[HN Gopher] Korean nuclear fusion reactor achieves 100MdegC for ...
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Korean nuclear fusion reactor achieves 100MdegC for 30 seconds
Author : yreg
Score : 263 points
Date : 2022-09-07 19:58 UTC (3 hours ago)
(HTM) web link (www.shiningscience.com)
(TXT) w3m dump (www.shiningscience.com)
| gerdesj wrote:
| When I was at school in Abingdon, Oxfordshire (UK) around 1988 my
| physics class (A level aged 17) was somewhat enlivened by a visit
| by a bunch of clever chaps from JET at the Culham labs from up
| the road.
|
| This was the first time I heard the "nuclear fusion is 25 years
| away" joke and it was told as such. We were also shown a graph of
| how many orders of magnitude away from ignition (for want of the
| correct word) by date. It had an initial steep decline but then
| turned right quite sharply and had annoying looking tendency to
| avoid the magic value.
|
| Now, once you have ignition, you have to sustain it and extract
| power from it. That's quite tricky too!
| cygx wrote:
| _We were also shown a graph of how many orders of magnitude
| away from ignition (for want of the correct word) by date_
|
| See p.4-5 of [1] for more recent plots. It includes earlier
| runs of both KSTAR (the experiment under discussion) and EAST
| (the Chinese one mentioned in another comment), but not their
| most recent ones.
|
| [1] https://arxiv.org/abs/2105.10954
| zamadatix wrote:
| For those wanting a quick in browser glance:
| https://i.imgur.com/z7MRk5X.png
| elihu wrote:
| > "This team is finding that the density confinement is actually
| a bit lower than traditional operating modes, which is not
| necessarily a bad thing, because it's compensated for by higher
| temperatures in the core," he says. "It's definitely exciting,
| but there's a big uncertainty about how well our understanding of
| the physics scales to larger devices. So something like ITER is
| going to be much bigger than KSTAR".
|
| This made me wonder when ITER was going to actually be up and
| running. From wikipedia:
|
| > "The reactor was expected to take 10 years to build and ITER
| had planned to test its first plasma in 2020 and achieve full
| fusion by 2023, however the schedule is now to test first plasma
| in 2025 and full fusion in 2035."
|
| So, it sounds like it'll start doing something within a few
| years, but it'll probably be a long time before it produces
| significant scientific results.
|
| By the time ITER is running, maybe some other group will beat
| them to it (like the MIT ARC or SPARC reactors, which use more
| recent, better superconductors and don't need to be anywhere near
| as big).
|
| https://en.wikipedia.org/wiki/ITER
| scifibestfi wrote:
| Let's say they manage to scale this up. What effect would it have
| on humanity? Climate change is solved. What else?
| [deleted]
| sien wrote:
| With the knowledge that comes out of building fusion power
| plants the next thing to build is fusion rockets.
|
| https://en.wikipedia.org/wiki/Project_Daedalus
| MichaelCollins wrote:
| Little effect I think. Fusion power can do little that fission
| power can't do already, which is provide "free" power after you
| look past the cost to build and maintain the plant. The best
| advantage of fusion power is the public perception is presently
| better.
| ithkuil wrote:
| Is the safety profile any better? Or is it just public
| perception?
| cygx wrote:
| There are major differences. For one, in case of
| catastrophic failure, the plasma will dissipate, its
| temperature will drop and the fusion reaction will stop.
| AnimalMuppet wrote:
| This. The hard part is keeping it going, not getting it
| to stop.
|
| Also, if I understand correctly, the waste products are a
| lot less nasty.
| wizofaus wrote:
| > The hard part is keeping it going, not getting it to
| stop.
|
| I'm rather glad that doesn't apply to the fusion reactor
| in the sky that we'll be fully dependent on for a while
| yet.
| MichaelCollins wrote:
| It's a lot easier to build passively safe fission power
| plants than _any_ sort of fusion power plant.
|
| https://en.wikipedia.org/wiki/Passive_nuclear_safety
| u320 wrote:
| The safety profile is better with fusion, but I think you
| underestimate how good the safety profile of nuclear is
| these days. We haven't had any significant incidents since
| Fukushima, but we upgraded the safety mechanisms of our
| nuclear plants a lot based on that experience. Nuclear is
| on a path similar to flight, were we started off with very
| risky airline travel and got to a point where you are more
| likely to suffer an accident on the taxi on your way to the
| airport.
| coffeeblack wrote:
| Fission power is already the second safest form of energy
| production, after hydro.
| 93po wrote:
| At least one source saying hydro causes more deaths than
| fission:
|
| https://www.businessinsider.com/dam-safety-statistics-
| risk-o...
| ok_dad wrote:
| The lack of major radioactive waste is a plus, only the
| pipes and stuff inside the core of the reactor will have
| radioactive elements due to neutron activation. The only
| waste from it otherwise is helium (and tritium, which is
| re-used in the reaction later).
| rosywoozlechan wrote:
| isn't helium valuable? seems like a good "waste" to
| produce
| OJFord wrote:
| Yeah that's GP's point by the 'only'. It's 'waste' as in
| a byproduct.
|
| It's part of the reason fusion's so sought after - it
| doesn't result in anything bad or that has to be
| carefully sequestered.
|
| (Apart from extraordinary heat I suppose. Perhaps there's
| an argument the actual reactor would always be a pretty
| risky place. But any incident isolated at least, worst
| case a remote industrial building burns down beyond
| economical repair.)
| Apocryphon wrote:
| Safe airships for all!
| throwaway0a5e wrote:
| Doesn't matter.
|
| Public perception > reality.
|
| Look at hydroelectric. Terrible for ecosystems, decent
| number of deadly failures over the years, way better
| perception and less pushback from the public than fission.
| z3rgl1ng wrote:
| Jevon's paradox implies we'd have a brief respite,
| chronologically speaking, before having to tackle something
| like heat shedding.
| hinkley wrote:
| Climate change not solved. This is another in our long series
| of silver bullets.
|
| Greenhouse gases retain heat. Sea level temperature is a
| function of ambient heat due to sunlight and other heat
| sources, minus the rate at which it dissipates into outer
| space, mediated by the insulation effect of the atmosphere.
|
| Projects that try to reduce the carbon intensity of energy are
| focused on changing the denominator in the equation. The
| current aim of these projects is to produce a cheap and
| plentiful energy source, via a heat engine. What they are
| actually chasing, whether they admit it to themselves or not,
| is a cheap and plentiful heat source. If they succeed they
| change both the numerator and the denominator, which ends up
| partially cancelling each other.
|
| Wind and solar are different because they tap into an existing
| heat engine, instead of trying to build a new one.
|
| What we as a people need is a fusion plant that costs less per
| KWH than a fossil fuel power plant with tariffs to account for
| the cost of the carbon dioxide, but still about as expensive as
| a fossil fuel plant where the carbon is free. If we actually
| got a fusion plant that was 10x more cost efficient then we'll
| just introduce the concept of heat pollution to the
| conversation, swapping out the villain in the story but keeping
| the same outcome.
| robertlagrant wrote:
| Adding some invented constraints on to the problem of nuclear
| fusion is the most bikesheddy thing I've ever read.
| hinkley wrote:
| What invented constraints? We've been chasing nuclear
| fusion since long before we really cared about greenhouse
| gas emissions. We want 'cheap and plentiful power'.
| Greenhouse gas intensity is a recent addition to the set of
| goals. It doesn't replace the existing motives, and to
| claim otherwise is greenwashing.
| 93po wrote:
| Are you saying the heat output of a fusion generator would be
| so great that it would impact climate change?
| hinkley wrote:
| If you give people a generator that produces "cheap and
| plentiful energy"? Absolutely. Total world power
| dissipation increases as fast as they can build the plants.
| If we never produce another molecule of CO2 again we might
| be okay in that situation, but things like that don't
| change overnight.
|
| edit: conclusion
|
| edit again: I'm extrapolating from
| https://en.wikipedia.org/wiki/Jevons_paradox but didn't
| remember what it was called
| coffeeblack wrote:
| Question is, how much will the kWh cost, all costs considered.
| And how much time does it take to build.
| quonn wrote:
| Long term, yes. But much of the climate change problem is
| decided in the next 25 years. Even if this reactor would work
| right now, building enough of them in that time frame
| everywhere, switching all industry and factories to electric,
| switching all transportation and cars and heating systems in
| all the houses to electric is very tough.
|
| So it's still very challenging.
| notfish wrote:
| Exactly. I'd also add that climate change is a just a symptom
| of us reaching the natural carrying capacity of Earth for
| humans, so adding new ways of generating power doesn't
| completely eliminate the issue.
| vanviegen wrote:
| Very true. Though an abundance of cheap energy may prove
| helpful in brute force engineering some other problems out
| of existence. I'm thinking of recycling and geo-engineering
| in particular.
| u320 wrote:
| Can you explain what you mean by "the natural carrying
| capacity of Earth for humans". You framed this like it's
| something that exists outside of technology.
| elf25 wrote:
| Schroedingersat wrote:
| Peak everything is happening over the next little while.
|
| Direct thermal climate foring is a couple of orders of
| magnitude out from current energy use.
|
| Classical computing is almost finished.
|
| Many minerals are at the point where extraction takes a
| rapidly increasing amount of energy per tonne.
|
| Land used for grazing and agriculture is over half of
| habitable land.
|
| Fishing is wiping out entire ecosystems.
|
| It's time to think about moving earth to a steady state
| economy.
| Schroedingersat wrote:
| > What effect would it have on humanity? Climate change is
| solved.
|
| Not really. It'll just be another tool for the fossil fuel
| lobby to use to misdirect attention from what will make them
| irrelevant forever (reduction and sunlight).
|
| Even if the reactor part is free and 100% reliable. Getting
| heat out of a 100 million degree chamber that is spewing
| neutrons everywhere and turning it into electricity is much
| much harder and more expensive than collecting some photons and
| building a train.
| alas44 wrote:
| Climate change has inertia so probably not solved by the time
| we have industrial scale fusion + would not solve the two other
| main anthropic activity related problems: biodiversity loss and
| depletion of natural resources
| wizofaus wrote:
| Would depletion of natural resources be so much of an issue
| if we could use fusion to recreate them? (after all, they
| didn't come into existence by magic...) Biodiversity is a
| bigger problem given the sheer levels of complexity and our
| relatively poor understanding of exactly how we depend on the
| exact make-up of the biosphere. Most likely humanity could
| survive without it, but it would be a poor sort of existence
| - our bodies and brains evolved in tandem with the huge
| diversity of life around us and is optimised to thrive in
| that context.
| blibble wrote:
| with unlimited cheap energy you can pull CO2 out of the
| atmosphere, produce hydrocarbons and pump them back into the
| wells
| macksd wrote:
| I don't know what the math looks like here, but there is
| waste heat in this, right? We could lower CO2, but
| "unlimited cheap energy" at the scale required to make a
| dent in climate change surely gives off a pretty phenomenal
| amount of heat. I wonder what the equation looks like for
| the overall effect on the planet.
| blibble wrote:
| my understanding of chemistry is poor, but presumably if
| energy is liberated from combustion, reversing that
| reaction requires energy
|
| (with some input to kick it off possibly)
|
| regardless, the earth receives 173,000 TW of solar
| radiation from the sun
|
| we have a way to go yet
| ben_w wrote:
| One could, but this is unlikely to actually be done unless
| there is an economic incentive, which is basically why
| everyone put the CO2 into the air in the first place
| despite knowing the consequences.
| blibble wrote:
| carbon credits and carbon trading were invented, what,
| twenty years ago?
| ben_w wrote:
| Indeed, and look how effective they've been.
| blibble wrote:
| extremely effective indeed?
|
| (where implemented)
|
| with unlimited clean energy you'd be able to print carbon
| credits as a result of direct hydrocarbon sequestration
| anon291 wrote:
| better yet... you can kep current hydrocarbon economy
| factories, vehicles, etc in operation by simply producing
| fuels from air. Wil be cheap enough. Hydrocarbons are a
| great, usable source of dense energy.
| X6S1x6Okd1st wrote:
| I really don't think all we need is cheap energy, it's
| still an economically unproductive thing to do, so you need
| a govt to tax people and use the $ to perform
| sequestration.
|
| You need to build out the sequestration plants, maintain
| and run them, only one of those inputs is cheap energy. You
| need to move the carbon to a safe storage facility etc.
|
| It's still a huge undertaking, but would be way simpler if
| we had cheap electricity (which it seems like we will get
| via solar anyways, carbon sequestration could probably be
| turned on and off as needed for grid conditions)
| blibble wrote:
| > You need to move the carbon to a safe storage facility
| etc.
|
| fortunately we already have millions of holes we drilled
| in the ground to get the stuff we burnt originally
| ahmedk92 wrote:
| My layman understanding tells me depletion of natural
| resources will be worse if we manage to find a sustainable
| source of energy.
| mihaifm wrote:
| Cheap energy means lower costs of manufacturing therefore lower
| prices for consumer goods, thus increasing quality of life.
| u320 wrote:
| There is no reason a priori to assume fusion power will be
| cheap. On the contrary, everything we know about it now
| suggests the opposite.
| haliskerbas wrote:
| At least in North America, things tend to maximize corporate
| profits rather than maximize quality of life.
| robertlagrant wrote:
| They are aligned, at least for those things where consumers
| are the purchaser.
| mmahemoff wrote:
| Terraforming, space exploration. On the compute side, running
| extremely fine grained simulations.
| lake_vincent wrote:
| "While the duration and temperature alone aren't records, the
| simultaneous achievement of heat and stability brings us a step
| closer to a viable fusion reactor - as long as the technique used
| can be scaled up."
|
| Half of the engineers on HN right now:
|
| [...as long as the technique used can be scaled
| up...](PTSD_Chihuahua.jpg)
| rr888 wrote:
| There was a positive fusion article in the WP a few weeks back.
| https://www.washingtonpost.com/technology/2022/08/26/nuclear....
| Looks like things are finally happening.
| rjzzleep wrote:
| It's interesting to see that South Korea has such strong nuclear
| research facilities. Taiwan lost a lot of nuclear researchers in
| the past decades. Some of it due to US lobby work and some of it
| due to stupid governmental policies in the recent past. Japan
| which is also quite strong in nuclear seems to be trying to sell
| part of their nuclear industry, a move which turned out
| disastrously for the french.
| cyclingfarther wrote:
| What do South Korea, Taiwan and Japan have in common? Hint: it
| starts with C.
|
| Which is why all three have/had such strong nuclear expertise.
|
| https://en.m.wikipedia.org/wiki/Nuclear_latency
| jimhi wrote:
| Can you spell that out?
|
| They are near / wary of China? That is why they have nuclear
| expertise?
| yongjik wrote:
| South Korea also wasted recent years trying to shut down
| nuclear reactors and painting the nuclear industry as evil
| anti-environmental cabals. It's infuriating that Korea's
| politics is governed by either conservatives (who think
| environmental regulations should bend over for industries) or
| liberals (who think it's "eco-friendly" to shut down nuclear,
| when 44% of the electricity is coming from freaking coal).
| onlyrealcuzzo wrote:
| > a move which turned out disastrously for the french.
|
| Any more to add?
|
| IIUC, France has one of the highest percentages of nuclear
| energy of any country in the world.
|
| Is this supposed to be bad?
| rjzzleep wrote:
| More than half of their reactors are currently out of
| commission. And Macron was one of the people responsible for
| signing off on the deal that sold off their turbine
| development to GE due to pressure of the DOJ. They were
| talking about buying "it" back. Although I don't know what
| the scope or timeline of the buyback is. I also remember that
| contrary to previous promises GE started dismantling one of
| those factories.
| onlyrealcuzzo wrote:
| IIUC, turbines are not really the bottleneck for nuclear
| power plants.
|
| Sure, they are necessary.
|
| But if France's existence depended on it - I imagine this
| is a problem they could solve relatively easily.
|
| On the flip side, Germany is not going to magically
| generate 80% of their electricity from Nuclear Energy
| anytime soon. Nor the US or Japan or South Korea for that
| matter...
| tomohawk wrote:
| Undergoing maintenance and scheduled to be back online in
| the next couple of months.
| Miraste wrote:
| It does seem like there's a deeper problem if over half
| the reactors are shut down for maintenance at the same
| time.
| fmajid wrote:
| French reactors are all the same design (derived from one
| licensed from Westinghouse). That's how they got the
| economies of scale and were able to ramp up so quickly.
| Unfortunately, that also means a flaw is reproduced in
| all of them. To compound this, the replacements were not
| started quickly enough so the current reactors are
| reaching the end of their design life, and because there
| was not a program to continuously build bew reactirsm the
| industrial skills base atrophied as qualified workers
| like welders retired. And the trifecta is France is
| experiencing its worst drought in recorded history, so
| some of the plants that get cooling from river water had
| to shut down due to low water levels. Even the mighty
| Rhine is a mere rivulet at the moment.
| onlyrealcuzzo wrote:
| IIUC - the reason so many are down is because of heat and
| low rivers.
|
| This won't be a problem in the Winter when they're most
| needed.
| u320 wrote:
| This is a bit of a myth. The heat wave and water levels
| was a problem, but most of it was maintenance issues
| unrelated to that. It was more a problem of
| mismanagement, and the fact that Macron went into office
| promising to shut down the fleet, making operators start
| to cut down on maintenance. He has now reversed course
| after realising that depending on Russian gas is bad. All
| wind/solar in Europe works by balancing it against
| natural gas or hydro, but the amount of hydro is fixed so
| expanding the wind/solar fleet increases the demand for
| gas. Hence why the renewable poster child Germany is in
| so deep shit right now.
| airstrike wrote:
| > > a move which turned out disastrously for the french.
|
| > Any more to add?
|
| The Battle of Waterloo?
| [deleted]
| [deleted]
| boringg wrote:
| Full steam ahead!
| stevage wrote:
| Steam behind. Fusion ahead.
| DubiousPusher wrote:
| Was this a successful ignition?
| enviclash wrote:
| Are there game-changing implications for this result?
| tinco wrote:
| Nope, it's just the expected gradual progression to the game-
| changing result that fusion eventually is going to be.
| Kukumber wrote:
| China managed to reach 120 millions degC for 1000 seconds last
| year already
|
| https://news.cgtn.com/news/2021-12-31/China-s-artificial-sun...
| motokamaks wrote:
| They managed to do it all separately in separate experiments.
| This is the first time both stability & temperature were
| achieved simultaneously.
| Kukumber wrote:
| Oh you are right, important detail indeed
| djyaz1200 wrote:
| What if the stars in the galaxy are the remnants of civilizations
| fusion reactor gone wrong ;p
| Aaronstotle wrote:
| What if stars are sentient beings?
| gajus wrote:
| What is the significance of this?
| groby_b wrote:
| Second sentence from The Fine Article: "While the duration and
| temperature alone aren't records, the simultaneous achievement
| of heat and stability brings us a step closer to a viable
| fusion reactor - as long as the technique used can be scaled
| up."
| zxcvbn4038 wrote:
| What? No reactor in every home? Those house of the future
| films lied to me in every way.
| stevage wrote:
| That's what solar plus battery is for.
| uwuemu wrote:
| Good luck trying to "scale up" (at least in the near future).
| Tokamaks are only getting to be "scaled up" now, after pretty
| much decades, and basically only thanks to ITER (factor of
| ten plasma volume compared to the second largest tokamak).
| And ITER is a megaproject comparable (both in budget and
| time) with the SLS program. Maybe even more expensive
| (depending on if you believe the official number, 22bn EUR,
| or the unofficial estimate, 40bn EUR) and DEFINITELY more
| complex with far more cutting edge science (plasma physics,
| material science...), technology, and engineering required.
|
| If ITER succeeds (proves that fusion in a magnetic
| confinement device can be used to produce net electricity and
| it's "just" a matter of scaling things up that is holding
| fusion back), then sure, investors are going to line up, even
| for alternative designs. Fusion will be all the rage. But
| until then, I doubt anyone is scaling anything fusion-related
| up. Well and if ITER fails, then we are all fucked, and we
| can turn the fusion "are we there yet" clock back 50 years.
| klabb3 wrote:
| Isn't total cost per reactor more constraining than cost
| per Wh for these mega projects? Say you spend $10B on a
| reactor that produces essentially free energy. You're still
| limited by plant lifetime, maintenance and crucially
| transportation of that energy - just breaking even would be
| a challenge in many locations. Thus, we have to have many
| plants distributed, similar to today's fission, at
| somewhere in the 500MW range per reactor (give or take an
| OOM).
|
| In short, we have diminishing returns for giant reactors,
| and instead need to have plants that can be mass produced,
| fast.
| samhain wrote:
| Have you taken a look at MITs SPARC reactor? I'm always
| skeptical of comments that only reference ITER, since it's
| very old news at this point, and there have been a plethora
| of innovation beyond ITER in just the last few years. The
| REBCO tape, and being able to get 10x magnetic field
| strength compared to ITER in a 3x smaller diameter seems
| like fairly significant progress to me.
| terrorOf wrote:
| AFAIK, China has record for temperature and duration however
| it is known as China heated up electron rather than heating
| up ion which is more proper.
| tinco wrote:
| I hadn't realized that was a different kind of record (150M
| degrees for over 1000 seconds). I suppose the ions have
| more mass than the electrons so that temperature is harder
| to maintain, but I have no idea about the physics of having
| them not heat up at the same rate.
|
| BTW I had to vouch for your comment to reply because you
| have a history of making short and sometimes brusque
| comments and HN has punished you for it. If you would make
| slightly longer comments in the future more people will
| engage with you and it will be more fun for you.
| npunt wrote:
| It's just the new hotness
| random314 wrote:
| Alright, take the upvote!
| mikeInAlaska wrote:
| "An error occurred during a connection to www.shiningscience.com"
|
| Was it hosted at the facility?
| Rackedup wrote:
| "as long as the technique used can be scaled up."
| teaearlgraycold wrote:
| OOF
| j15e wrote:
| As a newbie in nuclear fusion, this explanation is the most
| interesting part:
|
| > Lee Margetts at the University of Manchester, UK, says that the
| physics of fusion reactors is becoming well understood, but that
| there are technical hurdles to overcome before a working power
| plant can be built. Part of that will be developing methods to
| withdraw heat from the reactor and use it to generate electrical
| current.
|
| > "It's not physics, it's engineering," he says. "If you just
| think about this from the point of view of a gas-fired or a coal-
| fired power station, if you didn't have anything to take the heat
| away, then the people operating it would say 'we have to switch
| it off because it gets too hot and it will melt the power
| station', and that's exactly the situation here."
| baby wrote:
| Similar to how energy is extracted from fission reactors
| currently: the heat is used to boil water which makes large
| turbines spin and produce energy. It's dumb engineering. (I
| don't mean that in a bad way.)
| Gwypaas wrote:
| Could be interesting if they couple it with a Closed Cycle
| Gas Turbine [1] and a tiny steam plant, like the gas CCGT
| plants of today. Then the heat engine part should see
| similar, or even higher, efficiencies compared to gas based
| CCGT plants.
|
| Boiling water using the Rankine cycle [2] and it will be as
| dead in the water as nuclear and coal is today.
|
| A thing to keep in mind though is that it is very hard to
| compete with the engineering of an axle straight into a
| generator like wind turbines or a solid state system like
| solar PV. Working fluids, cooling loops and what not are
| awful to build and maintain.
|
| [1]: https://en.wikipedia.org/wiki/Closed-cycle_gas_turbine
|
| [2]: https://en.wikipedia.org/wiki/Rankine_cycle
| spoils19 wrote:
| Coal is very much alive in prospering countries, and I
| stand with other conservatives in that we don't need new
| fancy energy production.
| mlazos wrote:
| I suppose I'll bite here. We don't need "fancy" energy
| production as Southern California and the Midwest becomes
| uninhabitable, you serious? Coal power should be dead in
| the water if it isn't. It's bad for workers, bad for the
| air we breathe, water we drink, bad for the people who
| live around plants. That has been well established. It
| actually kills more people than nuclear, solar and wind
| combined. There's no redeeming quality to it other than
| being plentiful and cheap. It shouldn't be cheap based on
| the externality of the destruction it causes here and
| around the world.
| u320 wrote:
| If you think nuclear is dead in the water you haven't
| really been following where the energy debate is heading
| these days. Especially in Europe, where we no longer have
| the luxury of plugging the holes left by renewables with
| gas.
| pdpi wrote:
| I always find it slightly amusing how there's remarkably few
| forms of power generation that don't eventually boil down to
| "use water/air/steam to make a turbine spin".
| cm2187 wrote:
| Turbines and piston engines also rely on the mechanical
| power of gas expanding.
| gridspy wrote:
| It is amusing. But it's just because that is the most
| efficient way we know to turn heat into electricity at
| scale.
| [deleted]
| christophilus wrote:
| > boil down
|
| I see what you did there. I feel the same way, though. It
| feels primitive. But it's what we've got!
| JohnFen wrote:
| Yes, or as I like to think of it -- we're more of a steam-
| powered society now than we were during the "steam age".
| z3rgl1ng wrote:
| bryanlarsen wrote:
| It's also very expensive engineering. That's how a coal plant
| works, and the last coal plant that the US built cost $2B for
| a 600MW plant. Given how much cheaper solar & wind are,
| fusion will be dead in the water if it doesn't come up with a
| cheaper way of extracting energy from the reaction.
| tomatotomato37 wrote:
| Speaking of solar it would be nice if we could just plate
| the inside of a reactor with photoelectrics instead of
| blowing all the budget on a clusterfuck of a steam system.
| Too bad silicon doesn't like 100M degrees...
|
| Actually thinking about it figuring that out would make
| fission a lot more tenable too
| flavius29663 wrote:
| solar and wind can be free, if the sun does not shine and
| wind is not blowing 100% of the time...
| nemo44x wrote:
| Solar and wind are not serious solutions to the energy
| needs of the planet today or in the future. As billions
| more people become part of a global middle class our energy
| requirements will expand dramatically from today.
| ceejayoz wrote:
| > As billions more people become part of a global middle
| class our energy requirements will expand dramatically
| from today.
|
| https://www.nrel.gov/docs/fy04osti/35097.pdf
|
| "In the United States, cities and residences cover about
| 140 million acres of land. We could supply every
| kilowatt-hour of our nation's current electricity
| requirements simply by applying PV to 7% of this area--on
| roofs, on parking lots, along highway walls, on the sides
| of buildings, and in other dual-use scenarios."
|
| "We would need only 10 million acres of land--or only
| 0.4% of the area of the United States--to supply all of
| our nation's electricity using PV."
| didericis wrote:
| 0.4% of the entire country is a massive amount of land.
|
| That's 10 million acres of wires, maintenance, habitat
| and all kinds of mischievous creatures, not least of
| which are humans. And it only works when the weather is
| good. And not all countries have the grid or engineering
| and maintenance capacity of the United States.
|
| It's not a realistic solution.
|
| By all means, lets put solar panels everywhere we already
| have buildings and roofs and power hookups and make a
| dent. Maybe at some point it'll be possible to use solar
| alone, and we can keep up the maintenance.
|
| Going all in on solar right now would be suicide. It'd be
| worse than the effects of anthropogenic warming. People
| are going to freeze to death this winter in Germany
| because they bought into the promise of renewables before
| it delivered and didn't diversify their energy supply.
|
| You should only phase something out when you can meet
| demands without it. Nuclear is a way to do that. Natural
| gas is a way to do that. Renewables are a way to do that.
| But you have to actually _exceed demand_ and have a solid
| diversified base before you panic switch because of
| climate change. Otherwise you kill and impoverish more
| people than climate change.
| robertlagrant wrote:
| I really wish this sort of thing would either be better
| thought through or better articulated. 10 million acres
| is enormous. And is it continuous supply (if so, how?) Or
| just supply when it's sunny?
| sdenton4 wrote:
| It's easy enough to solve... point an energy-collecting
| device at the giant pre-built fusion reactor in the sky.
| gridspy wrote:
| Yes, but most of the time that fusion reactor is behind a
| giant hunk of iron covered in various other matter. Even
| when in the sky, the sky itself is an effective insulator
| that only allows 1/4 of the energy through.
|
| That's why we are considering placing a converter above
| the sky to more efficiently pierce the sky with energy.
| markdown wrote:
| Towing the converter _outside_ the environment is
| something I can get behind.
| gridspy wrote:
| I always liked how NASA realised in 1970 that the moon is
| a sandpit of fusion-converter material. It's such an
| awesome reason to build houses above the sky.
| gridspy wrote:
| I support moving all the smoking buildings outside the
| environment also. Then many of them can use the fusion
| reactor directly, with the aid of mirrors and lenses.
| u320 wrote:
| You cannot build a grid out of solar and wind alone.
| bryanlarsen wrote:
| A 100% renewable power grid is possible and inexpensive.
| Here's how to do it:
| https://mitpress.mit.edu/9780262545044/
| idiotsecant wrote:
| This is absolutely not true. My day job is designing
| control systems for renewable generation so I certainly
| don't have a bias against renewables - the opposite in
| fact.
|
| The fact remains that the physics of a grid powered only
| by distributed non-dispatchable wind and solar resources
| simply does.not.work. full stop without massive
| investments in storage and transmission upgrades. The
| physics isn't even debatable - it's simple. You only have
| to look at the very limited transmission infrastructure
| that currently exists and understand the simple fact that
| the power grid is a zero sum game. Power in = Power out
| or very bad things happen that lead to power out = 0.
| Zero sum generation + aging transmission = not enough
| power where you need it, when you need it if you get rid
| of traditional baseload sources.
|
| It's good to champion renewable generation, storage, and
| transmission upgrades. It's necessary infrastructure for
| the economic and actual health of our nation. It is _not_
| going to be inexpensive by any definition of the term. It
| 's going to be monumentally expensive even if it's
| completely necessary.
| zardo wrote:
| You also need transformers and batteries and power lines.
| salty_biscuits wrote:
| Then don't do it. Grids are expensive. Microgrids and
| storage seem like a winning plan.
| u320 wrote:
| Microgrids and storage cost way more than any method of
| generating power we are currently using. Please stop
| using buzzwords and look at the actual numbers.
| ben_w wrote:
| At grid scale, batteries were about the same cost as a
| functionally equivalent fission reactor last time I
| looked (a few years ago). Despite which, batteries are
| one of the more expensive ways to store energy at scale.
| u320 wrote:
| I don't know where you looked then because batteries are
| not anywhere near low cost enough to be deployed at grid
| scale at the amounts required to run a grid of wind and
| solar. Even in a sunny climate with reliable solar
| output, if you assume that there is a 10% chance that in
| any year you will have a 10 day period of cloud cover and
| 50% lower solar output and your entire grid cost goes up
| by 5x! The math for storage is BRUTAL.
| ben_w wrote:
| Only 50%? That's a small enough reduction that the
| cheapest solution is double the PV.
| ben_w wrote:
| You _can_. It probably isn't a great idea due to global
| geopolitics, but the physics is sound and the price isn't
| unreasonable.
| u320 wrote:
| Nobody has done it. Nobody has put forth a credible
| theoretical model on how to do it. If you believe
| otherwise please show how it can be done. With details.
| Things like frequency regulation, reactive power and all
| that stuff that makes the grid work. And include the
| economic calculations. The burden of proof is on you.
| ben_w wrote:
| > Nobody has done it
|
| So?
|
| > Nobody has put forth a credible theoretical model on
| how to do it.
|
| HVDC global grid, mentioned loads of times on this forum.
| 60% antipodal loss with existing components that were
| optimised for much shorter connections, but even that
| loss is fine given how cheap optimally placed PV is. Cost
| about a trillion USD (ok) and a few decades of current
| global aluminium and copper production (meh), but that's
| still absolutely in the realm of the "we could afford it,
| shame about the politics".
| compumike wrote:
| I'm not sure where your numbers are from, but just because
| $2B sounds like a big number, it isn't inherently a
| dealbreaker.
|
| If that's 600 MWe, running at 80% capacity factor,
| amortized over 30 years, then the $2B becomes: 2e9/(600 *
| 1000 * 0.8 * 24 * 365 * 30) = $0.0158 / kWh -- the $2B
| capital cost amortizes to 1.6 cents per kWh of electricity
| sold. Not zero, but 1.6 cents is far less than the current
| market price of a kWh.
|
| If you're going to compare to utility-scale solar or wind,
| be sure to include their much lower capacity factor: https:
| //en.wikipedia.org/wiki/Capacity_factor#/media/File:US...
|
| (Admittedly: we don't yet know the capital cost of a
| working fusion heat source, or its capacity factor. Both
| will determine whether this is economically competitive.)
| lake_vincent wrote:
| Yes, exactly! There are two problems here:
|
| 1. What's the most efficient way to boil water?
|
| 2. How do we generate electricity on a population scale
| without having to boil water?
|
| Question 1 is, apparently, much more tractable. We are still
| pretty much building the world's most sophisticated tea
| kettle.
| mrec wrote:
| As a Brit, I wholeheartedly approve.
| throwaway0a5e wrote:
| >1. What's the most efficient way to boil water?
|
| Doesn't need to be the most efficient. Just more efficient
| per energy transferred to the water than all the other
| options.
| robbomacrae wrote:
| I don't follow. What you said seems to me the definition
| of the most efficient. Or at least.. it is what I assumed
| they meant.
| heavyset_go wrote:
| Most efficient can mean theoretically optimal efficiency
| or more efficient than other options. I think the OP was
| using the first definition.
| dbetteridge wrote:
| Local maximum vs global maximum
|
| Most efficient conpared to what we have already, but
| there may still be more efficient ways
| TaylorAlexander wrote:
| I think there is a zeroth problem here, which is how to get
| the heat from the plasma to the water. You have a fusion
| reactor making hot plasma that also needs to have water
| circulating in the right way. From what I gleaned from some
| fusion presentations the solution to this is itself an
| engineering challenge.
| Symmetry wrote:
| Fusion plants also need to absorb the neutrons coming out
| of the reactor and secure themselves a supply of tritium
| for their reaction. The most common solution is to do all
| three with a blanket of molten lithium that can absorb
| neutrons and heat from the reaction, transmute into
| tritium, and go through a heat exchanger with water to
| heat it up.
| compumike wrote:
| "Fusion Reactor First Wall Cooling"
| https://www.youtube.com/watch?v=bHJyoqDO0zw talks about
| the steady-state heat transfer out of a proposed tokamak
| design. Around 1:09:23 they show "1.5 GW" deposited as
| "0.3 GW from radiative photons -> surface heating" plus
| "1.2 GW from 14.1 MeV neutrons -> volumetric heating".
|
| Designing the first wall and the volumetric blanket are,
| indeed, engineering challenges.
| sien wrote:
| There are fusion companies that are trying to make
| aneutronic fusion work. This form of fusion doesn't involve
| boiling water.
|
| https://en.wikipedia.org/wiki/Aneutronic_fusion
|
| Helion Energy is the best known.
|
| https://en.wikipedia.org/wiki/Helion_Energy
|
| HB11 is another one
|
| https://hb11.energy/
| ok_dad wrote:
| It's a fusion reactor, so how do you get the water into the
| part with the hot stuff? That's all inside a magnetic field,
| I think. Also, you have to consider the neutron radiation's
| effect on the pipes that carry the water into the core, it's
| going to activate several metals in there, and cause
| weakening of the pipe wall, which will necessitate
| inspections and replacements.
|
| It's a way harder engineering problem than you're letting on.
| Your comment is like a software user saying "How hard could
| it be just to add feature X?".
| johnbcoughlin wrote:
| The heat transfer is not (will not be) directly from the
| plasma to the water. The fusion neutrons will impact a
| "blanket", which is water-cooled, and kept at a temperature
| of around 600-800 C. Weakening of the pipes and all other
| structural components will primarily be from neutron
| irradiation. Not to say that any of it's easy, just not for
| the reasons you suppose. :)
| ok_dad wrote:
| Ah, cool! I wasn't sure how it would work, but it seems
| the hard part is the stuff leading to and including the
| "blanket? Thanks for clarification.
| Twirrim wrote:
| I was talking about this with the my kids (10, 7) the other
| day. Blew their minds a little that pretty much every power
| source comes back to the same central thing: moving magnets.
|
| Then I pointed out that our electric car does it in both
| directions too.
| gridspy wrote:
| Well, it's just another of our favorite converters -
| kinetic <-> electric energy.
|
| electric <-> kinetic - spinning magnets
|
| kinetic <-> pressure - turbine / pump
|
| pressure <- heat - boiler
|
| heat <- chemical potential - furnace
| tremon wrote:
| It's not my area, but I suspect that the heat extraction rate
| for a fusion reactor must be several orders higher than
| current fission reactors if we are to run them continuously.
| Fission reactions can be actively controlled by using
| reaction moderating material (control rods), which means we
| can tune the reactor activity to match the amount of heat
| extraction available.
|
| Fusion plasma must be sustained at a few million Kelvin or it
| shuts down again, and I'm not sure how finely we can control
| the operating temperature without either overheating the
| reactor or shutting down the plasma. I think it will take a
| lot more than dumb engineering to accomplish this.
| johnbcoughlin wrote:
| The heat flux management from the plasma is certainly not
| dumb engineering, true. However, the actual heat transfer
| technology is, I think it's fair to say, "dumb" compared to
| all of the plasma physics that has to enable the reactor in
| the first place. It's more or less just running cold water
| through the lithium blanket, which they hope to keep under
| around 1000 Celsius or so.
| [deleted]
| johndhi wrote:
| What % chance do we feel that we will have fusion power within
| the next 50 years?
| sien wrote:
| On Metaculus :
|
| Most likely - fusion ignition in the 2030s. Fusion supplying
| 10% of global electricity in the 2050s.
|
| https://www.metaculus.com/questions/?order_by=-rank&main-fee...
| zardo wrote:
| Those two predictions don't seem to fit together.
| weberer wrote:
| Construction of the DEMO plant is currently set to begin in
| 2040. It is made to follow ITER, so any delay in ITER will
| propagate to DEMO.
|
| https://en.wikipedia.org/wiki/DEMOnstration_Power_Plant#Time...
|
| https://en.wikipedia.org/wiki/ITER
| anigbrowl wrote:
| 73%
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