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Fusion energy breakthrough by Livermore Lab

ft.com

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Re: Fusion energy breakthrough by Livermore Lab

#231

Post by whimsicalism »

hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

> all fusion "got more energy out than we put in"

I'm curious - given that this is the first time we have ever done this (even with the constrained definition as discussed in this article), how there can be a '"usual caveat" about all of the "got more energy out than we put in" stories'?

AFAICT, this is the first such "story" to have ever happened artificially in history.

Re: Fusion energy breakthrough by Livermore Lab

#232

Post by JStanton617 »

chaps wrote: post #226

“The Lawrence Livermore National Laboratory experiment shows that scientists can get more energy out than put in by the laser itself. This is great progress indeed, but still more is needed: first we need to get much more out that is put in so to account for losses in generating the laser light etc (although the technology for creating efficient lasers has also leapt forward in recent years). Secondly, the Lawrence L…

The loss just on the lasers is 100x (i.e. delivered power is 1% of the input energy). Add in a combined cycle effeciency of only 50%, you're looking at needing a 200x improvement to have commercially relevant "net gain"

Re: Fusion energy breakthrough by Livermore Lab

#233

Post by operator-name »

hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

"That’s because they had to use 500 MJ of energy into the lasers to deliver 1.8 MJ to the target – so even though they got 2.5 MJ out, it’s still far less than the energy they needed for the lasers in the first place. In other words, the energy output (largely heat energy) was still only 0.5% of the input."

Re: Fusion energy breakthrough by Livermore Lab

#234

Post by alephnil »

hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

And they mention this right in the press release. Quote:

“The Lawrence Livermore National Laboratory experiment shows that scientists can get more energy out than put in by the laser itself. This is great progress indeed, but still more is needed: first we need to get much more out that is put in so to account for losses in generating the laser light etc (although the technology for creating efficient lasers has also leapt forward in recent years). Secondly, the Lawrence Livermore National Laboratory could in principle produce this sort of result about once a day – a fusion power plant would need to do it ten times per second. However, the important takeaway point is that the basic science is now clearly well understood, and this should spur further investment. It is encouraging to see that the private sector is starting to wake up to the possibilities, although still long term, of these important emerging technologies.”

While this spins it in an optimistic way, the challenges to make this work are significant. The laser is quite inefficient, so the gain must be much much larger before you have net energy gain. To scale it up to implode a capsule tens of times a second rather than a few times a day, is in the order of 100.000 times more frequent than today.Thus this is a long way from commercial production.

Re: Fusion energy breakthrough by Livermore Lab

#235

Post by eloff »

operator-name wrote: post #233
hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

"That’s because they had to use 500 MJ of energy into the lasers to deliver 1.8 MJ to the target – so even though they got 2.5 MJ out, it’s still far less than the energy they needed for the lasers in the first place. In other words, the energy output (largely heat energy) was still only 0.5% of the input."

I don't see that scaling anytime soon, still more than two orders of magnitude away. But never say never.

Re: Fusion energy breakthrough by Livermore Lab

#236

Post by BurningFrog »

operator-name wrote: post #233
hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

"That’s because they had to use 500 MJ of energy into the lasers to deliver 1.8 MJ to the target – so even though they got 2.5 MJ out, it’s still far less than the energy they needed for the lasers in the first place. In other words, the energy output (largely heat energy) was still only 0.5% of the input."

Converting the heat energy to electricity loses an additional 50-70%.

Re: Fusion energy breakthrough by Livermore Lab

#237

Post by DennisP »

JStanton617 wrote: post #232
chaps wrote: post #226

“The Lawrence Livermore National Laboratory experiment shows that scientists can get more energy out than put in by the laser itself. This is great progress indeed, but still more is needed: first we need to get much more out that is put in so to account for losses in generating the laser light etc (although the technology for creating efficient lasers has also leapt forward in recent years). Secondly, the Lawrence L…

The loss just on the lasers is 100x (i.e. delivered power is 1% of the input energy). Add in a combined cycle effeciency of only 50%, you're looking at needing a 200x improvement to have commercially relevant "net gain"

Yes but NIF's lasers date back to the 1990s, and laser technology has improved a lot since then. NIF-class lasers with over 20% efficiency are available now.

https://physicstoday.scitation.org/do/10.1063/pt.6.2.2021102...

Same article mentions that some petawatt lasers can fire more than once per second now.

Re: Fusion energy breakthrough by Livermore Lab

#238

Post by guelo »

whimsicalism wrote: post #231
hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

> all fusion "got more energy out than we put in" I'm curious - given that this is the first time we have ever done this (even with the constrained definition as discussed in this article), how there can be a '"usual caveat" about all of the "got more energy out than we put in" stories'? AFAICT, this is the first such "story" to have ever happened artificially in history.

The caveat still applied when experiments reported energy gains below 1.0.

Re: Fusion energy breakthrough by Livermore Lab

#240

Post by idlewords »

whimsicalism wrote: post #231
hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

> all fusion "got more energy out than we put in" I'm curious - given that this is the first time we have ever done this (even with the constrained definition as discussed in this article), how there can be a '"usual caveat" about all of the "got more energy out than we put in" stories'? AFAICT, this is the first such "story" to have ever happened artificially in history.

Because all the interest of these stories is in fusion as a source of energy, and there's a long history of declaring we're near to break-even by leaving the most energy intensive part of the apparatus out of the equation.

With no disrespect to the researchers in this experiment, it's not like we're surprised that fusion works or that a pellet can generate more power than is put in.

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