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Nuclear-fusion reactor doubles record for energy made from fusing atoms

nature.com

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Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#71

Post by samwillis »

ncmncm wrote: post #67
samwillis wrote: post #61

Earlier quoted context omitted.

Oh I’m not saying for a second it shouldn't be done. The main issue here is a combination NIMBY and misaligned incentives. Quite right you can graze sheep (and other cattle) under solar. You cannot grow crops though, which is what I was suggesting by “agricultural” land, should have made that more clear. I live about two miles from what is proposed to be the UKs largest solar farm [0], I believe it will be 8.7x the s…

You can, in fact, grow crops under solar. And they yield more that way. The panels do not cover every square inch of farm; 50% is common. Most plants, including the most productive crops, will only do a certain maximum of photosynthesis in a day; insolation after that just adds heat stress.

It can be done, but its not currently and there is legitimate problems with it due to the logistics of existing farm machinery. For example the structure required to position solar panels in a way that would enable existing combine harvesters or sprayers to continue to work is unlikely to be feasible. It would be a different way of farming, back towards smaller machinery. So it may be possible but I don't see it happing without massive government incentives and maybe more automation.

Fully support it if it can be made to work, but I'm sceptical.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#72

Post by ncmncm »

d-gearloose wrote: post #11
calibas wrote: post #8

Note, the power output was about 1/3 the power needed to sustain the reaction. > JET’s latest experiment sustained a Q of 0.33 for 5 seconds, says Rimini. JET is a scaled-down version of ITER, at one-tenth of the volume — a bathtub compared to a swimming pool, says Proll. It loses heat more easily than ITER, so it was never expected to hit breakeven. If engineers applied the same conditions and physics approach to IT…

The good thing about fusion is that a lot of problems stem from the size of the surface area as compared to the volume. The bigger the reaction vessel gets, the favorably this ratio is. This experiment just shows that the predictions about ITER seem to be in a realistic region.

Bigger being better is not a plus.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#73

Post by rhn_mk1 »

ncmncm wrote: post #65
rob74 wrote: post #59

Earlier quoted context omitted.

Why not do both? Unless the wind turbines are in my back yard of course (which they can't be, according to the rules where I live wind turbines have to be ~2 km away from anyone's back yard, but still).

Because money is fungible. A dollar spent on fusion is a dollar not spent on solar panels or turbines that would displace fossil fuels immediately. And, it would be a dollar wasted, because the fusion work will never produce any commercially competitive power, anyway. So, it is a choice between buying something that contributes to a solution, or just pissing it away.

> A dollar spent on fusion is a dollar not spent on solar panels or turbines that would displace fossil fuels immediately

I see this claim a lot, but what makes this true? Why would money allocation be so inelastic, and why can't it become flexible?

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#74

Post by ncmncm »

ClumsyPilot wrote: post #68
ncmncm wrote: post #38

Earlier quoted context omitted.

They are forever smashing this or that record, on the verge of break-even, on track to producing free energy without nasty radionuclides. But it is always a con. If they ever do get Q high enough to make energy production conceivable -- it will need Q > 100, when said and done -- a Tokamak reactor will cost 10x much as the equal-grade fission reactor, and cost >10x as much to operate. As fission reactors are today no…

> fission reactors are today not competitive, and get less competitive by the day No, we are just incompetent idiots. This has nothing to do with fissions and everything to do with degradation of contruction and practical egnineering skills - now it takes 30 years and 100 billion dollars to make a small railway in California. Victorian England or China could do this without much trouble. The english-speaking western…

It is much simpler than that: fission is mature tech; its cost is not on the way down. Solar costs are still in free fall, wind almost as much so. The cheaper those get, the less competitive fission gets, just standing still.

The corruption tax on fission projects just exacerbates its structural problem.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#75

Post by ahoka »

pyinstallwoes wrote: post #45
ahoka wrote: post #31

Earlier quoted context omitted.

Q=10 is still not enough if you actually measure the whole experimental setup. Don't forget that to goal is to make a power plant where the whole building produces more energy than it consumes, and does it economically.

A 1000% return is insane economically. Perhaps I'm not seeing the logic but the pure YOY return on 1000% seems to logically conclude a rational strategy of "nothing else matters besides building this and it will easily pay off and investment"

This just means for every n W of _heat_ injected the fusion creates 10n W of heat. But I'm pretty sure the experiment itself consumes much more electricity than it could theoretically produce (don't forget that converting heat to electricity has an efficiency below 50%). Fusion researchers mislead the public to get more funding when they say ITER will make more energy than it requires. Fusion might be never viable.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#76

Post by jillesvangurp »

samwillis wrote: post #18
epistasis wrote: post #5

Earlier quoted context omitted.

Fusion will not solve any energy problems we have today, and is unconnected to them. Fusion will have to, maybe, compete with solar/wind/storage in 20-30 years, and beat the prices for that 20-30 years from now. With solar+storage being cheaper than many fossil fuels today, fusion is going to have to be extremely cheap to be able to be a competitive terrestrial energy source with 20-30 years more of solar and storage…

The issue with solar is the land area usage in densely populated countries, less of a problem in the US but here in the UK the is a lot of push back against building solar farms on agricultural land. There is a convincing argument that we need to discourage the practice in order to maintain domestic food production. Obviously there are alternative locations such a roofs of commercial buildings and over the top of car…

There are loads of empty rooftops in much of the populated US which typically has a lot of suburbs with endless stretches of the usual franchises typically housed in boxy buildings and equipped with some power hungry AC units. That's a huge amount of largely unused roof and potentially a massive amount of power generation. These buildings typically have even larger parking lots right next to them. Ideal place to cover with solar. And you get nice shady/dry parking spots as a side effect. Also a great place to put up some car chargers. And lower power bills for the before mentioned AC. Win win.

Walmart figured that out years ago: https://corporate.walmart.com/newsroom/sustainability/201405...

The US has plenty of room for solar. And that's before you even consider vertical space. Several companies have solar power generating windows in the market already. Nice if you are building a new skyscraper.

And of course you can use good old fashioned copper cables to transport energy around. E.g. California has some nice salt lakes and deserts close to where millions of people live (e.g. LA). After all, you wouldn't put a nuclear plant in the middle of a city either. Nimby's wouldn't allow that. Solar is a lot less controversial.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#77

Post by ncmncm »

rhn_mk1 wrote: post #73
ncmncm wrote: post #65

Earlier quoted context omitted.

Because money is fungible. A dollar spent on fusion is a dollar not spent on solar panels or turbines that would displace fossil fuels immediately. And, it would be a dollar wasted, because the fusion work will never produce any commercially competitive power, anyway. So, it is a choice between buying something that contributes to a solution, or just pissing it away.

> A dollar spent on fusion is a dollar not spent on solar panels or turbines that would displace fossil fuels immediately I see this claim a lot, but what makes this true? Why would money allocation be so inelastic, and why can't it become flexible?

Meaning, why can't we just spend an unlimited amount on everything we think we might like?

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#78

Post by panick21_ »

Fusion has no practice reason to exist compare to advanced fission. The improvements in energy density are not really relevant factor at that scale, meaning the difference from oil to fission, and oil to fusion doesn't really gain you much.

Fusion fuel cost over the long term is likely more expensive then a fission fast breeder (not to mention a potential of thorium thermal breeder).

Is a fusion reactor going to be cheaper to build then a advanced fission reactor? Not from anything know so far. Advanced fission concept are viable with pretty normal tubes pretty industrial steels or at most advanced aerospace materials. Any fission reactors actually consider would have waste more complex and expensive parts.

The nuclear waste argument is sometimes made in favor of fusion but with the right kind of fission reactor this problem and issue that has very viable practical solutions and storage for a few hundred years is viable.

Its really cool science but don't wait for fusion to solve any of our practical energy problems.

Maybe at some point fusion can build really small making electricity directly (Aneutronic fusion). Then it would actually be relevant. I would prefer fusion research to focus on that problem, rather then trying to build an oversized power-plant style fusion.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#79

Post by panick21_ »

_0w8t wrote: post #64
ncmncm wrote: post #62

Earlier quoted context omitted.

The energy flux density in the most compressed plasma imaginable is orders of magnitude less than in fissile uranium. So, to match power out, it has to be big. Really, really big. And a fusion reaction chamber is a much more expensive affair than a fission pile: super high-tech materials and construction, enormous magnets (blasted by the hot-neutron flux output), piping for thousands of tons of melted lithium that ha…

This was with previous designs of fusion reactors. Read about proposed Ark and currently constructing Spark reactors. By using stronger superconductive magnets it was possible to reduce the size of the plant by order of magnitude. Spark even has a chance to get to Q>1 before ITER and it’s chamber is less than 2m in diameter. Plus it is possible to replace its parts without disassembling the whole reactor. [1] - https…

Compare that to a simple molten salt fission reactor. It will simply never be cheaper.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#80

Post by jillesvangurp »

londons_explore wrote: post #52

Are we actually learning new bits of fundamental science from these experiments? Are there still bits of these fusion reactions we can't simulate accurately enough due to insufficient compute? Or is it just a matter of ironing out engineering issues?

I think given recent progress from several companies and research institutes, we might be seeing an increasing shift to solving engineering challenges indeed. Fusion has definitely moved beyond the proof of concept stage. It's no longer just a theoretical possibility.

Many challenges still remain of course. But it might be a lot closer than the 20-30 years that people have historically assumed it would take. It seems there are a couple of companies shooting for working power plants a lot sooner than that that are getting a lot of funding. Maybe even this decade. From there to commercialization might still take a lot of time of course.

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