Spherical tokamak achieves crucial plasma temperatures
eetimes.com
eetimes.com
> A traditional tokamak has a toroidal confinement area that gives it an overall shape similar to a donut, complete with a large hole in the middle. The spherical tokamak reduces the size of the hole as much as possible, resulting in a plasma shape that is almost spherical, often compared with a cored apple.
The stellerator for instance is more traditionally toroidal.
The D-shaped "advanced tokamaks" and spherical tokamaks are similar shape but the spherical has smaller center hole. That is the most efficient but it is harder to build. The center hole is the most confined space in giant ITER.
especially government research science
"good enough for government work"
Complete with random bits of aluminum extrusion for bracing, random leftover cables no one's cleaned up yet, "interim" solutions, and duct tape.
Interesting to compare with the Nvidia latest keynote [1] where they opened up a 3D rendering of some ASML internals and how slick those systems are put together given the fantastic level of complexity involved also.
[1] https://youtu.be/DiGB5uAYKAg [22:40 ish]
without any hyperbole the 2-shot laser thing necessary to emit EUV is just mind bending.
[1] https://open.spotify.com/episode/5X1TXNQ9zIo5PGJe80xtpv?si=Z...
https://thebulletin.org/2017/04/fusion-reactors-not-what-the...
I don’t see what advantages it would have over wind, solar, fission, etc.
This is as equally true for consumer hardware as it is for massive scientific endeavours.
Of course predicting the future of new tech is always a kind of bet. I don't know enough about the details to make a judgement either way. Fairly obviously it just isn't going to be ready in time for the thing it's most often touted for - ie. the decarbonisation exigency. That's just the usual research funding opportunism.
But assuming we do make it over the next few decades (very unlikely in my view), cheap limitless energy is inevitably going to be transformational.
In the case of fusion, it’s something we do want (fission and burning fuels aren’t sustainable indefinitely) and as our energy needs increase year on year, the cost for energy will also increase if we don’t find a way to supply that demand. This makes a mass producer of clean energy more viable.
Renewable energy is great but it’s not exactly cheap to scale either. In fact the only reason it has gotten so cheap is precisely because the need for it has lead to plenty of advancements that have also driven down the cost.
So fusion in this form of reactor might prove to be a dead end but at some point humanity will end up with some form of fusion. Even if it’s not in our life time. And assuming we haven’t had an extinction event first…
I'm sure there must be academic studies looking into reasons for tech not getting to production. I don't know them, so I can only hazard a guess that this isn't quite right. I think many technologies just don't prove feasible outside the lab. One cause of infeasability is of course price (no route found to a true industrial scale learning curve). But sometimes it's safety or inherent limitations that weren't understood before trying to scale, or any number of other causes not predictable from basic science. You can't know 'till you know, and for fusion, we don't know yet. It's a bet (which to be fair is the same with nearly any new tech). A good one, perhaps.
there's a lot of interest nowadays in "progress studies" which tries to tackle this (or a very similar set of) questions
yes, sure commercial fusion is definitely one of the toughest nuts, but fission based small modular plants are viable, yet it's barely being done. and there are many products and technologies that are economical yet not widespread. (let's say public transport.)
This also makes commercail fusion very unlikely to happen in this civilisational iteration. It requires large advanced economies with highly functional and specialised supply chains. These conditions won't exist once climate refugees sweep the world in their billions, and wars break out everywhere. If, indeed, given Russia/Ukraine, and the joint determination of China & the US to go to war, we even last that long.
Fusion reactors has none of that. But the cost of gizmos as seen currently is a way too high indeed.
Disingenuous. Your bicycle costs less than a car, but can you use it to move 500 pounds at 60 mph in the rain? Talk about renewables + seasonable storage.
But then one still has to be skeptical about tokamaks. Plasma instabilities for unknown reasons alone is enough for that.
And then there is the flux of energetic neutrons with order of magnitude higher energies than that of a fission reactor. Spherical tokamaks are especially bad in that respect as the central thin handle cannot be protected sufficiently.
At least with stellarator designs there are no instabilities and the neutron flux can be managed with a sufficiently thick blanket, so those are safer bets than tokamaks.
A lot of renewables require massive amount of energy, raw materials and pollution to get done, and then last decade or two at best. I have yet to see a bigger wind turbines fields who are all fully working at given time, usually mote than half doesnt move even in stronger winds due to ie maintenance
Fusion on the other hand has no chance of a run away meltdown and the materials that are used are much easier to dispose of.
(Presumably, water to steam then turbines, like everything, but how do you get the heat out from the reaction?)
Materials are being investigated that can withstand the heat and neutron bombardment to attach a steam turbine the old fashioned way.
But we ain't there yet, not without having to constantly change the 'walls'.
> Most of the energy produced inside a fusion reactor is emitted in the form of neutrons, which heat a material surrounding the fusing plasma, called a blanket. In a power-producing plant, that heated blanket would in turn be used to drive a generating turbine
The fraction of the energy that is retained as velocity of particles with a charge vs that is lost as the velocity of neutrons turns out to be conveniently just about where you'd want it to be. So, to capture the energy you need to surround your reactor with something that effectively converts fast neutrons to heat, such as a blanket of molten lithium, which you then use as a heat source. Lithium is proposed because it would also breed the necessary tritium.
That's an energy output of 7 x 10^7 Wh per gram [1], or alternatively, a 70MW reactor needs one gram per hour, or alternatively, a very large 3.5GW plant needs 500 grams per hour, roughly the equivalent of the water drunk by a single thirsty person.
[0] https://en.wikipedia.org/wiki/Deuterium%E2%80%93tritium_fusi...
[1] https://www.wolframalpha.com/input?i=17.6+MeV+divided+by+ato...
The world final energy consumption (2018) [0] is around 9717Toe or 9,717*11.63=113,009TWh
1g for 70MW = 1T for 70TWh
113,009 / 70 = 1614
1614 ton of lithium every hour seems huge to me, does my calculations are wrong ?
[0] https://en.m.wikipedia.org/wiki/World_energy_supply_and_cons...
The worldwide primary energy consumption is ~600EJ. 1g/70MWh * 600EJ ~= 2400t per year.
Cost of cryogens, cost of steel, cost of working nitronic, cost of Beryllium, and cost of superconductors are the dominant sources to track.
Your fuel costs are replaced by the reactor replacement cost. Spent nuclear rod fuel waste is replaced by the irradiated materials in the reactor.
Since it is a complicated engineering problem there is space to turn engineering effort into reduced cost.
There are other reactions one can pursue that produce charged particles instead of neutrons. With these reactions, there are alternative energy conversion pathways that turn the kinetic energy of these charged particles directly into voltage, and you can skip the turbine. Of the fusion startups, Helion is probably the most prominent pursuing this kind of approach, with a D-He3 reaction. See https://en.wikipedia.org/wiki/Direct_energy_conversion for more info on this general approach.
New-build coal isn’t economically competitive anywhere, even where you get the coal essentially for free.
This article from DW explains it doesn’t make economic sense there either:
https://www.dw.com/en/why-build-600-new-unprofitable-coal-pl...
Provide a source or your own analysis for this claim:
>If the plan for energy conversion is a steam turbine, it’s never going to be economically competitive.
The key point is that only roughly 20% of the capital cost of a coal plant is related to coal handling and pollution control.
https://esmap.org/sites/default/files/esmap-files/TR122-09_G...
So even if the fusion reactor reduces all of those costs to zero, the capital costs would only be 20% cheaper than new-build coal.
As I mentioned earlier, coal isn't economically competitive with renewables pretty much anywhere, even places with very cheap coal resources that can't be traded on the global market. There's heaps of lignite in Texas, for instance, but nobody's building new plants to burn it.
As such, it's hard to see how fusion reactors turning steam turbines are going to be economically competitive either.
Some have a secondary steam turbine as an exhaust energy recovery system but as I understand it that’s becoming uncommon on new builds because new gas turbines are expected to be used less now that there’s a lot of renewable energy on a lot of grids.
For comparison, fusion fuel is $0.00014/kWh, equivalent to coal at $0.27/ton. There's no where on Earth where coal is that cheap. You couldn't move it from the mine to the powerplant for that cheap even if they were next door to one another. Even if all the costs got subsidized away, you couldn't count on the fuel remaining cheap for the lifetime of a powerplant.
And of course there's that pesky CO2 issue that makes investment in coal unattractive even if it could be economically competitive.
There are places where there is abundant brown coal, which cannot be economically transported long distances and is therefore basically loaded on a conveyer belt directly into power stations.
New-build brown coal isn’t economically viable either.
How about Sphekamak?
Quoting the Wiki: Spherical tokamak, essentially a spheromak formed around a central conductor/magnet
At some point they just have to give up on the design, because it just isn't working. But I suppose as long as there's funding there'll be people trying to get it to work.