OpenAI has being doing various remarkable technical things between 2015 and 2022. The most well-known of them is the 2020 GPT-3 revolution, but there has been a long list of remarkable achievements done by OpenAI before and after that.
So for an actual comparison one should compare what OpenAI has been doing before 2021 (this includes GPT-3) with what CFS has been doing before 2024. Do they have something comparable to the 2021 OpenAI in the sense of technical magnitude of achievements? Yes, fusion might be more difficult, and producing varying brilliant new experiments in fusion is way more difficult, so let’s adjust for that, but we would nevertheless like a tech comparison (e.g. with Helion Energy I can point to some of their technical milestones in this sense, and try to ponder the parallels, but I am not all that familiar with CFS and their tech in this sense).
In this sense, I would also love a more detailed argument in favor of the claim that
The leading startup for fusion is Commonwealth Fusions Systems (CFS)
Specifically, I would love to see a better argument for it being ahead of Helion (if it is actually ahead, which would be a surprise and a major update for me).
Helion has raised a similar amount of capital as Commonwealth: $2.2B. Helion also has hundreds of employees: their LinkedIn puts them in the 201-500 employees category. It was founded in 2013, so it is a bit older than CFS or OpenAI.
My general sense is that there’s more confidence in the plasma physics community that CFS will succeed than that Helion will succeed.
SPARC is a tokamak, and tokamaks have been extensively studied. SPARC is basically JET with a stronger magnetic field, and JET has been operational since the 1980s and has achieved Q=0.67. It’s only a small extrapolation to say that SPARC can get Q>1. Getting to Q~10 involves more extrapolating of the empirical scaling laws and trusting numerical simulations, but these are scaling laws and simulations that much of the plasma physics community has been working on for decades.
Helion uses a different design. This design has been tested much less, and far fewer plasma physicists have worked on it. They also haven’t published as much data from their most recent experiment: last time I checked, they had published the temperature they had reached on Trenta, but not the density or confinement time. Maybe the unpublished results are really good, and suggest that the scaling that has worked so far will continue to work for Polaris, but maybe they’re not. It’s plausible that Polaris will get Q>1 when it is built (planned for 2024), but I’m not as confident about it.
Also, Helion uses D-He3 rather than D-T. This means that they produce far fewer and less energetic neutrons, but it means that their targets for temperature and density / confinement time are an order of magnitude higher. Even if you think D-He3 is better in the long term (and it’s not clear that it is), using D-T for initial experiments is easier.
My general sense is that there’s more confidence in the plasma physics community that CFS will succeed than that Helion will succeed.
That is, indeed, an important indicator.
Otherwise, tokamaks being an old design works as an argument in the opposite direction for me (more or less along the following lines: tokamak design has been known for ages, and they still have not succeeded with it; perhaps an alternative and less tried design would have better chances, since at the very least it does not have the accumulated history of multi-decade-long delays associated with it).
(I guess, my assumption is that the mainstream plasma community has been failing us for a long time, feeding us more promises than actual progress for decade after decade, and that I would rather bet on something from the “left field” at this point, at least in terms of the chances to achieve commercial viability relatively soon, as opposed to the ability to attract funding or boost headcounts.)
Basically, yes, one thing we are comparing is their (Helion and CFS) respective 2024 and 2025 promises regarding Q>1, but more importantly from my viewpoint, Helion’s promise to actually ship electricity to the customers in 2028 does seem overoptimisitic, but perhaps not outrageously so, whereas with tokamaks, what’s our forecast for when they have a chance to actually ship electricity to the customers?
Tokamaks have been known for ages. We plausibly have gotten close to the best performance out of them that we could, without either dramatically increasing the size (ITER) or making the magnets significantly stronger. The high temperature superconducting[1] ‘tape’ that Commonwealth Fusion has pioneered has allowed us to make stronger magnetic fields, and made it feasible to build a fusion power plant using a tokamak the size of JET.
After SPARC, Commonwealth Fusion plans to build ARC, which should actually ship electricity to customers. ARC should have a plasma energy gain of Q~13, and engineering energy gain of about 3, and produce about 250 MWe. They haven’t made any public commitments about when they expect ARC to be built and selling electricity to the grid, but there has been some talk about the early 2030s.[2]
The higher temperature is not really what we care about. What we really want is higher magnetic field. These two properties go together, so we talk about ‘high temperature superconductors’, even if we’re planning on running it at the same temperature as before and making use of the higher magnetic fields.
You don’t need to have any insider information to make this estimate. Construction of SPARC is taking about 4 years. If we start when SPARC achieves Q>5 (2026?), add one year to do the detailed engineering design for ARC, and then 4 years to construct ARC, and maybe a year of initial experiments to make sure it works as expected, then we’re looking at something around 2032. You might be able to trim this timeline a bit and get it closer to 2030, or some of these steps might take longer. Conditional on SPARC succeeding at Q>5 by 2028, it seems pretty likely that ARC will be selling electricity to the grid by 2035.
Specifically, I would love to see a better argument for it being ahead of Helion (if it is actually ahead, which would be a surprise and a major update for me).
I agree with Jeffrey Heninger’s response to your comment. Here is a (somewhat polemical) video which illustrates the challenges for Helion’s unusual D-He3 approach compared to the standard D-T approach which CFS follows. It illustrates some of Jeffrey’s points and makes other claims like Helion’s current operational poc reactor Trenta being far from adequate for scaling to a productive reactor when considering safety and regulatory demands (though I haven’t looked into whether CFS might be affected by this just the same).
OpenAI has being doing various remarkable technical things between 2015 and 2022. The most well-known of them is the 2020 GPT-3 revolution, but there has been a long list of remarkable achievements done by OpenAI before and after that.
So for an actual comparison one should compare what OpenAI has been doing before 2021 (this includes GPT-3) with what CFS has been doing before 2024. Do they have something comparable to the 2021 OpenAI in the sense of technical magnitude of achievements? Yes, fusion might be more difficult, and producing varying brilliant new experiments in fusion is way more difficult, so let’s adjust for that, but we would nevertheless like a tech comparison (e.g. with Helion Energy I can point to some of their technical milestones in this sense, and try to ponder the parallels, but I am not all that familiar with CFS and their tech in this sense).
In this sense, I would also love a more detailed argument in favor of the claim that
Specifically, I would love to see a better argument for it being ahead of Helion (if it is actually ahead, which would be a surprise and a major update for me).
Helion has raised a similar amount of capital as Commonwealth: $2.2B. Helion also has hundreds of employees: their LinkedIn puts them in the 201-500 employees category. It was founded in 2013, so it is a bit older than CFS or OpenAI.
My general sense is that there’s more confidence in the plasma physics community that CFS will succeed than that Helion will succeed.
SPARC is a tokamak, and tokamaks have been extensively studied. SPARC is basically JET with a stronger magnetic field, and JET has been operational since the 1980s and has achieved Q=0.67. It’s only a small extrapolation to say that SPARC can get Q>1. Getting to Q~10 involves more extrapolating of the empirical scaling laws and trusting numerical simulations, but these are scaling laws and simulations that much of the plasma physics community has been working on for decades.
Helion uses a different design. This design has been tested much less, and far fewer plasma physicists have worked on it. They also haven’t published as much data from their most recent experiment: last time I checked, they had published the temperature they had reached on Trenta, but not the density or confinement time. Maybe the unpublished results are really good, and suggest that the scaling that has worked so far will continue to work for Polaris, but maybe they’re not. It’s plausible that Polaris will get Q>1 when it is built (planned for 2024), but I’m not as confident about it.
Also, Helion uses D-He3 rather than D-T. This means that they produce far fewer and less energetic neutrons, but it means that their targets for temperature and density / confinement time are an order of magnitude higher. Even if you think D-He3 is better in the long term (and it’s not clear that it is), using D-T for initial experiments is easier.
That is, indeed, an important indicator.
Otherwise, tokamaks being an old design works as an argument in the opposite direction for me (more or less along the following lines: tokamak design has been known for ages, and they still have not succeeded with it; perhaps an alternative and less tried design would have better chances, since at the very least it does not have the accumulated history of multi-decade-long delays associated with it).
(I guess, my assumption is that the mainstream plasma community has been failing us for a long time, feeding us more promises than actual progress for decade after decade, and that I would rather bet on something from the “left field” at this point, at least in terms of the chances to achieve commercial viability relatively soon, as opposed to the ability to attract funding or boost headcounts.)
Basically, yes, one thing we are comparing is their (Helion and CFS) respective 2024 and 2025 promises regarding Q>1, but more importantly from my viewpoint, Helion’s promise to actually ship electricity to the customers in 2028 does seem overoptimisitic, but perhaps not outrageously so, whereas with tokamaks, what’s our forecast for when they have a chance to actually ship electricity to the customers?
Tokamaks have been known for ages. We plausibly have gotten close to the best performance out of them that we could, without either dramatically increasing the size (ITER) or making the magnets significantly stronger. The high temperature superconducting[1] ‘tape’ that Commonwealth Fusion has pioneered has allowed us to make stronger magnetic fields, and made it feasible to build a fusion power plant using a tokamak the size of JET.
After SPARC, Commonwealth Fusion plans to build ARC, which should actually ship electricity to customers. ARC should have a plasma energy gain of Q~13, and engineering energy gain of about 3, and produce about 250 MWe. They haven’t made any public commitments about when they expect ARC to be built and selling electricity to the grid, but there has been some talk about the early 2030s.[2]
The higher temperature is not really what we care about. What we really want is higher magnetic field. These two properties go together, so we talk about ‘high temperature superconductors’, even if we’re planning on running it at the same temperature as before and making use of the higher magnetic fields.
You don’t need to have any insider information to make this estimate. Construction of SPARC is taking about 4 years. If we start when SPARC achieves Q>5 (2026?), add one year to do the detailed engineering design for ARC, and then 4 years to construct ARC, and maybe a year of initial experiments to make sure it works as expected, then we’re looking at something around 2032. You might be able to trim this timeline a bit and get it closer to 2030, or some of these steps might take longer. Conditional on SPARC succeeding at Q>5 by 2028, it seems pretty likely that ARC will be selling electricity to the grid by 2035.
I agree with Jeffrey Heninger’s response to your comment. Here is a (somewhat polemical) video which illustrates the challenges for Helion’s unusual D-He3 approach compared to the standard D-T approach which CFS follows. It illustrates some of Jeffrey’s points and makes other claims like Helion’s current operational poc reactor Trenta being far from adequate for scaling to a productive reactor when considering safety and regulatory demands (though I haven’t looked into whether CFS might be affected by this just the same).