6 ms·

> We’re still a few years away from having them in actual power plants I admire your optimism. I'd say half a century, if things go well, but I'm not convinced

by moogly 4y ago

> We’re still a few years away from having them in actual power plants I admire your optimism. I'd say half a century, if things go well, but I'm not convinced fusion will ever be economically feasible.

simonebrunozzi 4y ago
I think that 50 years is a reasonable timeframe to give fusion the possibility of delivering results. But I agree with you, it's pretty much impossible that anything will come out of fusion in the coming 10-15 years, despite the publicity we keep hearing lately.
- pfdietz 4y ago
  We've already given it more than 50 years.
  - kingkawn 4y ago
    Yes, but making long predictions allows them to pretend they are in pursuit of something
  - ForHackernews 4y ago
    Solving hard engineering problems is expensive. You have to put lots of money into it. Say, 30% of the funds invested by VCs in jitney cabs and collectable JPEGs.
    - 7thaccount 4y ago
      It is so sad how much money and talent goes into getting people to click on more ads.
  - Gud 4y ago
    It took humans hundreds(thousands?) of years to learn how to fly. 50 years is not really that long.
  - wongarsu 4y ago
    But apart from the part that's useful for nuclear weapons research, we've barely given it any funding. The idea of "we could have useful fusion reactors in 30 years" always came with the sentence "if we get the funding to do it". There's this [1] famous graph comparing US research spending into Fusion, compared to 1976 predictions how long it would take with different budgets. According to that, the US funded fusion below the "not enough to ever get it done" budget. With that in mind, we have come remarkably far. 1: https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._historical_fusion_budget_vs._1976_ERDA_plan.png https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._his...
    - pfdietz 4y ago
      That famous graph was for a crash program for tokamaks, and it was predicated on tokamak physics working much better than it turns out it does. If that program had been funded it would have been a guaranteed failure. It would probably have been a failure even if the physics had been favorable, for engineering reasons that didn't become a point of public controversy until the 1980s. Also, I think you have causality reversed. Fusion isn't remote because of lack of funding; rather, funding was low because there weren't stakeholders pushing for it, and that was because the stakeholders didn't see any value coming from it. For example, all the reactor designs utilities had been presented with were not things they had any interest in building, they were too large, complex, and expensive.
  - scythe 4y ago
    But we didn't have high-temperature superconductors that could be made into useful ribbons for most of that time. (I know I still owe you a detailed response on the thermo thing.)
okasaki 4y ago
The UK government plans to have a fusion power plant on the grid by 2040 https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1022540/towards-fusion-energy-uk-government-fusion-strategy.pdf https://assets.publishing.service.gov.uk/government/uploads/...
- tsimionescu 4y ago
  They can also plan to bring world peace and end world hunger by this winter. Doesn't mean it will happen.
  - okasaki 4y ago
    Well, they definitely aren't planning that.
- ncmncm 4y ago
  In other news, the UK government revealed it is wholly disconnected from reality.
  - okasaki 4y ago
    Yeah ok, or maybe you don't know what you're talking about.
    - ncmncm 4y ago
      Taking British ministerial announcements at face value has not worked out well for many, over recent decades.
Maken 4y ago
It feels like fusion energy is perpetually 50 years away.
- Retric 4y ago
  Minimal investment means minimal progress. ITER was basically a Regan/Gorbachev project from 1985 that’s still not built yet. It’s JET’s the current largest device was completed in 1983. Real progress has been made, but the major projects have been extremely conservative by necessity. Early designs for ITER where for a larger device that would have actually produced electricity though not cheaply enough to be economically viable, but it got scaled way down.
  - mjhay 4y ago
    And ITER's design is already wildly outmoded now that high-temp superconductors exist (which they have for quite some time). Just a multinational pork project.
    - XorNot 4y ago
      ITER exists to prove that fusion plasma stability can be sustained to extract useful energy. How it does it is irrelevant since the big news is having a sufficiently large tokamak vaccum vessel with instrumentation to study. HTSCs weren't usable when it was designed, and have only just become usable in the last 5 years or so but they are a fundamentally different material. You don't just drop them into a large, incredibly complex machine that depends on it's integrated magnetic containment system: you are functionally building a new device. If you can ITER, then you don't get a refund on spent dollars. You get a loss. And then you get to start another 30 year project to maybe build a new vacuum vessel, which you have to do because you still haven't actually tested plasma stability. "But but MIT skunkworks!"...yeah. It's still going along, and they haven't suddenly churned out a functioning reactor based on HTSCs because oh look, whatever the advantages they're a new material with different properties, manufacturing and handling behaviors all of which need to be developed, measured and inspected before you can use them effectively in a fusion device. If they look good then great: they can be used to make DEMO, the ITER-successor commercial powerplant prototype, cheaper and more powerful.
marcosdumay 4y ago
> but I'm not convinced fusion will ever be economically feasible Not on Earth. But put a good enough fusion reactor on a rocket, and you can reach neighboring stars in 3 or 4 decades instead of the 15 one would expect for fission. (Of course, nobody is even sure reactors can get that good, but it does look possible.)
- mjhay 4y ago
  Fission fragment rockets could actually compete with fusion here. The reaction mass is the fission fragments themselves, which could get a specific impulse of around 10^6 s. The technology to do this is within relatively easy reach, at least by interstellar rocket standards. https://en.wikipedia.org/wiki/Fission-fragment_rocket https://en.wikipedia.org/wiki/Fission-fragment_rocket
  - ethbr0 4y ago
    Neat links! I think nuclear propulsion is going to be the biggest beneficiary of higher mass-to-orbit-for-a-reasonable-price advances. There are a huge number of propulsion technologies that are physically possible but too heavy and/or dangerous for near-Earth use. Cheaper lift (to bootstrap) + more ongoing destinations and transit work (to drive) + outside of Earth orbit (to alleviate safety concerns) = rapid progress
  - Retric 4y ago
    Designs like that quickly start using a significant fraction of available fuel on earth if you want to do more than send a single tiny probe on a flyby. The proposed fuel is even worse as AM242 has a half life of 141 years making it hard to collect in bulk.
- zasdffaa 4y ago
  That is highly tangential to the issue of economic viability, and the energy crisis.
  - marcosdumay 4y ago
    Economic viability only exists relative to an application. And there is absolutely zero chance of fusion solving our current energy crisis, the odds for fission are already low enough. There is no point on speculating on that.
FBISurveillance 4y ago
Still sooner than Linux on Desktop if you'd ask me!
- tkubacki 4y ago
  Yet 1-2% of population is using Linux as of today and 0% is using fusion energy as of today. Witty but false.

by moogly 4y ago

simonebrunozzi 4y ago

I think that 50 years is a reasonable timeframe to give fusion the possibility of delivering results. But I agree with you, it's pretty much impossible that anything will come out of fusion in the coming 10-15 years, despite the publicity we keep hearing lately.

pfdietz 4y ago
We've already given it more than 50 years.
- kingkawn 4y ago
  Yes, but making long predictions allows them to pretend they are in pursuit of something
- ForHackernews 4y ago
  Solving hard engineering problems is expensive. You have to put lots of money into it. Say, 30% of the funds invested by VCs in jitney cabs and collectable JPEGs.
  - 7thaccount 4y ago
    It is so sad how much money and talent goes into getting people to click on more ads.
- Gud 4y ago
  It took humans hundreds(thousands?) of years to learn how to fly. 50 years is not really that long.
- wongarsu 4y ago
  But apart from the part that's useful for nuclear weapons research, we've barely given it any funding. The idea of "we could have useful fusion reactors in 30 years" always came with the sentence "if we get the funding to do it". There's this [1] famous graph comparing US research spending into Fusion, compared to 1976 predictions how long it would take with different budgets. According to that, the US funded fusion below the "not enough to ever get it done" budget. With that in mind, we have come remarkably far. 1: https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._historical_fusion_budget_vs._1976_ERDA_plan.png https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._his...
  - pfdietz 4y ago
    That famous graph was for a crash program for tokamaks, and it was predicated on tokamak physics working much better than it turns out it does. If that program had been funded it would have been a guaranteed failure. It would probably have been a failure even if the physics had been favorable, for engineering reasons that didn't become a point of public controversy until the 1980s. Also, I think you have causality reversed. Fusion isn't remote because of lack of funding; rather, funding was low because there weren't stakeholders pushing for it, and that was because the stakeholders didn't see any value coming from it. For example, all the reactor designs utilities had been presented with were not things they had any interest in building, they were too large, complex, and expensive.
- scythe 4y ago
  But we didn't have high-temperature superconductors that could be made into useful ribbons for most of that time. (I know I still owe you a detailed response on the thermo thing.)

okasaki 4y ago

The UK government plans to have a fusion power plant on the grid by 2040 https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1022540/towards-fusion-energy-uk-government-fusion-strategy.pdf https://assets.publishing.service.gov.uk/government/uploads/...

tsimionescu 4y ago
They can also plan to bring world peace and end world hunger by this winter. Doesn't mean it will happen.
- okasaki 4y ago
  Well, they definitely aren't planning that.
ncmncm 4y ago
In other news, the UK government revealed it is wholly disconnected from reality.
- okasaki 4y ago
  Yeah ok, or maybe you don't know what you're talking about.
  - ncmncm 4y ago
    Taking British ministerial announcements at face value has not worked out well for many, over recent decades.

Maken 4y ago

It feels like fusion energy is perpetually 50 years away.

Retric 4y ago
Minimal investment means minimal progress. ITER was basically a Regan/Gorbachev project from 1985 that’s still not built yet. It’s JET’s the current largest device was completed in 1983. Real progress has been made, but the major projects have been extremely conservative by necessity. Early designs for ITER where for a larger device that would have actually produced electricity though not cheaply enough to be economically viable, but it got scaled way down.
- mjhay 4y ago
  And ITER's design is already wildly outmoded now that high-temp superconductors exist (which they have for quite some time). Just a multinational pork project.
  - XorNot 4y ago
    ITER exists to prove that fusion plasma stability can be sustained to extract useful energy. How it does it is irrelevant since the big news is having a sufficiently large tokamak vaccum vessel with instrumentation to study. HTSCs weren't usable when it was designed, and have only just become usable in the last 5 years or so but they are a fundamentally different material. You don't just drop them into a large, incredibly complex machine that depends on it's integrated magnetic containment system: you are functionally building a new device. If you can ITER, then you don't get a refund on spent dollars. You get a loss. And then you get to start another 30 year project to maybe build a new vacuum vessel, which you have to do because you still haven't actually tested plasma stability. "But but MIT skunkworks!"...yeah. It's still going along, and they haven't suddenly churned out a functioning reactor based on HTSCs because oh look, whatever the advantages they're a new material with different properties, manufacturing and handling behaviors all of which need to be developed, measured and inspected before you can use them effectively in a fusion device. If they look good then great: they can be used to make DEMO, the ITER-successor commercial powerplant prototype, cheaper and more powerful.

marcosdumay 4y ago

> but I'm not convinced fusion will ever be economically feasible Not on Earth. But put a good enough fusion reactor on a rocket, and you can reach neighboring stars in 3 or 4 decades instead of the 15 one would expect for fission. (Of course, nobody is even sure reactors can get that good, but it does look possible.)

mjhay 4y ago
Fission fragment rockets could actually compete with fusion here. The reaction mass is the fission fragments themselves, which could get a specific impulse of around 10^6 s. The technology to do this is within relatively easy reach, at least by interstellar rocket standards. https://en.wikipedia.org/wiki/Fission-fragment_rocket https://en.wikipedia.org/wiki/Fission-fragment_rocket
- ethbr0 4y ago
  Neat links! I think nuclear propulsion is going to be the biggest beneficiary of higher mass-to-orbit-for-a-reasonable-price advances. There are a huge number of propulsion technologies that are physically possible but too heavy and/or dangerous for near-Earth use. Cheaper lift (to bootstrap) + more ongoing destinations and transit work (to drive) + outside of Earth orbit (to alleviate safety concerns) = rapid progress
- Retric 4y ago
  Designs like that quickly start using a significant fraction of available fuel on earth if you want to do more than send a single tiny probe on a flyby. The proposed fuel is even worse as AM242 has a half life of 141 years making it hard to collect in bulk.
zasdffaa 4y ago
That is highly tangential to the issue of economic viability, and the energy crisis.
- marcosdumay 4y ago
  Economic viability only exists relative to an application. And there is absolutely zero chance of fusion solving our current energy crisis, the odds for fission are already low enough. There is no point on speculating on that.

FBISurveillance 4y ago

Still sooner than Linux on Desktop if you'd ask me!

tkubacki 4y ago
Yet 1-2% of population is using Linux as of today and 0% is using fusion energy as of today. Witty but false.