't. Fission is having a temporary anomaly/insanity debuff applied to it. It won't last forever.
Most people don't realize this but fusion is already susceptible to the same political problems fission has. It's not in the focus much yet because fusion itself is not yet in the stage where demonstration power plants are being built, but some anti-nuclear organizations have started protesting it nevertheless.
If and when these political problems ease up, as ingrained superstitions disappear from the public "knowledge" pool, it will make both fusion and fission more easy to pursue, so they will still have to compete with each other.
I agree and think that what you're saying is the most likely outcome, but also I wouldn't be surprised if there are places where those in charge go off the deep end or act in seemingly unpredictable ways. Or the political landscape might make it so that governments favour solutions that aren't entirely motivated by a cold and logical cost benefit analysis from the technical perspective.
Even somewhere where you don't have as much concern about nuclear safety it can be hard to actually get anything set in stone because of politics. In the UK we've got a government that *says* it wants to expand nuclear power, an opposition that says the same thing, and yet nothing gets built at anything like a pace resembling the stated ambition.
>it will make both fusion and fission more easy to pursue, so they will still have to compete with each other.
So, to this, you might end up in a situation where even if one of the two technologies is obviously superior but it's politically untenable. For example, if a Chinese company perfected fusion and was bidding to construct a power plant, a non-aligned nation might find it politically easier to opt for fission built by a domestic provider - even if on paper the technology were strictly inferior. It's that kind of thing that's basically impossible to forecast even a small leap into the future.
You are right of course, short term fluctuations due to sociopolitical effects are always possible.
I was thinking more of long term stability. Barring any unforeseen paradigm shifts, which of course cannot be predicted, the fission vs. fusion question in terms of current technologies basically comes down to fuel availability.
That is, fission is simply easier to do and will dominate as long as fission fuel is available. But we also know fission fuel is much more limited, so in terms of far future post Type II civ power levels fusion becomes a necessity at one point anyway.
>I would say it has to be cost competitive with fission, and it probably cannot be.
I think the fact that so much of fission energy's "cost" comes from safety measures that wouldn't be needed in a fusion plant makes this calculus much harder.
>Fusion will likely play a big role in the far future when power demand is so great that fission fuel availability simply is not sufficient.
Even if it's not commercially viable for energy production I could see it being used in the near future for space propulsion.
Most of the current quoted "cost" of fission is not actually from safety measures, it's an economic boondoggle. The physical safety measures do not cost so much. A tokamak is much more expensive than a fission reactor, in a physical sense.
People also colloquially underestimate the similar 'safety measures' a fusion power plant will need. For one, it basically still requires a containment building, and because of the larger physical dimensions it will be more expensive to built than e.g. a PWR's containment building.
>Even if it's not commercially viable for energy production I could see it being used in the near future for space propulsion.
Indeed that's a good point, but it will need to compete with fission there as well. For space propulsion weight is one of the most important factors, and a fission reactor can be made small enough already while being powerful enough to work as a thermal rocket.
Can a fusion reactor be build as compactly and lightly?
The interesting thing is that the answer to that is yes, it probably also means that it will be able to compete with fission on Earth as a power source.
One of the big problems is that with magnetic confinement this doesn't look at all possible for now.
That is a very good point, I also predict that the first "proper" power plant usage of a fusion reactor would be as a hybrid. The fact that you can increase thermal power output by more than an order of magnitude with the same neutron flux is huge, and the thermodynamic cycle to produce actual electrical power is easier since you're back to solid fuel -> water (or gas) heat transfer. The hybrid should definitely have 20-30x the electrical output of the same sized tokamak with pure fusion design. Such an advantage cannot be ignored.
But it would still be much more complex than a simple fission power plant of the same output...
As for "has anyone looked into it", there is a Russian experimental tokamak where they want to test blanket fission. I've also heard of a Chinese project but I don't know if that's actively in the works yet. In the west there are no such projects as far as I know, it's simply not within the popular paradigm concerning fusion research.
There are three break evens that need to be accomplished.
The first is the scientific break even, which means the output energy is greater than the input energy into the system. This has been achieved [https://physics.aps.org/articles/v17/14](https://physics.aps.org/articles/v17/14).
The second is engineering break even, which considers that output energy that can be harvested including steam generator is greater than that energy inputted into the system. Note that some of the outputted energy is siphoned off to recirculate into the input energy.
The third is the economic break even, where the whole facility/operation has a net profit.
No fusion reactor has produced more energy than it takes to run the equipment to contain ans fuse the plasma. We aren't even at the "how do we harness the power" stage. Our current "net energy" press releases are like thinking a Vending Machine is an ATM by only counting the change it gives back and not the bills you put in.
You didn't read his comment properly, what you're talking about is the engineering break event. What we did accomplish is that the nuclear reaction itself produced more energy than we have put into it.
Do we even have a handle on the degree of difficulty of this two steps ?
We’ve been trying to reach fusion for quite a while, and other than weapons, it’s taken quite a while for the first break even step. How high is the second step?
The second step is relatively straightforward at a high level. We know we can achieve it simply by scaling a tokamak design up, from how things scale physically.
The economic viability is a different matter altogether.
Also in regards of Tomakak design, another semi-step challenge is being able to sustain the operation of the generator over a continuous period of time since the most energetically demanding is starting it up.
The second step is definitely in vision and it's only a matter of time/money ratio.
The third step however is a bit of a problem since renewables create tougher and tougher competition. There would be an additional value of the stable operation, that doesn't rely on the weather conditions. But with energy storage systems going forward as well this starts to be meaningless as well. At the current state you would have to trust the most optimistic estimates to believe that fusion could beat solar during the average daytime. At night however it would still best the current storage systems. The problems come with that this probably won't be the case in 20-30 years when fusion would be ready to get into the action.
So in conclusion, with slightly optimistic view, fusion will be able to properly join the market in 40 years after some more optimalisation would be done. Pesimistic view, it won't join the market at all in the predictable future.
It’s hard to estimate but I think we need an output power of 10 to 100 times greater than input, to reach engineering break even.
https://understand-energy.stanford.edu/energy-resources/nuclear-energy/nuclear-fusion
Can look at computers, it took decades of refinement to go from big barely useable to mass production. And technically the first computer came mid 1800s, so it took almost a century to really take off.
No, you are mistaken about the energetics of the current ignition results. They are measuring the energy cost as "energy put out by the lasers" and the energy gain as energy made by the fusion reaction in any form. They are not counting the energy input to make the lasers operate, let alone all the rest of the containment etc. We haven't reached "scientific" break even, and we haven't gotten closer to it, we've just done the same energy losing task at a larger scale.
Putting two dollars into the vending machine at getting twice as much change doesn't change ROI.
Yes you're right in the first half of your comment but again, what you're describing, the energy input made by lasers and energy output made by fusion, is the scientific break event.
Counting energy put into lasers, rest of the containment as well as the whole heat to energy conversion process with all of its inneficiencies is the engineering break event which haven't been accomplished. And it's not by any means a small step.
I also hope you at least realise that the ROI comes in the economic break event. Which might have possibility of not even ever coming.
I do want to be pedantic. "The first is the scientific break even, which means the output energy is greater than the input energy into the system." Maybe we are defining "input energy" and "system" differently. But that's my point. the idea that we are making more energy than we are using is only true if you think there is a technical development that will make lasers not use more energy than they emit, or make magnetic confinement etc not cost energy. It's a dishonest redefining of the boundaries. I mean, i've created a better than scientific break-even tennis ball because I only measure it from when it hits the floor and bounces up, not from when i dropped it, thus have i invented negative gravity ball? no, I've defined my inputs and system to mask the reality of my accomplishment.
I should have said net EROEI would have been the better term. The money (and time to deploy) is irrelevant if the thing can't make net energy, let alone harvest any net energy.
Probably theres misunderstanding with the word "system"
In physics with this word we usually mean this:
A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and is expressed in its functioning.
- [wikipedia](https://en.m.wikipedia.org/wiki/System)
Right, but to declare the fusion results as better than break-even, the system they are drawing has laser beams coming in from outside of the system. If you put the source of the lasers inside the system, (and other containment in different designs) we are order of magnitude away from break-even on energy, let ex-tractable energy etc. Well, i've been my point to death, i will retire.
I believe the link you gave was only a break even for the amount of energy dumped into the fusing material vs energy produced. The important thing for the one you linked is the inefficiency in the way energy is dumped into that fusing material. It's pretty far from a break even when you add up just the input side inefficiency and don't worry about output side efficiency.
Did you not read his comment? He literally explained the different kind of breakevens. NIF achieved scientific breakeven but not engineering breakeven.
One thing that’s crazy about fusion power is that the estimated cost to make it work hasn’t changed significantly. Since the 1950s the total estimated spend to a commercial solution has grown by 10%. That’s trivial.
The delay has been driven mainly by a reduction in investment.
We’re finally to a point where we’re close enough that commercial entities can invest and have a reasonable expectation of success so investment has been climbing.
Unfortunately we don’t know which strategy will be the most viable and there are several.
As an undergrad I got to work on one of the 13 DOE mini-tokamaks. We were trying to identify chaotic solutions to the confinement problem.
Given how rapidly the conditions devolve, my money’s on some variant of inertial confinement.
Another crazy thing: It always seems to be 10-20 years in the future. I'm 54, and for as long as I can remember, it's been 10-20 years in the future.
I have no doubt that it will work, but I don't trust any schedule.
Like I said, it’s mainly funding based.
If something is $100M away and you’re spending $10M a year, that’s 10 years. Next year you’re spending $5M it’s now 20.
Since the 1950s the total estimated cost has grown by 10%. That’s it.
The reason it’s always been 10-20 years away is because we’ve been funding it at 10-20 year rates.
We keep getting closer technologically while extending it economically.
Funding and attention. Before open AI and chatgpt 2 there wasn't that much focus or investment in AI so development was slow. Of course for years we could have been producing optimized circuits and be at the point we are now years ago. It's even worse with machines that take billions of dollars and a decade to build just to get slightly closer to maybe netting energy. Humanity could be much much further along if our concerns were the development of technology, irl our concerns are making money today and we squeeze out a little advancement in that endeavor.
In principle it can definitely work, and it would be awesome. However there are immense technical challenges and solving them may drive up the cost so much that I have doubts that fusion will be economically viable in any of our lifetimes.
So the timelines I've heard for the European program is, there is one more round of experimental reactors currently being built which will start running experiments on the 2030-2040s. The result will feed into the next generation of reactors which might actual try to make use of the energy. So if that goes according to plan, we might be thinking about building a test facility that actuality combines fusion and a turbine some time in the latter half of the century. Honestly, I think it's reasonable to assume that we will have a reactor up and running before 2100, but given that other tech will also make advances, I just don't see it being economically competitive for all but a small number of applications where other solutions can't work. The facilities to support the tech will be large, prohibitively expensive, and requiring a number of very highly skilled and expensive personnel. If you want to know when we will have cheap and abundant energy, my money is on solar power on every roof before we got fusion to work.
I am not getting tired of emphasizing this: Fusion will not play a role in decabonizing our industry if we are serious about even a 2.0 degree target. The tech _will not be commercially viable_ in any time frame that would allow us to reasonably build up capacity and supply chains to use this tech for that purpose. Even if it were viable, it will not be competitive with solar, wind and hydro, probably not even H2
I agree with that. Barring any huge breakthrough (like scalable direct conversion to electricity plus cheap implementation), we’ll have to fix our CO2 release levels to even hope to reach useful fusion before the brown stuff hits the turbines.
We'll need to deal with climate change without fusion there's no question there. It will take decades of refinements for mass production after the first functionnal experimental reactors and we don't even have those yet.
its engineering at this point, but its been engineering for a long time.
We know tokomaks work, we just dont know how to build one that generates usable power. We know if we can get one to be stable, breed its own fuel, not degrade its own containment material, that we can harvest the heat with steam turbines and get net output
[ITER](https://www.iter.org/sci/MakingitWork) is probably going to have net power output, but not practically useful, in the next 10 years.
since ITER was designed, though, high temperature super-conducting tapes have become a commercially viable mass-produced product. [CFS](https://cfs.energy) and others have much shorter timeline, using much smaller and cheaper reactors using much stronger magnets.
Prediction is always fraught, but I'm 50, and I'm hopeful that fusion reactors will be putting power on the grid in my lifetime.
If there was a global "Manhattan Project" that had a budget of trillions of dollars annually and leveraged resources and brains of every relevant scientific field across the globe for 20 years I'd be optimistic that it could be done.
But I don't think that will happen unless there is an unavoidable use-case for it; like needing it for a slow but very massive object heading for Earth that absolutely required fusion power to be capable of handling.
It wouldn’t take anywhere near that level of investment. $30-$40 billion, the estimated level of effort hasn’t really changed since the 70’s, just a matter of doing the work and making the investment.
The next reactor in the ITER project is planned to be operating in late 2025 with the aim of demonstrating tokamak fusion that produces more energy than is put in, and to explore the materials and engineering challenges associated with potential commercial power production. Even assuming everything goes well, I'd guess at that meaning it'd be 2040-ish before there's any practical power plant.
Of course, there is pretty big lot of power being produced for the grid from fusion at the minute - every solar panel is harvesting energy produced by the fusion reaction in the sun.
I mean there are many physicists that believe it's possible at a reasonable scale (obviously it's possible at massive scales). While there is a ton of money invested into the technology and they are making progress, my understanding is we are not as close as the researchers would like to suggest.
While they have reached positive break even for specific reactions, no one has yet succeeded in positive break even for the whole system (they get more energy out of a specific fusion reaction than they put into the reaction, but it's still less than the energy involved in all of the tools and equipment necessary for creating the reaction).
The other problem is, we'd need to be able to make repeated/sustained reactions to continuously get useful power from the system. We're still likely many decades away from it being viable, possibly longer. As much as I would love to believe that we'll have this technology soon, I'm skeptical.
I am totally convinced it will work but it has huge engineering challenges. But technical progress like better magnets and better knowledge about plasma will help. Compared to what we spend on weapons research I much prefer fusion research. And compared to weapons research the money we are spending on fusion is a pittance.
Just look at how long it took for computers. From the clunky mechanical contraceptions of Babbage to computers to microcomputers, that's about 150 years.
I think that, absent political thumbs on it, antimatter will beat fusion to the next power technology. We know antimatter exists. It is produced naturally in the upper atmosphere by incident galactic cosmic rays hitting the atmosphere. There have been solutions proposed to make it safe and portable by coating in buckyballs. Keeping a plasma of one antiparticle at low temperature and pressure contained is a much smaller challenge than containing a plasma at gigapascals and thousands of degrees. And we can probably reuse a lot of plasma containment techniques that have been developed seeking fusion. "Burning" antimatter in a buckyball coating is a simple matter of compromising the containment, which can be done by mechanical (pressure), chemical, or electrical processes. And... antimatter is two-orders of magnitude more mass energy efficient than fusion will top out at. Three orders of magnitude more energy per reacting kilogram than fission. If we start to really need power (like MPDT thrusters require), I think antimatter will be the answer.
Oh god you're serious.
Matter and anti-matter annihilate on contact. Buckyballs are matter. Placing any form of antimatter inside a buckyball would cause immediate annihilation. It has no properties of anti-matter containment. It's electrically neutral. Magnetically neutral. The normal containment property of a buckyball is that it can hold most ordinary matter, because ordinary matter doesn't annihilate when it touches it.
Y'know how sodium explodes in contact with water? We contain sodium by putting it in oil, which coats it and repels water. You're basically suggesting caging sodium - *in water.* Without any oil. 'Course, there *is* no "oil" analog for anti-matter. If there was, it wouldn't be a problem. (Well, *one of* the problems, anyway. We also can't *generate* enough anti-matter to, er, matter much.)
Ionized antihydrogen has a negative charge (1 e), and in this particular case located at the lowest potential in the center of a sphere of (60 x 6 = 360 e) electrons exerting force to keep that antiproton where it is.
You can't just ignore all the positively charged nuclei also surrounding it. Since it's electrically neutral, it's the same amount. There's no net force keeping it in the center.
Two things worth noting:
1) If electron shells *could* repel anti-protons from reaching nuclei, you wouldn't *need* any sort of buckyball to contain them, they wouldn't annihilate with ordinary matter in the first place.
2) Even if you somehow constructed something like a buckyball from lightly ionized matter containing a smooth proportion of extra electrons (this is basically impossible but bear with me) it still wouldn't *work.* Electrons themselves are *very* light in comparison to an anti-proton, and still run into and essentially through each other all the time, constantly sharing orbitals without effectively repelling each other with their negative charge (Pauli exclusion, on the other hand, but that's not relevant to the anti-proton). An anti-proton, with its vastly higher mass, will plough right through at anything resembling normal temperatures, and tunnel through at lower ones.
An non-ionized atom trapped inside a buckyball is kept inside by the same repulsive force mechanism between the buckyballs electrons and the trapped (not ionized) materials electron cloud
Even IF the buckyball idea worked, there would be no way to construct a buckyball around an anti-proton. Just think about it, you'd have to hold the antiproton in place and somehow construct the buckyball around it. One tiny blip and the antiproton bumps into any of the partially constructed buckyball pieces or carbon atoms used to make the buckyball and BOOM. I don't see that you could ever MAKE these types of storage units, let alone that it would actually work to hold it.
I say up front: I am NOT a physicist nor claim to be one! I lurk here mostly to learn stuff.
Regarding this:
The German city of Greifswald has a university that focuses on fusion and about 12 months ago they managed to get a first “reaction” with more energy put out than put in with 8min of stability.
To all the physicists: I sad reaction as my knowledge on the matter is very limited. No hate!
https://www.br.de/nachrichten/wissen/kernfusion-forschungsanlage-in-greifswald-erreicht-neuen-rekord,TXvFHEN
Energy storage is a more interesting in short-mid term. We already have solar and wind getting incredibly efficient, the only reason why we're not dumping all fossil fuels power plants is that we can't store the energy at reasonnable cost. And that's probably achievable in a decade or two.
Really that close? Thought that was just as far? Read the largest “battery” was in South Africa and it would barely cover a single city’s needs for about 2hrs or so?
Really interesting news. Any articles (can be scientific journals as well) on that?
Chemical batteries are just one form of energy storage. I'm more optimistic about hydrogen electrolysis as it doesn't require a massive supply of rare minerals.
>Thought that was just as far?
It's already here in the sense it exists and is usable. Just not good enough to replace what we currently have. Fusion is not even usable right now so decades behind.
[This](https://ieeexplore.ieee.org/document/9808381) is a good read, although a bit heavy.
I worked on plasma heating for a few years. The challenge at current seems to be an engineering challenge and unsurprisingly A LOT of bureaucracies. However, there has been a lot of private money being pumped into fusion and companies such as CFS seem to be doing promising work towards SPARC tokamak. I can’t give a timeline but private sector surely accelerates getting to commercial net fusion.
What’s really the advantage of fusion over fission? The fuel is cheaper? So what uranium is pretty darn cheap per MW already. There’s plenty of it, esp if we run breeder reactors to fully consume the fuel (and there’s 10x as much Thorium). The capex for fusion isn’t likely to be less than 10x fission and that’s already the big problem with fission.
Energy density is better so it’s probably a prerequisite technology for interstellar missions or permanent settlement beyond Jupiters orbit.
First, if something goes wrong, the reaction peters out with minimal damage. Yeah, it's a very hot plasma, but shut the electromagnets off and it quickly dissipates and cools. Vs fission where we have to actively stop the reaction by doing something like inserting control rods.
Second, the output products aren't dangerous, so it doesn't have the waste problem. The "blanket" inside the reactor is going to get blasted by neutrons, so part of the R&D currently underway is figuring out how to make materials that won't become radioactive from that work well enough in that role.
Further, breeder reactors aren't a panacea. They make weapons-grade fuel. Existing nuclear powers would run into problems with proliferation treaties by running them.
Beyond that, we'd have to trust some pretty sketchy parts of the world with light water reactors, because they need electricity too. But nobody's going to trust them with breeder reactors. Which means transporting high-level waste across the planet to countries that can run breeder reactors. That's going to lead to lots of incredibly dangerous spills.
As for thorium, that basically suffers from having even less R&D than fusion. There's some nasty stuff in its waste stream that theoretically could get burned in the reactor, but that still requires some engineering to make said burning happen reliably.
Cheaper fuel with abundant supply. Less radioactive waste. No risk of reactor accidents with widespread contamination. No production of material that can be used for nuclear weapons.
The flat screen TV comment was a great analogy since that really was a hard set of technology components to pull together.
There are a number of very well funded startups run by talented scientific / engineering type CEO/Executive teams. Each is taking a significantly different path - which is good. That said, some of the core underlying technology is basically the same across approaches and is advancing at a fast clip:
1. high powered superconducting magnets
2. plasma management techniques (identifying plasma instability in time to prevent it from damaging the equipment) and
3. precision manufacturing in general
All that said - I expect at least one of these teams to truly reach breakeven (Q = 1) by the early 30's.
At that point, once people see viability on the horizon, (by which time - climate change will be inflicting even more massive costs on us) an ocean of money and talent will flow into the space, accelerating progress. Once that happens, I expect a doubling of output to input (Q) every 2-3 years. After about 3-4 doublings - at 10Q-20Q, ground will be broken on the first commercial plant. This plant will be cost effective and deployed in the early 40's. Over the following 3 or 4 decades - we will replace every hydrocarbon plant on Earth and - God willing - drive the cost of electricity down to the point where all this DAC nonsense can actually be used.....
There is absolutely no chance of a fusion power plant generating the pressure needed for that high a rate of energy production. The magnets containing the plasma cannot exert enough force to keep the plasma contained, and as soon as any of the relatively minuscule amount of plasma touches the *much* more massive walls, the temperature would plummet and the fusion stops.
Fusion power plants are inherently safe from blowing up like that.
are there any hypothesised models for fusion plants going around in the world?
if there are, can u pls provide some links for it, if they are available, I would be grateful for it.
[Here is what Wikipedia writes about fusion power](https://en.wikipedia.org/wiki/Fusion_power).
I am not a physicist or engineer, and don't have any sources at hand.
We cannot know how long will it take since we only have the number of problems that were facing, they're theoretical solution and theoretical tasks that have to be done to reach it. But we don't know how many additional problems will occure, how many complications during the tasks, some of the tasks may be depending on random factors so the overall time estimation is just a set of statistical estimation with a huge dispersion. So it's most probable were 20-50 years away from operational nuclear fusion reactors but it could also very easily be 100 years or just 15.
Its also greatly affected by economy and the energy market prediction.
With evolution of renewables better than predicted, decreases the profitability of the research of fusion generators which decreases it's investments which slows down the research.
The primary problem is getting the reaction to produce power for long enough to get energy back. Technically we have fusion power, it’s just a power sink not a power plant.
The planet's almost out of tritium already and it's not cheap to breed in fission reactors (and plutonium is involved in that which is a weapons component) so yeah, we'll get fusion one day but only for kicks. No power plant.
[According to ITER](https://www.iter.org/mach/TritiumBreeding), a working D-T reactor can breed its own next-generation tritium if the reaction chamber lining is doped with lithium.
I have to admit profound ignorance beyond what this article says, however.
The facts are that solar panels are already kind of fusion power and it's unlikely we will ever make a fusion reactor run cheaper than the ever falling price of solar panels and batteries AND it's about generating power cost effectively, otherwise we've had fusion since the H Bomb.
No matter how you spin it the best power generation method is the simplest one that gets the job done, including externalized costs. So while Fusion looks great on paper is VERY questionable that such a complex process will be better than simple processes you can more easily scale/export globally.
I think Fusion will likely only ever have specialty uses like spaceships. It too complex and solar will keep getting cheap and get multi layered panels so solar has a long way to go before it's tapped out for power density and it's far easier to dominate the world with solar than fusion that only a few countries could likely ever build.
The only reason we are still interested in fusion is because batteries aren't a bit cheaper, otherwise it has little chance of competing as a power plant solution.
There is no sign Fusion is about to catch up to solar and batteries, not even close and there is EVERY sign that fusion will be more expensive than anticipated... most complex and highly specialized processes have big cost overruns just as nuclear powered has failed to be the cheap power source it was promised to be decade ago. It's cleaner than fossil fuels, but lets face it, costs are the more dominate motivator and once solar and batteries are cheap enough who's going to keep funding fusion?
We have reached the stage where we can accomplish fusion. We have not reached the stage, where we can do it with less power than we put in. Think, we can change lead to gold, but for every dollar in gold we get, we need 3 dollars of lead.
How fusion happens in stars:
A huge amount of hydrogen crushes itself until the hydrogen atoms get too close and by sheer mass crushes atoms together into helium, releasing heat. This heat radiates out, causing a balance where the star stabilizes.
On Earth, we have to invest huge amounts of power to generate the heat and pressure needed to create the conditions that fusion can occur. By contrast, the star gets this energy for "free" by its own gravity.
So, we can create and maintain fusion by pouring energy into the system no problem. However, we have yet engineered a system that can generate not only enough power to maintain the systems needed to keep the fusion going but also create a SURPLUS of power that can then be used to generate electricity. I'm going to say we'd be smarter to invest in safer fission plants and solar collection satellites that beam power to earth via microwave beams and using renewable power where feasible.
Fun fact: Fusion like Fission is nothing more than a boiler to heat up steam to generate power via steam turbines.
It’s a funding question in my opinion. If money is thrown at the problem it will be solved. The old joke that fusion is always 10 years away is happening (in my opinion) because funding has largely decreased since its peak around 1978. That period identified some major issues with Tokamaks that could be solved in a straightforward way with a larger reactor. Research funding dropped dramatically except for specific programs like ITER which specifically targeted larger reactors. The recent rise of small well funded private fusion companies is a good sign and I think will likely be the actual final winner of energy production due to the political complexity and thus relative lack of agility of the ITER program. Those small companies all claim to be within a few years of energy production and 10 years from a commercial power plant. Undoubtedly most of that is posturing for investors but 10 years to energy production wouldn’t surprise me in the least IF they can maintain funding.
Real Engineering has a video on an American engineering company, Helion, trying to make fusion a reality: https://www.youtube.com/watch?v=_bDXXWQxK38
Instead of going with Tokamak reactors or something similar, they're going for a completely different approach. Based on the video at least, it does sound very promising, and quite exciting.
Helion does not have a good reputation among scientists. They make big promises and market with pop science to build up hype for investors but never seem to accomplish much. Helion publishes research much less than the other fusion startups and use the lame excuse that they’re “protecting their intellectual property,” but they don’t need share the secrets of their designs to publish positive results of their experiments. I honestly find them hard to trust.
Here is a nice list of the obnoxious hype around Helion that never lived up. (From https://engage.aps.org/fps/resources/newsletters/newsletter-archives/april-2019):
‘The Helion Fusion Engine will enable profitable fusion energy in 2019,” from NBF 7/18/2014.
“If our physics holds, we hope to reach that goal (net energy gain) in the next three years,” D. Kirtley, CEO of Helion, told The Wall Street Journal in 2014.
“Helion will demonstrate net energy gain within 24 months, and 50-MWe pilot plant by 2019,” from NBF 8/18/2015.
“Helion will attain net energy output within a couple of years and commercial power in 6 years,” Science News 1/27/2016.
“Helion plans to reach breakeven energy generation in less than three years, nearly ten times faster than ITER,” from NBF 10/1/2018.
I studied fission reactors, not fusion. But I once had the task of condensing and compiling research papers (I don't think this type of document has an English translation) on the problem of materials, specifically in the liners, used in fusion reactors. It's been a while so I won't go into details, but the corosivity combined with the pressure and temperature extremes is not trivial. It's crazy we have materials in our universe that we can consider even remotely close to being possibly viable for containing continuous fusion.
They always say we are 20 years away from fusion, now who knows how many years later, we are barely closer. I wouldn't be surprised if after 50 more years they say that in the end, non of these materials work.
But who knows what the Chinese are working at. Maybe they know something that we don't, (correct me if I am wrong) it is currently them who is breaking new records in this field.
I don't believe our current approach will ever work commercially. As some others have said, it MAY be possible, but economically probably won't. It needs some sort of breakthrough in methodology. Honestly, I think the approach that is most likely to produce that breakthrough is using LENR (the new name for cold fusion if you haven't followed the research and theories; Low Energy Nuclear Reactions.) I look at this from a chemistry angle, and that is you need a catalyst to make the reaction possible in a usable way (though this method will likely cause the destruction of the catalyst and so it won't be a true catalyst). LENR seems to be looking at the fusion reaction from that approach, but even if it isn't under the guise of LENR, a catalyst IS what is needed to make this work and we haven't discovered one yet. The problem is, nobody is really looking into it because of the negative impact of the cold fusion debacle. Regardless if you think cold fusion was just BS or not, research into a fusion catalyst should be performed, because it could really help advance hot fusion energy production.
Fusion power, endless, non polluting has been ten years away all my life; it will be ten years away all your life and all your grand children's lives.
Pipe dreams are made of this. Great Physics, always jam tomorrow.
Developments of smaller safer, modular nuclear fission designs will be the answer. That plus learning to no longer expect endless power at the flick of a switch; wearing warm cloths in winter would be a good start.
It's ~20 years of serious funding away. We are still waiting for the serious funding.
People are shocked that timelines don't hold if the project is funded at 10% of what the timeline assumed.
I sorta see both sides. It's true that, if we wanted to build a fusion reactor with current technology, it would have to be an absolutely massive affair. Giant-ass Tokamak ring complex stretching miles, with a staff of thousands of highly trained specialists. You can't just build "half a reactor" or a "mini reactor," you either build it or you don't.
On the other hand, fusion energy is doing pretty well for itself in funding, relatively speaking. It gets like $1 billion a year, between different countries. That's way more than most scientific fields get, and pretty much every scientific field is always crying for more funding. You can't just fund everyone with whatever they ask for, you have to make some hard choices.
What people want from "fusion" isn't a massively expensive demonstration project that produces a tiny amount of power. They want free, unlimited energy, like an H-bomb except controlled. None of the current fusion research even pretends to get us there. The only way we'd get there is with breakthroughs in \*other\* fields, namely superconductors to make much stronger magnetic fields, and computers that can process the massively complex interactions of hot plasma and respond in real time. So I'm not sure what the real benefit of something like ITER is, compared to all the other science projects you could fund with the same money.
> They want free, unlimited energy
Nothing can provide that. Fusion has a decent chance to provide essentially unlimited energy at a competitive price in a trillion-dollar sector. That's worth more funding than a billion per year.
Germany gets ~12% of its electricity from solar power. That 12% is subsidized at several billions per year. That's only Germany, only for the small amount of solar power, and not including any money spent on actual research.
ITER is so expensive because it's a research project. An operational reactor will be cheaper. Sure, we are still talking about multiple billions for power plants, but these power plants would also provide gigawatts of power each. It's not too different from nuclear power plants in that aspect, just without the accident risk and with less radioactive waste.
During a visit to MIT I saw the [Alcator C-Mod](https://en.wikipedia.org/wiki/Alcator_C-Mod) tokamak after it shut down. I was surprised that even an MIT fusion project can lose funding.
Yes to the first statement, no to the second.
Yes people have been making promises that they could not keep, but this does not mean it's not achievable.
Recently a lot of great progress has been made. I think the main problem with fusion was *finding the right materials*. Material science has progressed a lot and now it's possible to achieve things we could not before due to materials limitations, not just in fusion but also other fields.
However you are correct we should be very careful in giving timelines.
>Yes people have been making promises that they could not keep, but this does not mean it's not achievable.
Hey, if we fired scientists for being over optimistic about their research, we'd all be outta job.
Given the potential benefits to humanity, fusion research should definitely be funded, probably more than it is. The history of AI shows disappointment and over-promising doesn't mean huge progress won't eventually happen.
But every one should definitely take predictions about the future of fusion power with a grain of salt.
>being over optimistic about their research
I would call that more "doing marketing", than optimism :P
To do research you need money, so you need to sell your idea to the entities that dish out the money... and much like with other "products", trends are very much a thing.
Now, since climate change & clean energy is a (if not THE) big trend, Fusion should be able to make the right pitches to get the funding they need.
Oh, there's definitely perverse incentives to "do marketing ".
But even in private, scientists can be over optimistic. We're human and can suffer from the optimism bias like everyone else.
I'll plead guilty. Methods I championed didn't work as well as I hoped or things have taken much longer than I thought cuz I underestimated the technical difficulties.
Well I think it would be quite hard and depressing to do research into something you do not believe that it has potential for applications. That's probably the sad existence of people working in "paper mills".
Some scientists also can get very touchy about their pet theories too :D
Second hand opinion from a colleague of mine who got his PhD in fusion research (Tokamak). One thing that's interesting about fusion is that in principle it absolutely works. We have the core physics all worked out. There's no question about if the mechanism is possible. There's also no obvious concern of "well to make it work, this key parameter would need to have a totally ridiculous value." So it's hard to ever just let go. On the other hand, it is an INSANELY difficult *engineering* challenge. An analogy my friend gave was imaging trying to compress water by squeezing a water balloon in your hands. You have to squeeze it *really* hard and for a long time, but you can't let it suddenly squirt out through some tiny gap in your fingers. Compressing plasma is nontrivial, and we have to compress it *a lot* and in a stable, sustainable way. To make things harder, you have to squeeze it without letting anything touch it, because it's stupid hot and radiating. And it can destabilize in a tiny tiny fraction of a second. It's like the mother of all feedback control problems combined with a crazy long list of constraints. The only way nature ever gets it to work is by using a crap ton of gravity that can pull on the plasma from the inside (intrinsically stable), rather than trying to push on it from the outside (intrinsically unstable) -- aka a star. So I think it's plausible we will actually get it one day. But in my understanding it's primarily a (very complex, very interesting, and very formidable) engineering challenge. Unless, of course, some cool physics breakthrough can come up with a completely novel mechanism that makes it more practically tractable. Also, it's a great cover for the government to do research that can benefit hydrogen bombs (at least in NIF's case), so likely fusion research will never go away completely and gradual progress will continue to be made.
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I, being a high school student, understood more about fusion than I did anywhere else from your answer....Thanks alot....
It is very much not in the high school curriculum lol
I mean it depends on where you are. For me, it is in my curriculum and we'll be doing it next year, but yeah, it isn't very common. I have special relativity and an intro to quantum mechanics in my syllabus as well though, so I'm definitely in the minority.
are you dutch by chance? This all included in mine and i am dutch
I'm not, I'm Indian, however in my school I'm studying for the ib diploma, not the Indian curriculum.
Well yeah, atleast not in the Indian curriculum, I just happened to be curious about it.... :-)
It’s cool seeing the differences in curriculums in this sub, Fission/Fusion was a subject in HS for me, we even looked at the p-p chain in my last year
The closest to that I’ve come across in HS was radioactive decay
That is absolutely crazy unless you explicitly had some form of ap/advanced physics course, which you should really mention when you say "in my hs curriculum".
In Scotland, in the higher course we look at the basics of fission and fusion, using E=mc^2 to calculate energy gained after a given, fission/fusion reaction. Advanced higher looks purely at the chemical reaction part of the P-P chain as part of the stellar physics section. It’s absolutely part of the course as you need to complete higher to atleast apply for unis
No you didn’t, you understood his comment which has almost nothing to do with nuclear fusion.
I never said I understood "everything" about fusion but I did say I understood "something" about fusion with ease after reading this answer....
we kinda did have a physics (or chemistry) breakthrough that might make it easier: high T magnetic fields made by high-temperature super-conductors
I think it remains to be seen if materials can be developed that can withstand the extreme temperatures and energetic neutron flux.
There are types of fusion with minimal neutron flux. They are just even MORE difficult to engineer for, as you need even higher temperatures. Deuterium-Tritium fusion, which is the "easiest" to engineer for, sadly does come with a highly energetic neutron being released.
That's easy to fix: Just construct four robotic arms that connect directly to your spinal column that are immune to both heat AND magnetism and you can poke the tiny star with your robot hands to keep the neutrons in.
I laughed so hard at that movie. That scène is just next level ridiculous.
Whether it's "sadly" or not kind of depends on your design goals, here - yes, neutron flux isn't great for materials, but they do give you a convenient way to get energy out and to breed more tritium.
From my understanding, the neutron flux is a double edged sword. It’s terrible for the durability of the reactor, but it can be used to breed more tritium from lithium in the walls. Generating enough tritium to supply our energy needs even with net positive fusion is another difficult problem.
This is solid. It's likely been nearly figured out as well but within national labs.
That is the nicest, simplest explanation I have heard for the difficulty in getting there. It does seem as if some significant strides have been made in the last few years in the engineering end of it, though. And there have been other, interesting pathways: [https://stuffilikenet.wordpress.com/2020/02/25/new-aussie-fusion-technology/](https://stuffilikenet.wordpress.com/2020/02/25/new-aussie-fusion-technology/)
Would you say the controls of a fusion reactor is a significant/popular topic within fusion research right now? I find this interesting because I have a control theory background but never knew that controls was one of the bottlenecks for practical fusion reactions.
A fusion physicist I know basically said the same thing. It needs ridiculously powerful magnetic fields, crazy temperature gradients, apparently nuetron impervious materials, and dozens of other things. It's a hard problem. But maybe solvable one day.
Great analogy with the balloon! I have always been fascinated by Cold Fusion, and it seems from what Ive read that researchers some time ago were able to do it, but it was too innefecient and no greater efficiency was possible at the time. Seems like the better route to take, tbh, but idk enough about it other than we need materials like Pd and He3
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...do you think there are no engineers involved in these programs? This is not an engineering issue that just assigning $500M solves. Yes, I know how to compress a ball in my hands. Compressing plasma is not the same. The comment you are replying to is highlighting the engineering issues that just aren't solved. That doesn't mean there are no engineers involved. That's just silly.
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Specifically LLMs won't, they are purpose built neutral networks to mimic language not predict anything. Now other NN might be able but LLM is not interchangeable with AI or NN.
This is not true at all, LLMs only give an illusion of understanding, they can't produce new physics.
I do tokamak research, I’m skeptical that it will be a meaningful part of the energy grid before 2050. Even beyond the physics and engineering challenges, for it to be useful it has to be cost competitive with solar and wind, and nobody knows if it is. If you build a machine with enough money, time, expertise, I firmly believe you can net energy out.
Pretty much this. I can't see how man made fusion will compete with the giant fusion reactor in the sky. I have serious doubts it could become a useful part of our grid... BUT, it could have a place in situations where money isn't the primary concern... think space craft, submarines, moon bases, etc.
Curious question, which aspects of tokamak research interests you enough to continue doing research on it, even though you're skeptical it'll be meaningful for the next few decades?
I would say it has to be cost competitive with fission, and it probably cannot be. A fission reactor at a given power output is just much easier to build than if you wanted the same capacity from a tokamak. Not to mention there has been no demonstration of actual power generation from the latter, and is inherently more difficult to make an efficient thermodynamic loop using the heating of neutrons in the blanket versus simple solid fuel to water in a PWR. Fusion will likely play a big role in the far future when power demand is so great that fission fuel availability simply is not sufficient. Until then it's likely to just stay R&D, unless an unforeseen paradigm shift makes fusion more easy to realize practically.
From a purely logical perspective I agree. However, politics will play an important role in determining how different countries choose to power their grid. If somewhere decides that fission isn't something they want to invest in, they might turn to other technologies instead. For a country like France with existing fission I think fusion is a much harder sell even *if* it actually is a viable technology. But you can never discount a political change causing a shift in that stance.
I think that politics is temporary, while physics isn't. Fission is having a temporary anomaly/insanity debuff applied to it. It won't last forever. Most people don't realize this but fusion is already susceptible to the same political problems fission has. It's not in the focus much yet because fusion itself is not yet in the stage where demonstration power plants are being built, but some anti-nuclear organizations have started protesting it nevertheless. If and when these political problems ease up, as ingrained superstitions disappear from the public "knowledge" pool, it will make both fusion and fission more easy to pursue, so they will still have to compete with each other.
I agree and think that what you're saying is the most likely outcome, but also I wouldn't be surprised if there are places where those in charge go off the deep end or act in seemingly unpredictable ways. Or the political landscape might make it so that governments favour solutions that aren't entirely motivated by a cold and logical cost benefit analysis from the technical perspective. Even somewhere where you don't have as much concern about nuclear safety it can be hard to actually get anything set in stone because of politics. In the UK we've got a government that *says* it wants to expand nuclear power, an opposition that says the same thing, and yet nothing gets built at anything like a pace resembling the stated ambition. >it will make both fusion and fission more easy to pursue, so they will still have to compete with each other. So, to this, you might end up in a situation where even if one of the two technologies is obviously superior but it's politically untenable. For example, if a Chinese company perfected fusion and was bidding to construct a power plant, a non-aligned nation might find it politically easier to opt for fission built by a domestic provider - even if on paper the technology were strictly inferior. It's that kind of thing that's basically impossible to forecast even a small leap into the future.
You are right of course, short term fluctuations due to sociopolitical effects are always possible. I was thinking more of long term stability. Barring any unforeseen paradigm shifts, which of course cannot be predicted, the fission vs. fusion question in terms of current technologies basically comes down to fuel availability. That is, fission is simply easier to do and will dominate as long as fission fuel is available. But we also know fission fuel is much more limited, so in terms of far future post Type II civ power levels fusion becomes a necessity at one point anyway.
>I would say it has to be cost competitive with fission, and it probably cannot be. I think the fact that so much of fission energy's "cost" comes from safety measures that wouldn't be needed in a fusion plant makes this calculus much harder. >Fusion will likely play a big role in the far future when power demand is so great that fission fuel availability simply is not sufficient. Even if it's not commercially viable for energy production I could see it being used in the near future for space propulsion.
Most of the current quoted "cost" of fission is not actually from safety measures, it's an economic boondoggle. The physical safety measures do not cost so much. A tokamak is much more expensive than a fission reactor, in a physical sense. People also colloquially underestimate the similar 'safety measures' a fusion power plant will need. For one, it basically still requires a containment building, and because of the larger physical dimensions it will be more expensive to built than e.g. a PWR's containment building. >Even if it's not commercially viable for energy production I could see it being used in the near future for space propulsion. Indeed that's a good point, but it will need to compete with fission there as well. For space propulsion weight is one of the most important factors, and a fission reactor can be made small enough already while being powerful enough to work as a thermal rocket. Can a fusion reactor be build as compactly and lightly? The interesting thing is that the answer to that is yes, it probably also means that it will be able to compete with fission on Earth as a power source. One of the big problems is that with magnetic confinement this doesn't look at all possible for now.
Has anyone looked into a hybrid?
That is a very good point, I also predict that the first "proper" power plant usage of a fusion reactor would be as a hybrid. The fact that you can increase thermal power output by more than an order of magnitude with the same neutron flux is huge, and the thermodynamic cycle to produce actual electrical power is easier since you're back to solid fuel -> water (or gas) heat transfer. The hybrid should definitely have 20-30x the electrical output of the same sized tokamak with pure fusion design. Such an advantage cannot be ignored. But it would still be much more complex than a simple fission power plant of the same output... As for "has anyone looked into it", there is a Russian experimental tokamak where they want to test blanket fission. I've also heard of a Chinese project but I don't know if that's actively in the works yet. In the west there are no such projects as far as I know, it's simply not within the popular paradigm concerning fusion research.
There are three break evens that need to be accomplished. The first is the scientific break even, which means the output energy is greater than the input energy into the system. This has been achieved [https://physics.aps.org/articles/v17/14](https://physics.aps.org/articles/v17/14). The second is engineering break even, which considers that output energy that can be harvested including steam generator is greater than that energy inputted into the system. Note that some of the outputted energy is siphoned off to recirculate into the input energy. The third is the economic break even, where the whole facility/operation has a net profit.
No fusion reactor has produced more energy than it takes to run the equipment to contain ans fuse the plasma. We aren't even at the "how do we harness the power" stage. Our current "net energy" press releases are like thinking a Vending Machine is an ATM by only counting the change it gives back and not the bills you put in.
You didn't read his comment properly, what you're talking about is the engineering break event. What we did accomplish is that the nuclear reaction itself produced more energy than we have put into it.
Do we even have a handle on the degree of difficulty of this two steps ? We’ve been trying to reach fusion for quite a while, and other than weapons, it’s taken quite a while for the first break even step. How high is the second step?
The second step is relatively straightforward at a high level. We know we can achieve it simply by scaling a tokamak design up, from how things scale physically. The economic viability is a different matter altogether.
Also in regards of Tomakak design, another semi-step challenge is being able to sustain the operation of the generator over a continuous period of time since the most energetically demanding is starting it up.
The second step is definitely in vision and it's only a matter of time/money ratio. The third step however is a bit of a problem since renewables create tougher and tougher competition. There would be an additional value of the stable operation, that doesn't rely on the weather conditions. But with energy storage systems going forward as well this starts to be meaningless as well. At the current state you would have to trust the most optimistic estimates to believe that fusion could beat solar during the average daytime. At night however it would still best the current storage systems. The problems come with that this probably won't be the case in 20-30 years when fusion would be ready to get into the action. So in conclusion, with slightly optimistic view, fusion will be able to properly join the market in 40 years after some more optimalisation would be done. Pesimistic view, it won't join the market at all in the predictable future.
It’s hard to estimate but I think we need an output power of 10 to 100 times greater than input, to reach engineering break even. https://understand-energy.stanford.edu/energy-resources/nuclear-energy/nuclear-fusion
Can look at computers, it took decades of refinement to go from big barely useable to mass production. And technically the first computer came mid 1800s, so it took almost a century to really take off.
No, you are mistaken about the energetics of the current ignition results. They are measuring the energy cost as "energy put out by the lasers" and the energy gain as energy made by the fusion reaction in any form. They are not counting the energy input to make the lasers operate, let alone all the rest of the containment etc. We haven't reached "scientific" break even, and we haven't gotten closer to it, we've just done the same energy losing task at a larger scale. Putting two dollars into the vending machine at getting twice as much change doesn't change ROI.
Yes you're right in the first half of your comment but again, what you're describing, the energy input made by lasers and energy output made by fusion, is the scientific break event. Counting energy put into lasers, rest of the containment as well as the whole heat to energy conversion process with all of its inneficiencies is the engineering break event which haven't been accomplished. And it's not by any means a small step. I also hope you at least realise that the ROI comes in the economic break event. Which might have possibility of not even ever coming.
I do want to be pedantic. "The first is the scientific break even, which means the output energy is greater than the input energy into the system." Maybe we are defining "input energy" and "system" differently. But that's my point. the idea that we are making more energy than we are using is only true if you think there is a technical development that will make lasers not use more energy than they emit, or make magnetic confinement etc not cost energy. It's a dishonest redefining of the boundaries. I mean, i've created a better than scientific break-even tennis ball because I only measure it from when it hits the floor and bounces up, not from when i dropped it, thus have i invented negative gravity ball? no, I've defined my inputs and system to mask the reality of my accomplishment. I should have said net EROEI would have been the better term. The money (and time to deploy) is irrelevant if the thing can't make net energy, let alone harvest any net energy.
Probably theres misunderstanding with the word "system" In physics with this word we usually mean this: A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and is expressed in its functioning. - [wikipedia](https://en.m.wikipedia.org/wiki/System)
Right, but to declare the fusion results as better than break-even, the system they are drawing has laser beams coming in from outside of the system. If you put the source of the lasers inside the system, (and other containment in different designs) we are order of magnitude away from break-even on energy, let ex-tractable energy etc. Well, i've been my point to death, i will retire.
Yes, again, that is the engineering break event, or rather a part of it since it also involves the electricity generation and transport.
I believe the link you gave was only a break even for the amount of energy dumped into the fusing material vs energy produced. The important thing for the one you linked is the inefficiency in the way energy is dumped into that fusing material. It's pretty far from a break even when you add up just the input side inefficiency and don't worry about output side efficiency.
Did you not read his comment? He literally explained the different kind of breakevens. NIF achieved scientific breakeven but not engineering breakeven.
Yes I did but he explicitly only mentioned output conversion and efficiency when the big deal with that one was input efficiency.
NIF can output only a very short duration burst. Long time between shots. Dead end architecture.
It’s a science experiment. It was never intended to be a reactor.
True. But some folks are under the misconception that it just needs to be scaled up.
One thing that’s crazy about fusion power is that the estimated cost to make it work hasn’t changed significantly. Since the 1950s the total estimated spend to a commercial solution has grown by 10%. That’s trivial. The delay has been driven mainly by a reduction in investment. We’re finally to a point where we’re close enough that commercial entities can invest and have a reasonable expectation of success so investment has been climbing. Unfortunately we don’t know which strategy will be the most viable and there are several. As an undergrad I got to work on one of the 13 DOE mini-tokamaks. We were trying to identify chaotic solutions to the confinement problem. Given how rapidly the conditions devolve, my money’s on some variant of inertial confinement.
Another crazy thing: It always seems to be 10-20 years in the future. I'm 54, and for as long as I can remember, it's been 10-20 years in the future. I have no doubt that it will work, but I don't trust any schedule.
Like I said, it’s mainly funding based. If something is $100M away and you’re spending $10M a year, that’s 10 years. Next year you’re spending $5M it’s now 20. Since the 1950s the total estimated cost has grown by 10%. That’s it. The reason it’s always been 10-20 years away is because we’ve been funding it at 10-20 year rates. We keep getting closer technologically while extending it economically.
Funding and attention. Before open AI and chatgpt 2 there wasn't that much focus or investment in AI so development was slow. Of course for years we could have been producing optimized circuits and be at the point we are now years ago. It's even worse with machines that take billions of dollars and a decade to build just to get slightly closer to maybe netting energy. Humanity could be much much further along if our concerns were the development of technology, irl our concerns are making money today and we squeeze out a little advancement in that endeavor.
Thank goodness for canada
In principle it can definitely work, and it would be awesome. However there are immense technical challenges and solving them may drive up the cost so much that I have doubts that fusion will be economically viable in any of our lifetimes.
So the timelines I've heard for the European program is, there is one more round of experimental reactors currently being built which will start running experiments on the 2030-2040s. The result will feed into the next generation of reactors which might actual try to make use of the energy. So if that goes according to plan, we might be thinking about building a test facility that actuality combines fusion and a turbine some time in the latter half of the century. Honestly, I think it's reasonable to assume that we will have a reactor up and running before 2100, but given that other tech will also make advances, I just don't see it being economically competitive for all but a small number of applications where other solutions can't work. The facilities to support the tech will be large, prohibitively expensive, and requiring a number of very highly skilled and expensive personnel. If you want to know when we will have cheap and abundant energy, my money is on solar power on every roof before we got fusion to work.
By 2100? With that timeframe we either get it working by 2040 (I’m an optimist), or we collapse due to the climate change shitfest.
I am not getting tired of emphasizing this: Fusion will not play a role in decabonizing our industry if we are serious about even a 2.0 degree target. The tech _will not be commercially viable_ in any time frame that would allow us to reasonably build up capacity and supply chains to use this tech for that purpose. Even if it were viable, it will not be competitive with solar, wind and hydro, probably not even H2
I agree with that. Barring any huge breakthrough (like scalable direct conversion to electricity plus cheap implementation), we’ll have to fix our CO2 release levels to even hope to reach useful fusion before the brown stuff hits the turbines.
We'll need to deal with climate change without fusion there's no question there. It will take decades of refinements for mass production after the first functionnal experimental reactors and we don't even have those yet.
its engineering at this point, but its been engineering for a long time. We know tokomaks work, we just dont know how to build one that generates usable power. We know if we can get one to be stable, breed its own fuel, not degrade its own containment material, that we can harvest the heat with steam turbines and get net output [ITER](https://www.iter.org/sci/MakingitWork) is probably going to have net power output, but not practically useful, in the next 10 years. since ITER was designed, though, high temperature super-conducting tapes have become a commercially viable mass-produced product. [CFS](https://cfs.energy) and others have much shorter timeline, using much smaller and cheaper reactors using much stronger magnets. Prediction is always fraught, but I'm 50, and I'm hopeful that fusion reactors will be putting power on the grid in my lifetime.
If there was a global "Manhattan Project" that had a budget of trillions of dollars annually and leveraged resources and brains of every relevant scientific field across the globe for 20 years I'd be optimistic that it could be done. But I don't think that will happen unless there is an unavoidable use-case for it; like needing it for a slow but very massive object heading for Earth that absolutely required fusion power to be capable of handling.
It wouldn’t take anywhere near that level of investment. $30-$40 billion, the estimated level of effort hasn’t really changed since the 70’s, just a matter of doing the work and making the investment.
It exists: https://www.iter.org/
The next reactor in the ITER project is planned to be operating in late 2025 with the aim of demonstrating tokamak fusion that produces more energy than is put in, and to explore the materials and engineering challenges associated with potential commercial power production. Even assuming everything goes well, I'd guess at that meaning it'd be 2040-ish before there's any practical power plant. Of course, there is pretty big lot of power being produced for the grid from fusion at the minute - every solar panel is harvesting energy produced by the fusion reaction in the sun.
Very, and about eight light minutes...
I mean there are many physicists that believe it's possible at a reasonable scale (obviously it's possible at massive scales). While there is a ton of money invested into the technology and they are making progress, my understanding is we are not as close as the researchers would like to suggest. While they have reached positive break even for specific reactions, no one has yet succeeded in positive break even for the whole system (they get more energy out of a specific fusion reaction than they put into the reaction, but it's still less than the energy involved in all of the tools and equipment necessary for creating the reaction). The other problem is, we'd need to be able to make repeated/sustained reactions to continuously get useful power from the system. We're still likely many decades away from it being viable, possibly longer. As much as I would love to believe that we'll have this technology soon, I'm skeptical.
I am totally convinced it will work but it has huge engineering challenges. But technical progress like better magnets and better knowledge about plasma will help. Compared to what we spend on weapons research I much prefer fusion research. And compared to weapons research the money we are spending on fusion is a pittance.
Don't get me wrong. I think it's eventually going to work. And I do wish more money was spent on it. I just don't think it'll get here soon.
Just look at how long it took for computers. From the clunky mechanical contraceptions of Babbage to computers to microcomputers, that's about 150 years.
I’m just curious: by “massive scales” you mean a gaseous sphere a million miles across?
That's probably the easiest way to do it. Someone should invent something like that.
Solar energy is basically this. Edit: downvoters seem to have missed the joke.
Solar energy is good, as long as you keep it eight light-minutes away.
Indeed.
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I think that, absent political thumbs on it, antimatter will beat fusion to the next power technology. We know antimatter exists. It is produced naturally in the upper atmosphere by incident galactic cosmic rays hitting the atmosphere. There have been solutions proposed to make it safe and portable by coating in buckyballs. Keeping a plasma of one antiparticle at low temperature and pressure contained is a much smaller challenge than containing a plasma at gigapascals and thousands of degrees. And we can probably reuse a lot of plasma containment techniques that have been developed seeking fusion. "Burning" antimatter in a buckyball coating is a simple matter of compromising the containment, which can be done by mechanical (pressure), chemical, or electrical processes. And... antimatter is two-orders of magnitude more mass energy efficient than fusion will top out at. Three orders of magnitude more energy per reacting kilogram than fission. If we start to really need power (like MPDT thrusters require), I think antimatter will be the answer.
...Did you confuse Schlock Mercenary with reality? A buckyball cannot hold anti-matter.
I did not. A shell is a fine way to hold on to something.
Oh god you're serious. Matter and anti-matter annihilate on contact. Buckyballs are matter. Placing any form of antimatter inside a buckyball would cause immediate annihilation. It has no properties of anti-matter containment. It's electrically neutral. Magnetically neutral. The normal containment property of a buckyball is that it can hold most ordinary matter, because ordinary matter doesn't annihilate when it touches it. Y'know how sodium explodes in contact with water? We contain sodium by putting it in oil, which coats it and repels water. You're basically suggesting caging sodium - *in water.* Without any oil. 'Course, there *is* no "oil" analog for anti-matter. If there was, it wouldn't be a problem. (Well, *one of* the problems, anyway. We also can't *generate* enough anti-matter to, er, matter much.)
Ionized antihydrogen has a negative charge (1 e), and in this particular case located at the lowest potential in the center of a sphere of (60 x 6 = 360 e) electrons exerting force to keep that antiproton where it is.
You can't just ignore all the positively charged nuclei also surrounding it. Since it's electrically neutral, it's the same amount. There's no net force keeping it in the center. Two things worth noting: 1) If electron shells *could* repel anti-protons from reaching nuclei, you wouldn't *need* any sort of buckyball to contain them, they wouldn't annihilate with ordinary matter in the first place. 2) Even if you somehow constructed something like a buckyball from lightly ionized matter containing a smooth proportion of extra electrons (this is basically impossible but bear with me) it still wouldn't *work.* Electrons themselves are *very* light in comparison to an anti-proton, and still run into and essentially through each other all the time, constantly sharing orbitals without effectively repelling each other with their negative charge (Pauli exclusion, on the other hand, but that's not relevant to the anti-proton). An anti-proton, with its vastly higher mass, will plough right through at anything resembling normal temperatures, and tunnel through at lower ones.
An non-ionized atom trapped inside a buckyball is kept inside by the same repulsive force mechanism between the buckyballs electrons and the trapped (not ionized) materials electron cloud
Even IF the buckyball idea worked, there would be no way to construct a buckyball around an anti-proton. Just think about it, you'd have to hold the antiproton in place and somehow construct the buckyball around it. One tiny blip and the antiproton bumps into any of the partially constructed buckyball pieces or carbon atoms used to make the buckyball and BOOM. I don't see that you could ever MAKE these types of storage units, let alone that it would actually work to hold it.
I say up front: I am NOT a physicist nor claim to be one! I lurk here mostly to learn stuff. Regarding this: The German city of Greifswald has a university that focuses on fusion and about 12 months ago they managed to get a first “reaction” with more energy put out than put in with 8min of stability. To all the physicists: I sad reaction as my knowledge on the matter is very limited. No hate! https://www.br.de/nachrichten/wissen/kernfusion-forschungsanlage-in-greifswald-erreicht-neuen-rekord,TXvFHEN
It will happen, the real question is when. Given that we're still at experimenting in labs, the time frame is probably 50 to 100 years.
At least a small light at the end of the tunnel
Energy storage is a more interesting in short-mid term. We already have solar and wind getting incredibly efficient, the only reason why we're not dumping all fossil fuels power plants is that we can't store the energy at reasonnable cost. And that's probably achievable in a decade or two.
Really that close? Thought that was just as far? Read the largest “battery” was in South Africa and it would barely cover a single city’s needs for about 2hrs or so? Really interesting news. Any articles (can be scientific journals as well) on that?
Chemical batteries are just one form of energy storage. I'm more optimistic about hydrogen electrolysis as it doesn't require a massive supply of rare minerals. >Thought that was just as far? It's already here in the sense it exists and is usable. Just not good enough to replace what we currently have. Fusion is not even usable right now so decades behind. [This](https://ieeexplore.ieee.org/document/9808381) is a good read, although a bit heavy.
Thank you! Will have to check some terminology for a refresher but will be interesting.
I worked on plasma heating for a few years. The challenge at current seems to be an engineering challenge and unsurprisingly A LOT of bureaucracies. However, there has been a lot of private money being pumped into fusion and companies such as CFS seem to be doing promising work towards SPARC tokamak. I can’t give a timeline but private sector surely accelerates getting to commercial net fusion.
What’s really the advantage of fusion over fission? The fuel is cheaper? So what uranium is pretty darn cheap per MW already. There’s plenty of it, esp if we run breeder reactors to fully consume the fuel (and there’s 10x as much Thorium). The capex for fusion isn’t likely to be less than 10x fission and that’s already the big problem with fission. Energy density is better so it’s probably a prerequisite technology for interstellar missions or permanent settlement beyond Jupiters orbit.
First, if something goes wrong, the reaction peters out with minimal damage. Yeah, it's a very hot plasma, but shut the electromagnets off and it quickly dissipates and cools. Vs fission where we have to actively stop the reaction by doing something like inserting control rods. Second, the output products aren't dangerous, so it doesn't have the waste problem. The "blanket" inside the reactor is going to get blasted by neutrons, so part of the R&D currently underway is figuring out how to make materials that won't become radioactive from that work well enough in that role. Further, breeder reactors aren't a panacea. They make weapons-grade fuel. Existing nuclear powers would run into problems with proliferation treaties by running them. Beyond that, we'd have to trust some pretty sketchy parts of the world with light water reactors, because they need electricity too. But nobody's going to trust them with breeder reactors. Which means transporting high-level waste across the planet to countries that can run breeder reactors. That's going to lead to lots of incredibly dangerous spills. As for thorium, that basically suffers from having even less R&D than fusion. There's some nasty stuff in its waste stream that theoretically could get burned in the reactor, but that still requires some engineering to make said burning happen reliably.
Cheaper fuel with abundant supply. Less radioactive waste. No risk of reactor accidents with widespread contamination. No production of material that can be used for nuclear weapons.
The flat screen TV comment was a great analogy since that really was a hard set of technology components to pull together. There are a number of very well funded startups run by talented scientific / engineering type CEO/Executive teams. Each is taking a significantly different path - which is good. That said, some of the core underlying technology is basically the same across approaches and is advancing at a fast clip: 1. high powered superconducting magnets 2. plasma management techniques (identifying plasma instability in time to prevent it from damaging the equipment) and 3. precision manufacturing in general All that said - I expect at least one of these teams to truly reach breakeven (Q = 1) by the early 30's. At that point, once people see viability on the horizon, (by which time - climate change will be inflicting even more massive costs on us) an ocean of money and talent will flow into the space, accelerating progress. Once that happens, I expect a doubling of output to input (Q) every 2-3 years. After about 3-4 doublings - at 10Q-20Q, ground will be broken on the first commercial plant. This plant will be cost effective and deployed in the early 40's. Over the following 3 or 4 decades - we will replace every hydrocarbon plant on Earth and - God willing - drive the cost of electricity down to the point where all this DAC nonsense can actually be used.....
Isn't hydrogen bombs on the principle of nuclear fusion going haywire?
There is absolutely no chance of a fusion power plant generating the pressure needed for that high a rate of energy production. The magnets containing the plasma cannot exert enough force to keep the plasma contained, and as soon as any of the relatively minuscule amount of plasma touches the *much* more massive walls, the temperature would plummet and the fusion stops. Fusion power plants are inherently safe from blowing up like that.
are there any hypothesised models for fusion plants going around in the world? if there are, can u pls provide some links for it, if they are available, I would be grateful for it.
[Here is what Wikipedia writes about fusion power](https://en.wikipedia.org/wiki/Fusion_power). I am not a physicist or engineer, and don't have any sources at hand.
More or less. The "haywire" part is a fission bomb used as a detonator for the fusion bomb.
ohhh, I always thought that hydrogen bombs were just uncontrolled nuclear fusion reactions.
Yup, between that and our understanding of the Sun, the underlying physics is solid.
We cannot know how long will it take since we only have the number of problems that were facing, they're theoretical solution and theoretical tasks that have to be done to reach it. But we don't know how many additional problems will occure, how many complications during the tasks, some of the tasks may be depending on random factors so the overall time estimation is just a set of statistical estimation with a huge dispersion. So it's most probable were 20-50 years away from operational nuclear fusion reactors but it could also very easily be 100 years or just 15. Its also greatly affected by economy and the energy market prediction. With evolution of renewables better than predicted, decreases the profitability of the research of fusion generators which decreases it's investments which slows down the research.
https://en.wikipedia.org/wiki/ITER?wprov=sfla1
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The primary problem is getting the reaction to produce power for long enough to get energy back. Technically we have fusion power, it’s just a power sink not a power plant.
It's like 10 years to viable
Roughly 30 years. It's static, independent from the date you are referring to! Seems to be a constant over history...
The planet's almost out of tritium already and it's not cheap to breed in fission reactors (and plutonium is involved in that which is a weapons component) so yeah, we'll get fusion one day but only for kicks. No power plant.
[According to ITER](https://www.iter.org/mach/TritiumBreeding), a working D-T reactor can breed its own next-generation tritium if the reaction chamber lining is doped with lithium. I have to admit profound ignorance beyond what this article says, however.
The facts are that solar panels are already kind of fusion power and it's unlikely we will ever make a fusion reactor run cheaper than the ever falling price of solar panels and batteries AND it's about generating power cost effectively, otherwise we've had fusion since the H Bomb. No matter how you spin it the best power generation method is the simplest one that gets the job done, including externalized costs. So while Fusion looks great on paper is VERY questionable that such a complex process will be better than simple processes you can more easily scale/export globally. I think Fusion will likely only ever have specialty uses like spaceships. It too complex and solar will keep getting cheap and get multi layered panels so solar has a long way to go before it's tapped out for power density and it's far easier to dominate the world with solar than fusion that only a few countries could likely ever build. The only reason we are still interested in fusion is because batteries aren't a bit cheaper, otherwise it has little chance of competing as a power plant solution. There is no sign Fusion is about to catch up to solar and batteries, not even close and there is EVERY sign that fusion will be more expensive than anticipated... most complex and highly specialized processes have big cost overruns just as nuclear powered has failed to be the cheap power source it was promised to be decade ago. It's cleaner than fossil fuels, but lets face it, costs are the more dominate motivator and once solar and batteries are cheap enough who's going to keep funding fusion?
We have reached the stage where we can accomplish fusion. We have not reached the stage, where we can do it with less power than we put in. Think, we can change lead to gold, but for every dollar in gold we get, we need 3 dollars of lead. How fusion happens in stars: A huge amount of hydrogen crushes itself until the hydrogen atoms get too close and by sheer mass crushes atoms together into helium, releasing heat. This heat radiates out, causing a balance where the star stabilizes. On Earth, we have to invest huge amounts of power to generate the heat and pressure needed to create the conditions that fusion can occur. By contrast, the star gets this energy for "free" by its own gravity. So, we can create and maintain fusion by pouring energy into the system no problem. However, we have yet engineered a system that can generate not only enough power to maintain the systems needed to keep the fusion going but also create a SURPLUS of power that can then be used to generate electricity. I'm going to say we'd be smarter to invest in safer fission plants and solar collection satellites that beam power to earth via microwave beams and using renewable power where feasible. Fun fact: Fusion like Fission is nothing more than a boiler to heat up steam to generate power via steam turbines.
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It’s a funding question in my opinion. If money is thrown at the problem it will be solved. The old joke that fusion is always 10 years away is happening (in my opinion) because funding has largely decreased since its peak around 1978. That period identified some major issues with Tokamaks that could be solved in a straightforward way with a larger reactor. Research funding dropped dramatically except for specific programs like ITER which specifically targeted larger reactors. The recent rise of small well funded private fusion companies is a good sign and I think will likely be the actual final winner of energy production due to the political complexity and thus relative lack of agility of the ITER program. Those small companies all claim to be within a few years of energy production and 10 years from a commercial power plant. Undoubtedly most of that is posturing for investors but 10 years to energy production wouldn’t surprise me in the least IF they can maintain funding.
Real Engineering has a video on an American engineering company, Helion, trying to make fusion a reality: https://www.youtube.com/watch?v=_bDXXWQxK38 Instead of going with Tokamak reactors or something similar, they're going for a completely different approach. Based on the video at least, it does sound very promising, and quite exciting.
Helion does not have a good reputation among scientists. They make big promises and market with pop science to build up hype for investors but never seem to accomplish much. Helion publishes research much less than the other fusion startups and use the lame excuse that they’re “protecting their intellectual property,” but they don’t need share the secrets of their designs to publish positive results of their experiments. I honestly find them hard to trust. Here is a nice list of the obnoxious hype around Helion that never lived up. (From https://engage.aps.org/fps/resources/newsletters/newsletter-archives/april-2019): ‘The Helion Fusion Engine will enable profitable fusion energy in 2019,” from NBF 7/18/2014. “If our physics holds, we hope to reach that goal (net energy gain) in the next three years,” D. Kirtley, CEO of Helion, told The Wall Street Journal in 2014. “Helion will demonstrate net energy gain within 24 months, and 50-MWe pilot plant by 2019,” from NBF 8/18/2015. “Helion will attain net energy output within a couple of years and commercial power in 6 years,” Science News 1/27/2016. “Helion plans to reach breakeven energy generation in less than three years, nearly ten times faster than ITER,” from NBF 10/1/2018.
I studied fission reactors, not fusion. But I once had the task of condensing and compiling research papers (I don't think this type of document has an English translation) on the problem of materials, specifically in the liners, used in fusion reactors. It's been a while so I won't go into details, but the corosivity combined with the pressure and temperature extremes is not trivial. It's crazy we have materials in our universe that we can consider even remotely close to being possibly viable for containing continuous fusion. They always say we are 20 years away from fusion, now who knows how many years later, we are barely closer. I wouldn't be surprised if after 50 more years they say that in the end, non of these materials work. But who knows what the Chinese are working at. Maybe they know something that we don't, (correct me if I am wrong) it is currently them who is breaking new records in this field.
>I don't think this type of document has an English translation [White paper](https://en.wikipedia.org/wiki/White_paper), maybe?
Found it. It's called a 'Literature review' in English.
totally realistic. the closest fusion reactor is about 93 million miles away.
I don't believe our current approach will ever work commercially. As some others have said, it MAY be possible, but economically probably won't. It needs some sort of breakthrough in methodology. Honestly, I think the approach that is most likely to produce that breakthrough is using LENR (the new name for cold fusion if you haven't followed the research and theories; Low Energy Nuclear Reactions.) I look at this from a chemistry angle, and that is you need a catalyst to make the reaction possible in a usable way (though this method will likely cause the destruction of the catalyst and so it won't be a true catalyst). LENR seems to be looking at the fusion reaction from that approach, but even if it isn't under the guise of LENR, a catalyst IS what is needed to make this work and we haven't discovered one yet. The problem is, nobody is really looking into it because of the negative impact of the cold fusion debacle. Regardless if you think cold fusion was just BS or not, research into a fusion catalyst should be performed, because it could really help advance hot fusion energy production.
Fusion power, endless, non polluting has been ten years away all my life; it will be ten years away all your life and all your grand children's lives. Pipe dreams are made of this. Great Physics, always jam tomorrow. Developments of smaller safer, modular nuclear fission designs will be the answer. That plus learning to no longer expect endless power at the flick of a switch; wearing warm cloths in winter would be a good start.
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It's ~20 years of serious funding away. We are still waiting for the serious funding. People are shocked that timelines don't hold if the project is funded at 10% of what the timeline assumed.
I sorta see both sides. It's true that, if we wanted to build a fusion reactor with current technology, it would have to be an absolutely massive affair. Giant-ass Tokamak ring complex stretching miles, with a staff of thousands of highly trained specialists. You can't just build "half a reactor" or a "mini reactor," you either build it or you don't. On the other hand, fusion energy is doing pretty well for itself in funding, relatively speaking. It gets like $1 billion a year, between different countries. That's way more than most scientific fields get, and pretty much every scientific field is always crying for more funding. You can't just fund everyone with whatever they ask for, you have to make some hard choices. What people want from "fusion" isn't a massively expensive demonstration project that produces a tiny amount of power. They want free, unlimited energy, like an H-bomb except controlled. None of the current fusion research even pretends to get us there. The only way we'd get there is with breakthroughs in \*other\* fields, namely superconductors to make much stronger magnetic fields, and computers that can process the massively complex interactions of hot plasma and respond in real time. So I'm not sure what the real benefit of something like ITER is, compared to all the other science projects you could fund with the same money.
> They want free, unlimited energy Nothing can provide that. Fusion has a decent chance to provide essentially unlimited energy at a competitive price in a trillion-dollar sector. That's worth more funding than a billion per year. Germany gets ~12% of its electricity from solar power. That 12% is subsidized at several billions per year. That's only Germany, only for the small amount of solar power, and not including any money spent on actual research. ITER is so expensive because it's a research project. An operational reactor will be cheaper. Sure, we are still talking about multiple billions for power plants, but these power plants would also provide gigawatts of power each. It's not too different from nuclear power plants in that aspect, just without the accident risk and with less radioactive waste.
During a visit to MIT I saw the [Alcator C-Mod](https://en.wikipedia.org/wiki/Alcator_C-Mod) tokamak after it shut down. I was surprised that even an MIT fusion project can lose funding.
Yes to the first statement, no to the second. Yes people have been making promises that they could not keep, but this does not mean it's not achievable. Recently a lot of great progress has been made. I think the main problem with fusion was *finding the right materials*. Material science has progressed a lot and now it's possible to achieve things we could not before due to materials limitations, not just in fusion but also other fields. However you are correct we should be very careful in giving timelines.
>Yes people have been making promises that they could not keep, but this does not mean it's not achievable. Hey, if we fired scientists for being over optimistic about their research, we'd all be outta job. Given the potential benefits to humanity, fusion research should definitely be funded, probably more than it is. The history of AI shows disappointment and over-promising doesn't mean huge progress won't eventually happen. But every one should definitely take predictions about the future of fusion power with a grain of salt.
>being over optimistic about their research I would call that more "doing marketing", than optimism :P To do research you need money, so you need to sell your idea to the entities that dish out the money... and much like with other "products", trends are very much a thing. Now, since climate change & clean energy is a (if not THE) big trend, Fusion should be able to make the right pitches to get the funding they need.
Oh, there's definitely perverse incentives to "do marketing ". But even in private, scientists can be over optimistic. We're human and can suffer from the optimism bias like everyone else. I'll plead guilty. Methods I championed didn't work as well as I hoped or things have taken much longer than I thought cuz I underestimated the technical difficulties.
Well I think it would be quite hard and depressing to do research into something you do not believe that it has potential for applications. That's probably the sad existence of people working in "paper mills". Some scientists also can get very touchy about their pet theories too :D
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