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.