It seems that for the last couple decades fusion is always 30 years away and by this point we’ve well passed the initial 30 and seemingly little progress has been made.
Is it just that it’s so difficult to make efficient?
Has the technology improved substantially and we just don’t hear about it often?
In: Physics
The technology has improved substantially but it’s so extreme in terms of temperature and pressure – essentially you’re trying to cage a bit of the sun – that finding a method to keep it contained that doesn’t take more energy to hold it in place than it creates is ferociously difficult. And when you’ve suceeded at laboratory scale, you then have to make it up to production scale, and the problems amplify exponentially.
In short it’s like climbing a lot of mountains – just when you think you have reached the top, you find you’ve just reached a false summit and the real one is further away. And when I was 50 years younger it was 50 years away, so we have made some progress.
You look at current progress and say “we’ve solved 1/3 of the problem in 10 years so 1/3 every decade is 30 years”. The problem of course is you’ve solved all the easy problems and the harder ones take longer. You have literally no idea how long it takes to solve each problem you know about and you don’t even know all the problems.
The biggest problem with Fusion research is the overall lack of funding.
The paltry amount of research funding for Fusion was once described by a Scientific Journal as *”Fusion Never”*.
There’s tons of brilliant engineers and scientists with good ideas willing and able to work on it, but there just isn’t the money to build and run the test equipment required for every project.
The big government funding throughout the 20th century was put against fission research because a by-product of Fission reactors is enriched uranium and plutonium used in Nuclear Weapons. So it was very politically motivated by the Cold War.
As a result Fusion power research was entirely niche and the few teams working on it make very limited progress.
If we assume that there’s a 98% chance that any particular fusion concept is actually a dead-end, there’s hundreds of potential design concepts, and we only have 3 projects on the go at any time, we make very little progress. Each experiment though teaches us more and more about Fusion, so saying that we are making no progress would be incorrect, it’s just very very slow.
There’s been a significant uptick in research in the past 20 years because of the push towards green energy, but what politicians don’t realize is that Fusion is such a game changer that what we really need is a *’Manhattan Project’* for Fusion. If you give the scientists effectively unlimited funding and have multiple teams working on it we could probably figure out viable means of using it within a decade.
The first country that figures out sustainable and practical fusion will have a huge economic and scientific advantage for decades and will make the investment worth it. Let alone the benefits of cheap power that comes with it.
Because we never quite know enough to be certain of our estimate but know we are doing well so 10 is too close but 50 is too far.
We then get 30 years on and have made leaps and filled the knowledge gap but found another hole so the time moves on.
When will it finish? When we give altruistic science proper funding and killing others less funding so we can save the fucking planet and ourselves
first one will come on line in a couple of years. It will power Microsoft. Helion Fusion. The 30 year thing is for government funded research facilities who will likely never produce a kilowatt of electricity. Primarily because they fuse tritium and it is extremely rare.
the version of the joke I’d heard from people involved was that it always has and will always be 10 years away. granted what NIF did was a breakthrough. So maybe it always will be 5 years away now
Can someone eli5 how fusion would benefit us in real life? I’m not a science person and google isn’t helping
“In 1976, the US Energy Research and Development Administration (ERDA) published a detailed fusion program plan [4] suggesting that, if a sequence of advanced test facilities were constructed in a timely fashion, fusion electricity could be on the grid in a Demonstration Power Plant by the year 2000. This plan was codified by Congress in the Magnetic Fusion Energy Engineering Act of 1980, signed by President Carter on October 7, 1980. The Act was signed just as the US “energy crisis” was coming to an end, as proclaimed by President Reagan upon taking office in January 1981. The provisions of the Act were never implemented. Furthermore, fusion and other energy R&D programs experienced major funding reductions during the 1980s and 1990s.”
[Historical Perspective on the United States Fusion Program](https://fire.pppl.gov/Dean_US_fusion_TOFE_2004.pdf)
It’s a very hard problem. It’s “30 years away” because it’s previously been very difficult to even know what further challenges lay ahead until you get over some roadblock problem that’s holding you back right now.
I’m going to talk a little about how we’ve mostly been trying to do fusion over the last few decades – using a reactor shaped like a big donut, which is called a “tokamak”. It’s from a Russian acronym that means “toroidal chamber with magnetic coils”. “Toroidal” just means “donut shaped” and we’ll get to the magnetic coils in a bit.
It’s a hard problem because it relies on getting matter (gas/plasma) VERY hot (millions of degrees), and holding it together close enough for long enough (confinement) that fast moving particles of this energetic gas collide with each other, and combine to make heavier elements. When this happens the resulting combination (fusion!) releases a lot of energy as heat and radiation, which we want to harvest – the usual approach has been to collect some of the excess heat, then use that heat to heat water into steam, to turn a turbine so we can then use the rotational energy along with magnets to produce electricity. The steam turbine thing is also how “regular” nuclear power (fission power) works. Except in that application, you just gather up enough radioactive material together in one place, the material decays (which means tiny particles shoot off of it) producing heat.
The trouble with fusion is that when you get these particles so super hot, you a) can’t let them touch the walls of the vessel you’re containing them in, and b) they *really* want to repel each other. So you have to put a ton of energy in to get the reaction to work in the first place – think of squeezing some things together at really high pressure. That’s essentially what they’re doing, only it’s primarily with magnets. The donut-shaped chamber is wrapped with wires which, when you run electric current through them, produce specifically shaped/directional magnetic fields which work to contain the electrically charged plasma inside and “squeeze” it together.
The idea with a tokamak is that you have a “sustained” reaction where you put a lot of heat/energy in initially to get the reaction started, then the heat released from the reaction itself helps to keep it going over a long time period, and then you can extract some of that heat. This is called “ignition” and it’s really the hardest part to achieve. We can make fusion for short amounts of time but you have to really control the conditions to get a sustained reaction. The plasma is flowing around the ring and there is turbulence due to the changing magnetic fields as you go around, and understanding how every particle moves and how that affects the reaction is really, really difficult.
There are also issues with just how you actually extract the excess heat out of the system – if you let too much heat out through some part of your reactor, it’ll melt/vaporize and the whole thing will be destroyed (note – this would not be a nuclear explosion like a nuclear bomb – those need very specific conditions to happen). Also you need to keep enough heat in the system (inside the plasma, really) to keep the reaction going. Even if you can control the release of heat in the way you want to, there are issues with the inside of your reactor degrading over time due to the very high heat and radiation.
So it’s difficult because of the extreme conditions needed to sustain the reaction. There are physics challenges (understanding how it all works, how the reactions work etc.) and engineering challenges (what materials to use, how to build the devices, etc.) which all play into each other.
We can’t easily foresee the challenges and the solutions which will come up because we don’t know what advances in technology will be made which might help. There are several big advancements that have happened which will definitely help though. For one thing, there’s been a big advancement in superconducting magnets: [https://news.mit.edu/2021/MIT-CFS-major-advance-toward-fusion-energy-0908](https://news.mit.edu/2021/MIT-CFS-major-advance-toward-fusion-energy-0908)
This means that they can produce the magnetic fields needed to achieve the containment needed much more easily/efficiently, which means they can make the reactors smaller, which makes the whole thing easier.
Another thing is more gradual: Computer hardware. Simulation of the reactors takes a LOT of processing power, and of course since the 1980s computing power available has increased massively. This helps a lot in loads of different ways.
There are also huge advances in manufacturing technologies to build the reactors. Computer controlled machinery, 3D printing, advanced 3D CAD, materials technology advances, all sorts.
And finally, there has been a recent explosion in people trying fundamentally different technologies. We thought that the best way was with a big donut-shaped reactor but now there seems to be more funding available for fusion research, there are companies trying out different ways.
One company is essentially making a big cannon which fires a specifically-shaped bullet at a specifically-shaped target, which creates shockwaves which collapse and create the very high temperature and pressure needed for a fusion reaction – for a split second. They would do repeated shots (say, 10 per minute) inside a chamber and extract excess heat from the chamber.
Another is using a different type of simpler reactor and instead of extracting heat, using the radiation produced to directly produce electricity.
Another is trying to use big pistons to compress plasma to create the right conditions.
There are other approaches using ~100 massive lasers to heat a tiny fuel capsule which causes is to collapse and create massive temperature and pressure.
Basically there are lots of different approaches being tried now. Lots of people think they have an answer, and it’s entirely possible that some of them will work, relatively soon. However a large part of the whole “30 years away” thing is that you don’t really know if something will work, or what challenges you will face, until you build something and try it. And building the reactors, depending on the design and the approach being used, has led to some of the most complex engineering challenges, and largest projects ever conceived, in any field. The most famous one right now is ITER being built in France. It’s the largest tokamak reactor we’ve ever built and should be ready to start making plasma in 2025.
If the last two years have shown anything, it’s that it doesn’t matter if the secret to viable fusion energy is discovered. The corporation that controls it will not sell energy at a discount to anyone.
They will charge whatever they can get away with, and they will have lobbyists that bribe politicians into voting the way they choose.
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