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Major breakthrough on nuclear fusion energy

bbc.co.uk

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Re: Major breakthrough on nuclear fusion energy

#191

Post by GoodJokes »

marginalia_nu wrote: post #166
limaoscarjuliet wrote: post #109

According to Sabine Hossenfelder, published numbers are frequently mis-stated on purpose. When you look at frequently reported Q Plasma (or plasma efficiency) we are not that far from it being > 1. However, we should look at Q Total (total efficiency), which is still way below https://www.youtube.com/watch?v=LJ4W1g-6JiY For years, I was hoping fusion is close. After watching Sabine's video, I'm not so optimistic anym…

Nothing concrete to add, just the anecdote that the plasma physics class I took in grad school hands down had some of the sketchiest looking physicist math I think I have ever seen. Felt like a SWAT team from the mathematics department might burst through the door at any time.

No post body was provided.

Re: Major breakthrough on nuclear fusion energy

#192

Post by Out_of_Characte »

kiba wrote: post #112
m_fayer wrote: post #104

Earlier quoted context omitted.

I'm happy to hear someone make this point. Rather than sneering "vaporware" when decades fail to crack a problem, I would prefer us to keep in mind that if we never try multi-generational projects, we will never taste the fruit of multi-generational projects, and those are some sweet fruit indeed.

I am not sure if we have a project that spans multiple generations? It would be easier to do a project that provide some kind of immediate benefit while having long term multigenerational long term effect. Science is kinda that way. We get immediate knowledge with long term unknown payoff.

The Netherlands would like a word. Holding back the sea was a monumental project that will definitely last generations to come. Maybe not as exiting as high temp superconductors and fusion but still a nationwide unique product.

Re: Major breakthrough on nuclear fusion energy

#193

Post by rat9988 »

lisper wrote: post #188
SamBam wrote: post #176

Earlier quoted context omitted.

I don't believe that this is entirely mis-stated. We already know that fusion power plants are going to operate by igniting plasma in short bursts -- a few seconds, maybe 10s at most -- and generating a huge amount of power during that single burst. You then ignite it again and again. The question is how much total energy you can extract from each of those bursts. By that metric, the total energy is what's important,…

> "59 megajoules of sustained fusion energy" means a single burst produced that much. In what sense is that "sustained"? A typical power plant produces that much energy in less than a second on a continuous (i.e. sustained) basis. Producing 59 megajoules once is basically a joke. It is analogous to detonating a pipe bomb (at a cost of several billion dollars) and claiming that as significant progress towards an inter…

> A typical power plant

Fusion power plant aren't typical though

Re: Major breakthrough on nuclear fusion energy

#194

Post by rootusrootus »

mschuster91 wrote: post #69
nicoburns wrote: post #61

Earlier quoted context omitted.

A $50b program from 1 country would likely have the same problem (as indeed would a large private program). Injecting a large amount of capital all at once into a project just isn't efficient.

> Injecting a large amount of capital all at once into a project just isn't efficient. SpaceX would beg to disagree here. The reason why they are so cheap, agile and sustainable (=reusable rockets) is precisely because SpaceX got a load of money without the "pork" requirements that were commonplace with ULA & friends. That enabled SpaceX to embrace vertical, on-site integration and go for what was technically the bes…

It helps that SpaceX is just iterating on 1960s technology.

Re: Major breakthrough on nuclear fusion energy

#195

Post by mmazing »

marginalia_nu wrote: post #166
limaoscarjuliet wrote: post #109

According to Sabine Hossenfelder, published numbers are frequently mis-stated on purpose. When you look at frequently reported Q Plasma (or plasma efficiency) we are not that far from it being > 1. However, we should look at Q Total (total efficiency), which is still way below https://www.youtube.com/watch?v=LJ4W1g-6JiY For years, I was hoping fusion is close. After watching Sabine's video, I'm not so optimistic anym…

Nothing concrete to add, just the anecdote that the plasma physics class I took in grad school hands down had some of the sketchiest looking physicist math I think I have ever seen. Felt like a SWAT team from the mathematics department might burst through the door at any time.

Like an ECON 101 course?

I felt like the Calculus SWAT Team was going to burst through the doors in that class, ha.

Re: Major breakthrough on nuclear fusion energy

#196

Post by Archelaos »

knapcio wrote: post #124
formvoltron wrote: post #105

OK so with fusion everybody loves it because the fuel would be clean and nearly endless. Isn't that what solar power offers? Nobody wants to deploy solar due to high upfront cost. However, wouldn't the startup on a fusion reactor be much greater?

I remember that early this autumn Sweden had to borrow energy from other countries because it relied too much on renewables which turned out to be unstable.

The electricity import and export of individual countries fluctuates constantly. A nice map with live data can be found here: https://app.electricitymap.org/map (in German).

Dealing with the instability of solar and wind energy is very complex and requires numerous measures, such as better integration of wide-area electricity grids, more electricity storage, more generation reserves, etc.

But even nuclear power generation is dependent on the weather. During heat waves, nuclear power plants located on rivers in Germany and France repeatedly had to shut down because there was not enough cooling water available or the water in the rivers would otherwise have become too warm.[1] During cold spells, nuclear power plants had sometimes to be shut down because the supply of cooling water was no longer guaranteed due to ice.[2]

[1] For example: https://www.reuters.com/article/us-france-electricity-heatwa...

[2] For example: https://fortune.com/2019/01/31/ice-shutdown-new-jersey-nucle...

Re: Major breakthrough on nuclear fusion energy

#199

Post by lisper »

robbomacrae wrote: post #187
SamBam wrote: post #176

Earlier quoted context omitted.

I don't believe that this is entirely mis-stated. We already know that fusion power plants are going to operate by igniting plasma in short bursts -- a few seconds, maybe 10s at most -- and generating a huge amount of power during that single burst. You then ignite it again and again. The question is how much total energy you can extract from each of those bursts. By that metric, the total energy is what's important,…

Your description made me wonder if it would be possible to make an ICE to extract the power. I then found a paper called Fusion Internal Combustion Engine from 2010 [0]. Does anyone know if there was any merit to this idea and if anything else has come of it since? 0: https://www.researchgate.net/publication/215544178_Fusion_In...

A few elementary calculations reveal how feasible this might be. A typical ICE produces a few hundred horsepower using 4-8 cylinders rotating at a few thousand RPM. 1 HP = 745 watts. Figure out how much energy is released per cylinder on each cycle, and compare that to the energy released in a typical fusion ignition. Also note the cycle time of an ICE rotating at a few thousand RPMs, and compare that to the cycle time of a current state-of-the-art fusion reactor. (Hint: the former is measured in milliseconds, the latter currently in months if not years.)

Re: Major breakthrough on nuclear fusion energy

#200

Post by [deleted] »

knapcio wrote: post #124
formvoltron wrote: post #105

OK so with fusion everybody loves it because the fuel would be clean and nearly endless. Isn't that what solar power offers? Nobody wants to deploy solar due to high upfront cost. However, wouldn't the startup on a fusion reactor be much greater?

I remember that early this autumn Sweden had to borrow energy from other countries because it relied too much on renewables which turned out to be unstable.

[deleted]
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