I'm not aware of Helion publishing any peer reviewed data claiming a physics breakeven (the point where the total energy generated by the reactor exceeds the external energy fed in to maintain the reaction going); let alone an engineering breakeven (the point where the fission generates about an order of magnitude more energy, to allow for the energy conversion losses, cooling and fuel breeding etc. so as to actually output any useful amount of electricity); let alone an economic breakeven, where the reactor generates sufficient useful energy that its market price can allow the capital and operating costs of the reactor and associated infrastructure to be recovered in a certain number of decades.
If fusion had all three today, it would still e a though sell; fission has them and is still failing economically.
I don't disagree with any of what you say but if Helion's approach works (and that's a huge if) it would generate electricity directly, without need for a steam turbine or any of the associated plumbing. My understanding is that a big part of the cost for fission is the turbine etc.
And how would you "generate electricity directly", specifically? Let's talk physics and engineering, not vague statements.
How would that energy generated from nuclear fusion be transformed into electricity "directly"? By which process / series of processes?
See "Induction systems"[1] The concept was proposed in 1963, but nobody ever made it work. That's the plan. Magnetohydrodynamic generators [2] do work, but they have electrodes in the gas. That works for jet engine type MHD generators, but fusion plasma is too hot for any solid material.
What they're trying to do is known physics but very hard engineering.
They're also trying for aneutronic fusion, using helium-3. If the plant generates large volumes of neutrons, it chews up the first wall between the reaction and the outside. It also makes what it hits radioactive, so there's a waste problem. Aneutronic fusion uses reactions that (mostly) generate alphas and betas. This is, again, known physics but very hard engineering.
If they can get a demo machine going which solves either problem, that would be a huge advance. So far, that does not seem to have happened.
There are other startups in this space. It's probably the way commercial fusion power will eventually be done. Not via the tokamaks, like ITER.
[1] https://en.wikipedia.org/wiki/Direct_energy_conversion
[2] https://en.wikipedia.org/wiki/Magnetohydrodynamic_generator
[3] https://spectrum.ieee.org/aneutronic-fusion
> There are other startups in this space. It's probably the way commercial fusion power will eventually be done. Not via the tokamaks, like ITER.
There is literally no evidence to suggest this: Helion are making big claims but as noted have shown little incremental progress on their machines.
The balance of history says if it happens it'll come out of a large government funded project: that's how fission happened, and there's plain old fission startups too who also are yet to deliver anything and we know fission works.
There is plenty of evidence. This is your ignorance speaking here.
I feel very comfortable saying in 5 years Helion won't have anything.
Because HackerNews was soooo confident that a startup style skunkworks initiative would lead to over-unity fusion in 5 years[1]...in 2014.
Then they were soooo confident that MIT was going to blow past ITER to over unity fusion[2] ... in 2020.
It's 2025, and the latter project is still running but now predicting it'll finish it's big reactor post-2030.
Helion are currently now reporting no new results, but claiming they'll hit net-energy in 2028 somehow despite little technical detail. After claiming they'll show net-energy fusion in 2024.[3]
So there's my evidence. Where's your evidence?
It should be noted that I'm not actually against private fusion research - more research is great. But the unfounded confidence with which HackerNews users make predictions of the obvious superiority and success of private industry in achieving fusion has a track record of "we still don't have fusion" despite company's dating back as early to early last decade when we're mid-2020s now.
[1] https://news.ycombinator.com/item?id=8458339
[2] https://news.ycombinator.com/item?id=24629828
[3] https://en.wikipedia.org/wiki/Helion_Energy
The problem with Helion is that their "Polaris" device isn't working yet. That was supposed to do some fusion and recapture some energy, even if not breakeven. It was supposed to be operational by now.
Success with Polaris would be a big deal. Helion isn't mentioning it much any more. Not good. December 2024 discussion on Reddit.[1] Discussion in the last month on Reddit.[2] Video from Helion that mentions mostly Trenta, the previous machine.[3]
Yet they're pouring concrete for the next machine.
Uh oh.
[1] https://www.reddit.com/r/fusion/comments/1hlojqu/any_news_on...
[2] https://www.reddit.com/r/fusion/comments/1lv4e2h/what_has_ch...
[3] https://www.youtube.com/watch?v=nuB3bIsJeJA
I like how your mode of argument would have led you to confidently assert SpaceX was going to fail. Please conduct some QA on your logic, mkay?
Who here is "soooo" confident Helion will succeed? One can be excited about a company without thinking they're a sure thing. The world is going to spend maybe a quadrillion dollars on energy in this century, so even low odds bets can be very worthwhile.
Those two HN links there were to stories about companies other than Helion. I agree the DT efforts are dubious.
Helion has been reporting results, btw. Have you been reading? Maybe you're complaining they haven't finished all of the next machine yet? "They didn't snap their fingers to make their machine, therefore they're frauds!" isn't a good look.
https://x.com/helion_energy?lang=en
SpaceX had a ton of help from NASA.
Also:
> Fusion generates electricity by ramming atoms into each other, releasing energy without emitting significant greenhouse gases or creating large amounts of long-lasting radioactive waste. But despite billions of dollars of investment, scientists and engineers still have not figured out a way to reliably generate more energy with fusion than it takes to create and sustain the reaction. Helion is still working on how to do that with its current prototype, called Polaris, which is housed in Everett, Washington, where it plans to build components for the machine to be built at Malaga, called Orion.
1. https://www.reuters.com/business/energy/helion-energy-starts...
And Helion has built upon "a ton" of work from predecessors as well.
The quoted argument is basically "it hasn't happened yet, therefore it can't happen". Why does this argument not also apply to SpaceX, for all the things they've been the first to do?
I get that skepticism is warranted, but please don't cross the line into blatant technical nihilism.
Skepticism is more than warranted. I would be skeptical that they could put out a working reactor in 3 years even if they had already established the technical and commercial feasibility in a lab setting!
I’m curious if you’d make a bet on this and how much you’d wager?
From their Wikipedia page
> Energy is captured by direct energy conversion that uses the expansion of the plasma to induce a current in the magnetic compression- and acceleration – coils. Separately it translates high-energy fusion products, such as alpha particles directly into a voltage. 3He produced by D–D fusion carries 0.82 MeV of energy. Tritium byproducts carry 1.01 MeV, while the proton produces 3.02 MeV.
> This approach eliminates the need for steam turbines, cooling towers, and their associated energy losses. According to the company, this process also allows the recovery of a significant part of the input energy at a round-trip efficiency of over 95%.
https://en.m.wikipedia.org/wiki/Helion_Energy
Well, at least they know how to invest in good PR.
I assume their building permit includes plans. Someone should look them up.
https://en.wikipedia.org/wiki/Magnetohydrodynamic_generator is the gist of it. If you have enough conductive plasma then just moving it through a magnetic field generates a current. Applied to fusion power, you heat the plasma through the fusion reaction then divert part of the plasma through the MHD generator.
Tbh, I very much doubt that this is a realistic path in the coming decade (but would love to be proven wrong). AFAIK no experimental reactor has yet generated any net electrical power at all, let alone with any big (ie dozens to hundreds of) MW MHD generators. Getting even one of these aspects working would be a major advance, let alone doing both at once.
Their system can reversibly compress the plasma by energizing a coil. If the plasma acquires more energy in that time (by fusion producing energetic charged particles), the expansion stroke can return more energy to the capacitors than the compression consumed.
It's the electromagnetic plasma equivalent of a reciprocating internal combustion engine.
... except for the fact that they're claiming 95%+ efficiency in an engine type nobody has ever seen running when actual existing reactors of that type can't seem to make it to 1%, and the two types of engine you can compare this (ICE, steam turbine) have SOTA efficiencies of 35% and 48%. This seems less than realistic.
Then again, this is being done with private funds. So let them, and frankly, I really hope it works. Hell, if they wanted reasonable subsidy for this, I say give it to them.
They have been doing compression and reexpansion on plasmas for a long time. They are claiming high efficiency on energy recovery in these (non-fusion) plasmas. They can also do energy injection and recovery just by pulsing the coils around an empty vacuum chamber (or one filled with nonconductive gas).
There's nothing that should be unbelievable about this claim, and to dispute it would be to assert that they are outright lying. For short timescales where do you expect the energy to be going, if not back to the capacitors? Inductive energy storage on short time scales should be very efficient. Both the coils used and the plasma itself have sufficiently low resistivity. I think the gating technology for this was the switches.
The 1% figure you give there isn't for anything resembling this process, so I don't know why you brought it up except for reasons of obfuscation or your own confusion.
> And how would you "generate electricity directly", specifically?
Using a particle accelerator (decelerator?) in reverse. I'm an investor in Tri-Alpha Energy, and they have tested a direct converter with the claimed 90+% efficiency.
Conceptual overview: https://www.youtube.com/watch?v=HlNfP3iywvI
Sure, they aim to extract energy directly from the field, but the three breakeven points are still important. A significant part of the energy will be lost as x rays and neutrons, since their D-H3 fuel cycle is not aneutronic; they will also have significant D-D reactions that are required to breed Tritium which they capture and then let ti decay to Helium-3.
Overall, when you look at the total complexity and energy balance of the full reactor + fueling cycle, maintaining vacuum, keeping superconducting magnets at cryogenic temperatures, tritium extraction etc. then generating an order of magnitude more energy than inserted still seems necessary to achieve engineering breakeven.
In the cycle under question (two DD reactions per D3He reaction), 91% of the fusion energy goes into charged nuclei, not into neutrons. In steady state where T is being allowed to decay into 3He and there's just one DD reaction, the fraction of energy in charged nuclei is even higher.
X-ray emission is strongly dependent on electron temperature. One of the important aspects of Helion's scheme is the electron temperature is much lower than the ion temperature. Not only does this greatly reduce x-ray emission, it reduces plasma pressure at a given ion temperature vs. a plasma where the ions and electrons are in thermal equilibrium, thereby increasing the ion density and fusion rate. The pulses in Helion's scheme end (and the plasma energy is recovered) before the electrons can heat up.
And danger. Turbines are more powerful at high temps, and now you have hot liquids near your reactor. Or you use molten salt as a middleman so the potential steam explosions are a little farther from the reactor.
why would they need to publish a peer reviewed paper? that'd be a distraction, unless they needed to snag a customer. they apparently have a customer.
Comparing the economics of fission and fusion is quite a stretch. Even with the massive number of unknowns they've literally nothing in common.
Well, a dolar is still a dollar and they need to sell on the same energy market. It's well understood that fission projects have become economically infeasible because they are dominated by capital costs, and the risks these projects come with are not compatible with the decades required for economic breakeven.
Everything we know about current approaches to fusion seem to indicate they will have the same economic problems. The scaling factors of confinement, power and reaction rates push towards immense reactors with vacuum chambers the size of apartment buildings, massive superconducting magnets etc. hence the ITER project spiraling out of control trying to build one just big enough that at least have a fair chance of achieving engineering breakeven. The basic plasma physics works the same for Helion, and the best triple product they achieved places them two orders of magnitude behind tokamaks, albeit with much less capital.
So when and if the best approaches to fusion succeed, it looks like they will yield these massive plants that share the costs problems of fission. While they won't be able to meltdown, the regulatory constraints will be very similar, the intense neutron flux will activate the structure of the reactor and poses similar proliferation and decommissioning concerns, there is radiological risk to the civil population in the form of Tritium leaks etc.
And unlike fission, which is very well understood and mature, fusion plants will be much riskier economically, on par with the attempt to introduce fast fission breeders into commercial service, which notoriously failed.
So while the physics is indeed very different, we know enough to compare fusion and fission economically, and the outlook is very bleak.
Why do you think fission plants are expensive? Do you think it's the pumps and turbines and concrete?
Pro tip: it's not. It's because there is millions of man-hours of regulatory burden attached to every decision, to every bolt, to every instrument or valve installed.
There is a reason for all that regulatory burden, of course. It's the release of long lived and deadly radiation from a meltdown. If it wasn't for that regulation building a nuke plant would actually be quite inexpensive, relative to current costs- On the scale of a hydro dam.
Fusion has none of those costs because it has none of the same dangers. It's a wildly different problem with wildly different cost basis. The expensive part is research. Once that's done that cost is gone.
Fission plants are expensive because malfunctions cannot be tolerated. Malfunctions cannot be tolerated because the government would not give them a liability cap if there was a significant chance of serious accident.
Guess what? Fusion reactors also can't tolerate malfunctions. Not because of public safety, but because large (DT reactors being 40x the size of a fission reactor for a given power output) complex devices that are too radioactive for hands on maintenance are unrepairable.
Helion is claiming they can go with materials with very low beyond short term activation, and that the cylindrical geometry would make swapping out hot components easier. Whether that is enough remains to be seen, but IMO DT approaches are complete dead ends.
Solar energy has achieved such a cost reduction that nuclear can't compete even if the actual nuclear reactor part is free. Just the classical, steam turbine parts are becoming more expensive than solar, and this is evident for new natural gas plants, who don't even have any radiation concerns. Sure, fusion energy would be dispatchable, unlike solar, but momentum is building towards large scale interconnections, perhaps even at intercontinental levels, spanning many time-zones and climates and achieving highly reliable solar.
While it's unclear when all this will be achieved, nobody is ready to bet 10 billions that it won't happen in the next two decades they need to recover costs.
I agree solar is very tough to beat, and even more so as storage improves. As I've said before, I consider Helion is the least dubious fusion approach, but that doesn't imply I think their absolute chance of commercial success is high.
One very significant issue with Helion's scheme is the enormous quantity of tritium produced. To put this in context: to power the world with such reactors might require ~10 TW. If using 2DD + D3He, this would produce 12 grams of tritium per second. If this stream were all released into the environment (which it would not be, but this is for purposes of illustration) it would lift all the water in the entire biosphere close to the US legal limit for tritium in drinking water, including all 1.3 billion cubic kilometers in the oceans. Tritium capture and containment will have to be extremely good for this technology to be globally acceptable.
Thank you for your very well informed perspective. Fusion proponents seem to be either industry insiders with vested interests, or less informed fanboys who are simply unaware of the technical and economic realities.
This issue of safety is particularly prone to handwaving; in reality, the combined effects of activation and proliferation risks and the substantial radionuclide release potential will make the operational realities, regulations, environmental litigation and associated costs very similar to fission.
That's not too say fusion is inherently dangerous, rather that modern fission projects are already very safe and fusion won't improve on that. Yet fision still failed. So if fusion can't improve on the economics - and they quite clearly can't for the foreseeable future - then they bring nothing to the table.