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Experts Urge U.S. To Continue Support for Nuclear Fusion Research

344 points by tshannon 8y ago

devy 8y ago
Nuclear fusion is probably still decades away. But I am going tangent here, nuclear fission still have great potentials. Scientists from the Oak Ridge National Laboratory actually helped China to built Molten Salt reactors in the 70s during Nixon administration. [1] And since then thorium based molten salt Gen IV reactors have been having renewed interests around the global. China actually tested the whole system feasibility in Giga Watts scale in recent years. [2] Nuclear power is vital part of the energy infrastructure to curb worsening environment due to climate change - it's still considered superior than all the other green alternative energies in terms of either 24/7 availability (vs. solar/wind) or massive scale (vs. geothermal) or location restricted (vs. hydro) or carbon-free (vs. biomass/bio-fuel). China realized that in their dire request to transition out their entire energy reliance on carbon-based energies, it's impossible to do without nuclear. Also, newer reactor designs are much safer and last longer so a lot of the concerns of radioactive waste have largely been alleviated. [1]: https://news.ycombinator.com/item?id=10229697 https://news.ycombinator.com/item?id=10229697 (2015) [2]: https://news.ycombinator.com/item?id=17813614 https://news.ycombinator.com/item?id=17813614 (2018)
- toomuchtodo 8y ago
  > China realized than in their dire request to transition out their entire energy reliance on carbon-based energies, it's impossible to do without nuclear. Also, newer reactor designs are much safer and last longer so a long of the concerns of radioactive waste have largely been alleviated. https://www.technologyreview.com/s/612564/chinas-losing-its-taste-for-nuclear-power-thats-bad-news/ https://www.technologyreview.com/s/612564/chinas-losing-its-... (December 12, 2018 | Sustainable Energy China’s losing its taste for nuclear power. That’s bad news.) HN: https://news.ycombinator.com/item?id=18675453 https://news.ycombinator.com/item?id=18675453 Quick points: Too expensive with necessary safety measures, Chinese citizens don't want it after Fukushima, renewables are already cheaper, and electrical demand growth has declined unexpectedly. My opinion: We should still explore fusion technology and spend on R&D, but fission is already dead. Renewables and storage full speed ahead.
  - devy 8y ago
    Fukushima is bad press and also Fukushima was designed and constructed in 1960s, that's Gen I design and let alone they cut corners in safety. Like I said, Gen IV is much much safer and produce much less radioactive wastes. Also nuclear fission might not be relevant if humanity cannot survive after 2040, according to IPCC's climate change report (I am doubtful we will even be able to get nuclear fission power plants commercialized by 2050 TBH.)
    - barney54 8y ago
      Where does the IPCC day the humanity won’t survive beyond 2040?
  - kenneth 8y ago
    If fission is dead, then earth is dead. There is no way we'll survive if we continue to burn coal at the rate we do, and renewable don't work at scale yet and storage is not yet solved. Fission is the only thing that can provide us with enough clean energy in the near term (next 50 years).
    - dv_dt 8y ago
      We have to solve the problem in the next 10-12 years. The median nuclear plant construction is 7.5 years, with the US medians being more in the 18-20 year duration - with the very most recent nuclear projects mostly being shut down mid construction because of cost and schedule overruns. Even France, with one the most mature and well run nuclear power programs is concluding that the next wave of power investment makes more sense to make in renewables instead of nuclear. I suspect we will solve our problems with renewables + storage (which are still rapidly declining in cost).
      - Xixi 8y ago
        Regarding France, it seems that we have lost the actual knowledge on how to build nuclear power plants. Which should have been expected given that we stopped building those for quite a while, so of course the know-how is gone. Flamanville, the first EPR in France, was schedule to start running in 2012 for a construction cost of 3.3 billion EUR. It is now expected to start producing electricity in 2020 for a construction cost of 10.9 billion EUR. Emphasis on expected...
- sandworm101 8y ago
  China's approach to nuclear isn;t just environmentalism. It is largely a national pride project. Fission is an area of science that china knows it can excel in because, frankly, the west isn't doing much. I applaud china's efforts. I think we need fission energy. But I worry national pride isn't reason enough to maintain the program indefinitely. Coal prices are dropping. Will china continue to roll out fission reactors if/when coal falls off the price cliff?
  - devy 8y ago
    > It is largely a national pride project It's much less a pride than a survival instinct. Just think about it, Beijing was under siege of heavy smog for over a decade by now. If Washington D.C. was like that for since Trump became the president, would he still advocate coal?
    - jacknews 8y ago
      Though Trump has to worry about those pesky elections.
- hirundo 8y ago
  > Nuclear fusion is probably still decades away. I wrote that sentence in a 10th grade report on fusion, in 1977. Disappointing that it's likely still true four decades later. In another four decades it's up to you to make this comment. On the other hand, so much has arrived that I never dreamed of in high school, though I consumed scifi obsessively. Not sure I'd swap the internet for cheap fusion energy. But not sure I wouldn't.
  - jessriedel 8y ago
    Note that we've never spent as much money as we've always known would be necessary to achieve useful fusion power, so the oft-repeated idea that it's been surprisingly technologically difficult is not actually justified by the historical track record. > Typically, outsiders cannot comprehend how the massive expenditures never manage to yield energy. Typically, insiders cannot comprehend how little is being invested in a project that presents such immense technical obstacles and also such potential. A graph commonly passed around among the insiders—an enduring scrap of twentieth-century budgetary ephemera—depicts the 1976 federal plan to build a working thermonuclear reactor. The graph tracks various scenarios for attaining fusion energy. The “maximum” effort, the most expensive up front, with initial spending as high as nine billion dollars a year, was projected to yield a reactor by 1990. The “moderate” effort, with spending never exceeding four billion dollars in a year, would take fifteen more years. The fusion community might be easy to criticize for its many unmet milestones, but for decades the United States has never come close to even the moderate effort. In 1977, when the American fusion budget was at its peak, government investment in the research, adjusted for inflation, was seven hundred million dollars; by 1991, this had fallen by more than half. It is now half a billion, not appreciably more than the Korean budget. http://www.newyorker.com/magazine/2014/03/03/a-star-in-a-bottle http://www.newyorker.com/magazine/2014/03/03/a-star-in-a-bot... The chart was produced by Energy Research and Development Administration (ERDA), which was later subsumed into the Department of Energy and presumably represented the expert wisdom at the time. It can be found, in 1976 dollars, as figure 1 here: http://www.21stcenturysciencetech.com/Articles_2010/Winter_2009/Who_Killed_Fusion.pdf http://www.21stcenturysciencetech.com/Articles_2010/Winter_2...
    - 8y ago
- matt4077 8y ago
  This reads like a parody of every thread on nuclear technology on HN or, before it, slashdot. It’s always „decades away“, but there’s always pebble bed/molten salt/thorium/whatever technology that’s far better, basically functional, mostly free, and only held up by those darn environmentalists/idiot politicians/liberals/oil lobby/NIMBYs/Elton John/… It feels like the tech community is forever trapped in the science fiction of the 50s, while actual science (and politicians) have created options that, frankly, are far better in every regard, including costs.
  - mywittyname 8y ago
    A major issue is that people on HN are largely ignorant of nuclear power generation. It's largely a bunch of wikipedia-educated people debating youtube-educated people. So none of the discussions are realistic, because there's probably four people on HN with any real world subject matter knowledge. There's not the same blind-optimism to solar power generation.
    - Pica_soO 8y ago
      We like big problems more then big solutions. What we like even less, are small solutions to big problems.
    - ggm 8y ago
      There's not the same blind-optimism to solar power generation. Well.. it's hard to be overtly skeptical to a form of lower intensity power which works at scale, but lower intensity. The only claims to be rebutted are ones which overstate the pace of improvement to the forseen asymptote. What's more baffling is the constant jeremiad of hate against solar wind and battery because of prejudice favouring large centrally managed gigawatts. Nobody disputes big lumps of powerstation are good. What we're doing is fighting an ill informed skirmish inside the linear programming and O/R model of future power, rather pointlessly. I would like nuclear fusion and fission power research to continue. I would like the funding to lower intensity power to continue as well. I would like a grown up conversation about how much each should get annually as funding.
- DennisP 8y ago
  Also uranium-fueled molten salt reactors, using chloride salt. These will be fast reactors and have pretty much the same advantages as the thorium designs. Terrapower, Moltex, and Elysium are going this route (though Moltex is planning a thorium-fueled version as well).
  - qwerty456127 8y ago
    Isn't thorium more abundant than uranium and easier to mine?
    - DennisP 8y ago
      It's three or four times as abundant as uranium, and about 400 times more abundant than U235. However, with fast reactors you can get power from all the uranium, not just the U235. Uranium is currently a small portion of the cost of nuclear, so it can't be that hard to mine, especially after we only need 1% as much for the same amount of power. Either keeps us going for thousands of years, and after that we could extract uranium from seawater until the sun goes out.
- ohiovr 8y ago
  There was a startup recently for molten salt reactors but didn’t conclude successfully https://www.technologyreview.com/the-download/612193/nuclear-startup-to-fold-after-failing-to-deliver-reactor-that-ran-on-spent-fuel/ https://www.technologyreview.com/the-download/612193/nuclear...
  - DennisP 8y ago
    Transatomic claimed to have the fuel utilization of fast reactors without being a fast reactor. That turned out not to be the case. However, there are a bunch of other startups working on molten salt reactors, including Bill Gates' Terrapower, Terrestrial Energy, Thorcon, Moltex, Elysium, and Flibe. The farthest along is probably Terrestrial Energy, which has gotten through the hardest part of Canada's licensing process.
    - ohiovr 8y ago
      I would really like to see the particle beam fission concept explored also due to its versitility and control: https://en.wikipedia.org/wiki/Accelerator-driven_subcritical_reactor https://en.wikipedia.org/wiki/Accelerator-driven_subcritical...
      - pfdietz 8y ago
        It's a niche technology, and doesn't address the main problem of fission (that the reactors are too expensive). At least it serves as a counterargument to those who want to make fusion-fission hybrid reactors.
- njarboe 8y ago
  There have been a series of breakthrough in helicity injection techniques and the understanding of spheromak physics in the last decade. Some believe that economical fusion power plants are possible with today's technology[1] and need a ~$30 million to prove out a scale model reactor before building a full scale one on the order of $2-3 billion of a 1-2 Gigawatt power plant. This is an order of magnitude less cost that the ITER project, which is spending a lot of money on cement and magnets on a probably doomed technology path of commercial fusion. These same breakthroughs are also likely to be able to produce a fusion engine for spacecraft. This is actually an easier problem to solve than electricity generation as the deuterium can be used as fuel and as a propellant ejected straight out of the plasma core at variable ISP up to around 100,000. No inefficient fusion to electricity to rocket engine cycle is necessary. I am not a fusion scientist, but my father is. For more info and technical references, drop me an email (see profile). [1]https://www.washington.edu/news/2014/10/08/uw-fusion-reactor-concept-could-be-cheaper-than-coal/ https://www.washington.edu/news/2014/10/08/uw-fusion-reactor...
  - philwelch 8y ago
    > This is actually an easier problem to solve than electricity generation as the deuterium can be used as fuel and as a propellant ejected straight out of the plasma core at variable ISP up to around 100,000. Jesus. For reference, chemical rockets tend to have ISP in the low-to-mid hundreds, and ion thrusters are in the thousands—not ten thousands, but single thousands. A 100,000 ISP rocket is like a car that can drive from Bangkok to Vladivostok to Lisbon, then back to Istanbul and down to Johannesburg without refueling or recharging. It’s like a phone battery that lasts years rather than days. And it’s all powered by the most plentiful elements in the universe. I’m pretty sure you could generate electricity by flying this rocket around in a circle tethered to an electric turbine if you wanted to. I mean, all of your electricity would probably be in space, because a high ISP usually implies that the rocket doesn’t work as well on the earth’s surface (not as a physical law, just as a limitation of our technology), but of all the monumentally impressive things you can build from a fusion reactor, a 100k ISP rocket has got to be up there. As for ITER, I’m not necessarily bearish on it, but if there’s a credible chance of an alternative design that can be proven for anything <$1 billion...I hate to say it, but any person, venture capital fund, or government with more than $10 billion to their name would be hard pressed to find any better use for it. Even if the damn thing is 95% likely to fail, that’s a 5% chance you literally end up having a stake in the single most valuable technology in the single most valuable sector of the economy—one that will provide untold benefits to mankind. 30 million dollars, really? Like—does Y Combinator know about this? Never mind the “benefits to mankind”—if a single business can be first to market with an economical fusion power plant, that will become the single most valuable business in human history. There’s like five tech companies that are up there in the ranks of “most valuable business in the world”, and they’re approximately the same value as any of about ten oil and gas conglomerates, and those lists usually don’t even count state-owned companies that are even more valuable. (“All the oil in Saudi Arabia”—that’s wealth.) Fusion power would immediately be more valuable than every single oil and gas company in the world put together. Even if nobody bought fusion plants, you could just build the damn things yourself, use them to synthesize hydrocarbons from the damn atmosphere, and undercut the market while simultaneously fixing climate change by making fossil fuel usage a closed loop with no new net CO2 introduced into the atmosphere and an economical method for extracting the excess we already have.
- ArtWomb 8y ago
  Construction time for nuclear plants average 10-20 years, vs 2-4 years for wind and solar grids. There are other risks to consider as well. From the forthcoming textbook, 100% Clean, Renewable Energy and Storage for Everything https://web.stanford.edu/group/efmh/jacobson/Articles/I/NuclearVsWWS.pdf https://web.stanford.edu/group/efmh/jacobson/Articles/I/Nucl...
- derblitzmann 8y ago
  If I recall the fusion meme correctly, it is perpetually 10 years from now... Assuming it gets properly funded. Though I also believe that fission research and plants still have their place, especially if you care about carbon emissions.
- Krasnol 8y ago
  > Also, newer reactor designs are much safer and last longer so a lot of the concerns of radioactive waste have largely been alleviated. ...in countries that are large enough to make it "disappear". Meanwhile normal sized countries are still struggling with old waste and new waste. See Germany. Meanwhile reprocessing as it exists is economically pointless, while it reduces the amounts of highly radioactive material enlarges the amounts of mid and low radioactive material and doesn't help with the stuff that has been insufficiently stored already. Also Sellafield and La Hague are probably polluting water. Hooray...
- tim333 8y ago
  >Nuclear fusion is probably still decades away Maybe but startups are having a crack at it eg. "UK Atomic Energy Authority and First Light Fusion team up for project that aims to deliver fusion breakthrough by 2024" https://web.archive.org/web/20181206125841/https://www.businessgreen.com/bg/news/3067747/fusion-island-uk-start-up-reveals-plans-for-pioneering-nuclear-fusion-research https://web.archive.org/web/20181206125841/https://www.busin...
- cenal 8y ago
  There is also a major advancement in disposal technology: http://www.deepisolation.com http://www.deepisolation.com
pmarreck 8y ago
A well-built modern fission plant is far safer and more environmentally-friendly than almost all the other solutions out there save for solar/wind/geothermal. Fusion is the holy grail, though, and with good reason. At least with fusion (as with flight 100+ years ago), we have only to look up during the day to know it's feasible because it's being demonstrated, live, every day!
- Retra 8y ago
  The sun's fusion is powered by the gravitational attraction of ~10e30 Kg of matter. That is not even remotely an option on Earth, so there is no evidence of feasibility about the energy produced by the sun, aside from the fact that it demonstrates that fusion as a concept makes sense.
  - dekken_ 8y ago
    I was asked recently if "I believed in fusion" my response - "I don't think it will cost effective" and what you have posted is basically that reason
  - dogma1138 8y ago
    Does it tho? Star fusion produces the exact amount of pressure needed to counter the gravitational attraction which is why they don’t collapse or blow up while the fusion reaction is stable, when it’s not the result isn’t pretty. So in essence stars aren’t energy possitvie (or if so only slightly relative to the energy of the reaction) they just convert one type of energy into another.
    - pfdietz 8y ago
      This argument makes no sense at all. "Pressure" and "power" don't even have the same units. They are entirely different things. Let's try to rephrase things in a way that makes physical sense. There is energy embodied in the Sun. This is the kinetic energy of the electrons and ions that make it up, the energy of the thermal radiation mixed with this plasma, and the (negative) gravitational potential energy. As the sun formed, energy was liberated by gravitational collapse. This heated up the Sun's material and got things going. We know (by the wonderful Virial Theorem) that the negative gravitational binding energy of the Sun is ~2 times the internal energy of its particles and radiation. We can then ask: how does this energy compare to the rate that the Sun is radiating energy? This ratio would give a timescale over which the Sun would cool off, if there was no energy input. This ratio is on the order of ten million years. But the sun is hundreds of times older than this. So, we can conclude the energy yield of the sun, the ratio of fusion energy output to the initial gravitation energy input that heated it up, is pretty darned good, on the order of hundreds.
zachrose 8y ago
At the risk of inciting a flame war that I might not be able to understand, is there any way to characterize current fusion projects against each other? For example, what can be said about the promise of ITER vs Wendelstein 7-x? Part of me realizes that there’s no such thing as a “failed” scientific experiment and that diversity of approaches is good. The other part of me thinks that a public and competitive spectacle would also be good.
- dukoid 8y ago
  ITER will be an actual tokamak fusion reactor producing energy. Wendelstein 7-X is a plasma containment experiment based on the stellarator design. There will be no fusion. Technology for magnetic enclosure was advanced significantly by both. In this regard, they profit from each other. Tokamak reactors require a pulsed operation mode. There is no way to sustain fusion for longer time. The Stellarators design allows continuous operation, putting less stress on the structure. The calculation of the winded enclosure structure is quite complex and it has only become possible to design and implement with sufficient precision recently. If I'd have to "bet" on a design, it would be Stellarator. If you understand German, listen to this podcast. You won't regret it: https://alternativlos.org/36/ https://alternativlos.org/36/
  - DennisP 8y ago
    People keep saying Wendelstein won't do fusion but that's not the case. Currently the 7-X isn't doing fusion because they're using hydrogen. But they plan to use deuterium later, just like all the other fusion research reactors, and they'll get fusion reactions when they do. There's really no reason not to; you get more data and it's easy. People fuse deuterium in their garages with home-built fusors.
    - sterlind 8y ago
      Exactly! AFAICT, the trickiest unknown is maintaining plasma stability and not degrading the insides (and then, breaking even on power while doing so.) Wendelstein seems to be on track to steady-state operation; they've held plasma for 100s, and their graphite shielding seems to be delivering cleaner plasma streams. The design for the 7-X wasn't feasible until supercomputers got powerful enough. We know how to run those simulations; fusion should get more practical as computers get faster.
deleted 8y ago
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aftbit 8y ago
I suspect we will transition to PV before fusion actually becomes viable. Even if we had a working net-positive-energy-balance fusion plant today, it would be incredibly complicated and expensive to build and maintain. The temperatures and energies involved are simply massive. On the other hand, we already have a giant self-sustaining fusion reaction happening in our sky. We can throw down some solid state and increasingly cheap panels to collect that energy. Regardless, we should continue to invest in fusion, but we should also invest in PV research, especially into ways to decrease cost and complexity of manufacturing solar cells.
- scrumbledober 8y ago
  PV just doesn't scale in the same way. There's only so much surface area to cover in panels. The power density of fusion is so many orders of magnitude larger that even with cheap reliable solar panels I think there will always be a use for working fusion
  - adrianmonk 8y ago
    If nothing else, it could be useful for portability. You can't make a solar powered aircraft carrier. You might be able to make a fusion-powered one.
    - cagenut 8y ago
      you say that like its a bad thing
      - mmirate 8y ago
        Oh, it is a bad thing, very much so. The more efficiently we can maintain the U.S. Navy, the bigger we can keep it, and the less likely it is that some smaller nation will threaten the balance-of-power by pulling a competitively-sized navy out of their butts.
    - pfdietz 8y ago
      Fusion has very bad power density compared to fission, so a fusion-powered ship would be idiotic.
b_tterc_p 8y ago
I get that fusion can theoretically transform vast quantities of stuff into useful energy. Can anyone comment on how scalable it would be if proven viable? Can it be built on a large scale profitably? Can it be built to serve remote locations off major grids? Can we ship it in reasonably sized space ships and use it to build bases elsewhere? Can we write off low energy costs to just churn on some sort of climate saving terraformer?
- swebs 8y ago
  >Can it be built to serve remote locations off major grids? No, fusion reactors are required to be a certain (very large) scale before they can provide a net output of energy. You can find kits online to build an actual fusion reactor in your garage, but it will consume more energy than it produces.
  - pontifier 8y ago
    CURRENT fusion reactors are required to be very large scale... I've got a design that might scale down to the size of a D cell battery, or smaller. It's completely untested due to lack of funds, but on paper I haven't found enough flaws to count it out.
    - Dylan16807 8y ago
      So will you say what you plan to trigger the fusion with? And let's say you build one into a 1-liter box. How many watts should we expect it to produce?
- scrumbledober 8y ago
  Fusion scales incredibly well. For a given working reactor design, efficiency increases with size. I think viable working fusion would lead to a more interconnected grid because of this as opposed to smallscale fusion reactors being deployed in semi-remote areas. On the other hand truly difficult to reach places would be perfect for fusion as once it's built it takes very little fuel to run.
AcerbicZero 8y ago
I have no idea if nuclear fusion is feasible in the near future, or what kind of timeline is required, but I don't see any downside to spending money on projects like this. Pure scientific pursuits seem to be fund able at relatively low prices, with massive upsides and no obvious downsides, other than the opportunity cost of the money being spent.
- pfdietz 8y ago
  Fusion absolutely will not be feasible in the near future. We don't even have the materials that would be needed to build them. In any other field of engineering, lack of materials is a showstopper, and new material development is always painful and slow. And if you examine any of the designs with a skeptical eye none of them seem promising, and all involve lots of handwaving.
  - dwaltrip 8y ago
    You are saying that ITER will fail?
    - pfdietz 8y ago
      ITER cannot lead to an economically competitive reactor, even if it achieves every one of its stated operational goals. It's a massive dead end waste of money.
      - dwaltrip 8y ago
        Although I happen to disagree, that is a different, more reasonable critique than your original comment.
        pfdietz 8y ago
        My original comment is entirely reasonable. Fusion faces generic obstacles that are likely unsolvable, and certainly unsolvable in the near term. Consider the problem of tritium breeding. Fusion reactors have to make their own tritium -- T from fission reactors would be far too expensive -- but tritium breeding blankets cannot be tested without a working fusion reactor. And the requirements for the breeding blankets are seriously constraining. They must achieve some neutron multiplication (from (n,2n) reactions of energetic fusion neutrons) to offset losses, not lose too many neutrons to penetrates/parasitic capture, and be able to give up the produced tritium fairly quickly. And there are very strict limits on how much tritium can be lost to permeation into reactor materials (or lost from the reactor exhaust, since ~99% of the injected tritium doesn't fuse). No one knows how to do this, or if it can be done economically, or even if it can be done at all. And I repeat: testing it is going to require a working fusion reactor! This circular dependency in development will be painful to run around, and won't happen quickly. Then there's the matter of materials that can withstand prolonged exposure to fusion neutrons. These materials have not been developed, in part because this again requires something close to a working fusion reactor (at least, something with Q at least ~0.1), and much painful rebuilding as that reactor, built with less adequate materials, destroys itself over time. This material development will not be fast, so we will not have working, practicl fusion reactors soon. Even when all that is solved, the fundamental problem of fusion -- low volumetric power density -- remains. That alone seems insurmountable. When you see a fusion reactor design, ask what this power density is. For ITER, it's 0.05 MW/m^3. For ARC or Lockheed's design, it's around 0.5 MW/m^3. These are very bad compared to fission reactors. A final point: the complexity of the irradiated part of a fusion reactor (the part that's too radioactive for hands-on maintenance) will be MUCH higher than that of the similar part of a fission reactor. Reliability is going to be an enormous problem. Making fusion reactors reliable enough for them to be practically interesting, even if all other problems were solved, will take much experience and time.
hsnewman 8y ago
I unfortunately believe that this is a dead issue given the current administration. Unless Fusion will increase the carbon footprint and line the pockets of certain individuals, I see no support by the U.S. government. I for one want the support to continue.
- rpiguy 8y ago
  Trump and the Republican congress doubled fusion funding in the May omnibus bill, literally saving ITER from having to delay again. Republicans have always been solidly for nuclear power and its derivatives because the only companies with the capital and guaranteed future cashflows to build nuclear fission or fusion plants are the existing energy companies, who have traditionally aligned with Republicans.
dogma1138 8y ago
Do we even had a model for Fussion that is energy poasitive? The only Fusion reactors we know to work, work by converting gravitational potential energy into light/heat through fusion this is how stars operate. All fusion reactions so far require an external input of energy not only to start them but often to sustain them and even those which are self sustaining for a short period of time grind to a halt once you try to extract energy from the system. So in all honesty while I’m not by any stretch of the imagination an expert in fusion physics I can at least understand conservation laws, does any of the current experiments even relies on a model that is at least proven in principle to be energy positive?
- dogma1138 8y ago
  To the trolls downvoting all the questions here stellar fusion works because of hydrostatic equilibrium which is maintained between gravity and the outbound pressure of the fusion reaction of a star. ∆P · A = −GM(r)m http://www.ucolick.org/~woosley/lectures_fall2012/lecture12.12.pdf http://www.ucolick.org/~woosley/lectures_fall2012/lecture12.... So essentially they are giant springs in space that convert one form of energy into another by fusing matter. Now I hope someone would be able to answer my actual question regarding the energy positive fusion models.
  - strainer 8y ago
    That was bad luck with the downvoting, I have heard the gravitational narrative of stellar evolution and element creation before, perhaps in a Feynman lecture? I recall the idea that a cloud of hydrogen atoms has more gravitational potential than the equivalent cloud of heavier elements, basically because the matter is more evenly dispersed. It seems to make a certain sense. Particles get very fast when they close distance, if they can then stick together their kinetic energy has to become something. Interesting to calculate the gravitational energy involved in a neutron and proton getting close enough to be held by each others nuclear forces, beginning from an average separation of say a few microns? I know they have to get through repulsive nuclear forces in order to stick, I don't know if the reaction always liberates kinetic energy. Maybe it depends on what element results. An interesting topic of stellar fusion should be supernova reaction/s. The creation of heavier elements there can clearly release enough kinetic energy to explode the condensed body. Does that energy owe to the distance that has been closed by particles forming heavier elements, or to loss of mass in the nuclear reactions? I wonder about the gravitational energy of a cloud of billard balls rather than atoms. If another cloud has the same volume but half the number of larger balls that are twice as heavy. I guess if the two clouds have the same size, weight and density, they have the same gravitational potential - if they start cold, they will both implode with the same force at the center. But this seems to contradict the narrative that conversion of hydrogen to helium should consume or liberate that potential energy.
ohiovr 8y ago
Just because deuterium is cheap doesn’t mean Fusion energy plants will be anywhere near economically competitive with conventional power sources even most renewables. Many of the presumed benefits such as waste control are not as rosey as most people believe. It is clear now that plant scaling with known methods are entirely dependent on magnetic field strength. More powerful magnets will mean more hope for tokamaks. Entirely new designs are probably not what the doctors are ordering because nothing of the sort is anything close to a surefire success in the wings. So many concepts have come and gone. Tokamak was the closest they ever got. Look at the plant schematics. Its like building a furnace from a humongous collection of delicate swiss watches.
- deleted 8y ago
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- pfdietz 8y ago
  Even with powerful magnets, the power density of a fusion reactor is limited by what the first wall can withstand, and will always suck compared to fission reactors. There's little hope a fusion reactor will be able to compete with fission, never mind the technologies that are beating fission. What high fields might do is allow use to make small, uncompetitive fusion reactors, instead of large, uncompetitive fusion reactors.
  - ohiovr 8y ago
    Correct and 17 tesla magnets are already hugely powerful. Its a tremendous amount of structural stress. If it quenches it can explode!
sien 8y ago
The full report can be read at : https://www.nap.edu/read/25331/chapter/1 https://www.nap.edu/read/25331/chapter/1
DrNuke 8y ago
Fusion is a materials science problem and materials informatics (machine learning methods for improving properties and / or devising new alloys) will help immensely once a new generation of digital-native scientists comes into the working force. Fusion might not become economically viable for a long time yet, though, so investments could very probably be moved elsewhere sooner than later. Healthcare for aging populations in the West and a new space race from China come quickly to my mind as powerful “distractions” from ITER part II, in the case part I ignition goes well by 2030. Smaller, more efficient reactors would not solve the energy problem even if they go successfully past the laboratory stage, in that being out of question imho.
- pfdietz 8y ago
  Distractions from ITER would be welcome. The power density of ITER is ~0.05 MW/m^3, some 400x worse than the power density of an LWR reactor vessel (and 2000x worse than the power density of the LWR core inside that reactor vessel). It's a project where research money goes to die, and new materials are not going to help that.
  - DrNuke 8y ago
    Power density is irrelevant for fusion, though: you will never exhaust fusion “fuel” on planet Earth. It will never be an efficiency problem, like it is for fission aka uranium.
    - pfdietz 8y ago
      No, power density is very important, since it directly affects how expensive fusion reactors will be. The cost of a machine is a function of its complexity and size; fusion reactors will be both much larger and much more complex than fission reactors of the same power output.
      - DrNuke 8y ago
        Possibly yes but, even the case, the US, the UK, Japan and France would switch to fusion immediately, if feasible, to get rid of fission and its waste. Renewables & nuclear are the perfect mix to contain greenhouse gases emissions, that’s why the debate is so hot.
deleted 8y ago
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AngryData 8y ago
I don't think we have a choice. Human activities are currently completely dependent upon the availability of energy. Right now most of that energy comes from non-renewable sources and is limited. Our only other choice besides nuclear technologies is covering large portions of our planet's surface with solar panels, which in itself might cause problems because they will shade out plants and change weather and climate patterns as they scale. Traditional nuclear plants get us quite aways farther, but have their own risks, and still require absolutely enormous mining fields which isn't ideal. Fusion power however is the holy grail of energy production. We can go pretty much anywhere and find plentiful sources for fuel. Of course this is assuming small fusion reactors will ever actually work, but we have yet to find a hard limit or insurmountable barriers. We have been progressing slowly but consistently but the payoff would be world changing, potentially even galaxy changing int he longer run.
- lutorm 8y ago
  covering large portions of our planet's surface with solar panels Have you calculated it? If I recall correctly, it's actually not a large portion at all. It's large in the sense that it would be a large infrastructure project, but it's not larger than the combined area already covered by buildings.
  - neolefty 8y ago
    Yes. I think the main limitation is not land use — rather: political will, energy storage, transport, manufacturing, and power leveling.
  - AngryData 8y ago
    That is assuming we keep similar power usages as today, but many of our largest industries are consuming unaccounted for fossil fuel energy. Fertilizer for example, fossil fuels are used as a reagent in creating artificial fertilizer, on top of already huge energy costs. The energy required to make fertilizer out of the air and water, rather than fossil fuels, is 100x more at best case. 60% of our total crop yield is the result of artificial fertilizer. Then look at plastics, how much more energy is required to create nonfossil fuel hydrocarbon precursors? You can make hydrocarbons from trees, but it might take an entire tree just to make a few cheap plastic containers. Many other industries are also powered by mined and drilled organic fuels and minerals, but are still fairly limited in availability, at least for such cheap prices/energy requirements anyways which will rise into the future. Building solar panels to power our planet today isn't insurmountable, but what about 20 years from now? 50? 100? Power costs are the limiting factor in many industrial processes, including farming, steel and aluminum production, aviation and rocketry, indoor farms, plastics, and nearly every other form of material synthesis. Don't get me wrong, im not advocating against solar power in anyway, however I don't think it is an effective source for powering our largest industrial processes into the future. Even a small 10 man ceramics shop can draw enough power that they need to call up the local power companies before they turn their large furnaces on, I see no reasonable way of storing and supplying those kind of immense power requirements with solar panels and current storage technologies in any economical way.
dicroce 8y ago
We should be funding the shit out of Fusion and molten salt fission reactors. We're gonna also need to build shitloads of carbon scrubbers and water desalinization plants.
- robertAngst 8y ago
  This reminds me of the confidence Alt-coiners had in their alt coins.
- neolefty 8y ago
  If our goal is basic research, sure, fusion is great. But if our goal is to achieve carbon neutrality ASAP, we can't count on fusion to help because we don't know when it will start working. On the other hand, renewables + battery leveling are here today and ready for intensive investment. Yes, let's do both. But I don't believe fusion research will provide a short-term alternative to CO2-emitting power sources. I think it's fine with to spend 1000x on conventional renewables compared to fusion. We can employ an absolute army of technicians and factory workers today to build out renewable generation infrastructure, while fusion gets a steady research budget for post-docs, career physicists, materials engineers, etc.
  - jcranberry 8y ago
    What about fission reactors?
jacknews 8y ago
Is terrestrial fusion even desirable, I understand it will not use the same "clean" reaction as stellar fusion (deuterium-tritium or D-D vs ordinary hydrogen). Can someone with more knowledge comment on whether this report is accurate? https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre-cracked-up-to-be/ https://thebulletin.org/2017/04/fusion-reactors-not-what-the... To me it seems to annul the entire enterprise (other than as a pure research project) if true?
- ajross 8y ago
  Stellar fusion isn't really clean in the way you imagine; there are lots of reactions in the star core that produce free neutrons, they just get reabsorbed by something else because they can't realistically exit the system like they can in a tiny reactor. Nor is it realistically achievable, anyway. Fusing products out of bare protons just isn't productive enough at achievable temperatures.
  - pfdietz 8y ago
    In a star like the Sun there are very few free neutrons produced. There are non-exploding stars that produce some neutrons, but they are AGB stars where the core gets hot enough for (alpha,n) reactions to occur.
    - ajross 8y ago
      Hm... maybe I'm misremembering, but I swear I saw an analysis that showed neutron loss from a small (i.e. reactor scale) blob of solar core plasma would be comparable to what you get from existing power reactions. It's true that almost all the energy production in the sun happens from reactions that don' t involve neutrons, but the neutrons are flying around nonetheless (and, in a reactor, would fly right out of the containment).
      - pfdietz 8y ago
        What nuclear reaction in the solar core are you imagining would produce neutrons?
chiefalchemist 8y ago
> A fusion power plant, it estimated, “could use only 5 kilograms [11 pounds] of hydrogen to generate the energy equivalent of 18,750 tons of coal, 56,000 barrels of oil or 755 acres of solar panels.” Translation: The coal industry, the oil industry, and the solar industry do __not__ benefit from fusion. Using history as a reference, it's fairly safe to presume they will use their influence to sway any decisions in their best interest.
beezle 8y ago
Lets be honest about fusion - Experts urge the US to continue employing them for another 20 years. And thats coming from someone with a physics background. The fusion industry (and thats what it really is) has managed to string the public and policy makers along for 60 years so I guess why stop trying now. Fusion will never be cheap and won't be clean either.
ngcc_hk 8y ago
“Nuclear fusion is still decade away” ... heard that before. Decade before.
timwaagh 8y ago
I all for research into potentially valuable tech. but we have to consider the fast-falling cost of renewable energy. by the time fusion gets realized at scale, we might not need it anymore.
- Lev1a 8y ago
  Fusion (once realized): steady energy regardless of weather conditions, from maybe a few installations per country Renewables (solar, wind): dependent on weather conditions, would thus require battery farms for backup during wind-still nights or days with overcast etc. In my mind the ideal future scenario is a compromise between both solutions: Have fusion always on and provide a base level of energy production sufficient for need plus a few percent. Then have renewables lower the target for energy production through fusion when available. Then we would not need giant battery farms and renewables would get used to the best of their ability/availability while not restricting energy consumption due to them not being available 24/7. Maybe even leave a select few coal/fission plants available but powered down as a sort of UPS for the energy infrastructure, just in case fusion is N/A and renewables aren't enough to cover the need.
NoblePublius 8y ago
This feels like hydrogen fuel cell tech — “something better on the horizon” that will keep you from investing in the obvious: free energy from the fusion reactor that already works in the sky. I would put every dollar of public fusion research money into solar and battery storage. That works now. The only thing fusion research accomplishes, like HFC, is prolong dependence on carbon energy.
- starbeast 8y ago
  Funny comparison. If you like batteries, fuel cell tech would be one of the places you would want to be putting some of your primary research money.
  - NoblePublius 8y ago
    There is no naturally occurring source of hydrogen. That’s why you see ads for HFC from Shell and Chevron. Hydrogen must be made from oil or gas. Salt water electrolysis doesn’t really work at scale as it requires even more oil and gas. Even if you do SWE with renewable energy, it’s about 22x less efficient than putting the electricity in a battery. We have fusion. It’s in the sky. We don’t need it on earth.
    - starbeast 8y ago
      I'm talking about fully reversible fuel cells for grid storage, not a hydrogen fuels economy. So this kind of thing - https://www.energy.gov/sites/prod/files/2014/03/f11/rev_fc_wkshp_anderson.pdf https://www.energy.gov/sites/prod/files/2014/03/f11/rev_fc_w...
- bigblind 8y ago
  I know extremely little about the subject, but aren't we decennia away from battery storage at the necessary scale as well?
  - NoblePublius 8y ago
    Gigafactory 1 is two years from full production. Gigafactory 2 is five years from full production. Fusion is infinity years from full production
jayalpha 8y ago
While I agree that there is too little money in Fusion research, I would recommend building Thorium reactors. Thorium reactors could be in a production setting, if financed, in less then 5 years.
jillesvangurp 8y ago
A lot of people are saying fusion is still decades away. That might very well be true but it might be centuries away unless we change the way we fund the research. Nuclear fission and fusion research are still happening but there's no sense of urgency at this point and it's not a very popular topic with politicians given the issues with reactors invented half a century a go. Back in those days there was a real sense of urgency and no cost were spared to get things done. Kennedy says go to the moon. Ten years later it's done. The fear of the Russians getting there first drove the US to do amazing things. This stuff doesn't happen by itself and will need a lot of investments and planning to get it done. At this point a reasonable question to ask is whether the US will be the one that makes the breakthrough here. They are not the only ones working on this and arguably it's not a big priority in the US to be working on this at all. What happens when e.g. China gets there first? They are working on this as well and they seem to be getting some results. They are also planning to go to the moon pretty soon. And a lot of the clean energy tech we use comes from them as well.
vasili111 8y ago
If we want to really colonize other planets then we need fusion reactors.
- pfdietz 8y ago
  Why would we need fusion reactors for that? Describe the use case for which they are essential, and I will then tell you why they aren't.

344 points by tshannon 8y ago

devy 8y ago

Nuclear fusion is probably still decades away. But I am going tangent here, nuclear fission still have great potentials. Scientists from the Oak Ridge National Laboratory actually helped China to built Molten Salt reactors in the 70s during Nixon administration. [1] And since then thorium based molten salt Gen IV reactors have been having renewed interests around the global. China actually tested the whole system feasibility in Giga Watts scale in recent years. [2] Nuclear power is vital part of the energy infrastructure to curb worsening environment due to climate change - it's still considered superior than all the other green alternative energies in terms of either 24/7 availability (vs. solar/wind) or massive scale (vs. geothermal) or location restricted (vs. hydro) or carbon-free (vs. biomass/bio-fuel). China realized that in their dire request to transition out their entire energy reliance on carbon-based energies, it's impossible to do without nuclear. Also, newer reactor designs are much safer and last longer so a lot of the concerns of radioactive waste have largely been alleviated. [1]: https://news.ycombinator.com/item?id=10229697 https://news.ycombinator.com/item?id=10229697 (2015) [2]: https://news.ycombinator.com/item?id=17813614 https://news.ycombinator.com/item?id=17813614 (2018)

toomuchtodo 8y ago
> China realized than in their dire request to transition out their entire energy reliance on carbon-based energies, it's impossible to do without nuclear. Also, newer reactor designs are much safer and last longer so a long of the concerns of radioactive waste have largely been alleviated. https://www.technologyreview.com/s/612564/chinas-losing-its-taste-for-nuclear-power-thats-bad-news/ https://www.technologyreview.com/s/612564/chinas-losing-its-... (December 12, 2018 | Sustainable Energy China’s losing its taste for nuclear power. That’s bad news.) HN: https://news.ycombinator.com/item?id=18675453 https://news.ycombinator.com/item?id=18675453 Quick points: Too expensive with necessary safety measures, Chinese citizens don't want it after Fukushima, renewables are already cheaper, and electrical demand growth has declined unexpectedly. My opinion: We should still explore fusion technology and spend on R&D, but fission is already dead. Renewables and storage full speed ahead.
- devy 8y ago
  Fukushima is bad press and also Fukushima was designed and constructed in 1960s, that's Gen I design and let alone they cut corners in safety. Like I said, Gen IV is much much safer and produce much less radioactive wastes. Also nuclear fission might not be relevant if humanity cannot survive after 2040, according to IPCC's climate change report (I am doubtful we will even be able to get nuclear fission power plants commercialized by 2050 TBH.)
  - barney54 8y ago
    Where does the IPCC day the humanity won’t survive beyond 2040?
- kenneth 8y ago
  If fission is dead, then earth is dead. There is no way we'll survive if we continue to burn coal at the rate we do, and renewable don't work at scale yet and storage is not yet solved. Fission is the only thing that can provide us with enough clean energy in the near term (next 50 years).
  - dv_dt 8y ago
    We have to solve the problem in the next 10-12 years. The median nuclear plant construction is 7.5 years, with the US medians being more in the 18-20 year duration - with the very most recent nuclear projects mostly being shut down mid construction because of cost and schedule overruns. Even France, with one the most mature and well run nuclear power programs is concluding that the next wave of power investment makes more sense to make in renewables instead of nuclear. I suspect we will solve our problems with renewables + storage (which are still rapidly declining in cost).
    - Xixi 8y ago
      Regarding France, it seems that we have lost the actual knowledge on how to build nuclear power plants. Which should have been expected given that we stopped building those for quite a while, so of course the know-how is gone. Flamanville, the first EPR in France, was schedule to start running in 2012 for a construction cost of 3.3 billion EUR. It is now expected to start producing electricity in 2020 for a construction cost of 10.9 billion EUR. Emphasis on expected...
sandworm101 8y ago
China's approach to nuclear isn;t just environmentalism. It is largely a national pride project. Fission is an area of science that china knows it can excel in because, frankly, the west isn't doing much. I applaud china's efforts. I think we need fission energy. But I worry national pride isn't reason enough to maintain the program indefinitely. Coal prices are dropping. Will china continue to roll out fission reactors if/when coal falls off the price cliff?
- devy 8y ago
  > It is largely a national pride project It's much less a pride than a survival instinct. Just think about it, Beijing was under siege of heavy smog for over a decade by now. If Washington D.C. was like that for since Trump became the president, would he still advocate coal?
  - jacknews 8y ago
    Though Trump has to worry about those pesky elections.
hirundo 8y ago
> Nuclear fusion is probably still decades away. I wrote that sentence in a 10th grade report on fusion, in 1977. Disappointing that it's likely still true four decades later. In another four decades it's up to you to make this comment. On the other hand, so much has arrived that I never dreamed of in high school, though I consumed scifi obsessively. Not sure I'd swap the internet for cheap fusion energy. But not sure I wouldn't.
- jessriedel 8y ago
  Note that we've never spent as much money as we've always known would be necessary to achieve useful fusion power, so the oft-repeated idea that it's been surprisingly technologically difficult is not actually justified by the historical track record. > Typically, outsiders cannot comprehend how the massive expenditures never manage to yield energy. Typically, insiders cannot comprehend how little is being invested in a project that presents such immense technical obstacles and also such potential. A graph commonly passed around among the insiders—an enduring scrap of twentieth-century budgetary ephemera—depicts the 1976 federal plan to build a working thermonuclear reactor. The graph tracks various scenarios for attaining fusion energy. The “maximum” effort, the most expensive up front, with initial spending as high as nine billion dollars a year, was projected to yield a reactor by 1990. The “moderate” effort, with spending never exceeding four billion dollars in a year, would take fifteen more years. The fusion community might be easy to criticize for its many unmet milestones, but for decades the United States has never come close to even the moderate effort. In 1977, when the American fusion budget was at its peak, government investment in the research, adjusted for inflation, was seven hundred million dollars; by 1991, this had fallen by more than half. It is now half a billion, not appreciably more than the Korean budget. http://www.newyorker.com/magazine/2014/03/03/a-star-in-a-bottle http://www.newyorker.com/magazine/2014/03/03/a-star-in-a-bot... The chart was produced by Energy Research and Development Administration (ERDA), which was later subsumed into the Department of Energy and presumably represented the expert wisdom at the time. It can be found, in 1976 dollars, as figure 1 here: http://www.21stcenturysciencetech.com/Articles_2010/Winter_2009/Who_Killed_Fusion.pdf http://www.21stcenturysciencetech.com/Articles_2010/Winter_2...
  - 8y ago
matt4077 8y ago
This reads like a parody of every thread on nuclear technology on HN or, before it, slashdot. It’s always „decades away“, but there’s always pebble bed/molten salt/thorium/whatever technology that’s far better, basically functional, mostly free, and only held up by those darn environmentalists/idiot politicians/liberals/oil lobby/NIMBYs/Elton John/… It feels like the tech community is forever trapped in the science fiction of the 50s, while actual science (and politicians) have created options that, frankly, are far better in every regard, including costs.
- mywittyname 8y ago
  A major issue is that people on HN are largely ignorant of nuclear power generation. It's largely a bunch of wikipedia-educated people debating youtube-educated people. So none of the discussions are realistic, because there's probably four people on HN with any real world subject matter knowledge. There's not the same blind-optimism to solar power generation.
  - Pica_soO 8y ago
    We like big problems more then big solutions. What we like even less, are small solutions to big problems.
  - ggm 8y ago
    There's not the same blind-optimism to solar power generation. Well.. it's hard to be overtly skeptical to a form of lower intensity power which works at scale, but lower intensity. The only claims to be rebutted are ones which overstate the pace of improvement to the forseen asymptote. What's more baffling is the constant jeremiad of hate against solar wind and battery because of prejudice favouring large centrally managed gigawatts. Nobody disputes big lumps of powerstation are good. What we're doing is fighting an ill informed skirmish inside the linear programming and O/R model of future power, rather pointlessly. I would like nuclear fusion and fission power research to continue. I would like the funding to lower intensity power to continue as well. I would like a grown up conversation about how much each should get annually as funding.
DennisP 8y ago
Also uranium-fueled molten salt reactors, using chloride salt. These will be fast reactors and have pretty much the same advantages as the thorium designs. Terrapower, Moltex, and Elysium are going this route (though Moltex is planning a thorium-fueled version as well).
- qwerty456127 8y ago
  Isn't thorium more abundant than uranium and easier to mine?
  - DennisP 8y ago
    It's three or four times as abundant as uranium, and about 400 times more abundant than U235. However, with fast reactors you can get power from all the uranium, not just the U235. Uranium is currently a small portion of the cost of nuclear, so it can't be that hard to mine, especially after we only need 1% as much for the same amount of power. Either keeps us going for thousands of years, and after that we could extract uranium from seawater until the sun goes out.
ohiovr 8y ago
There was a startup recently for molten salt reactors but didn’t conclude successfully https://www.technologyreview.com/the-download/612193/nuclear-startup-to-fold-after-failing-to-deliver-reactor-that-ran-on-spent-fuel/ https://www.technologyreview.com/the-download/612193/nuclear...
- DennisP 8y ago
  Transatomic claimed to have the fuel utilization of fast reactors without being a fast reactor. That turned out not to be the case. However, there are a bunch of other startups working on molten salt reactors, including Bill Gates' Terrapower, Terrestrial Energy, Thorcon, Moltex, Elysium, and Flibe. The farthest along is probably Terrestrial Energy, which has gotten through the hardest part of Canada's licensing process.
  - ohiovr 8y ago
    I would really like to see the particle beam fission concept explored also due to its versitility and control: https://en.wikipedia.org/wiki/Accelerator-driven_subcritical_reactor https://en.wikipedia.org/wiki/Accelerator-driven_subcritical...
    - pfdietz 8y ago
      It's a niche technology, and doesn't address the main problem of fission (that the reactors are too expensive). At least it serves as a counterargument to those who want to make fusion-fission hybrid reactors.
njarboe 8y ago
There have been a series of breakthrough in helicity injection techniques and the understanding of spheromak physics in the last decade. Some believe that economical fusion power plants are possible with today's technology[1] and need a ~$30 million to prove out a scale model reactor before building a full scale one on the order of $2-3 billion of a 1-2 Gigawatt power plant. This is an order of magnitude less cost that the ITER project, which is spending a lot of money on cement and magnets on a probably doomed technology path of commercial fusion. These same breakthroughs are also likely to be able to produce a fusion engine for spacecraft. This is actually an easier problem to solve than electricity generation as the deuterium can be used as fuel and as a propellant ejected straight out of the plasma core at variable ISP up to around 100,000. No inefficient fusion to electricity to rocket engine cycle is necessary. I am not a fusion scientist, but my father is. For more info and technical references, drop me an email (see profile). [1]https://www.washington.edu/news/2014/10/08/uw-fusion-reactor-concept-could-be-cheaper-than-coal/ https://www.washington.edu/news/2014/10/08/uw-fusion-reactor...
- philwelch 8y ago
  > This is actually an easier problem to solve than electricity generation as the deuterium can be used as fuel and as a propellant ejected straight out of the plasma core at variable ISP up to around 100,000. Jesus. For reference, chemical rockets tend to have ISP in the low-to-mid hundreds, and ion thrusters are in the thousands—not ten thousands, but single thousands. A 100,000 ISP rocket is like a car that can drive from Bangkok to Vladivostok to Lisbon, then back to Istanbul and down to Johannesburg without refueling or recharging. It’s like a phone battery that lasts years rather than days. And it’s all powered by the most plentiful elements in the universe. I’m pretty sure you could generate electricity by flying this rocket around in a circle tethered to an electric turbine if you wanted to. I mean, all of your electricity would probably be in space, because a high ISP usually implies that the rocket doesn’t work as well on the earth’s surface (not as a physical law, just as a limitation of our technology), but of all the monumentally impressive things you can build from a fusion reactor, a 100k ISP rocket has got to be up there. As for ITER, I’m not necessarily bearish on it, but if there’s a credible chance of an alternative design that can be proven for anything <$1 billion...I hate to say it, but any person, venture capital fund, or government with more than $10 billion to their name would be hard pressed to find any better use for it. Even if the damn thing is 95% likely to fail, that’s a 5% chance you literally end up having a stake in the single most valuable technology in the single most valuable sector of the economy—one that will provide untold benefits to mankind. 30 million dollars, really? Like—does Y Combinator know about this? Never mind the “benefits to mankind”—if a single business can be first to market with an economical fusion power plant, that will become the single most valuable business in human history. There’s like five tech companies that are up there in the ranks of “most valuable business in the world”, and they’re approximately the same value as any of about ten oil and gas conglomerates, and those lists usually don’t even count state-owned companies that are even more valuable. (“All the oil in Saudi Arabia”—that’s wealth.) Fusion power would immediately be more valuable than every single oil and gas company in the world put together. Even if nobody bought fusion plants, you could just build the damn things yourself, use them to synthesize hydrocarbons from the damn atmosphere, and undercut the market while simultaneously fixing climate change by making fossil fuel usage a closed loop with no new net CO2 introduced into the atmosphere and an economical method for extracting the excess we already have.
ArtWomb 8y ago
Construction time for nuclear plants average 10-20 years, vs 2-4 years for wind and solar grids. There are other risks to consider as well. From the forthcoming textbook, 100% Clean, Renewable Energy and Storage for Everything https://web.stanford.edu/group/efmh/jacobson/Articles/I/NuclearVsWWS.pdf https://web.stanford.edu/group/efmh/jacobson/Articles/I/Nucl...
derblitzmann 8y ago
If I recall the fusion meme correctly, it is perpetually 10 years from now... Assuming it gets properly funded. Though I also believe that fission research and plants still have their place, especially if you care about carbon emissions.
Krasnol 8y ago
> Also, newer reactor designs are much safer and last longer so a lot of the concerns of radioactive waste have largely been alleviated. ...in countries that are large enough to make it "disappear". Meanwhile normal sized countries are still struggling with old waste and new waste. See Germany. Meanwhile reprocessing as it exists is economically pointless, while it reduces the amounts of highly radioactive material enlarges the amounts of mid and low radioactive material and doesn't help with the stuff that has been insufficiently stored already. Also Sellafield and La Hague are probably polluting water. Hooray...
tim333 8y ago
>Nuclear fusion is probably still decades away Maybe but startups are having a crack at it eg. "UK Atomic Energy Authority and First Light Fusion team up for project that aims to deliver fusion breakthrough by 2024" https://web.archive.org/web/20181206125841/https://www.businessgreen.com/bg/news/3067747/fusion-island-uk-start-up-reveals-plans-for-pioneering-nuclear-fusion-research https://web.archive.org/web/20181206125841/https://www.busin...
cenal 8y ago
There is also a major advancement in disposal technology: http://www.deepisolation.com http://www.deepisolation.com

pmarreck 8y ago

A well-built modern fission plant is far safer and more environmentally-friendly than almost all the other solutions out there save for solar/wind/geothermal. Fusion is the holy grail, though, and with good reason. At least with fusion (as with flight 100+ years ago), we have only to look up during the day to know it's feasible because it's being demonstrated, live, every day!

Retra 8y ago
The sun's fusion is powered by the gravitational attraction of ~10e30 Kg of matter. That is not even remotely an option on Earth, so there is no evidence of feasibility about the energy produced by the sun, aside from the fact that it demonstrates that fusion as a concept makes sense.
- dekken_ 8y ago
  I was asked recently if "I believed in fusion" my response - "I don't think it will cost effective" and what you have posted is basically that reason
- dogma1138 8y ago
  Does it tho? Star fusion produces the exact amount of pressure needed to counter the gravitational attraction which is why they don’t collapse or blow up while the fusion reaction is stable, when it’s not the result isn’t pretty. So in essence stars aren’t energy possitvie (or if so only slightly relative to the energy of the reaction) they just convert one type of energy into another.
  - pfdietz 8y ago
    This argument makes no sense at all. "Pressure" and "power" don't even have the same units. They are entirely different things. Let's try to rephrase things in a way that makes physical sense. There is energy embodied in the Sun. This is the kinetic energy of the electrons and ions that make it up, the energy of the thermal radiation mixed with this plasma, and the (negative) gravitational potential energy. As the sun formed, energy was liberated by gravitational collapse. This heated up the Sun's material and got things going. We know (by the wonderful Virial Theorem) that the negative gravitational binding energy of the Sun is ~2 times the internal energy of its particles and radiation. We can then ask: how does this energy compare to the rate that the Sun is radiating energy? This ratio would give a timescale over which the Sun would cool off, if there was no energy input. This ratio is on the order of ten million years. But the sun is hundreds of times older than this. So, we can conclude the energy yield of the sun, the ratio of fusion energy output to the initial gravitation energy input that heated it up, is pretty darned good, on the order of hundreds.

zachrose 8y ago

At the risk of inciting a flame war that I might not be able to understand, is there any way to characterize current fusion projects against each other? For example, what can be said about the promise of ITER vs Wendelstein 7-x? Part of me realizes that there’s no such thing as a “failed” scientific experiment and that diversity of approaches is good. The other part of me thinks that a public and competitive spectacle would also be good.

dukoid 8y ago
ITER will be an actual tokamak fusion reactor producing energy. Wendelstein 7-X is a plasma containment experiment based on the stellarator design. There will be no fusion. Technology for magnetic enclosure was advanced significantly by both. In this regard, they profit from each other. Tokamak reactors require a pulsed operation mode. There is no way to sustain fusion for longer time. The Stellarators design allows continuous operation, putting less stress on the structure. The calculation of the winded enclosure structure is quite complex and it has only become possible to design and implement with sufficient precision recently. If I'd have to "bet" on a design, it would be Stellarator. If you understand German, listen to this podcast. You won't regret it: https://alternativlos.org/36/ https://alternativlos.org/36/
- DennisP 8y ago
  People keep saying Wendelstein won't do fusion but that's not the case. Currently the 7-X isn't doing fusion because they're using hydrogen. But they plan to use deuterium later, just like all the other fusion research reactors, and they'll get fusion reactions when they do. There's really no reason not to; you get more data and it's easy. People fuse deuterium in their garages with home-built fusors.
  - sterlind 8y ago
    Exactly! AFAICT, the trickiest unknown is maintaining plasma stability and not degrading the insides (and then, breaking even on power while doing so.) Wendelstein seems to be on track to steady-state operation; they've held plasma for 100s, and their graphite shielding seems to be delivering cleaner plasma streams. The design for the 7-X wasn't feasible until supercomputers got powerful enough. We know how to run those simulations; fusion should get more practical as computers get faster.

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aftbit 8y ago

I suspect we will transition to PV before fusion actually becomes viable. Even if we had a working net-positive-energy-balance fusion plant today, it would be incredibly complicated and expensive to build and maintain. The temperatures and energies involved are simply massive. On the other hand, we already have a giant self-sustaining fusion reaction happening in our sky. We can throw down some solid state and increasingly cheap panels to collect that energy. Regardless, we should continue to invest in fusion, but we should also invest in PV research, especially into ways to decrease cost and complexity of manufacturing solar cells.

scrumbledober 8y ago
PV just doesn't scale in the same way. There's only so much surface area to cover in panels. The power density of fusion is so many orders of magnitude larger that even with cheap reliable solar panels I think there will always be a use for working fusion
- adrianmonk 8y ago
  If nothing else, it could be useful for portability. You can't make a solar powered aircraft carrier. You might be able to make a fusion-powered one.
  - cagenut 8y ago
    you say that like its a bad thing
    - mmirate 8y ago
      Oh, it is a bad thing, very much so. The more efficiently we can maintain the U.S. Navy, the bigger we can keep it, and the less likely it is that some smaller nation will threaten the balance-of-power by pulling a competitively-sized navy out of their butts.
  - pfdietz 8y ago
    Fusion has very bad power density compared to fission, so a fusion-powered ship would be idiotic.

b_tterc_p 8y ago

I get that fusion can theoretically transform vast quantities of stuff into useful energy. Can anyone comment on how scalable it would be if proven viable? Can it be built on a large scale profitably? Can it be built to serve remote locations off major grids? Can we ship it in reasonably sized space ships and use it to build bases elsewhere? Can we write off low energy costs to just churn on some sort of climate saving terraformer?

swebs 8y ago
>Can it be built to serve remote locations off major grids? No, fusion reactors are required to be a certain (very large) scale before they can provide a net output of energy. You can find kits online to build an actual fusion reactor in your garage, but it will consume more energy than it produces.
- pontifier 8y ago
  CURRENT fusion reactors are required to be very large scale... I've got a design that might scale down to the size of a D cell battery, or smaller. It's completely untested due to lack of funds, but on paper I haven't found enough flaws to count it out.
  - Dylan16807 8y ago
    So will you say what you plan to trigger the fusion with? And let's say you build one into a 1-liter box. How many watts should we expect it to produce?
scrumbledober 8y ago
Fusion scales incredibly well. For a given working reactor design, efficiency increases with size. I think viable working fusion would lead to a more interconnected grid because of this as opposed to smallscale fusion reactors being deployed in semi-remote areas. On the other hand truly difficult to reach places would be perfect for fusion as once it's built it takes very little fuel to run.

AcerbicZero 8y ago

I have no idea if nuclear fusion is feasible in the near future, or what kind of timeline is required, but I don't see any downside to spending money on projects like this. Pure scientific pursuits seem to be fund able at relatively low prices, with massive upsides and no obvious downsides, other than the opportunity cost of the money being spent.

pfdietz 8y ago
Fusion absolutely will not be feasible in the near future. We don't even have the materials that would be needed to build them. In any other field of engineering, lack of materials is a showstopper, and new material development is always painful and slow. And if you examine any of the designs with a skeptical eye none of them seem promising, and all involve lots of handwaving.
- dwaltrip 8y ago
  You are saying that ITER will fail?
  - pfdietz 8y ago
    ITER cannot lead to an economically competitive reactor, even if it achieves every one of its stated operational goals. It's a massive dead end waste of money.
    - dwaltrip 8y ago
      Although I happen to disagree, that is a different, more reasonable critique than your original comment.
      - pfdietz 8y ago
        My original comment is entirely reasonable. Fusion faces generic obstacles that are likely unsolvable, and certainly unsolvable in the near term. Consider the problem of tritium breeding. Fusion reactors have to make their own tritium -- T from fission reactors would be far too expensive -- but tritium breeding blankets cannot be tested without a working fusion reactor. And the requirements for the breeding blankets are seriously constraining. They must achieve some neutron multiplication (from (n,2n) reactions of energetic fusion neutrons) to offset losses, not lose too many neutrons to penetrates/parasitic capture, and be able to give up the produced tritium fairly quickly. And there are very strict limits on how much tritium can be lost to permeation into reactor materials (or lost from the reactor exhaust, since ~99% of the injected tritium doesn't fuse). No one knows how to do this, or if it can be done economically, or even if it can be done at all. And I repeat: testing it is going to require a working fusion reactor! This circular dependency in development will be painful to run around, and won't happen quickly. Then there's the matter of materials that can withstand prolonged exposure to fusion neutrons. These materials have not been developed, in part because this again requires something close to a working fusion reactor (at least, something with Q at least ~0.1), and much painful rebuilding as that reactor, built with less adequate materials, destroys itself over time. This material development will not be fast, so we will not have working, practicl fusion reactors soon. Even when all that is solved, the fundamental problem of fusion -- low volumetric power density -- remains. That alone seems insurmountable. When you see a fusion reactor design, ask what this power density is. For ITER, it's 0.05 MW/m^3. For ARC or Lockheed's design, it's around 0.5 MW/m^3. These are very bad compared to fission reactors. A final point: the complexity of the irradiated part of a fusion reactor (the part that's too radioactive for hands-on maintenance) will be MUCH higher than that of the similar part of a fission reactor. Reliability is going to be an enormous problem. Making fusion reactors reliable enough for them to be practically interesting, even if all other problems were solved, will take much experience and time.

hsnewman 8y ago

I unfortunately believe that this is a dead issue given the current administration. Unless Fusion will increase the carbon footprint and line the pockets of certain individuals, I see no support by the U.S. government. I for one want the support to continue.

rpiguy 8y ago
Trump and the Republican congress doubled fusion funding in the May omnibus bill, literally saving ITER from having to delay again. Republicans have always been solidly for nuclear power and its derivatives because the only companies with the capital and guaranteed future cashflows to build nuclear fission or fusion plants are the existing energy companies, who have traditionally aligned with Republicans.

dogma1138 8y ago

Do we even had a model for Fussion that is energy poasitive? The only Fusion reactors we know to work, work by converting gravitational potential energy into light/heat through fusion this is how stars operate. All fusion reactions so far require an external input of energy not only to start them but often to sustain them and even those which are self sustaining for a short period of time grind to a halt once you try to extract energy from the system. So in all honesty while I’m not by any stretch of the imagination an expert in fusion physics I can at least understand conservation laws, does any of the current experiments even relies on a model that is at least proven in principle to be energy positive?

dogma1138 8y ago
To the trolls downvoting all the questions here stellar fusion works because of hydrostatic equilibrium which is maintained between gravity and the outbound pressure of the fusion reaction of a star. ∆P · A = −GM(r)m http://www.ucolick.org/~woosley/lectures_fall2012/lecture12.12.pdf http://www.ucolick.org/~woosley/lectures_fall2012/lecture12.... So essentially they are giant springs in space that convert one form of energy into another by fusing matter. Now I hope someone would be able to answer my actual question regarding the energy positive fusion models.
- strainer 8y ago
  That was bad luck with the downvoting, I have heard the gravitational narrative of stellar evolution and element creation before, perhaps in a Feynman lecture? I recall the idea that a cloud of hydrogen atoms has more gravitational potential than the equivalent cloud of heavier elements, basically because the matter is more evenly dispersed. It seems to make a certain sense. Particles get very fast when they close distance, if they can then stick together their kinetic energy has to become something. Interesting to calculate the gravitational energy involved in a neutron and proton getting close enough to be held by each others nuclear forces, beginning from an average separation of say a few microns? I know they have to get through repulsive nuclear forces in order to stick, I don't know if the reaction always liberates kinetic energy. Maybe it depends on what element results. An interesting topic of stellar fusion should be supernova reaction/s. The creation of heavier elements there can clearly release enough kinetic energy to explode the condensed body. Does that energy owe to the distance that has been closed by particles forming heavier elements, or to loss of mass in the nuclear reactions? I wonder about the gravitational energy of a cloud of billard balls rather than atoms. If another cloud has the same volume but half the number of larger balls that are twice as heavy. I guess if the two clouds have the same size, weight and density, they have the same gravitational potential - if they start cold, they will both implode with the same force at the center. But this seems to contradict the narrative that conversion of hydrogen to helium should consume or liberate that potential energy.

ohiovr 8y ago

Just because deuterium is cheap doesn’t mean Fusion energy plants will be anywhere near economically competitive with conventional power sources even most renewables. Many of the presumed benefits such as waste control are not as rosey as most people believe. It is clear now that plant scaling with known methods are entirely dependent on magnetic field strength. More powerful magnets will mean more hope for tokamaks. Entirely new designs are probably not what the doctors are ordering because nothing of the sort is anything close to a surefire success in the wings. So many concepts have come and gone. Tokamak was the closest they ever got. Look at the plant schematics. Its like building a furnace from a humongous collection of delicate swiss watches.

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pfdietz 8y ago
Even with powerful magnets, the power density of a fusion reactor is limited by what the first wall can withstand, and will always suck compared to fission reactors. There's little hope a fusion reactor will be able to compete with fission, never mind the technologies that are beating fission. What high fields might do is allow use to make small, uncompetitive fusion reactors, instead of large, uncompetitive fusion reactors.
- ohiovr 8y ago
  Correct and 17 tesla magnets are already hugely powerful. Its a tremendous amount of structural stress. If it quenches it can explode!

sien 8y ago

The full report can be read at : https://www.nap.edu/read/25331/chapter/1 https://www.nap.edu/read/25331/chapter/1

DrNuke 8y ago

Fusion is a materials science problem and materials informatics (machine learning methods for improving properties and / or devising new alloys) will help immensely once a new generation of digital-native scientists comes into the working force. Fusion might not become economically viable for a long time yet, though, so investments could very probably be moved elsewhere sooner than later. Healthcare for aging populations in the West and a new space race from China come quickly to my mind as powerful “distractions” from ITER part II, in the case part I ignition goes well by 2030. Smaller, more efficient reactors would not solve the energy problem even if they go successfully past the laboratory stage, in that being out of question imho.

pfdietz 8y ago
Distractions from ITER would be welcome. The power density of ITER is ~0.05 MW/m^3, some 400x worse than the power density of an LWR reactor vessel (and 2000x worse than the power density of the LWR core inside that reactor vessel). It's a project where research money goes to die, and new materials are not going to help that.
- DrNuke 8y ago
  Power density is irrelevant for fusion, though: you will never exhaust fusion “fuel” on planet Earth. It will never be an efficiency problem, like it is for fission aka uranium.
  - pfdietz 8y ago
    No, power density is very important, since it directly affects how expensive fusion reactors will be. The cost of a machine is a function of its complexity and size; fusion reactors will be both much larger and much more complex than fission reactors of the same power output.
    - DrNuke 8y ago
      Possibly yes but, even the case, the US, the UK, Japan and France would switch to fusion immediately, if feasible, to get rid of fission and its waste. Renewables & nuclear are the perfect mix to contain greenhouse gases emissions, that’s why the debate is so hot.

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AngryData 8y ago

I don't think we have a choice. Human activities are currently completely dependent upon the availability of energy. Right now most of that energy comes from non-renewable sources and is limited. Our only other choice besides nuclear technologies is covering large portions of our planet's surface with solar panels, which in itself might cause problems because they will shade out plants and change weather and climate patterns as they scale. Traditional nuclear plants get us quite aways farther, but have their own risks, and still require absolutely enormous mining fields which isn't ideal. Fusion power however is the holy grail of energy production. We can go pretty much anywhere and find plentiful sources for fuel. Of course this is assuming small fusion reactors will ever actually work, but we have yet to find a hard limit or insurmountable barriers. We have been progressing slowly but consistently but the payoff would be world changing, potentially even galaxy changing int he longer run.

lutorm 8y ago
covering large portions of our planet's surface with solar panels Have you calculated it? If I recall correctly, it's actually not a large portion at all. It's large in the sense that it would be a large infrastructure project, but it's not larger than the combined area already covered by buildings.
- neolefty 8y ago
  Yes. I think the main limitation is not land use — rather: political will, energy storage, transport, manufacturing, and power leveling.
- AngryData 8y ago
  That is assuming we keep similar power usages as today, but many of our largest industries are consuming unaccounted for fossil fuel energy. Fertilizer for example, fossil fuels are used as a reagent in creating artificial fertilizer, on top of already huge energy costs. The energy required to make fertilizer out of the air and water, rather than fossil fuels, is 100x more at best case. 60% of our total crop yield is the result of artificial fertilizer. Then look at plastics, how much more energy is required to create nonfossil fuel hydrocarbon precursors? You can make hydrocarbons from trees, but it might take an entire tree just to make a few cheap plastic containers. Many other industries are also powered by mined and drilled organic fuels and minerals, but are still fairly limited in availability, at least for such cheap prices/energy requirements anyways which will rise into the future. Building solar panels to power our planet today isn't insurmountable, but what about 20 years from now? 50? 100? Power costs are the limiting factor in many industrial processes, including farming, steel and aluminum production, aviation and rocketry, indoor farms, plastics, and nearly every other form of material synthesis. Don't get me wrong, im not advocating against solar power in anyway, however I don't think it is an effective source for powering our largest industrial processes into the future. Even a small 10 man ceramics shop can draw enough power that they need to call up the local power companies before they turn their large furnaces on, I see no reasonable way of storing and supplying those kind of immense power requirements with solar panels and current storage technologies in any economical way.

dicroce 8y ago

We should be funding the shit out of Fusion and molten salt fission reactors. We're gonna also need to build shitloads of carbon scrubbers and water desalinization plants.

robertAngst 8y ago
This reminds me of the confidence Alt-coiners had in their alt coins.
neolefty 8y ago
If our goal is basic research, sure, fusion is great. But if our goal is to achieve carbon neutrality ASAP, we can't count on fusion to help because we don't know when it will start working. On the other hand, renewables + battery leveling are here today and ready for intensive investment. Yes, let's do both. But I don't believe fusion research will provide a short-term alternative to CO2-emitting power sources. I think it's fine with to spend 1000x on conventional renewables compared to fusion. We can employ an absolute army of technicians and factory workers today to build out renewable generation infrastructure, while fusion gets a steady research budget for post-docs, career physicists, materials engineers, etc.
- jcranberry 8y ago
  What about fission reactors?

jacknews 8y ago

Is terrestrial fusion even desirable, I understand it will not use the same "clean" reaction as stellar fusion (deuterium-tritium or D-D vs ordinary hydrogen). Can someone with more knowledge comment on whether this report is accurate? https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre-cracked-up-to-be/ https://thebulletin.org/2017/04/fusion-reactors-not-what-the... To me it seems to annul the entire enterprise (other than as a pure research project) if true?

ajross 8y ago
Stellar fusion isn't really clean in the way you imagine; there are lots of reactions in the star core that produce free neutrons, they just get reabsorbed by something else because they can't realistically exit the system like they can in a tiny reactor. Nor is it realistically achievable, anyway. Fusing products out of bare protons just isn't productive enough at achievable temperatures.
- pfdietz 8y ago
  In a star like the Sun there are very few free neutrons produced. There are non-exploding stars that produce some neutrons, but they are AGB stars where the core gets hot enough for (alpha,n) reactions to occur.
  - ajross 8y ago
    Hm... maybe I'm misremembering, but I swear I saw an analysis that showed neutron loss from a small (i.e. reactor scale) blob of solar core plasma would be comparable to what you get from existing power reactions. It's true that almost all the energy production in the sun happens from reactions that don' t involve neutrons, but the neutrons are flying around nonetheless (and, in a reactor, would fly right out of the containment).
    - pfdietz 8y ago
      What nuclear reaction in the solar core are you imagining would produce neutrons?

chiefalchemist 8y ago

> A fusion power plant, it estimated, “could use only 5 kilograms [11 pounds] of hydrogen to generate the energy equivalent of 18,750 tons of coal, 56,000 barrels of oil or 755 acres of solar panels.” Translation: The coal industry, the oil industry, and the solar industry do __not__ benefit from fusion. Using history as a reference, it's fairly safe to presume they will use their influence to sway any decisions in their best interest.

beezle 8y ago

Lets be honest about fusion - Experts urge the US to continue employing them for another 20 years. And thats coming from someone with a physics background. The fusion industry (and thats what it really is) has managed to string the public and policy makers along for 60 years so I guess why stop trying now. Fusion will never be cheap and won't be clean either.

ngcc_hk 8y ago

“Nuclear fusion is still decade away” ... heard that before. Decade before.

timwaagh 8y ago

I all for research into potentially valuable tech. but we have to consider the fast-falling cost of renewable energy. by the time fusion gets realized at scale, we might not need it anymore.

Lev1a 8y ago
Fusion (once realized): steady energy regardless of weather conditions, from maybe a few installations per country Renewables (solar, wind): dependent on weather conditions, would thus require battery farms for backup during wind-still nights or days with overcast etc. In my mind the ideal future scenario is a compromise between both solutions: Have fusion always on and provide a base level of energy production sufficient for need plus a few percent. Then have renewables lower the target for energy production through fusion when available. Then we would not need giant battery farms and renewables would get used to the best of their ability/availability while not restricting energy consumption due to them not being available 24/7. Maybe even leave a select few coal/fission plants available but powered down as a sort of UPS for the energy infrastructure, just in case fusion is N/A and renewables aren't enough to cover the need.

NoblePublius 8y ago

This feels like hydrogen fuel cell tech — “something better on the horizon” that will keep you from investing in the obvious: free energy from the fusion reactor that already works in the sky. I would put every dollar of public fusion research money into solar and battery storage. That works now. The only thing fusion research accomplishes, like HFC, is prolong dependence on carbon energy.

starbeast 8y ago
Funny comparison. If you like batteries, fuel cell tech would be one of the places you would want to be putting some of your primary research money.
- NoblePublius 8y ago
  There is no naturally occurring source of hydrogen. That’s why you see ads for HFC from Shell and Chevron. Hydrogen must be made from oil or gas. Salt water electrolysis doesn’t really work at scale as it requires even more oil and gas. Even if you do SWE with renewable energy, it’s about 22x less efficient than putting the electricity in a battery. We have fusion. It’s in the sky. We don’t need it on earth.
  - starbeast 8y ago
    I'm talking about fully reversible fuel cells for grid storage, not a hydrogen fuels economy. So this kind of thing - https://www.energy.gov/sites/prod/files/2014/03/f11/rev_fc_wkshp_anderson.pdf https://www.energy.gov/sites/prod/files/2014/03/f11/rev_fc_w...
bigblind 8y ago
I know extremely little about the subject, but aren't we decennia away from battery storage at the necessary scale as well?
- NoblePublius 8y ago
  Gigafactory 1 is two years from full production. Gigafactory 2 is five years from full production. Fusion is infinity years from full production

jayalpha 8y ago

While I agree that there is too little money in Fusion research, I would recommend building Thorium reactors. Thorium reactors could be in a production setting, if financed, in less then 5 years.

jillesvangurp 8y ago

A lot of people are saying fusion is still decades away. That might very well be true but it might be centuries away unless we change the way we fund the research. Nuclear fission and fusion research are still happening but there's no sense of urgency at this point and it's not a very popular topic with politicians given the issues with reactors invented half a century a go. Back in those days there was a real sense of urgency and no cost were spared to get things done. Kennedy says go to the moon. Ten years later it's done. The fear of the Russians getting there first drove the US to do amazing things. This stuff doesn't happen by itself and will need a lot of investments and planning to get it done. At this point a reasonable question to ask is whether the US will be the one that makes the breakthrough here. They are not the only ones working on this and arguably it's not a big priority in the US to be working on this at all. What happens when e.g. China gets there first? They are working on this as well and they seem to be getting some results. They are also planning to go to the moon pretty soon. And a lot of the clean energy tech we use comes from them as well.

vasili111 8y ago

If we want to really colonize other planets then we need fusion reactors.

pfdietz 8y ago
Why would we need fusion reactors for that? Describe the use case for which they are essential, and I will then tell you why they aren't.