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Major breakthrough on nuclear fusion energy

bbc.co.uk

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Re: Major breakthrough on nuclear fusion energy

#681

Post by gameswithgo »

rurp wrote: post #668
Xixi wrote: post #656

Earlier quoted context omitted.

It took more than 300 years to build the cathedral [1] in my home town (albeit with a 60-year pause in the middle). So indeed it might take another 4 or 5 generations to master nuclear fusion, but I see no issue with that. We should not shy away from starting projects that we won't see any benefit in our lifetime. But of course, it also means that we should not rely on nuclear fusion being available in the short term…

I suspect there was a lot of inceramental value to be had while the construction was ongoing. A cathedral doesn't need to be 100% complete to use as a house of worship, an inspiration for the community, a display of wealth and soft power, and so on. Fusion hasn't really produced much utility at all so far, aside from some interesting discussions.

I imagine there have been some practical and theoretical gains from efforts to make fusion work already:

https://www.energy.gov/science/articles/fusion-research-igni...

Re: Major breakthrough on nuclear fusion energy

#682

Post by avidphantasm »

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…

At this point, I think fusion has the best chance of saving us from ourselves wrt to climate change, so long as the unforeseen consequences aren’t too bad.

Re: Major breakthrough on nuclear fusion energy

#683

Post by credit_guy »

bsder wrote: post #652
mcv wrote: post #646

Earlier quoted context omitted.

I used to like the idea of fusion energy, but practical application has always seemed to be 40 years in the future, and it's starting to sound more like 60 years now. I hope it will be possible some day, but it's not going to help with out energy needs in our lifetime. (Unless that longevity research is going to pay off, I guess.)

> I used to like the idea of fusion energy, but practical application has always seemed to be 40 years in the future, and it's starting to sound more like 60 years now. You have to understand that fusion has been funded at "fusion never" levels for 5 decades now. The amount of money that we poured at the mining engineering that later became "fracking" was larger. Had we funded fusion at the amount we have funded petr…

Who is "we"? Fracking was funded with private money. It was "conventional" technology, no edge-of-science stuff, so private entrepreneurs could afford it, and the rewards were quick to materialize.

Nuclear fusion? There's this urban myth that fusion could have been achieved if only we'd have poured more money into it, but where's the evidence? Plasma modeling requires a lot of computational power. What you have now in your iPhone in your pocket you could not have had for 10 billion dollars back in 1970. How much money were we supposed to put into fusion research? Do you think with lots of money and just a slide rule, you can solve the fusion problem?

Re: Major breakthrough on nuclear fusion energy

#684

Post by qquark »

ketozhang wrote: post #642
advisedwang wrote: post #348

Earlier quoted context omitted.

Water has a specific heat capacity of 4184J/kg/C. Lets say to get to the boil you need to go from 20C to 100C and that a kettle holds 1.75L. 59MJ / (80C * 4184J/kg/C) = 176kg ~= 176L ~= 100 kettles. Water has a latent heat of vaporization of 2260 kJ/kg. So to boil it dry: 59MJ / (80C * 4184J/kg/C + 2260 kJ/kg) = 22kg ~= 22L ~= 12 kettles. I have no idea what the journalist calculated.

I think the journalist is calculating load capacity. A 1500A @120V kettle requires 0.18 MW. Rounding up, 60 kettles requires 12 MW. It's not how much water you can boil, it's how many kettles you can run at the same time.

A 180kW kettle ?! Great Scott !

Re: Major breakthrough on nuclear fusion energy

#686

Post by advisedwang »

ketozhang wrote: post #642
advisedwang wrote: post #348

Earlier quoted context omitted.

Water has a specific heat capacity of 4184J/kg/C. Lets say to get to the boil you need to go from 20C to 100C and that a kettle holds 1.75L. 59MJ / (80C * 4184J/kg/C) = 176kg ~= 176L ~= 100 kettles. Water has a latent heat of vaporization of 2260 kJ/kg. So to boil it dry: 59MJ / (80C * 4184J/kg/C + 2260 kJ/kg) = 22kg ~= 22L ~= 12 kettles. I have no idea what the journalist calculated.

I think the journalist is calculating load capacity. A 1500A @120V kettle requires 0.18 MW. Rounding up, 60 kettles requires 12 MW. It's not how much water you can boil, it's how many kettles you can run at the same time.

59MJ over 5 seconds would be 11GW, so if it was load, that would be 6000 2kw kettles!

Although obviously those kettles wouldn't achieve much in those 5 seconds!

Re: Major breakthrough on nuclear fusion energy

#687

Post by dkbrk »

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…

> Theory dictates that with stronger magnets, the reactor can be scaled down (with the square/cube, can't remember exactly), and thus cost and time to develop

Here's the quick summary:

B: magnetic field strength

R: length scale

Fusion rate ∝ (plasma pressure)^2 ∝ B^4

Energy gain (Q) ∝ R^1.3 B^3

Power density ∝ R B^4

Cost ∝ R^3

So, say for example you're targeting a fixed Q. Doubling the magnetic field strength results in R1 = R0 / 2^(3/1.3) = 0.2 R0. And 0.2 R0 translates to 1/(0.2)^3 = 0.008 = 0.8% the cost.

The scaling is absolutely insane, and a stronger magnetic field has other advantages (such as making plasma instability far less of a concern), though structural loads can be an issue (that, at least is a relatively straightforward engineering problem).

If you take 12T for ITER and 20T for SPARC, that's not actually 2x, it's 1.67, which translates to 30% the size and 3% the cost (and time). It should also be noted that this is just rough, order-of magnitude estimation, but it should be broadly accurate.

For a more detailed explanation: https://youtu.be/KkpqA8yG9T4

Re: Major breakthrough on nuclear fusion energy

#688

Post by noetic_techy »

gameswithgo wrote: post #680
noetic_techy wrote: post #679

Not a breakthrough, just a milestone. Yet again they cite the "20 years out" which has become a joke among anyone that follows fusion research. There is really nothing to see in this article, move along.

when i was a boy it 40 years out, seems good that even the hyper cynical snarky comments are twice as optimistic now.

LMAO.

I really think these fusion people just need more money. MIT wants to build their SPARC reactor prototype, which will make ITER look stupidly large and expensive, but they need $40 Billion.

I dream of the future of SpaceX fusion powered star-ships with quantum computers and Alcubier warp drives are thing.

Re: Major breakthrough on nuclear fusion energy

#690

Post by PaulDavisThe1st »

formvoltron wrote: post #676
spywaregorilla wrote: post #580

Earlier quoted context omitted.

Solar is, without a doubt, a major part of future energy grids. But this chart is the levelized cost of energy. Its not the price at which you can get it. Energy demands are higher in winter. They are non trivial at night. The cost of energy might be low, but the price at which you can get it may be very high if not enough is available.

A lot of the "not available at night" argument can be solved with.... owning an EV. I use 6kWh / day. (not sure how! but that's what the power company says) A decent EV battery holds 20 kWh or more. Boom. There is my night time storage buffer.

to be fair, you need more than the EV. Using your EV battery as a power source to feed into your main house/home wiring is not crazy complicated, but it's not just a plugin.
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