They're still a very long way from getting a net gain in energy: https://youtu.be/LJ4W1g-6JiY
Haven’t we already had fusion experiments with net positive energy?
[deleted]
Major breakthrough on nuclear fusion energy
481–490 of 827 posts
Re: Major breakthrough on nuclear fusion energy
#482Re: Major breakthrough on nuclear fusion energy
#483Can 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.
Re: Major breakthrough on nuclear fusion energy
#484Earlier quoted context omitted.
Sorry for being like this but what I like most about that remark is the joyful optimism that there will be a society to power in the first place, and secondly one that can (still) build and operate such technology. Edit: maybe I’m needlessly pessimistic but I feel societies are much more fragile than they seem. We had it unreasonably good in ‘the west’ for the last 77 years but that time span is so short in the grand…
Are there any studies on what the world might look like in 50 years, based on a reasonable, realistic projection of climate change, human change in behaviour etc etc? Just to be clear, I 100% believe in climate change, and do what I think is a fair amount to help (cycle as much as I can, don't take long haul flights, take train instead of short haul flights, drive EV, insulate house, don't eat much meat, Solar PV pan…
Exactly this! I believe global warming can become an inconvenience but nothing totally off the scale compared to the problems we face today (and especially have faced in the past). If there is even a 1% chance of a nuclear war that would be much more devastating (even in expected value) than climate change. I actually have grown to fear the opposite: We come up with an efficient cycle to capture carbon (like the one to create starch that was all over the news some time ago) and suddenly it becomes a race to the bottom where we need international treaties so people are not sucking all the carbon from the atmosphere. I have no clue about chemistry whatsoever so I can hardly tell if this is plausible but if it is, it appears far more dangerous to me than a couple degrees in global warming.
Re: Major breakthrough on nuclear fusion energy
#485Earlier quoted context omitted.
Did you factor in the inefficiencies of the power distribution grid and the heating element of the kettle? I'd say the journalists are just repeating what they've been told by the scientists, and the scientists factored inefficiency in on a calculation similar to your first.
Nope, I didn't factor in anything like that. Also kettle's don't actually heat every ml to 100C so there's some fudge in the other direction. I mostly was just getting nerdsniped.
Thermodynamics is very good at sniping nerds. The first law is basically a universe builder. The second law is maybe a universe destroyer? :)
Re: Major breakthrough on nuclear fusion energy
#486Earlier quoted context omitted.
"with very expensive and massive fission reactors" The laws if physics don't owe us a free lunch. Light, safe and cheap powersource does not exist Fossil fuels aren't a power source, they wre a power store - that power was collected and millions of years ago. Also 100% productivity on 25 years is quite good - what did combustion engines improve in that time, 5%?
The 1997 F-150 made 220bhp and got 18mpg [0], while the 2022 F-150 makes 400bhp and 19mpg [1], so fusion is doing way better than that! (...i think i chose comparable trim levels to do that comparison, there are a stunning number of choices there!) [0] https://www.cars.com/research/ford-f_150-1997/specs/103719/ [1] https://www.edmunds.com/ford/f-150/2022/features-specs/
The real question would be, what's the fuel consumption for a given, sustained, bhp, for both? The mpg numbers are often pretty unrealistic. [-1]
[-1] https://www.edmunds.com/fuel-economy/heres-why-real-world-mp...
Re: Major breakthrough on nuclear fusion energy
#487I noticed the waste output is helium. Does this fix the worldwide helium scarcity issue?
Let's make some back of the envelope calculation: * World electricity production: 25000TWh/year https://en.wikipedia.org/wiki/Electricity_generation * Energy per Helium atom: 17.6MeV https://en.wikipedia.org/wiki/Deuterium%E2%80%93tritium_fusi... So per year (with a 100% efficiency [1]) you would produce as a side effect 25000TWh/17.6MeV ~= 3E31 Helium atoms. The Avogadro constant is 6,022E23 and that produces 22.4 l…
This calculation was done on an HN thread a few years ago. I have not reviewed it recently.
If all power generated right now was from D+T fusion, it would generate about 8.2% of the current helium consumption. We consume 153,596 TWh of thermal energy per year [1]. Each D+T reaction releases 17.59 MeV [2]. Multiply by the atomic mass of He4 and divide by Avogadro's number to get the mass of He4 produced per energy produced. Divide by the density of He4 at STP to get volume of He4 produced per second [3]. Divide by the consumption of He4 to get the ratio of He4 produced to He4 consumed [4].
(153596 TWh / year) / (17.59 MeV) / (avogadro's number 1/mol) * (4.002602 g/mol) / (0.1786 g / liter) / (88 million m^3 / year)
https://www.wolframalpha.com/input/?i=(153596+TWh+%2F+year)+...
1. https://ourworldindata.org/energy-production-and-changing-en...
2. http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.htm...
3. https://www.engineeringtoolbox.com/gas-density-d_158.html
4. https://link.springer.com/article/10.1007/s11053-017-9359-y
Re: Major breakthrough on nuclear fusion energy
#488In 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 OTOH, in a tokamak, the plasma volume (and potential energy output) scales quadratically with the torus' aspect ratio (ratio of major to minus radius), so I'm not sure that tokamak-based fusion really is particularly suitable to miniaturization.
Tokamak output scales with the square of reactor volume but the fourth power of magnetic field strength, so with sufficiently powerful magnets, scaling down the size can be an option.
Re: Major breakthrough on nuclear fusion energy
#489Quoted post unavailable.
" Eschew flamebait. Avoid unrelated controversies and generic tangents. " https://news.ycombinator.com/newsguidelines.html We detached this subthread from https://news.ycombinator.com/item?id=30272413 . (No, we're not trying to defend lizard people, great resets, population control, 5G, or whatever else comes up in this context. We're just trying to have an internet forum that doesn't suck. Repeating the same flamewa…
Saying Bill Gates isn't a good person is flamebait?
Sorry then, it wasn't my intention.
Re: Major breakthrough on nuclear fusion energy
#490In 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 OTOH, in a tokamak, the plasma volume (and potential energy output) scales quadratically with the torus' aspect ratio (ratio of major to minus radius), so I'm not sure that tokamak-based fusion really is particularly suitable to miniaturization.
This technical deep-dive by Dr. Dennis Whyte goes into the scaling considerations: https://www.youtube.com/watch?v=rY6U4wB-oYM
TLDR: Tokamak economics scale in size with 1/B^5 -- so doubling the magnet field strength reduces the physical size substantially. This factor dominates other scaling parameters by a substantial margin, and is entirely enabled by high-temperature superconductors. A host of other key fusion parameters also scale beneficially with B^x (for some value of x) -- most of which are discussed in first half the video.