Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Major breakthrough on nuclear fusion energy

bbc.co.uk

Post reply on HN
Print view View original

581–590 of 827 posts

Re: Major breakthrough on nuclear fusion energy

#581

Post by noah_buddy »

spdegabrielle wrote: post #483
TrevorJ wrote: post #458

Can someone explain something about fusion for me? To make a fusion reactor that's useful you have to solve two problems: First you have to build a working fusion reactor. Second, you have to capture that energy to do useful work. Given that, wouldn't it make more sense to focus on technology to capture energy from the giant, already working fusion reactor in the sky?

The economics don’t make sense. Everyone has access to the sun. Even in poor countries.

What an incredibly cynical take. Perhaps if abundant and easy to harvest free energy existed in the sky, we would have abundant cheap ways to capture it? The issues are more profound than rich people want to keep the poor people down.

Re: Major breakthrough on nuclear fusion energy

#582

Post by 1_player »

dymk wrote: post #551
spywaregorilla wrote: post #259

Earlier quoted context omitted.

We haven't invented commercial fusion power, so none; but theoretically that is how they would function. Solar and batteries are nice but they're not yet cost effective. They're getting better. But you can't just handwave away real problems from your armchair viewpoint and assume thats all fine.

> They're getting better. Solar is getting so much cheaper, at such a fast pace, that I really don't understand how one can disagree that it's the future of our energy grids. Installing solar is a no-brainer in some parts of the world now, and in the very near future (extrapolating from the last 10 years), it'll be every part of the world soon. What problems am I hand waving away? https://www.statista.com/chart/26085…

I don't get why you and many other commenters are so against the idea of fusion. Solar is decent, not perfect by any stretch, so we should just give up trying to solve the energy technology for the next 200 years? It's not even like it's one or the other. No one is abandoning solar to work on fusion. But fusion, if it works, is orders of magnitudes more efficient than solar is. It opens avenues that are considered impossible and science fiction today.

It's like being back in the 1700s and arguing that research into petrol is a waste of time. I absolutely do not understand this mindset.

Re: Major breakthrough on nuclear fusion energy

#583

Post by mbgerring »

It would benefit the discourse on this subject a great deal if these stories were subject to having their headlines edited, or if there were a sticky comment summarizing the actual substance of the “breakthrough.”

A great deal of VC money is going into nuclear fusion at the moment, and there is obvious interest in creating the impression that economically viable fusion reactors are just around the corner. It would be prudent to guard against the efforts of publicists and PR professionals by providing context.

Re: Major breakthrough on nuclear fusion energy

#584

Post by anyfoo »

dghughes wrote: post #431
jedberg wrote: post #417

Earlier quoted context omitted.

I think you mean 230V, but it was picked because it's more efficient and cheaper (you can use smaller wires for the same output).

But the size of those wall plugs tho...

Other European countries use ~230V as well and have smaller plugs than the UK.

The UK has fuses in their plugs, which if I recall correctly had something to do with copper shortage during the war constraining the electrical cabling for houses, but I don't want to accidentally put wrong information out, so better look it up yourself.

Re: Major breakthrough on nuclear fusion energy

#585

Post by anyfoo »

GordonS wrote: post #501
dghughes wrote: post #431

Earlier quoted context omitted.

But the size of those wall plugs tho...

IMO they are not meaningfully larger than US plugs (I'm British, but have travelled to the US several times, as well as many other countries), but they are safer.

They're definitely larger, but as I said in a sibling comment they're not directly a result of the higher voltage specifically.

German Schuko is also 230V and even safer (in countries that use it), yet still significantly smaller than British plugs.

Re: Major breakthrough on nuclear fusion energy

#586

Post by skykooler »

andruby wrote: post #572
DennisP wrote: post #496

Earlier quoted context omitted.

We're not that far off. JET previously achieved Q=0.67, ie. two-thirds as much energy output as input. (The new result has higher output but lower Q.) For a practical reactor we need Q around 30, which might seem far away but tokamak output scales with the square of reactor volume and the fourth power of magnetic field strength. Double the field, 16X the output, and we can generate much more powerful magnetic fields…

Any source on that Q=30 requirement for practical reactors? I’d assume that anything >1 is theoretically “profitable” and something like 2~5 might already be economically viable.

Q=1 just means that the plasma is putting out more energy then is put in. However, that doesn't mean you can recover all of that energy; you can't run a heat engine at millions of degrees, so energy generation has to be fairly indirect, which means you need about Q=30 to handle all the various conversion inefficiencies and still come out net positive enough to be practical.

Re: Major breakthrough on nuclear fusion energy

#587

Post by baq »

pkulak wrote: post #575
bityard wrote: post #516

Earlier quoted context omitted.

The US grid (the last-mile bits anyway) isn't 110 volts, it's 220. It's just our houses that are wired for (mostly) 110 V. Edit: I would love to see some sort of hybrid 110/220 V residential wiring/plug standard take hold in the US. It would require more expensive cable in the walls (since you need one additional conductor) and plugs, but it's totally doable. Most electrical products and appliances made these days ar…

I kinda like that all but a couple outlets in my house can't kill me. Also, I boil my water on an induction stove plugged into 50 amps at 220 volts. I'm not waiting around, to put it mildly.

30A at 400V is how we roll in the EU.

Re: Major breakthrough on nuclear fusion energy

#588

Post by whiskyant »

twobitshifter wrote: post #91
dfdz wrote: post #80

> This is more than double what was achieved in similar tests back in 1997. The experiment produced > 11 megawatts of power and at Jet > two 500 megawatt flywheels are used to run the experiments log_2(2*500/11)*(2022-1997) + 2022 = 2185 At this rate we will have fusion by 2185 I guess?

Even if it takes 200 years it is likely still worthwhile. Unfortunately we, as a culture, have a problem seeing and planning across generations. https://longnow.org/

Would it? We could have hundreds of runaway-meltdown proof nuclear fission reactors now if we wanted.

Re: Major breakthrough on nuclear fusion energy

#589

Post by onlyrealcuzzo »

px43 wrote: post #385
ppaattrriicckk wrote: post #59

In extension to this news and the press conference, one thing I am super excited about, is the private SPARC project and the MIT-spinoff Commonwealth Fusion Systems (CFS). If you don't know about it already, I would highly recommend checking it out (e.g. by searching YouTube for "MIT Sparc Fusion Reactor" for some fairly accessible videos on the theory behind why they should achieve fusion way faster than the current…

The insane thing that people should realize about the 20T CFS test back in September was that it was them completing the first of 18 coils, and it performed incredibly well. The secret sauce is better high temperature superconductors, and the ridiculous magnets you can build with them. They're pretty much putting these coils together as quickly as they can accumulate the HTSC wiring, and once they have all 18, they b…

> in theory they'll be generating over 10x the amount of power that they're putting into it

Does this mean 9/10ths of the power can be sold and the other 1/10th can be re-used to power the reactor endlessly?

How much power does this produce compared to a nuclear reactor?

Re: Major breakthrough on nuclear fusion energy

#590

Post by wizzwizz4 »

onlyrealcuzzo wrote: post #589
px43 wrote: post #385

Earlier quoted context omitted.

The insane thing that people should realize about the 20T CFS test back in September was that it was them completing the first of 18 coils, and it performed incredibly well. The secret sauce is better high temperature superconductors, and the ridiculous magnets you can build with them. They're pretty much putting these coils together as quickly as they can accumulate the HTSC wiring, and once they have all 18, they b…

> in theory they'll be generating over 10x the amount of power that they're putting into it Does this mean 9/10ths of the power can be sold and the other 1/10th can be re-used to power the reactor endlessly? How much power does this produce compared to a nuclear reactor?

> Does this mean 9/10ths of the power can be sold and the other 1/10th can be re-used to power the reactor endlessly?

In theory, yes, but in practice it doesn't. But it does mean that they'll've proven the concept sound, and we can start making real fusion reactors.

Post reply on HN