Not to mention that this is likely a very short-term debate. Modern AI/ML/compute has been a huge boost to fusion R&D, and tons of AI/tech capital is flowing into companies like Helion and CFS. Necessity is the mother of invention and all.

It may be a valid criticism today, but no one will be complaining about AI's environmental impact after those first few plants go live and mass production begins within the next decade. Knock on wood.

I'm skeptical about that. Helion in particular might work (https://www.youtube.com/watch?v=HlNfP3iywvI) but all the other fusion-energy companies' plans are to convert fusion energy to thermal energy and then convert the thermal energy to electrical energy in the usual way, using steam engines. That's never going to be cheaper than thermal energy powering steam engines, because thermal energy powering steam engines is part of it.

But solar energy is.

Helion's strategy is to directly convert the hot plasma's expansion into electrical energy by, basically, pushing against a powerful magnetic field. This is potentially higher efficiency than steam engines (because it's working at a higher temperature) and potentially higher power density and reliability. So it could at least theoretically get to be cheaper than steam engines. But I think it's more likely to be far more expensive for the next several decades.

I'm definitely more optimistic about Helion. It's the one that would really dramatically change the economics of power generation at scale, and they seem to have substantially engineered around major challenges like not requiring ignition and minimizing losses to Bremsstrahlung radiation. I like that they're laser-focused on launching and delivering commercial value, even if that means a bit less transparency and less focus on research demonstrations than many would prefer.

If Helion delivers Orion on anywhere close to the target timeline, it seems like they'd be primed to kick off mass production and start shipping units all over the country with minimal regulatory hurdles. With sufficiently high productive capacity, it would effectively make all other forms of power generation obsolete at utility scale. Solar would still great for small/decentralized use cases, but there wouldn't be as much reason for a power company to build new solar plants if they had the option to fill the same real estate with a bunch of Helion machines.

That being said, I'm not not optimistic about steam-based fusion power. It would be less revolutionary, but from what I understand would still be a huge advancement. My read is that it would effectively obsolete fission power and plausibly fossil fuel power as well, if not also grid-scale renewables. It would be like having SMRs with higher efficiency and no major proliferation or meltdown concerns that amplify costs. High neutron output and steam conversion add costs and complexity, but if CFS panned out and Helion didn't, I'd hardly turn my nose at that.

I could also see a world where multiple forms of fusion power pan out, and it turns out to be economical for Helion to sell tritium to other vendors like CFS rather than storing it for 12 years until it decays to He3. Maybe we'd even have colocated plants in a certain ratio where Helion provides on-site tritium generation in the exact volume needed for a D-T reactor.

https://www.helionenergy.com/articles/starting-to-build-the-... (undated) says Orion is intended to deliver 50 megawatts. If they could deliver that for under US$100 million they'd be competitive with fossil-fuel plants, assuming no fuel cost or other opex; if they could deliver it for under US$30 million they'd be competitive with solar, unless solar gets even cheaper. (It's fallen in cost by 45% over the last two years, according to https://www.solarserver.de/photovoltaik-preis-pv-modul-preis..., but almost all of that was more than a year ago; it's only fallen 10% in the last year.)

Helion's latest funding round was US$425 million, bringing total funding to over a billion, on a US$5 billion valuation. To give that money back to their investors, assuming a 40% profit margin, they'd need to sell something like 100 copies of Orion at US$30 million each, totaling 5 gigawatts. For the investors to consider them successful, it would need to be more like 2000 copies of Orion, totaling 100 gigawatts.

That's a completely plausible market size (although it's not just "all over the country", because the country they're in only has 1161 GW of generation capacity and is barely building any), so their NRE costs to date are not an impossible burden. It really depends on four things:

1. Can they hit such a low price target as US$30 million per 50-megawatt power plant? Can they ship anything for US$30 million a pop?

2. Will they be allowed to sell to China, where the customers are?

3. Will solar energy get cheaper still, forcing them to an even lower price point?

4. Will opex of the resulting reactors be manageable?

I'm not an expert on the subject, but is there an obvious bottleneck that would prevent Helion from manufacturing an arbitrarily large number of generators that scales with demand? 2000 generators doesn't seem like an overwhelmingly large number if they get paid enough to build out capacity for it, and they've already started on an assembly line manufacturing plant.

I'd expect that they probably wouldn't focus on copying Orion exactly, since Orion is just the initial PoC and will only use a single 50 MW generator. Their Nucor plant is planned to have 10x higher capacity, which seems likely to be more in line with typical deployments outside of remote areas. Opex also seems like a non-issue to me, given that the machines will be automated, the fuel will be cheap, and they won't have the same safety-critical need for strict regulation and human oversight as fission plants.

My understanding is that exporting might not be a huge hurdle to get a green light for due to the low proliferation concerns, although I wouldn't be surprised if Helion itself had some reservations around that or blocked it on designing some sort of tamper-resistant enclosure for IP protection purposes.

But I also don't see a reason why the US couldn't be a highly lucrative market for Helion, particularly given the increasing demand from AI. Solar in China today benefits from major alignment of interests and political tailwinds. Similarly, fusion could cut through partisan divides and NIMBYism that have hamstrung power buildout in the US. The left will buy in for climate benefits, the right will buy in for energy independence, both will buy in for economics + practicality, and NIMBYs will buy in for lower electric bills with minimal risks or drawbacks. Whether or not directly publicly funded, there will at least be every incentive to collectively get out of private industry's way and allow mass fusion deployment with minimal regulatory burdens.

That said, I'm sure solar will continue to get cheaper, and iron-air batteries from companies like Form Energy seem to be an extremely promising solution for high-scale storage. I also like the idea of using Prometheus Fuels to repurpose existing fossil fuel plants as storage for renewables. But there are still theoretical limits on the efficiency of solar panels, and space usage and intermittency could make it less cost-efficient than fusion in many if not most cases. We can't really make an apples-to-apples comparison between a mature technology in active high-volume production and a speculative future technology, but the latter in this case does seem to me to have a higher ceiling on its potential value over the long run.

> I'm not an expert on the subject, but is there an obvious bottleneck that would prevent Helion from manufacturing an arbitrarily large number of generators that scales with demand?

No, nothing is obvious to anyone outside the company.

> I'd expect that they probably wouldn't focus on copying Orion exactly,

Hopefully their next model will come out before another billion dollars of investment goes down the drain.

> Opex also seems like a non-issue to me, given that the machines will be automated, the fuel will be cheap,

Yes, that could happen, but what it really means is that we don't have any idea what the opex is.

> My understanding is that exporting might not be a huge hurdle to get a green light for due to the low proliferation concerns,

I think the bigger concern there would be whether China would import it.

> But I also don't see a reason why the US couldn't be a highly lucrative market for Helion,

Well, the US hasn't been a highly lucrative market for power plants for 50 years. Maybe the advent of new, radically cheaper technology could change that, but I suspect it won't; the advent of new, radically cheaper energy in the late 18th century didn't turn China or Japan into a highly lucrative market for power plants, for essentially social or political rather than technical and economic reasons.

> We can't really make an apples-to-apples comparison between a mature technology in active high-volume production and a speculative future technology, but the latter in this case does seem to me to have a higher ceiling on its potential value over the long run.

Yes, I agree. But we weren't talking about the long run, but rather about currently existing companies that need to return money to their investors in the next ten or twenty years. Breakthroughs do happen, but rarely.

Yeah, there are lots of unknowns and valid reasons to be pessimistic or optimistic. I lean toward cautious optimism based on the information that is available, but of course no one knows the future until it happens.

Just to clarify, Orion is one site, not a particular generator model. Orion working would be the green light to build and ship more generators, not a sign that they'd need to go back to the drawing board on an "Orion v2".

re: opex, we do have some idea of what it will be. We know that deuterium is cheap, we know that fusion produces low waste, we know that extensive safety protocols to protect against meltdown are not required, we know that preventing theft of fissile materials is not a security concern, and we know that these machines are substantially automated. We may not have precise balance sheets, but it's also not entirely opaque or mysterious.

I'm not sure the examples of historical China and Japan apply. They didn't invent coal power and then decide not to use it (although Japan was nevertheless fairly quick to industrialize). Fusion as of now seems likely to reach commercialization first in the US, and there's currently a lot of demand for power here with insufficient supply to meet projected growth. It's a very different market from when we were actively shipping our high-power-consumption industries overseas.

I don't agree that breakthroughs happen "rarely". I mean, we wouldn't be here in this thread without the massive breakthrough of useful LLMs, which were considered sci-fi before ChatGPT's release less than three years ago; fusion had the breakthrough of ignition at NIF just a few days after that; and we're only in the position of considering solar and batteries as a competitive energy source due to many small breakthroughs that have occurred in recent history. Breakthroughs happen all the time, but we quickly forget their significance and let them become boring.