4 ms·

To be clear, NIF's ignition is getting more energy out of the fuel than the laser they hit it with put in, but there are other energy drains and inefficiencies

To be clear, NIF's ignition is getting more energy out of the fuel than the laser they hit it with put in, but there are other energy drains and inefficiencies in the system that make it nowhere close to break-even fusion energy. That requires building a new machine designed for continuous fusion detonations. So it's a scientific accomplishment, but not that scientific accomplishment.

dist-epoch 3y ago
And they don't have any mechanism to capture the generated energy and convert it to electricity.
- SteveNuts 3y ago
  What are the chances that will be anything other than the tried and true "boil some water to make steam to turn a turbine"
  - rzzzt 3y ago
    Fusion produces helium, you fill party balloons with it, they lift an anvil which falls on a pair of scissors that cuts a piece of string in half...
    - tmccrary55 3y ago
      The Incredible Fusion Machine
      - rzzzt 3y ago
        Phew!
    - noobermin 3y ago
      This is like saying "burning gasoline produces CO2, how do you make energy with that?" Literally the quoted energy they use to calculate the ignition criterion for NIF is the neutron yield.
      - bandyaboot 3y ago
        It’s also like saying, “This is kind of an amusing joke for those that enjoy amusing jokes”.
  - DennisP 3y ago
    That's exactly what it would be, for any fusion that's not using aneutronic fuel.
  - noobermin 3y ago
    That literally is it, just like fission you capture neutrons and heat water. The engineering issue of getting a stream of pellets to shoot is the issue, the "how do you convert neutrons from DT into electricity" just betrays severe ignorance. The engineering issue is a bigger jump.
    - tsimionescu 3y ago
      The issue of capturing power out of the exploding pellet is not at all the same as the issue of capturing neutrons out of a MCF reactor, and neither is the same as the problem of capturing the neutrons from a fission power plant. The neutrons from fusion reactos are far more powerful, so they punch much more easily through materials you put in the way. Also, the ICF reactor has many moving parts (the pellet needs to be put in a very precise position for the lasers to shoot), so transferring heat from it is not nearly as easy as a much simpler fission reactor (which is mostly just a hunk of uranium which stays hot, and all the complexity comes out of being able to prevent the uranium from getting too hot).
  - zirgs 3y ago
    When I first learned how nuclear reactors actually generate power it was a big WTF moment for me. Wait - do they really just heat water? For some reason I thought that there was a more advanced process to extract electricity from the reactor.
    - OnlyMortal 3y ago
      Yup. It does seem inefficient. I assume the cost is “good enough”.
  - sillywalk 3y ago
    In Back to The Future, Doc Brown not only invented a time machine, but a device that fits into a Delorean that can directly convert plutonium into electricity.
  - justinclift 3y ago
    This was announced back in 2008, but it sounds like it didn't go anywhere: https://www.newscientist.com/article/dn13545-nanomaterial-turns-radiation-directly-into-electricity/ https://www.newscientist.com/article/dn13545-nanomaterial-tu...
NotYourLawyer 3y ago
“Energy drains and inefficiencies” underplays it. The laser they’re using is, what, 10% efficient? So they’re at least an order of magnitude away from net power. Probably two orders.
- DennisP 3y ago
  0.5% efficient, but they're old lasers. Equivalent modern ones are over 20% efficient. Also, with their first Q>1 shot they increased the laser power 8% and got 230% more output. They think the nonlinear scaling will continue for a while. If they're right, then they're not actually that far from overall net power, if you correct for the obsolete laser tech.
noobermin 3y ago
Whenever anyone brings this up, it's important to remind everyone this is the best in the world to this day, so every time people (namely, people invested in MCF or various private companies) shit talk NIF understand they are saying their schemes per the data are even worse than what is apparently a bad result.
- SamBam 3y ago
  I question your assumption that most people who bring this up are people invested in MCF or various private companies. I think for most people, the question isn't between this fusion and that fusion, it's about fusion and anything else. We haven't yet been able to get useable energy out of fusion. It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines. If it really is the case that it will not be possible to power the world without fusion, then that might be money well invested, but it's quite possible that we should just be putting everything into existing renewable technologies.
  - noobermin 3y ago
    >It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines. You care to back your armchairing with data? I'll bet you 100usd that it's a pittance compared to what goes into solar and wind turbines world wide. This point is not salient. >I think for most people, the question isn't between this fusion and that fusion, it's about fusion and anything else. That's a more valid point. The point for ICF is the potential, this is a sure push in the direction of "this actually has potential," justifying more research, not that we'll have a power plant in 5 years. There isn't this antagonism towards other aspirational research like superconductors or quantum computers.
    - SamBam 3y ago
      >> every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines. > You care to back your armchairing with data? I'm confused by your confusion. I'm literally saying we could optionally be spending the money we currently spend on fusion on solar panels instead. This isn't a statement that needs data. The question is simply which is going to go further in decarbonizing our energy: $1 spent on solar or $1 spent on fusion research? That's an open question, of course, and people don't have the answer, since one is based on probabilities of future success. Note, though, that even if fusion is successful, it may still be more expensive than solar, and so then would it actually be successful? We would have saved more tons of CO2 by making more solar panels. [1] [2] [3] 1. https://www.wired.com/story/no-fusion-energy-wont-be-limitless/ https://www.wired.com/story/no-fusion-energy-wont-be-limitle... 2. https://futurism.com/elon-musk-fusion-more-expensive-wind-solar https://futurism.com/elon-musk-fusion-more-expensive-wind-so... 3. https://engineering.princeton.edu/news/2023/03/16/fusions-future-u-s-could-come-down-dollars-and-cents https://engineering.princeton.edu/news/2023/03/16/fusions-fu...
analog31 3y ago
Indeed, in the laser business, during a time period when it seemed like someone was coming up with a new kind of laser every month, the field developed a term, "wall plug efficiency," which meant how much laser power per unit of power drawn from the electrical outlet. It was meant to capture the true energy efficiency of the system, rather than just the efficiency of the lasing process.

dist-epoch 3y ago

And they don't have any mechanism to capture the generated energy and convert it to electricity.

SteveNuts 3y ago
What are the chances that will be anything other than the tried and true "boil some water to make steam to turn a turbine"
- rzzzt 3y ago
  Fusion produces helium, you fill party balloons with it, they lift an anvil which falls on a pair of scissors that cuts a piece of string in half...
  - tmccrary55 3y ago
    The Incredible Fusion Machine
    - rzzzt 3y ago
      Phew!
  - noobermin 3y ago
    This is like saying "burning gasoline produces CO2, how do you make energy with that?" Literally the quoted energy they use to calculate the ignition criterion for NIF is the neutron yield.
    - bandyaboot 3y ago
      It’s also like saying, “This is kind of an amusing joke for those that enjoy amusing jokes”.
- DennisP 3y ago
  That's exactly what it would be, for any fusion that's not using aneutronic fuel.
- noobermin 3y ago
  That literally is it, just like fission you capture neutrons and heat water. The engineering issue of getting a stream of pellets to shoot is the issue, the "how do you convert neutrons from DT into electricity" just betrays severe ignorance. The engineering issue is a bigger jump.
  - tsimionescu 3y ago
    The issue of capturing power out of the exploding pellet is not at all the same as the issue of capturing neutrons out of a MCF reactor, and neither is the same as the problem of capturing the neutrons from a fission power plant. The neutrons from fusion reactos are far more powerful, so they punch much more easily through materials you put in the way. Also, the ICF reactor has many moving parts (the pellet needs to be put in a very precise position for the lasers to shoot), so transferring heat from it is not nearly as easy as a much simpler fission reactor (which is mostly just a hunk of uranium which stays hot, and all the complexity comes out of being able to prevent the uranium from getting too hot).
- zirgs 3y ago
  When I first learned how nuclear reactors actually generate power it was a big WTF moment for me. Wait - do they really just heat water? For some reason I thought that there was a more advanced process to extract electricity from the reactor.
  - OnlyMortal 3y ago
    Yup. It does seem inefficient. I assume the cost is “good enough”.
- sillywalk 3y ago
  In Back to The Future, Doc Brown not only invented a time machine, but a device that fits into a Delorean that can directly convert plutonium into electricity.
- justinclift 3y ago
  This was announced back in 2008, but it sounds like it didn't go anywhere: https://www.newscientist.com/article/dn13545-nanomaterial-turns-radiation-directly-into-electricity/ https://www.newscientist.com/article/dn13545-nanomaterial-tu...

NotYourLawyer 3y ago

“Energy drains and inefficiencies” underplays it. The laser they’re using is, what, 10% efficient? So they’re at least an order of magnitude away from net power. Probably two orders.

DennisP 3y ago
0.5% efficient, but they're old lasers. Equivalent modern ones are over 20% efficient. Also, with their first Q>1 shot they increased the laser power 8% and got 230% more output. They think the nonlinear scaling will continue for a while. If they're right, then they're not actually that far from overall net power, if you correct for the obsolete laser tech.

noobermin 3y ago

Whenever anyone brings this up, it's important to remind everyone this is the best in the world to this day, so every time people (namely, people invested in MCF or various private companies) shit talk NIF understand they are saying their schemes per the data are even worse than what is apparently a bad result.

SamBam 3y ago
I question your assumption that most people who bring this up are people invested in MCF or various private companies. I think for most people, the question isn't between this fusion and that fusion, it's about fusion and anything else. We haven't yet been able to get useable energy out of fusion. It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines. If it really is the case that it will not be possible to power the world without fusion, then that might be money well invested, but it's quite possible that we should just be putting everything into existing renewable technologies.
- noobermin 3y ago
  >It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines. You care to back your armchairing with data? I'll bet you 100usd that it's a pittance compared to what goes into solar and wind turbines world wide. This point is not salient. >I think for most people, the question isn't between this fusion and that fusion, it's about fusion and anything else. That's a more valid point. The point for ICF is the potential, this is a sure push in the direction of "this actually has potential," justifying more research, not that we'll have a power plant in 5 years. There isn't this antagonism towards other aspirational research like superconductors or quantum computers.
  - SamBam 3y ago
    >> every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines. > You care to back your armchairing with data? I'm confused by your confusion. I'm literally saying we could optionally be spending the money we currently spend on fusion on solar panels instead. This isn't a statement that needs data. The question is simply which is going to go further in decarbonizing our energy: $1 spent on solar or $1 spent on fusion research? That's an open question, of course, and people don't have the answer, since one is based on probabilities of future success. Note, though, that even if fusion is successful, it may still be more expensive than solar, and so then would it actually be successful? We would have saved more tons of CO2 by making more solar panels. [1] [2] [3] 1. https://www.wired.com/story/no-fusion-energy-wont-be-limitless/ https://www.wired.com/story/no-fusion-energy-wont-be-limitle... 2. https://futurism.com/elon-musk-fusion-more-expensive-wind-solar https://futurism.com/elon-musk-fusion-more-expensive-wind-so... 3. https://engineering.princeton.edu/news/2023/03/16/fusions-future-u-s-could-come-down-dollars-and-cents https://engineering.princeton.edu/news/2023/03/16/fusions-fu...

analog31 3y ago

Indeed, in the laser business, during a time period when it seemed like someone was coming up with a new kind of laser every month, the field developed a term, "wall plug efficiency," which meant how much laser power per unit of power drawn from the electrical outlet. It was meant to capture the true energy efficiency of the system, rather than just the efficiency of the lasing process.