Also, I spent a few years as an engineer at a stellarator. This video[0] recently came out and I find it's the best crash course on the nuances of reactor design that I've seen. It really nails the thoughts and feelings of fusion researchers. It was especially refreshing to hear in public that ECRH is the only viable heating method for a reactor.
If you watch this you might think I'm pessimistic about fusion, but I'm not. Fusion has been sold as this secret Ace up our sleeve that will come in and decarbonize our grid in a matter of decades. It isn't that. That's what's been sold because it's difficult to justify the field when the timelines don't decarbonize the grid in 50 years. The important thing to know is that the world doesn't end in 50 years. Energy demands are ever increasing and the supply is ever diminishing. Fusion science is expensive and time consuming. Humans will have to do the work if they want to stay on the current track beyond the next 100 years. It might seem like a subtle point and a doomed one to make considering how shortsighted we as a society have demonstrated to be.
These past 2 years have highlighted to many how a combination of poor critical thinking and politicisation of so many aspects of our lives can lead to literal catastrophes.
Will the public see Fusion as the wonderful advancement for humanity that it will likely be, or will they see it as another dangerous nuclear thing? Will they see it as taking jobs from hard-working coal/oil workers? Will it be spun as the green energy sector not making their minds up and flip flopping between solar/wind/fusion/etc? Will there be stories about how we could accidentally create a black hole and destroy the world?
Hopefully I'm just being cynical, but I am worried about how the general public will perceive it, and/or how it will be sold by politicians and the less reputable parts of the media.
Human energy consumption has always gone up when the supply got more efficient, from coal to oil to fission. While here, the power generation itself won't have such a drastic impact (unless humanity overdoes it, though, we seem to always do that) but maybe more power means more consumption and demand for other goods that get used up while using things that consume power. And with enough power you can think about making things that consume more or even build more things that consume more power. Lots of processes that were considered too wasteful suddenly become feasible.
Just like with digital documents, when people predicted that paper wouldn't be needed in the modern economy and the demand for paper would decline, it has actually skyrocketed - because a paper document isn't important anymore. You throw it away and print a new one when it has a crease.
Historically, we've been very bad at predicting such side effects. So I won't buy in a 'fusion solves everything' mindset. Fusion power can be a boon for humanity on a global scale but it could also make some problems worse.
And we are much better at running an energy-efficient economy: energy use/real $ GDP has halved in the last century.
The trend may not continue. People might start to do much more air travel (which would require massive runway building). Global warming might increase the need for AC. But my intuition is that there is some limit to the amount of energy one person can consume.
[1] https://www.eia.gov/totalenergy/data/annual/pdf/sec1_13.pdf
I worry about this, too, but couldn't there be some positive effects here, too? E.g. what if it made desalination a lot cheaper?
Eh, we are sitting on a giant ball of matter. Not much worry about using stuff up.
(We might use up any one particular thing. But there are substitutes.)
I think this really understates the case against nuclear power. The problem with nuclear power stations is they are prone to the same kind of industrial accidents all large plants are prone to, and they are on the more dangerous end of the scale when it comes to what can happen if there is an industrial accident. You can say that people aren't accurately weighing the risks, but you can't say it's irrational for people in, say, Japan, to be very skeptical of their government's capacity to either regulate industry or respond to industrial accidents and spills in a way that protects public health.
Fusion power, as far as I can see, is not on the more dangerous end of the scale, so would probably pass all of the mainstream, basically reasonable objections to new nuclear plants.
(For the record, I'm not anti-nuclear.)
Fusion promises to make this main problem worse, not better.
Fusion is a great example of solving the wrong problem.
Since fusion does not work sustainable yet (or at all), I would not classify it as green energy. (Where is for example the tritium coming from?)
But once it works - it likely will not magically supply all of humanity at once in a way, that is way cheaper than what we can have with wind, water and sun now.
So why flip flopping? We use what works. If fusion really works soon, awesome.
But honestly, I have to see, to believe. What I see is, that solar and co. are working now and do not require a fundamental breakthrough for very, very complex machinery under heavy fusion fire to work consistently.
And desserts for solarfarming, we have enough. As well, as many, many roofes in the cities. Solarfoils might be the next big thing to cover them big scale cheaply. And stationary batteries can be made of cheap materials avaible in abundance. Lots of other possibilities, too. Simple, reliable tech, compared to Fusion. So fusion would be nice to have, but I would not allocate more critical ressources to it, that might be better spend elsewhere.
Sure, investing into the energy grid, sounds not as sexy and interesting as building a fusion reactor. But maybe that is, what is currently more needed, to make it more flexible for the fluctating renewable energy sources.
And with the sun, we have already a big working fusion reactor. Why not focus on harvesting that energy more?
> Will it be spun as the green energy sector not making their minds up and flip flopping between solar/wind/fusion/etc?
Well, the green energy sector is big. Solar companies push solar, wind folks push wind, and well, fusion folks are pushing for funding and VC money.
But the important thing is, we need all of them. Plus batteries (and battery-like systems).
And, yes, there will be spin doctors trying to discredit "green" because X, but that's what they do anyway, fusion or not.
> Will there be stories about how we could accidentally create a black hole and destroy the world?
Good idea, maybe :D But we'll sure hear a lot about how much irradiated/activated waste it will produce, and how it's not green at all, and so on.
IMO it is not clear that fusion will ever be useable for power plants: Depending on costs (construction/maintenance/decomissioning), it might never be competitive with (battery backed) photovoltaics (or wind), no matter how much progress we make.
Personally I believe that fusion research is worthwile no matter the outcome, but calling it a "purely academic waste of ressources without positive environmental/economical ROI" might turn out to be correct (playing devils advocate here but this is important to consider, no matter how much pro-nuclear you are).
Whenever they talk about putting a fusion reactor in a shipping container, or on the back of a truck that's a red flag. Any fusion plant capable of useful power output is going to have to kick out enough neutron radiation to need some pretty serious shielding that just makes that impossible.
Another problem is the way they often pitch the energy gain numbers. Q=1 sounds great, the output energy equals the input energy, but that's only the input energy required to maintain the plasma. The actual energy to power the plant and run the heat exchange system and such as a whole (Engineering Gain = 1) is likely to be about 22x that. Then to be economically viable in practice the gain might need to be an order of magnitude or more again.
One thing to remember is that a major goal of fusion research is also weapons applications, those that is never publically admitted.
Fusion, in any of its forms, requires some of the highest technology ever produced by mankind. It then exposes these ultra-high-tech wonders to extreme temperatures, and extreme temperature differences, and large amounts of extreme radiation (neutron bombardment), plus corrosion from the extremely fine hydrogen gas. Initial fusion power plants will operate at a very small energy efficiency, and they will need constant maintenance via high-tech robots capable of withstanding the radioactive environment that the neutron bombardment will create all around the reactor. Most pieces of the reactor will probably not last for more than a few months or at best years, due to all of the pressures described before.
Not to mention, the potential for catastrophic failure, though much less than with fission, is still enough to completely destroy the reactor and a good chunk of the plant, if the plasma containment fails. While of course incomparably safer than a fission reactor meltdown, it would still be a massive economic issue.
So commercial fusion, when it does finally arrive (or if), will be extremely expensive, with its only plausible use case as a somewhat reliable base load. Cheap fusion, if it is even possible, is much further away into the future than that - I would confidently bet that cheap fusion will not exist this century, even if ITER or others reach all of their milestones as planned.
I think the first ~50 years of fusion projects are likely to be very expensive and I'd expect that reputation to stick.
If you claim either fuel cost or waste handling cost, neither of those is a major part of the cost of fission power. Capital cost is, and fusion moves that in the wrong direction.
Fission devices have been very well understood since the early 1950s, but fusion reactions are somewhat less so. The NIF provides an instrument for probing the plasma densities and temperatures that occur inside a nuclear fireball, so is directly relevant to H-bomb research.
This becomes trivially obvious when you realize that a laser implosion fusion reactor producing power would need to achieve in excess of ten ignitions per second to produce the sort of power output needed just to power its own lasers ... and that each hohlraum costs on the order of a third of a million dollars. (What kind of power plant costs $11Bn per hour to operate?) Answer: it's not a remotely practical design for generating electricity, so it must be something else, and promoting it as "clean energy from fusion power" is a cynical propaganda move to disguise a nuclear weapons research tool.
The final clue is that the NIF is operated by Lawrence Livermore National Laboratory, whose primary job is designing and ensuring the reliability of nuclear weapons.
Indeed, the brute-force approach is to simply detonate a hydrogen bomb underground, tap off steam, then repeat. That was seriously investigated (I believe as part of Project Plowshare https://en.wikipedia.org/wiki/Project_Plowshare ), but the high cost of the bombs made it uncompetitive with other methods.
We have know for centuries that all you need to go high is a big fire pointing down, but soon realized that the hard part was maintaining the fire long enough to reach orbit or other planets.
And even when that would become possible, the problem of how to land in the destination, build shelters and grow food remains.
So, why we insist on this irrational pursuit?
First because we can.
Second because the the search needed to achieve that generates far more societal benefit than just the space goals.
And third because society can pursuit many goals at once. We have several people, just let them explore.
So, fusion is hard, but very probably not impossible. The pursuit of it will advance science and technology. If successful, can trigger societal changes we can only imagine today (serious carbon capture becomes possible. Smelting of very energy intensive alloys becomes cheaper and possible).
And if the ultimate goal of a miniaturized reactor becomes possible, our spaceships can fly basically anywhere.
This is where we are at, that is what we are aiming for.
ED: By now I assume I would be ignored if I was wrong.
The theory is there, but the implementation is not and worse than that, there is no "it will get cheaper with industrialization" in sigh, because we are not even at that stage and there is no indication there is a realistic path to achieve the efficiency needed to be economically viable ( ever! ).
The best positioned to deliver something tangible seems to be ITER, many of the rest seems to be more of a pump & dump scheme than anything else.
It's also possible ITER will just deliver a negative outcome, if they can't figure out how to control disruptions sufficiently. A reactor that violently breaks itself is not something anyone would want to buy.
Whenever there are articles written about inertial confinement, they always describe the current process (which I understand at a layperson level) but never how this design could be implemented in a repeatable manner?
The initial investment may be scary, but I think this is discounted per people's experience with Moore's law (whether right or wrong).
"Energy too cheap to meter" was already an obvious scam with nuclear power in 1954* (because plants obviously cost TONS of money to build/operate/decomission).
I don't see how fusion power is going to change that.
edit: * "Obvious scam" might be a bit harsh, but it was definitely naive overenthusiasm at the very least.
Or is it just various fusion startups making PR waves to get more investments?
NIF is inertial confinement fusion. Magnetic confinement fusion startups have been making waves because of a new type of magnet which doesn’t need to be supercooled and can create the same amount of magnetic pressure w a smaller device (I think). In addition to that, there are the same old and not-so-old publicly funded experiments which have been making good progress of their own. ITER is still being built, but a lot of these publicly funded experiments are tied to ITER.
I have a hard time seeing the NIF approach becoming economical. It's more of a science experiment.
