MIT-designed project achieves major advance toward fusion energy
news.mit.eduPlenty of skepticism in these comments. I've been following CFS for a while and can present a point of view for why this time might be different.
Fusion energy was actually making rapid progress in the latter half of the twentieth century, going from almost no power output in the fifties and sixties to a power output equal to 67% of input power with the JET reactor in 1997. By the eighties there was plenty of experimental evidence to describe the relationships between tokamak parameters and power output. Particularly that the gain is proportional to the radius to the power of 1.3 and the magnetic field cubed. The main caveat to this relationship was that we only had magnets that would go up to 5.5 Tesla, which implied we needed a tokamak radius of 6 meters or so in order to produce net energy.
Well that 6 meter tokamak was designed in the eighties and is currently under construction. ITER, being so large, costs tens of billions of dollars and requires international collaboration; the size of the project has led to huge budget overruns and long delays. Recently however, there have been significant advances in high-temperature super conductors that can produce magnetic fields large enough that we (theoretically) only need a tokamak with a major radius of about 1.5 meters to produce net gain. This is where SPARC (the tokamak being built by the company in the article) comes in. The general idea is that since we have stronger magnets now, we can make a smaller, and therefore cheaper tokamak quickly.
Small tokamaks do have downsides, namely that the heat flux through the walls of the device is so large that it will damage the tokamak. There have been breakthroughs with various divertor designs that can mitigate this, but to the best of my knowledge I'm not sure that CFS has specified their divertor configuration.
This was just a short summary of the presentation by Dennis Whyte given here [0]. I do not work in the fusion community.
You are right, people who flippantly dismiss fusion just don't understand it.
-Fusion has made consistent improvement, roughly in line with expectations for the level of investment (20 years away predictions were considering if we invested massively, which we did not).
- Fusion is in theory something that could give us true energy abundance. Want to just desalinate water like crazy? Want to extract gigatons of carbon? Working fusion enables these to happen woth existing technologies.
I like to think of solar, batteries, fission, and wind as compelling ways to go mostly carbon free and lower energy costs about 2x over the next 20 years or so.
Fusion is what reduces energy cost potentially another 10x, which really changes the game for lots of things. Exciting stuff. Kudos to this team.
I'd add the sentiment of GP that this particular team also seems to have something special. I've been following them for a while as well, and they've impressed me by meeting self-imposed deadlines for project milestones (like this magnet experiment), being quite ingenious in designing economical components (the design of their original superconductor is quite simple but brilliant), and just having a no-BS approach.
> Fusion is in theory something that could give us true energy abundance.
Well, at least for a few hundred years but then:
> if you plot the U.S. energy consumption in all forms from 1650 until now, you see a phenomenally faithful exponential at about 3% per year over that whole span. The situation for the whole world is similar. […] the Earth has only one mechanism for releasing heat to space, and that’s via (infrared) radiation. We understand the phenomenon perfectly well, and can predict the surface temperature of the planet as a function of how much energy the human race produces. The upshot is that at a 2.3% growth rate [in energy consumption] (conveniently chosen to represent a 10× increase every century), we would reach boiling temperature in about 400 years. […] And this statement is independent of technology. Even if we don’t have a name for the energy source yet, as long as it obeys thermodynamics, we cook ourselves with perpetual energy increase.
Source: https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...
The quoted argument is too simplistic and ignores feedback processes that would prevent reaching the catastrophic prediction. We can't predict 400 years so flippantly.
The population will most definitely not continue to grow (in fact it will start to decrease slightly the more countries reach "developed" status), and the energy consumption per-capita will also stagnate. After all, there is a huge difference between going from living in a log house to a modern apartment with utilities and AC, and not much of a difference between one laptop and a slightly better one some years down the line. Also, attitudes towards environmental protection are changing with the generations so we are likely making different decisions 50 years from now.
Reminds me of those late 19th century predictions according to which in 50 years London would be neck-deep in horse poop
US per capita energy consumption peaked in 1980.
This idea seems like the CICO (Calories-In, Calories-Out) argument, and is misleading/wrong for exactly the same reasons - neither the Earth+people (or even just the Earth) nor the human body just stock energy like that linearly.
If you increase the amount of energy flowing into the human body, the metabolism increases as well (although almost never proportionally - there are many variables) to compensate.
Similarly, it's rather unlikely that humans will continue to use exponentially increasing amounts of energy, unless we intentionally do something to effect that. Human population growth, which is partially driving energy consumption, is not exponential (it would be exponential absent of resource constraints or cultural factors, but guess what - both of those are in effect rather strongly in the real world) - and neither is energy consumption per capita. For instance, from 2005 to 2020, the US gained 30M people[1] while keeping energy consumption roughly constant[2].
[1] https://datacommons.org/place/country/USA [2] https://www.statista.com/statistics/201794/us-electricity-co...
You can’t just look at electricity consumption. You have to look at total energy consumption. Including the energy necessary to produce the goods you consume. And that is increasing exponentially.
In a way, the US (and Western countries) are outsourcing their energy consumption.
> Including the energy necessary to produce the goods you consume.
Exactly, the original link I posted is more or less an argument against infinite economic growth.
I'd take that statement with a grain of salt. If there's something that COVID has taught me is that in reality exponential curves almost always turn into sigmoids wherever there are limiting factors. The key here is where the curve starts flattening.
The same goes for infinite growth. In the close future it sure looks infinite, but I'd say it's infinitely hard too to predict what will happen in say a 100 years (a fourth of the time before we hit the heat death wall predicted here).
Sigh. I really shouldn't have included a quote in my comment and instead only linked to the full text.
That text is exactly an argument against infinite economic growth – and it carries out said argument by looking at energy consumption (which necessarily grows with economic activity).
Yeah I read it. Thats why I said that bit about infinite economic growth. I felt that by saying that exponential heat growth is probably sigmoid I was somehow validating the notion of infinite growth, which I think sometime in an unforeseeable future will just plateau.
Ah, sorry, looks like I misunderstood. :)
If there is enough ambient energy to literally boil the seas then we're probably going to find it easy enough to leave the earth and go somewhere cooler.
I don't think it'll be easy.
We would have the same (if not higher) energy consumption per capita on any other planet. And unless that planet is humongously large (which would also increase its surface-level gravity, thus rendering it uninhabitable), the relation between surface temperature and energy consumption will be similar[0]. Now there's only a finite number of planets in our solar system and leaving our solar system, say in the direction of Proxima Centauri (the star nearest to the Sun), amounts to traveling ~4.2 light-years. At a velocity of 0.1c (which is a lot – especially if you're trying to move an entire species[1]) that means a travel time of 42 years (as seen from our current frame of reference). Any velocity lower than that and we're getting into hundreds-of-years territory, so we'll be needing space ships across we can live for generations.
Also, a space ship is not that different from a planet, in that it also has to obey thermodynamics. So the surface temperature issue there is just the same. (In fact it's worse, since our space ship will likely be smaller and we also need to factor in additional waste energy of the space ship's propulsion engine or whatever we're using.)
[0]: https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law
[1]: Or, say, half the species (or whatever amount necessary to make the total energy consumption on the planets we already inhabit drop to levels such that the planets' surfaces don't start to boil).
We're talking a world where humanity has enough energy on tap that not only could it have feasibly evaporated the Pacific Ocean, but that it basically has evaporated the Pacific Ocean, as a side effect of doing something else.
We can barely speculate about such a world, but interstellar travel would not be much of a challenge with that sort of energy abundance. We'll find a way.
I believe the two of you are talking about different things.
The argument in the UCSD blog post linked above will apply to any finite system if you assume exponential growth in power use, and exponential beats cubic for expansion to other worlds (I’m assuming no FTL for a cubic limit to expansion).
Abundant power — be it from fusion or solar or quantum magic — does not actually need to guarantee eternal exponential growth of power use, but the absence of such growth would necessarily lead eventually to the absence of economic growth.
We can still have a SciFi future without that, it will just look different in a way our current society can’t properly envision (which I think is an unsurprising a claim to make even in the absence of the rest of this argument).
> but interstellar travel would not be much of a challenge with that sort of energy abundance.
I don't think I agree.
1) The extremely high (but still finite) amount of energy required to evaporate the Pacific Ocean is still much less than the infinite energy you need to accelerate even one single space traveler to the speed of light. Infinity is weird.
Of course we won't be trying to reach the speed of light but the energy (and fuel) required to move half the species (so that the other half can stay on Earth/Mars/…) will still be significant.
2) My second argument was that the Stefan-Boltzmann law is just the same on board the space ship. And if we live there for generations, chances are our energy consumption per capita will be similar as on the planet we left, and so we will be running into similar issues with Stefan-Boltzmann's law. Sure, we can split up the passengers across multiple space ships and make each ship much bigger (to increase surface size) but not only will this increase the total mass and thus fuel required for the trip but we would probably still not achieve the (rather high) surface area per capita ratio that we have on Earth.
Addendum to 1):
Thinking a bit further, just because we can produce a high amount of energy that doesn't necessarily mean we can automatically convert it into kinetic energy for a space ship very well. Most propulsion systems in space still require expelling a propellant and conservation of momentum means this is unlikely to change. (Sure, one could imagine solar sails but the little momentum exchanged there won't get half of humanity to Proxima Centauri very fast.) So while we might have unlimited energy we might still be constrained by momentum requirements.
The only way I can see to solve this conundrum would be producing enough propellant on board the space ship, e.g. (lots of) photons, using a laser. Definitely not impossible (especially not at these energy levels) but it'll be interesting to see what these propulsion systems will look like exactly. :)
Ideally, we would of course try to use the propellant to also get rid of the waste heat mentioned earlier but I'm not sure whether this would work entropy-wise.
> The extremely high (but still finite) amount of energy required to evaporate the Pacific Ocean is still much less than the infinite energy you need to accelerate even one single space traveler to the speed of light.
True, but how many tons of space junk can you accellerate to 95% of light speed for the same amount of energy?
Quick back-of-the-envelope calculation:
=> Energy needed to make Pacific Ocean boil:Approx. mass of Pacific Ocean[0]: m_ocean = 7.1×10²⁰kg Specific heat of water: c = 4.2kJ/(kg · K) Temperature of Pacific Ocean: T_1 ~ 293K Temperature at which water starts boiling: T_2 ~373K
On the other hand, the relativistic kinetic energy formula is:E_heat = c m_ocean ΔT = c m_ocean (T_2 - T_1) ~ 3×10²⁶ J
where γ = 1/sqrt(1-v²/c²) = 1/sqrt(1-0.95²) and m is the space junk's mass.E_kin = (γ-1) m c²,Setting E_kin = E_heat therefore yields:
For comparison: The mass of all of humanity combined is somewhere between 10¹¹kg and 10¹²kg. Now those numbers do look somewhat comparable but:=> m = E_heat / [(γ-1)c²) = 3×10²⁶ J / (2.2×10¹⁶ m²/s²)] = 10¹⁰ kg- We haven't taken into account the space ships required to transport everyone
- E_heat was waste heat but since practically all energy will become waste heat at the end of the day, E_heat gives us a pretty good estimate of the total energy we will have (had) access to.
All in all 0.95·c doesn't seem feasible for moving humanity to Proxima Centauri, given E_heat. For moving 10¹⁰ kg of space junk, sure, though I'm not sure what you were planning to do with all that space junk in the first place?
Not quite sure I follow. On earth we're mostly limited to radiation to get rid of excess heat, I understand that part. But on a space-ship, can we not just expel the heat via mass? I.e. We super-heat some dense materials and just shoot them out.
Where will you be getting all that mass from, though?
> We super-heat some dense materials
This won't work as you would need to put in additional work (leading to additional waste heat) in order for this process to lower ambient temperature. The only thing you could do is shoot stuff out that's precisely at ambient temperature, compare https://news.ycombinator.com/item?id=28471620 .
> So the surface temperature issue there is just the same.
On an interstellar ship far from a star, I think you're more likely to freeze to death, because temperature in space is near zero Kelvin.
Inside the solar system however, you could reflect away the received radiation (and heat) using mirrors.
> I think you're more likely to freeze to death, because temperature in space is near zero Kelvin.
We're talking about a civilization on board an interstellar ship that had to leave their home planet because they were consuming so much energy that the resulting waste heat ended up making the oceans boil. So the assumption that they'll keep on consuming lots of energy (and producing lots of waste heat) on board such a ship sounds rather reasonable to me.
> Inside the solar system however, you could reflect away the received radiation (and heat) using mirrors.
The discussion is about getting rid of heat produced on board the space ship, not heat that's received from elsewhere.
Huh, that's interesting!
I wonder, in a strictly thermodynamic way (ignoring CO2 etc), how big of an impact it would have to remove all internal combustion engines in land-based transportation and power generation (coal plants).
ICE's have like a 30-40% efficiency? Compared to electric engines 80-90%. But on the other hand, you probably consume quite a bit of energy producing the batteries...
Per battery or overall to the planet?
Per unit of storage, Wikipedia says the lifetime storage capacity of batteries etc. relative to energy needed to construct them is:
Lead acid: 5 times construction energy; Vanadium redox: 10; LiIon: 32; Pumped hydro: 704; Compressed air: 792.
I can’t remember where I’ve seen this, but I think a unit of PV produces all the energy it took to manufacture after a month or two.
If you mean overall? As a rough guide we emit about 35GT CO2/year which is about 9.5e12 kg carbon; burning carbon releases about 32MJ/kg; so about 3e20 J/year, or 9 TW, or 19 mW/m^2.
There’s more energy in the hydrogen in gases and oils, this is just a ballpark estimate of the thermodynamic output of burning that much does to directly heat the planet.
How do we know that global temp rise isn't just due to energy usage? I mean "does that calculation fit at all?", not "carbon dioxide is fake".
Not even close.
Global energy use is around 170,000 TWh/year (1). This includes electricity generation, as well as fuel for transport, burning wood for heat, etc.
Heat flow from mantle is 403,000 TWh/year (2)
Solar irradiance is ~1200W/m2, which adds up to massive 5B TWh/year.
Extra radiative forcing from greenhouse gases in IPCC scenarios is ~3W/m2, or around 12.5M TWh/year.
The radiative forcing is two orders of magnitude larger than our energy use.
(1) https://en.wikipedia.org/wiki/World_energy_supply_and_consum...
I believe total annual solar irradiance is closer to 1.5BTWh/yr.
The 1200-ish W/m/m figure is hitting a flat plate circle, not hitting the whole spherical surface.
Taking 173,000TW of continuous solar energy* times 24h/d times 365.25 d/yr yields a little over 1.5B TWhr/yr
Thanks, this is the calculation I was looking for.
Because we know that so far humanity's energy use is so small that the heating effect via increased blackbody radiation equilibrium temperature is utterly dwarfed by what mainstream climate focuses on, like GHG gasses.
It's the difference between a hand-warmer and a coat. The hand-warmer adds extra heat to the system (like the heat from burning fossil fuels). A coat doesn't add any extra heat, it just traps some of the heat that would otherwise be lost (like greenhouse gasses).
Hand-warmers can keep part of the body warm for a few hours. Coats can keep the whole body warm for years.
Well if we transform solar into electric then into motion or bound carbon, that should actually help reduce the heat balance?
> into motion
Kinetic energy will end up getting converted to waste heat nonetheless.
> or bound carbon
This seems hard to imagine. We're dealing with waste energy here, so a very high-entropy type of energy. Bound carbon is low-entropy, so the conversion is impossible[0] unless we put that entropy elsewhere.
As an analogy, consider a fridge: It brings your food from a high-entropy (high-temperature) to a low-entropy (low-temperature) state but in order to do that it also has to produce waste heat (entropy) on the outside.
[0]: https://en.wikipedia.org/wiki/Second_law_of_thermodynamics
We're not necessarily talking about a closed system, though. If you've got an energy supply that rounds to limitless, constructing planet-scale heatsinks starts to look tenable.
> We're not necessarily talking about a closed system, though.
Short of shooting hot lava into space[0] we pretty much are because, once again, thermalization through radiation is governed by Stefan-Boltzmann's law and there's no way around that.
Stefan-Boltmann talks about emission per surface area. So... increase the surface area. We're not limited to a sphere.
The same problem crops up when you're talking about moon bases and so on - you've got the same problem of venting heat from an ecosystem into a vacuum. For that situation, one of the solutions that got designed out was to basically spray an oil mist across a gap, catch it, and recycle it into the cooling system. As a fine mist, the oil has a colossal surface area compared to its mass, and all that surface area can radiate heat off into the vacuum.
So... scale that up? I realise it's a hell of a leap, to go from human-scale to humanity-scale, and I don't know exactly what it would need to look like, but limitless energy is a hell of a springboard.
But then what do you do with that motion?
Eventually it all decays to heat, as per the 2nd law of thermodynamics
Absolutely yes. Energy is captured by solar panels. They make a shade, obviously, and what is in their shade does not get heated by the sun.
If you were to use 100% of solar panel energy to heat up something else the overall balance would be 0.
Contrarily, nuclear fission/fusion that releases energy from its fuel, ultimately heating up the planet.
The thermodynamics argument would hold only for a closed system. If we send big blobs of lava into space, and import big chunks of solid rock back to Earth, then theoretically we should have no problem.
> If we send big blobs of lava into space
I honestly can't tell if you are joking. The energy expenditure to get anything into orbit would produce more heat than you are offsetting.
Depending on the design of the system, the energy could well be expended in orbit and not contribute to the heating of earth (think about designs like a space elevator).
He's basically describing a giant air conditioner... it's definitely theoretically possible.
> it's definitely theoretically possible.
In theory yes, but in practice: Not so much.
Even if we put aside GP's concerns, shooting big blobs of lava into space would require heating up the lava/rock in the first place. But this process doesn't happen on its own (through thermalization) given the average temperatures on Earth, meaning that the process of moving waste heat (from the environment, i.e. air/ocean) to the lava will once again decrease entropy (of the combined lava + air/ocean system) and you thus need to move the missing entropy elsewhere. (Meaning that you have to do work to accomplish this heat transfer / dethermalization and you will once again incur waste heat.)
Sure, we could also try to tap the heat bath of the Earth's core but then we would build a deep-Earth elevator to transport lava and solid rock (or, say, water) back and forth and GP's concerns apply once more.
There's another option, though: Don't build an air conditioning system/fridge – use thermalization with another (lower-temperature) system. That is, don't take lava (or anything that needs to be heated beyond ambient temperature) – "just" take rock at (Earth's) ambient temperature, move it to a lower-temperature $PLANET and then move cool rock from $PLANET back to Earth. I doubt this would be very efficient/fast, though.
In any case, the difference between the two approaches is that an air conditioner (or a fridge) cools things below ambient temperature and requires additional energy for that (which it will expel as waste heat), while the second approach "simply" moves energy from the heat bath that is Earth to some lower-temperature reservoire (i.e. $PLANET). If $PLANET and Earth were thermodynamically connected not just through the exchange of infrared radiation, this would happen by itself over time through thermalization.
>(infrared)
How to tell an undereducated journo.
> Fusion is what reduces energy cost potentially another 10x
How did you arrive at that conclusion?
Yeah, really, how?
Fusion power plants still need land, buildings, generators, switchyards, wire, own power consumption, environmental impact reports, planning permits, regulations, inspections, and all the rest. And they need exotic materials and weird engineering in their construction.
Really: how does fusion get us to ~1% (correction: ~5%) of current power prices?
I've never seen a convincing explanation. Usually it's bare assertion. Infrequently it's handwavium/unobtanium.
One of the big problems with existing power plants is that you have to build them near where people are. So then land is expensive and you get a bunch of regulations because people are worried about what's happening in their back yard.
If you could hypothetically build a fusion plant that would generate several times more power than existing fission reactors at a similar construction cost, you would have so much power you wouldn't have to worry much about transmission losses. At which point you could put it in the middle of nowhere without those constraints and make it actually less expensive for several times more power.
Then for cities power gets cheaper, but for anything that can be built out in the middle of nowhere near the reactor, power gets a lot cheaper.
How is that reasoning specific to fusion?
Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken.
Alternatively you can use truly massive air heat transfer structures, driving up your construction costs again.
I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs.
> How is that reasoning specific to fusion?
A major cost of the most utilized existing power plants (coal and natural gas) is fuel. If you build a natural gas plant which is twice as big so that you can put it out where the land is cheaper and eat the transmission losses, now you need twice as much natural gas.
Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land. If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land.
> Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken.
An obvious solution is to build them out in the ocean. Then you have plenty of water and you're still not near anything.
And the good spots near population centers are already taken. Some lake a hundred miles from any city won't be.
> I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs.
That's only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology.
> A major cost of the most utilized existing power plants (coal and natural gas) is fuel.
Coal is dead. The competition is PV, and to a lesser extent wind.
> Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land.
Yes, and you use odd bits of land close to consumption sites, many of which will have simultaneous use for other purposes. Edit: the linearity is an advantage in that it enables mass production, and gets the benefit of the manufacturing learning curve. So your suggestion of overbuilding on cheap land a long way away from cities applies even more to PV.
> If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land.
Quadrupling your construction costs. Edit: mainly in the finance cost of the time taken.
Also, making your generators much bigger than current practise increases project risk and therfore cost.
> An obvious solution is to build them out in the ocean.
Quadrupling your construction costs again, and decreasing reliability, capacity factor and productive lifetime. Seawater is nasty stuff.
> And the good spots near population centers are already taken. Some big lake a hundred miles from any city won't be.
It will be used for productive farmland, though. Again, why aren't fission or CCGT plants being built in those places? How is fusion different?
> [High finance cost is] only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology.
It's about time to cashflow for utility finance types, and they also tend to want a longer track record than "it worked once". The linearity/modularity of wind and PV is an advantage in the time to cashflow aspect.
Edit: I haven't so far seen anything significant in your replies that doesn't also apply to fission. Utilty project financiers are hard-headed; they'll finance fission if it makes them enough money soon enough.
You are fiddling around the edges rather than demonstrating an order of magnitude cost reduction from PV.
> Coal is dead. The competition is PV, and to a lesser extent wind.
Coal is dying but it's still ~20% of US generation. The natural gas share of US generation has gone up.
> Yes, and you use odd bits of land close to consumption sites, many of which will have simultaneous use for other purposes.
Until you run out of those and then your costs increase worse than linearly because you have to start using more expensive land.
> the linearity is an advantage in that it enables mass production, and gets the benefit of the manufacturing learning curve.
Anything you're going to use for a large fraction of the power grid is going to be mass produced.
> Quadrupling your construction costs.
This is the opposite of how economies of scale work. If you make something bigger, the variable costs scale linearly and the fixed costs stay the same but are amortized over more units.
> Also, making your generators much bigger than current practise increases project risk and therfore cost.
This is no different than needing twice as many turbines to generate twice as much power. It's a variable cost, offset by you getting twice as much power without increasing your fixed costs.
> Quadrupling your construction costs again, and decreasing reliability, capacity factor and productive lifetime.
You keep saying "quadrupling your construction costs" without evidence. We build oil platforms in the ocean on a regular basis. They cost some tens of millions of dollars. Existing fission reactors cost some billions of dollars. The difference from being on the ocean is evidently not the dominant cost. And then you don't have to pay for land.
> Seawater is nasty stuff.
Many existing reactors are situated on coastlines and cooled by seawater. It's not some kind of insurmountable problem.
> It will be used for productive farmland, though.
The price of "productive farmland" compared to the price of land near a city is multiple orders of magnitude less, and high density power generation doesn't need that much land.
> Again, why aren't fission or CCGT plants being built in those places? How is fusion different?
New fission reactors largely aren't being built at all because of regulatory suppression. CCGT plants can't afford to spend fuel generating power which is then lost to long distance transmission.
> It's about time to cashflow for utility finance types, and they also tend to want a longer track record than "it worked once".
If it worked once but is now generating ten times more power per unit of investment capital than any of the alternatives then investors would be lining up, and may not even be needed because the plant operator could use revenues from selling such a large amount of electricity to build more plants with.
Here, look: take case 11 from this study by Sargent and Lundy[1](PDF): an AP1000 fission reactor, 2.156GW, $6041/kW, swap out the fission reactor for fusion generation at $0, and show us how to get to $176/kW (a tenth the per-kW price of a small-scale PV plant with battery storage, case 25).
Also note the construction timetables: 72 months vs 18 months for PV.
1. EIA 2020, Capital Cost and Performance Estimates for Utility Scale Power Generating Technologies: https://www.eia.gov/analysis/studies/powerplants/capitalcost...
> This is the opposite of how economies of scale work. If you make something bigger, the variable costs scale linearly and the fixed costs stay the same but are amortized over more units.
That's not how construction works. Past some small scale, construction cost scales quadratically or worse with size. Building a 100m tall sky scraper is not 10 times as expensive as building a 10m tall 3-story house - it is at least a hundred times more. The only reason why it's sometimes worth it is in ultra-high land-cost areas, such as Manhattan. But you'll never see sky scrapers outside city centers, because construction costs scale horribly with size, even for simple structures. Building a fusion chamber twice the size of ITER would likely be a new 50 to 100 year research project.
> You keep saying "quadrupling your construction costs" without evidence. We build oil platforms in the ocean on a regular basis. They cost some tens of millions of dollars. Existing fission reactors cost some billions of dollars. The difference from being on the ocean is evidently not the dominant cost. And then you don't have to pay for land.
Is anyone building fission reactors, or any kind of huge concrete building out in the ocean at all? Extracting oil from the ocean is many times more expensive than extracting oil on land. I have no idea why you even imagine that it's possible at all to construct a nuclear power plant out in the ocean. There is certainly no precedent for anything even close to that.
I will note that fusion reactors have serious diseconomies of scale.
First, the power output of a fusion reactor is limited by what the first wall can withstand. Therefore, the power goes as radius^2, where as the cost goes (at least) as radius^3.
Second, the larger a fusion reactor becomes, the more parts it has, and the more reliable each individual part has to be (since there will be no redundancy in many; an leak into the vacuum chamber shuts down the reactor, for example). Reliability is expensive, so each part becomes more expensive as it is required to be more reliable.
Renewables sources are extremely redundant, so they'd scale just fine even with unexceptional per-unit reliability.
Wouldn't running many small fusion reactors instead of one per facility help with these issues?
> Building a 100m tall sky scraper is not 10 times as expensive as building a 10m tall 3-story house - it is at least a hundred times more.
Most of your cost difference is that a commercial building isn't just taller than a house, it's also wider. Instead of taking up a third of the lot, it uses the whole thing, and then has 30 times more interior space despite being only 10 times taller. They're also built to commercial building standards which are more expensive to meet.
The costs start getting non-linear when you get into extremely tall buildings that pose special engineering challenges, but nobody is talking about building a fusion reactor into a skyscraper.
> I have no idea why you even imagine that it's possible at all to construct a nuclear power plant out in the ocean. There is certainly no precedent for anything even close to that.
Nuclear submarines survive the ocean just fine.
> Is anyone building fission reactors, or any kind of huge concrete building out in the ocean at all?
Yes, they are and it is a huge political issue in nearby countries.
https://en.wikipedia.org/wiki/Russian_floating_nuclear_power...
Again this assumes fusion power will be cheap. But in reality it may cost about as much as (fission) nuclear power. So yes it may help with making energy production carbon-free (together with solar, wind, hydro), but it won't necessarily create a some sort of energy abundance.
The theory isn't that the cost will be low, it's that the output will be high. If it costs the same amount as a fission reactor but produces ten times more power, that's lower cost per MW than anything on the market. Even if it costs more than fission, it could be competitive as long as the more it costs is less than the more it outputs.
But how should that gain in energy output be possible without making the whole system huge, too? The heat generating part of a nuclear power station only makes up a small fraction, most of the material is for transforming the heat to electricity and to shield off radiation. If you want to process more heat, you need more infrastructure to do so.
But why would a fusion reactor produce 10 times more power than a fission reactor of the same cost? A fission reactor is, comparatively, very simple. Just a steel cylinder filled with fuel and control rods. No superconducting magnets, no zillion degree plasma to contain and control, low neutron field (as long as we're comparing to D-T fusion). Also heat transfer is much more efficient, enabling high power density, since you pump coolant through the entire reactor vessel instead of just the outer edges.
> One of the big problems with existing power plants is that you have to build them near where people are.
I don't know how it works in the US, but this is notably not true in the UK and Europe. Gas plants are comparatively small and nestled in, but big coal (to a limited degree) and particularly fission plants are frequently in the middle of nowhere. They're somewhere near a village that can supply a workforce, but siting concerns for nukes were more based on making sure any criticality excitement could be shared with neighbours across whatever nearby border was handy than putting them anywhere near cities.
That’s about the same infrastructure than a nuclear fission reactor. And nuclear electricity is already pretty cheap.
I don’t know how it costs in US, but in France, fully charging a Model 3 costs about ~5€ at night. That’s not 10x cheaper than gas but that’s a lot cheaper.
Retail electricity prices in France are €0,13/kWh, so not that cheap (€0,18/kWh pre pandemic).
https://www.statista.com/statistics/418087/electricity-price...
This doesn't matter, though, because France doesn't need many nukes anymore, therefore doesn't subsidizes new plants anymore. One new plant is built in France, and it already is hellishly expensive: "As of 2020 the project is more than five times over budget and years behind schedule. Various safety problems have been raised, including weakness in the steel used in the reactor." https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan...
There are two problems with this reasoning. First, you are comparing the cost of written-off plants, for a technology that has huge upfront costs and much lower fuel costs.
Fission is not cheap if you build a new nuclear plant, not in the Western world. That's why almost no nuclear plants are being build. Making a safe plant is just really, really complicated.
Second, this specific argument can be used to see why fusion is a pipe dream. The primary competitor to fusion is fission. And the fuel costs of fission are pretty low, as you just said. So fusion will not be competitive unless you can built them around the same price as fission plants.
Someone else in this thread talked about S curves. Well, those kind of S curves happen for tech that gets produced in larger quantities, where it is economical to spend engineering resources making the production of the tech cheaper.
Maybe I’m wrong but fission also don’t need extreme cooling utilities. And fission seems to be way more secure than fusion. So, while I do agree on the « new tech » costs, I’m pretty confident we’ll be able to build this plants anywhere in the world and not only near rivers.
But maybe I’m too optimistic :)
I think you mixed up fission and fusion there. Regardless, a fusion reactor will need similar amount of cooling infrastructure if you want to output a similar amount of electricity.
Theoretically? Pure brute force. Fusion just generates that much electricity that it has the potential to be insanely profitable. There's a lot of ifs, but there's a good reason to bet big on it.
People often make the mistake of looking at the reaction energy of fusion, and comparing that with fission or burning fossil fuels.
But the majority of the reaction energy is carried away by high-speed neutrons, which are pure waste - they can't be captured by magnetic fields, they are heavy and penetrate almost any material, leaving holes behind that make the structure brittle, and when they do get absorbed, they make the atom that absorbed them unstable, turning the material radioactive.
So, at least as long as we use neutri-producing fusion (and any realistic fusion reactor has to) the actually usable energy is not that impressive compared to fission.
Please explain how it generates that much electricity that cheaply.
Direct conversion is theoretically about 60% thermally efficient, on par with combined cycle gas generators.
> Please explain how it generates that much electricity
This is the non-theoretical part
> that cheaply.
This is the theoretical part. I think a lot of people are misinterpreting my comment. I have absolutely no idea if it can be done that cheaply. But I can say for a fact that the yield of energy is massive. The question is if it can be done cheaply. That's the bet. The question is if you want to take that bet. You have to make similar bets on tons of technologies. It usually takes 10-20 years after something is made till it starts to follow the S curve and become cheap. Even solar and wind followed this.
Responding for the parent. They are basically making predictions with S curves. Technology often starts out as really expensive but after awhile gets super cheap, following what appears to be an exponential curve (bottom of the S), before it levels off (top of the S). Yeah, look more like an integral sign or sigmoid.
But with fusion the endless claims of "too cheap to meter" are because how much energy there is in a fusion reaction. [0] We know that fission produces a lot of energy (but is expensive) but fusion produces significantly more. It also doesn't have the radiation drawbacks and so it is expected to follow the S curve (fission did initially but things changed. This is part of why France has so much nuclear).
So if (big if) fusion does follow this S curve (which there are good reasons to expect it to) then it could provide a very cheap and sustainable energy source. Yes, it is a bet, but every technology is. We won't know until we spend significant time and money into researching it. But honestly, a few billion dollars isn't that crazy for the potential upsides. We've spent that money on far greater risks with lower payout. Despite what the OP said, the money for ITER does not require international collaboration. Any rich country could do it themselves.
[0] (Fission and fusion can yield energy graph) http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/nucbin.htm...
If we got to the point where cost wasn't a factor would the carbon footprint be extremely low? I assume at some point we'll be unable to ignore climate change and our survival will depended on minimizing it using large amounts of energy from a source that doesn't have a high carbon footprint.
If only ~30% of CO2 emissions are from power-plants (at least in the US, probably higher globally considering developing nations) then replacing those installations with fusion won't directly zero things out...
... But if "cost wasn't a factor" then we could just simply dedicate the electrical output of fusion plants to brute-force CO2 out of the air.
If fusion drives electricity prices into the ground, transportation is going to rapidly go electric.
PV is already driving electricity prices into the ground, the limiting factor right now is that batteries are expensive enough that long-term savings aren’t enough to overcome the sticker-price shock at the point of sale.
If cost wasn't a factor to any energy technology then you could probably negate its carbon footprint because you could use that electricity to cheaply pull carbon from the air.
But there are other environmental impacts. Fusion, even compared to fission, has an extremely small footprint (per megawatt). Its fuel is easily available (isotopes of hydrogen). It does require some pretty advanced magnets though, so it will contribute to the strip mining that we do for rare earth materials (though this applies to all energy forms, including solar and wind). I don't have numbers to say if a fusion reactor would use less total rare earth metals per megawatt compared to something like solar or wind.
One thing to note though. Once we get sustainable fusion reactors, it will still take a bit for that cost to come down significantly. That usually takes 10-20 years. This is a pretty common pattern. We've seen it from the price of laptops and cellphones to the price of solar panels.
Yes. The reactor could more than pull out the carbon equivalent to its manufacture and then many many times more.
Probably counting in the cost of unlimited global warming and all the damage it will do if we don't stop it, which we won't if current efforts are par for the course.
That would make sense if he's comparing only against fossil fuels. But what was written was:
> I like to think of solar, batteries, fission, and wind as compelling ways to go mostly carbon free and lower energy costs about 2x over the next 20 years or so.
> Fusion is what reduces energy cost potentially another 10x, which really changes the game for lots of things. Exciting stuff. Kudos to this team.
If the 10x is from avoiding fossil fuels, why does fusion get that credit, but the other non-fossil sources don't?
> which we won't if current efforts are par for the course.
Because while renewable energy production is increasing rapidly, it is nowhere where we need it to cancel fossil fuels.
Nothing will be soon enough. That would have been now or ten years ago.
But anything that gets us there sooner will reduce the damage we have done, and fingers crossed, allow us to start undoing it.
If you have a cheap means to an end or an expensive one, and you have limited funding because of politics, you will want to pour all your money into scaling the cheap means - then you'll get there much, much faster.
I live close to a wind turbine factory. They could easily have scaled production multiple times over the past five years. The only reason they didn't is funding, in fact during that period they at some point cut production when subsidies were cut.
I think it's getting to a point now where subsidies are not needed. But still, if you're talking about speeding up the process, you can just provide a little extra funding and get big results.
Anybody looking at numbers sees fusion never, ever producing so much as a single erg of commercially viable energy. So, anybody saying otherwise is simply making it up.
> So, anybody saying otherwise is simply making it up.
You do see the irony of embedding this statement in a comment full of generalization and hyperbole, and lacking any evidence or credible sources, right? I genuinely laughed until I realized it may not have been intended as a joke.
What numbers are those? Or perhaps you even have a citation from work done on the topic by reputable physicists?
And neither did any other invention until they reached a certain scale, price point or level of sophistication. The counter to your comment would be, fusion is still very much in the R&D phase. As being in the R&D phase like so many other products were at one time, of course it has not met your expectation. But neither did Airplanes after the first flight.
The sun does pretty well.
Except we didn't need to invest money in it...
The fusion equivalent of Ballmer’s infamous “developers developers developers” line is “materials materials materials”… and we’re getting there quickly!
And materials may not be the biggest problem! That should be "RAMI RAMI RAMI" (Reliability Availability Maintainability Inspectability).
Paper studies of fusion reactor designs given an availability figure, but this is mere aspiration, chosen because that number is necessary, not because it known to be achievable. The few actual studies of how available a fusion power plant would be (using MTBF and MTTR figures from related technologies) have come to very troubling conclusions: the plant may be operating just a few percent of the time. Getting fusion technology to the point where working reactors aren't perpetually down for repair is even more important than developing materials tolerating higher neutron displacements-per-atom (because it's hard to do the latter without the former). This requires building an experience base with all the kinds of things that will go into a fusion reactor. It also argues for making fusion reactors as small as possible (so there are fewer things to break); this is probably the best argument for these small high field devices (but an even better argument for high-beta plasma configurations).
Is it really limitless if both generating and consuming energy produces heat? Or is that too small of an effect even despite the heat inefficiency of fusion?
Earth gets multiple orders of magnitude more heat from the Sun than humans can ever hope to generate. In concrete terms, Earths gets 153 PW of energy in terms of solar radiation. It also radiates as much. In comparison, humanity uses something like 20 TW in total (that includes not only electricity, but also transportation etc). So, we could increase our energy use 100 times, and still be only around 1% of what we get from the Sun.
So that's between 150 and 250 years with the 2.5% energy consumption grows, then that much again for us to produce more energy than the sun shines on Earth.
https://en.wikipedia.org/wiki/World_energy_supply_and_consum...
Yes, and with 2.5% energy consumption growth, in only 2500 years, we'll consume entire power output Milky Way galaxy.
Extrapolating exponential growth over long timescales leads to silly results.
nothing silly about it if the purpose is to make a point in a discussion with an economist. some of them just don't get it that energy consumption is correlated with economic growth and you can't just grow yourself out of every problem.
> Fusion is in theory something that could give us true energy abundance.
The biggest problem is the 'in theory' part. With current plausible designs, the vast majority of the fusion reaction's energy is carried away by high-powered neutrons, which are entirely waste products.
The neutrons are what we will extract energy from, the alpha particles continue heating the plasma.
Some do, but most of them escape from the plasma, carrying away energy, and need to be captured by the neutron blanket. This amounts to a whopping 80% of the reaction energy.
The real dream are fusion reactions which don't produce neutrons, such as H1+H1 or much more realistically, H2+B11 (though still many times harder than H2+H3).
This is the kind of comment that make me really hope that we can kill energy intensive coins before that happens.
I mean if we 10x the waste heat that could be produced by asics solely for the purpose of mining coins, it could be enough to create a mini climate.
Yeah we need Fusion if we want to put back the carbon into the ground as the rest can mostly help us bring down new carbon use but Fusion can bring down the cost of carbon capture to actually reverse global warming as well. So far the world is just looking at mitigating or slowing it down only which is simply put not enough.
> we need Fusion if we want to put back the carbon into the ground
There is nothing about fusion that makes it essential for putting carbon back into the ground.
> I like to think of solar, batteries, fission, and wind as compelling ways to go mostly carbon free and lower energy costs about 2x over the next 20 years or so.
> Fusion is what reduces energy cost potentially another 10x, which really changes the game for lots of things. Exciting stuff. Kudos to this team.
Citation needed... If the fusion reactors end up needing tape of room temperature superconductors to keep their confinement going, and they degrade rapidly due to neutron radiation, I could easily see solar being cheaper in the long run. I'm not saying this is exactly what will happen, but I have never seen compelling proof that fusion will really be so cheap in terms of capex or opex per Watt.
don't solar panel prices half every five years (similar to moores law modified)? fusion would need to speed up then to be competitive with the solar revolution
solar needs sun and massive batteries to handle base load. fusion base load + solar + wind + batteries sounds like the end game.
Don’t forget long distance transmission in that mix: HVDC can be done with losses of only 3.5%/1000km, which makes it a cost/geopolitics issue for your night to be someone else’s day, your winter someone else’s summer.
The issue with long distance transmission is not efficiency. It is the raw amount of material needed.
Feeding 100% of Europe electricity use with solar panels in North Africa would required many years (!) of the world’s current aluminium production, just to build the transmission cables.
Do the calculation, you’ll see.
Long distance power lines do not work to transmit massive amount if electricity on a global scale.
I’m not sure why you imagine that building this at full-grid power levels might take less than a decade, nor why it might be an all-or-nothing proposition given every single gigawatt can be seen as as a (12GWh? I’m not sure but that magnitude) battery system not purchased, but I’ll gladly do the maths.
1) HVDC designs I’ve seen are copper (towers use aluminium because it’s light, IIRC)
2) http://www.necplink.com/docs/Champlain_VT_electronic/04%20L....
Gives 2500mm^2 cross section for a 1 GW cable
3) WolframAlpha says Europe’s electricity production is 410 GW: https://www.wolframalpha.com/input/?i=total+Europe+electrici...
Which means the total conductor cross section needed is ~1 million mm^2 = 1m^2. Ok, this sounds like it’s going to be a lot.
4) Lets put a line across the Sahara to connect all the panels plus connections to the existing EU grid in Gibraltar, Athens, and Milan.
It’s about 3700km from Casablanca to the middle of Egypt: https://www.wolframalpha.com/input/?i=casablanca+to+egypt
Likewise 350km for Gibraltar, 1000 km Awjilah to Athens: https://www.wolframalpha.com/input/?i=Awjilah+to+athens
This gives a total length of about 5000km, if I spec the cable for 100% of EU power going through each cable, which is excessive as I was trying to suggest this as an adjunct to batteries and local PV rather than a total replacement for either: any combination (including none) of transmission and storage only has to cover lower nighttime/seasonal averages).
This gives me a total volume of 5000km * 1m^2 = 5e6 m^3.
5) This is copper, worldwide production of copper is 14.6e6 tons/year, given the density this is indeed 1.4e6 m^3/year and therefore multiple years at current mining.
6) Global aluminium production is 82.6 million tons/year: https://www.wolframalpha.com/input/?i=worldwide+aluminium+pr...
Aluminium is 60% the conductivity of copper; I assume that means I need the conductor to be 1/0.6 times the cross section? Not my field. Assuming that, I want 8.3e6 m^3 aluminium, given the density that’s 22 million tons, so 3 months.
Edit: I forgot Milan!
7) Tataouine to Milan is about 1500 km: https://www.wolframalpha.com/input/?i=Tataouine+to+Milan+
Therefore multiply my mass estimates by 1.3
Edit 2:
410 GW is also 2-2.5 times current global PV installation: https://en.wikipedia.org/wiki/Growth_of_photovoltaics
If you did put enough PV for all of Europe on top of/along side the Casablanca-Egypt line, the PV would need to be about 550m wide: http://www.wolframalpha.com/input/?i=%28410GW%2F%281kW%2Fm%5...
(I only need to care about peak power in this case, not average, hence only the 20% efficiency factor and not including the additional 25% duty factor).
Your calculations are mostly correct, but pretty optimistic when put in regard of your initial claim (“your winter is my summer”), so you end up with 3month or the worlds production where I end up with several years.
Couple examples: You put a line to cities in the south of Europe. But existing lines from there are nowhere large enough to take all that power, you will have to build lines from Milan and others all the way inside Europe. You can’t build a line to Gibraltar and call it a day, it has to go all the way up to Norway (albeit with tapering)
You also overestimate the efficiency of aluminium power lines, don’t take into account the amount of towers and/or plastic material that would be needed to wrap the lines if you make them underground.
We are talking about years of production, and that’s just for Europe, if you want to replicate this to other continents you quickly get a supply challenge, even if you spread this over 30years, at which point it will be too late, regarding global warming. Not to mention that m the CO2 emissions associated with building such massive lines would take decades (if ever) to be offset with the gains from the use of Solar, which was the point of the thing in the first place...
But in the end my point was not that this is impossible, but that efficiency is not the largest limiting factor here. Material supply is the largest problem. It is not insurmountable but it is a real challenge.
Thanks; sorry I didn’t reply sooner, I normally only look at the first page of my comments to see if I have replies.
> But existing lines from there are nowhere large enough to take all that power, you will have to build lines from Milan and others all the way inside Europe.
Really? Okay. All I can do is look at maps like this one:
https://www.researchgate.net/figure/7-Modelled-AC-transmissi...
Which look, to my completely non-expert eye, like a decent size grid already exists.
I know that picture doesn’t contain enough info even though this isn’t my domain, but it represents the limited level I’m coming from.
I have a Dyson sphere to sell you..
"Fusion is in theory something that could give us true energy abundance."
What does fusion give us that existing nuclear power plant tech doesn't?
>What does fusion give us that existing nuclear power plant tech doesn't?
The energy generated per unit mass in a fusion reaction is ~9 times that generated in a fission reaction[0]:
Which leads to a great deal of confusion on my part as to why we're not spending enormous amounts of money on Fusion R&D. Given the potential of the technology, you'd think we'd have long ago decided to spend whatever was necessary to commercialize hydrogen fusion as a power generation mechanism.Considering the mass of the four protons/hydrogen nuclei (4.029106u) and the mass of the Helium produced (4.002603u) we get a mass difference of 0.026503u or 24.69MeV. So it is easy to see that fusion reactions give out more energy per reaction. However, the energy per unit mass is more relevant. This is 0.7MeV for fission and 6.2MeV for fusion so it is obvious that fusion is the more effective nuclear reaction.The phrase "electricity too cheap to meter" is likely somewhat hyperbolic, but in comparison to pretty much any other mechanism fusion is enormously more productive and efficient.
Would you be willing to elaborate why "energy per unit mass" matters when the mass in question is a completely different substance with different cost and availability profile?
If we found a way to extract 10x as much energy from coal as we currently do, electricity from coal wouldn't become 10x cheaper, nor would we build power plants 10x as big.
>Would you be willing to elaborate why "energy per unit mass" matters when the mass in question is a completely different substance with different cost and availability profile?
Sure. Specific energy (or energy per unit mass) between different types of materials makes a huge difference. For example (Source here[0]):
Note the specific energy of a Kg of burned coal compared with a Kg of fused hydrogen. Fused hydrogen generates roughly 200,000 times the energy per unit mass than burning coal.Material Type of generation Specific energy (MJ/Kg) Hydrogen Fusion 639,780,320 Coal Oxidation 24.0-35.0You're right. Cost and availability play into this as well. There are estimated to be ~1.06 trillion tons of coal on earth[1], hydrogen is the most abundant element in the universe and even makes up a significant amount of the mass of coal.
Burning hydrogen/hydrocarbons is, compared to fusing hydrogen, an incredibly inefficient process.
I'd say that being able to generate 200,000 times the energy per unit mass is an important consideration.
As for availability, hydrogen is more abundant and cheaper to produce (unless you have petatons of plant matter, the right conditions and a few tens of millions of years at no cost to you) than any fossil fuels. Or just about anything else.
[0] https://en.wikipedia.org/wiki/Energy_density#List_of_materia...
[1] https://www.worldcoal.org/coal-facts/what-is-coal-where-is-i...
Edit: Clarified availability.
It's not that cost plays into it, it's that cost (broadly defined) matters, and the metric you have chosen doesn't matter. As a consumer I don't care how energy dense a fuel is; I care only about what it costs me to get that energy.
You might try to argue high fuel energy density implies low cost, but this is clearly not the case in general.
Exactly, and fuel is only a part of the consideration.
Though it's also true that the infrastructure to process, deliver and store large amounts of fossil fuel comes at a higher cost than is usually considered (as some of it is subsidised and socialised), plus there's the pollution.
The reactor can’t meltdown and contaminate the whole planet. Also there is no radioactive waste
Well, there is some radioactive waste [1], but its decay time is far smaller and is thus far easier to handle. (Moreover, there is a larger choice of elements.)
[1] https://en.wikipedia.org/wiki/Fusion_power#Radioactive_waste
Aren't fast decay times harder to handle?
it's easier in the sense that a single accident doesn't make the area uninhabitable in the human civilization timescales. fast decay = it'll kill you today in a minute, but will be safe to approach in a week, or 50 years.
>>What does fusion give us that existing nuclear power plant tech doesn't?
Water is more abundant than Uranium?
Fair enough, I hope fusion plants aren't adjacent to bomb technology in that case? Because that could lead to a lot of nuclear proliferation.
What is the downside?
Imagine how much Bitcoin we could mine with that kind of energy source...
> Imagine how much Bitcoin we could mine with that kind of energy source...
Not much more nor less, since the amount of Bitcoin generated every 10 minutes is controlled by an algorithm independent on how many machines are mining.
Yea, but imagine how secure we could make the blockchain! /s
>You are right, people who flippantly dismiss fusion just don't understand it.
I have a couple of physics degrees, hot fusion is the energy of the future and it always will be. This is not a physics problem, this is an engineering problem and we are just not willing to invest enough money to solve the engineering.
I had a chat with Professor Whyte about this about 5 years ago when he was starting on this quest. The key insight that he emphasized to me (that I could understand!) was the need to deal with the engineering. He told me that compact magnets would facilitate construction and maintenance because simply they would need less space and energy to be physically manipulated. This, as I understood it, would allow for huge reductions in cost because buildings and components scale in cost massively as their size increases. Small magnets won't need a huge building, they won't need special vehicles to move them, they won't need cranes to install, they can be swapped in and out during maintenance, and the work can be planned and executed by small teams at low risk. Who really cares if a team of 5 working for a week have a 10% overrun - that's 2.5 person days. On the other hand a team of 500 working for a year -> 50 person years. Scale is the overhead that they are targetting.
>I have a couple of physics degrees, hot fusion is the energy of the future and it always will be. This is not a physics problem, this is an engineering problem and we are just not willing to invest enough money to solve the engineering.
You're spot on. Which makes no sense at all. Given the potential of commercial fusion, we should be (globally) spending at least several tens of billions per year on R&D.
Assuming the engineering issues are solved, those hundreds of billions would be chump change compared to the economic benefits of volume of cheap, clean power.
If things are not making sense, you need to reexamine your assumptions. I will argue that fusion actually doesn't have much potential, and the relatively low interest in it (as reflected by money being spent vs. alternatives) reflects that.
Commonwealth Fusion Systems is privately funded and aiming to demonstrate net energy gain in 4 years. It's not like the lumbering ITER project.
I've always wondered: why exactly is ITER so expensive, and slow? Is the engineering required at such a standard that it should takes decades of planning and construction and tens of billions of dollars? The timeline is so dilated (started in 1988, first plasma planned for 2025!) it feels like the kind of project that's expected to be cancelled from the start.
It just doesn't strike me as obvious that reducing the major radius by a few meters would have such a huge impact on cost/timelines.
Anecdotally, ITER was the largest of few options for a fusion researcher to run their experiment in a new tokamak. Everybody wanted to put their work into it, and as more features were added, the more funding it sucked up, leaving less money for other experiments, leading to more people wanting to put their experiment into ITER. Here's a presentation [0] that goes over why SPARC, being so much smaller and simpler than ITER could be more likely to succeed.
[0] https://library.psfc.mit.edu/catalog/online_pubs/iap/iap2016...
This quote from the presentation summarizes it well:
“The more money that's involved, the less risk people want to take. The less risk people want to take, the more they put into their designs, to make sure their subsystem is super-reliable. The more things they put in, the more expensive the project gets. The more expensive it gets, the more instruments the scientists want to add, because the cost is getting so high that they're afraid there won't be another opportunity later on- they figure this is the last train out of town. So little by little, the spacecraft becomes gilded. And you have these bad dreams about a spacecraft so bulky and so heavy it won't get off the ground- never mind the overblown cost.”
“That boils down to the higher the cost, the more you want to protect your investment, so the more money you put into lowering your risk. It becomes a vicious cycle.” - Rob Manning, Chief spacecraft engineer, JPL
SPARC (as proposed this year, by CFS, which was founded in 2018) also has the benefit of 3 decades worth of advancement in materials science, computers, and other technologies over ITER, which was started sometime in the 1980's. Sometimes being first to market takes a long time and is very expensive because you first have to invent all of the components yourself.
SpaceX's advancement is impressive, but if NASA had never happened, I doubt SpaceX would even exist today.
SpaceX's main innovation was that they decided to build a rocket that wasn't optimized for performance or reliability, but cost. They were willing to bear huge development risks to create a new price category and capture latent demand for cheaper launches.
I'd say what SpaceX optimises for most is iteration time. They have benefited hugely from an iterative development pattern contrasted to the waterfall pattern of NASA et al. Time is your biggest cost.
I'd say yes and no. You most definitely have a point here as I agree that their model, or view, is different than NASA. However, if NASA had not happened, would even conceiving of a different model or target had happened? Not to mention just initial research into rocketry. It maybe could have happened without NASA, but probably with a severely higher initial investment.
The soviets had a very strong space program and arguably their rocket designs have had a significant impact on spacex…
I should have included them also. It is very much a "standing on giants." As many scientists and engineers from different countries and nationalities have made major contributions. I believe it was an early soviet scientist in the 20s who came up with the formula for how much fuel needed to be loaded into a rocket.
Super Heavy does look a lot more like an N1 than a Saturn V, after all.
For NASA science probes, this cost increase and risk averseness spiraling is called when missions become "Battlestar Galactica".
I thought this was some joke involving Bears and Beets. Turns out it is an actual thing [1].
>In 1992, Dan Goldin became the NASA Administrator. Goldin believed in a philosophy of Faster… better… cheaper—i.e., he thought NASA could do more with less. Hence, Goldin did not support the idea of having large EOS platforms in space and in fact once referred to them as “Battlestar Galactica.” He believed smaller, less expensive missions that could be built more quickly were the way to go and supported development of new programs that actually diverted funds from EOS.
[1] https://eospso.nasa.gov/sites/default/files/eo_pdfs/Perspect...
Arguably the Shuttle suffered from this too— instead of being a tightly focused space truck, it needed to be able to do ridiculous things like fly polar missions and grab Soviet spy satellites right out of the air.
Point of order: if the space shuttle were grabbing satellites out of the air, something has gone terribly wrong with both launching the satellite and the shuttle.
I think the idea was that early spy satellites would use film rather than digital transmission, so it would be at the very least necessary to potentially grab one's own satellites.
In any case, this exact question was asked here, and the top-rated response indicates that it's unlikely that the design requirement was ever meant to refer to grabbing an uncooperative payload:
https://space.stackexchange.com/questions/41741/was-the-spac...
I think the joke was that the satellite isn't supposed to be in the "air".
Parent was being overly pedantic in that satellites were likely to be grabbed out of space and not air.
This is also why it's exciting to see the huge drop in satellite launch costs driven by SpaceX. Your satellite design is going to be much different if you have a few chances to launch on a $1B rocket per year, vs launching it for $10M anytime. Rather than one complicated reliable one, you might make 10 simpler ones and buy extra flights to do repairs if necessary.
The first step to correction is awareness right? Lets turn this tanker of human behavior away from these pitfalls.
This is an amazing observation, and something I've seen in many realms.
Sounds like politics more than technological. Although I guess it is unavoidable.
Here's a render of the completed reactor: https://www.iter.org/doc/all/content/com/gallery/media/7%20-... Note human for size.
It's all completely bespoke scientific equipment hand made for this project only. The cryostat will be the largest stainless steel vacuum vessel ever made-- all welded by hand.
After welding, a substantial number of in-vessel components have to be installed by threading them through access ports, which is also quite a task: https://www.youtube.com/watch?v=pt70mO2nQac
Here's a similar picture for SPARC from wikipedia: https://upload.wikimedia.org/wikipedia/commons/thumb/7/74/SP...
It still need a lot of the (same) support infrastructure. Plus ARC will be bigger than SPARC.
That said building the first is a lot harder than scaling it up.
I believe SPARC is a magnet demo, so it won't have tritium breeding blankets like ITER. It also has a shorter pulse time, 10 seconds vs 1000.
(That's right. ITER, which will cost more than $65 billion and take decades to build, can't run continuously!)
Nor ever produce so much as one solitary erg to flash an LED.
You do seem to be going on quite the hatefest of Fusion, but continue to add nothing to the conversation, including sources of information. So how much energy is in an erg?
3000 ergs is enough to flash an LED.
When you have no turbine or any other means to extract power from a heat source, none gets extracted. Do you need a source for that?
That will become a level in an FPS game for sure.
Lol, I have the same though. They'll probably need to make the equipment a little sparser though, because it gets super crowded once everything is installed. Those cut-aways don't show all the detail.
Expensive because it's a custom built physics lab, not a commercial power plant. Slow because it's an international project. Not just that, but it also requires lots of infrastructure to be built and entire industries to develop in multiple countries, before it can be useful. ITER is massive, but it's also just a tip of the iceberg.
>It just doesn't strike me as obvious that reducing the major radius by a few meters would have such a huge impact on cost/timelines.
It would, easily. Past a certain size, production costs rise exponentially and require one-off tech.
Is it massive because it's 6 meters? Like - a 6 meter diamond would be "massive" - but a 6 meter boat isn't that impressive.
Or is it massive like the tokamak is a 6 meter engine to a 100 km collider? Like there's a ton of other stuff being built in a massive structure?
A 6 meter superconducting magnetic containment vessel is massive, as such things go. But ITER is also an entire facility built around the containment vessel.
The magnets are so large they had to build a factory on-site to put them together. If you can make the magnets small enough to transport from a centralized factory, that's a huge win.
If production costs rise exponentially with reactor size then the exponential power gain with size isn’t very impressive.
I have a pet theory that the major cause for cost/time overruns on large projects is the cost constraint itself. In other words, attempting to do things on too small of a budget results in the overall cost increasing, not decreasing. I suspect that there are a few main mechanisms for this:
1. As budget constraints tighten, the number of man-hours spent wrestling with bean counters (and/or waiting around with nothing to do until the bean counter wrestling completes) increases exponentially.
2. "Cheap solutions" often end up being unfit for purpose, and have to be reworked later at great expense.
3. Budget overruns lead to time overruns which lead to more budget overruns, ad infinitum.
Time has its own cost, especially multi-stage construction projects.
Being delayed imposes costs on downstream work, which must now be ready but in some kind of holding pattern, which imposes costs on work downstream of that work.
So a large part of throwing "Manhattan project" / excess funding (and the potential savings by just funding it that way from the start) is avoiding these delays, to the extent possible.
It costs +$200,000 to tackle some challenge in a critical piece? Sometimes it's cheaper just to pay.
Also, it’s a multi-national government funded program that was never intended to return a profit.
So there’s very little incentive to constrain costs.
The budget overruns are the whole point of the project. Any sort of apparent science or engineering goal is a smokescreen.
Citations? Or just idle theorizing?
It is the same process we see everywhere that massive cost overruns and unlimited delays manifest. Modern management methods can control cost and schedule where that is an actual goal. Where they don't demonstrates the actual goal. Every penny of cost overrun goes into some pocket. Smart management ensures many, many pocketholders are allied to keep the gravy train running.
Don't attribute to conspiracy what can be adiquately explained by beurocracy.
Millions of large buildings, and tens of thousands of huge ships, dams, and bridges are built on time and on budget.
The alternative would be that management cannot be judged on its results.
Some bridges, invariably urban, go massively over budget and schedule. Urban tunnels, routinely. Military procurement, routinely. Are people who manage those systematically dumber than the rest? Or do they have different measures of success?
What is common to those apparent failures is that they serve as a reliable, legal, long-term conduit from public funds to a multitude of private pockets. F-35 can never be cancelled, no matter what, because it has subcontractors in 48 states. The F-35 is a massive success to its backers: it secured monumental patronage. That it can actually take off and land, too, is a miracle.
An experimental fusion reactor is not a large building, or ship, or dam, or bridge. We've been building large buildings since the pyramids of Giza. We've been building large ships since before the Dreadnought. We've been building large dams since at least the Great Depression. The same goes for bridges. I don't think it's intellectually honest to compare budget and time overruns for fusion reactors to budget and time overruns for skyscrapers. You kind of say it without realizing it - "millions of large buildings", well yeah: if we have a lot of practice doing something - like building millions of large buildings - then wouldn't you expect us to do a better job of being on time and on budget than the handful of research efforts into the holy grail of energy production?
This is not a comparison of "budget and time overruns for fusion reactors to budget and time overruns for skyscrapers". It is a statement about management practices, regardless of the project.
The statement is that a blue-sky project such as a fusion system is easily recognized by people on the lookout for sources of unlimited money with no strings attached. When they get control of the project, the bulk of the money will not end up spent on the extremely difficult problems entailed. If the problems are as difficult as expected, handing the money over to people who benefit by not solving them will reliably fail to solve them.
We know with absolute certainty, already, that there is no "holy grail of energy production" at the end of it. The most favorable imaginable result is a system much more expensive to operate than a fission plant that produces no more power.
Or, Occam’s razor. A sufficiently complex engineering task can exist such that it fully taxes even international, multi-nation state-backed parallel capacity for engineering, and science.
This is already demonstrated by your own examples provided, just at a smaller scale.
If there were ever such a project to push against the capacity of our ability to do truly enormous, complex engineering, I’d say a massive, cutting-edge fusion reactor is as good a candidate as one could propose.
Moreover, the economic and educational stimulus these projects provide cannot be ignored when accounting for the indirect, long-tail returns this project, and those similar, provide.
Put another way: ostensibly, achieving net energy gain from fusion is the end of our near-term (energy) needs, conveniently breezing over the evolution and refinements of any system, as well as delivery and storage, but these are paths that are comparatively well mapped out. It then follows that, short of catastrophic losses prior to succeeding (which while not a given per se, seems more a function of time than of ability outright), any reasonable cost is worthwhile. Reasonable, in this context, meaning one that doesn’t bankrupt, or otherwise severely impact the participants in a negative fashion. Given the scale of these budgets vs. that of social welfare programs, military spending, etc. I don’t see that as an issue worth being concerned over. One can know the budget has been exceeded, without that also bringing down the house.
Ultimately, to an extent you’re asserting a false dichotomy. It can be true that there’s continued, substantial progress towards the stated goals of these projects, even if the budgets, horizons, and timelines aren’t to your taste. It can also be true that there’s waste, inefficiencies, and even (both legalised and otherwise) corruption. One does not preclude the other.
It doesn't matter what physics you get when none of the absolute fortune spent over decades ends up contributing toward a resulting source of commercially competitive power.
We know already that if the project achieves all of its projected goals, the result will be much more expensive than fission. We know already that if any power is ever generated, at any price, it can come no sooner than decades in the future.
It's just an absolutely giant construction project. The mass and volume of the construction goes as the cube of the major radius of the reactor. Back of the envelope, SPARC is (6/1.5)^3 = 64 times smaller than ITER. The construction budget for SPARC is ~$500M, so ITER being tens of billions is in line.
How do projects like LIGO ever get completed? I’m probably totally naive here, but I thought LIGO is physically larger and has many difficult constraints. The LHC comes to mind as well, and that absolutely dwarfs ITER in physical size. What’s the difference? Dealing with heat output? Superconductors are really hard maybe?
LIGO did take decades to construct, like the LHC. According to LIGO's wikipedia article, it was the most expensive project ever funded by the NSF in 1994.
LIGO's size is also deceptive, the legs are kilometers long but the design is an L with the important bit being to vibrationally isolate things, maintain dimensional stability, and maintain vacuum.
ITER is likely bigger in terms of volume of concrete or actual footprint.
Hmm, looks like ITER and LHC both use about the same amount of superconductor: around 500 tons.
[0]https://ieeexplore.ieee.org/document/1018583 [1]https://www.iter.org/mach/Magnets
ITER is a victim of a process seen frequently in large public-works projects, but particularly those where no one understands what anything really should cost, and where there is no practical deadline for completion. It is worst when there is no expected utility when it is done.
We see it lately in the numerous military procurements (particularly the F-35 program), in NASA's SLS rocket, in California's bullet train to nowhere, and urban tunnels such as New York's 2nd Avenue subway extension. It is why nuke plants are invariably so expensive and late.
In a word, corruption.
Lately, this corruption has been arranged to be wholly legal, so there is no possibility of prosecution. The majority of the money spent is funneled into myriad private pockets without moving the project toward completion. Nobody involved, at the monetary level, has any desire for it ever to be completed, because that is when the gravy train stops.
Fusion projects represent the worst case of this phenomenon. Nobody knows what it should cost, and nobody in control of spending wants it over with, ever.
The chance that anything of any practical use could come out at the end was openly foreclosed before it ever started: it was never promised to produce any electrical power, and no turbines, or space for any, appear in any site plan.
Any sort of practically useful Tokamak plant would need to be overwhelmingly bigger and more expensive than ITER, and could never come anywhere near producing commercially competitive power, so the project is a known dead end, to be milked until it is finally cancelled in shame.
What is tragic is that each euro diverted to this boondoggle brings climate disaster terrifyingly closer.
That's some hating BS right there. ITER might fail to produce economically viable fusion energy, but it certainly won't fail to produce a massive amount of scientific and engineering innovation.
The sole fact that such a scientific undertaking can be done internationally, over decades, is a great thing considering the global problems we face.
Yes, ITER doesn't follow the USA economic ideology of "much", "cheap", and "now", but the world doesn't consist only of the USA and not everything works well with that ideology.
ITER is not a PV or battery factory. It is more like the ISS.
ISS is an apt comparison. Its apparent purpose while the Shuttle was flying was to be a place the Shuttle could get to. What it is for now is anybody's guess. In just a few years it will be a celestial light show, somewhere.
I have no doubt that plasma fluid physicists will learn a great deal from trying to get ITER lit up. Just handed the money, they could have learned a thousand times more, and maybe even achieved practical D/H-3 fusion propulsion for spacecraft. But that will not happen at ITER.
"Just handed the money", my ass. Did you ever work in science? How to you even think that money should be distributed in scientific institutions? Everyone gets a share based on ... what? Their degree? Number of publications? Consensus by committee?
And for comparison, look what the ISS has brought us commercially: We have a fully commercial manned spaceflight planned for next week. That is a massive achievement without even considering all the scientific work on the station.
Handing 99% of the money to contractors for what will in short order be thousands of tons of radioactive slag contributes minimally to actual research. The developers of the overwhelmingly more practical FRC reactor are left to get by on scraps. Elsewhere in science, money is, in fact, being "granted" directly to scientists. This has gone on since long before you were born.
All of the "scientific work on" ISS is done with crew literally pushing an "on" button on each bit of automated equipment running it. Experiments are forbidden to involve more interaction, and also forbidden to operate without that "on" button, so the crew has something, anything to do.
Commercial manned spaceflight could better have been worked without ISS. ISS's role was nothing more than a place to take them. Plus, a huge money sink on its own. It will soon fall out of the sky, and with any luck not hurt anybody where it crashes down.
> All of the "scientific work on" ISS is done with crew literally pushing an "on" button
Why is this relevant?
I assume he means that the crew was superfluous because the "on" button could be pushed remotely or automated at a fraction of the cost of sending people to space.
This sounds like a whole lot of speculation to me. Can you cite actual sources and documents that prove it?
You write like someone unfamiliar with the history of the other projects cited. Copious materials are readily found online. Read up on them. Try to identify any reason to imagine ITER is different. I will wait.
Hey, that's not fair, there were many people "working" on the 2nd avenue tunnel who were never there. There's still illegal corruption!
Actually you can scale magnetic field stength or size to produce more power. SPARC (and later ARC) aims for the former with modern superconductor tech and is on track to potentially produce energy at Q~=11 by 2025.
I don't doubt it will produce plenty of of fast neutrons. Producing useful energy without destroying the most expensive parts of your reactor in the process is a whole other project. Doing it anywhere nearly as cheaply as overwhelmingly simpler systems whose costs are still in free fall is another, probably impossible project.
Margin?
Akin's law of spacecraft #29 "To get an accurate estimate of final program requirements, multiply the initial time estimates by pi, and slide the decimal point on the cost estimates one place to the right."
Think cubically!
A 6m device occupies 666 (say) --216 m^3
a 10m device occupies 10 10 6 (say) -- 600 m^3
The scale of volume means that you have to build a much bigger facility to put it in (in order for the electronics to be kept dry and for people to be able to get around it to keep birds off it and things.
But worse - the weight. Concrete is 2400kg m ^3 so the small device might weigh 518 tonnes, but the bigger device is 1440 tonnes, so moving parts of it round becomes 3 * harder, the floors have to be 3* stronger, the supply chain has to be 3* better.
And then time - 3* scale, 3* engineering challenge -> many times more time to deliver, many more $$$ -> risk -> planning -> admin... the less capital at risk the less it's worth spending on avoiding the risk.. the less the overhead of the project is.
FWIW ITER is a science experiment - it's designed to find out more about fusion and that data will be very valuable for future reactor designs.
>The general idea is that since we have stronger magnets now, we can make a smaller, and therefore cheaper tokamak quickly.
It's not that simple. The big problem with magnetic confinement fusion is that you need to control turbulence in the plasma so that you can contain the reactions for a reasonable amount of time to extract useful energy. However, turbulence increases with stronger magnetic field gradients, which is exactly what you get when making a smaller reactor chamber with stronger magnets. This wouldn't be the first project claiming to be able to build a small reactor, only to discover that it's virtually impossible without a major theoretical breakthrough. This is usually left out in the venture capital advertisements for these fusion startups. There's a reason why so much money and effort is spent on ITER - it is the only more or less guaranteed path to fusion with the tech and knowledge we have today.
>However, turbulence increases with stronger magnetic field gradients
Mmm, this isn't right. The stronger magnetic field reduces turbulence, it's the gradient of the pressure that generates turbulence. As best as anyone can tell, SPARC should be able to get Q~10 without any miracles involved -- the engineering rules of thumb and the advanced simulations all say the same.
https://www.cambridge.org/core/journals/journal-of-plasma-ph...
>The stronger magnetic field reduces turbulence
That's why I specifically said field gradients - i.e. the thing that gets larger when you have a stronger field in a smaller volume.
>it's the gradient of the pressure that generates turbulence
How exactly do you think that pressure is created?
Also, that link you provided is an editorial from one of the directors behind SPARC. If you want an objective analysis that is not geered towards possible investors, you need to look elsewhere. FYI, anyone selling you Q~10 designs without a considerable theoretical breakthrough is almost certainly conning you. If you don't believe me just look at how Lockheed's compact fusion reactor panned out. Stronger magnets are not some kind of miracle solution that will enable fusion tomorrow.
Not an expert, but... "Net gain" seems to be the "give us enough $Billions and years and we'll find it" holy grail of fusion power. Vs. a $4 Casio calculator I can buy on Amazon today includes a zero-maintenance solar cell that is good for "net gain, plus useful work". Large-scale solar and wind power are already real-world at commercial scale, with costs per MW-h that pretty much beat every alternative. ( https://en.wikipedia.org/wiki/Cost_of_electricity_by_source ) Old-type nuclear (fission) energy has a horrible "what was promised, vs. what was delivered" record.
Maybe your equations and power laws are right, and a "big enough" tokamak would be a competitive source of power. But then there are the details, like "big enough will cost $25 Trillion". Followed by delays, cost overruns, etc.
I'm thinking that a rational, non-expert taxpayer would say, "This fusion thing is a hundred times worse than NASA's Senate Launch System. Stop wasting my money on it NOW, and let gullible investors waste theirs instead."
A march 2019 talk by Dr. Dennis Whyte of MIT working on SPARC https://www.psfc.mit.edu/sparc
Delay in fusion progress seems to mirror HTS design difficulties. A brittle ceramic, in a punishing maelstrom ;)
VIPER: an industrially scalable high-current high-temperature superconductor cable
There are still fundamental problems with fusion reactors that are unlikely to make them economically viable, or even carbon neutral.
Most notably, the extreme temperatures, hydrogen pumping, and high-energy neutron bombardment mean that, even with liquid metal blankets, the reactors will very quickly become brittle, probably not lasting more than a year or two. Since neutron bombardment also turns any material radioactive, not only do you need to tear down your fusion plant (or at least the expensive reactor part of it) every few years, but you have to do it with radiation-resistant robots, as human workers can't get close to the reactor after it's been operating for a while.
CFS has plans for swappable vacuum chambers (1 year lifespan) and the liquid blanket will protect the magnets for a 10 year lifespan.
This talk by the MIT Nuclear Science department head explains the whole rationale behind ARC/SPARC, and this timestamp is where he starts talking about maintenance and the neutron blanket (5 minutes later): https://www.youtube.com/watch?v=KkpqA8yG9T4&t=2400s
> Since neutron bombardment also turns any material radioactive, not only do you need to tear down your fusion plant (or at least the expensive reactor part of it) every few years, but you have to do it with radiation-resistant robots, as human workers can't get close to the reactor after it's been operating for a while.
I bought a new screen cover yesterday for my phone. It came with a full mounting kit that I discarded after the ten minutes that took me to place the cover. The same kit could have been used to mount at least a hundred covers. The small slice of civilization I'm part of is extremely wasteful!
But, let's analyze that waste. First, energy went into collecting and transporting those materials, plus collateral environmental degradation. Now, energy will be spent collecting and processing my waste, and if it can't be recycled, it will end up also provoking collateral damage.
But, if we had infinite cheap energy, recycling all of it would be a no-brainier. Even recycling materials contaminated by radiation would be easy; after all, we already do that to refine fission fuel.
Economic incentives? Those are trivial to legislate, absent the environmental cost and with a promise of green-house gases neutrality. Heck, had we infinity cheap energy, we can pack, move out of planet an leave all of Earth as a bio-reserve.
In other words, nuclear fusion holds the promise of being such a civilization game-changer, that the question of "is it better than solar in the next ten to thirty years?" is moot. With that said, the next ten to thirty years will be vital to attenuate climate change, so nuclear fusion should not be used as a deterrent for other climate investments we can do today.
You're assuming that the plant will produce more than enough energy in one year to power itself, power the country, and power the recycling effort. This assumption is based on nothing - current fusion dreams aren't even close to that kind of power generation.
The nuclear engineering side of fusion has been underfunded for a long time. It's only been in the last couple years that the plasma physics side of the house has been willing to say "OK, we're close enough now that it's time to rebalance the budgets -- even if that means some of us lose our jobs."
Are those calculations of net gain referring to the total energy generated, or the amount we can realistically capture and put to use?
You can assume that they're talking about the total generated. They call this the "scientific gain" whereas the "engineering gain" would include all the inefficiencies of the particle beam injectors that put power into the tokamak, and the inefficiency of the steam turbine that makes electrical power from the fusion heat exhaust, and the auxilliary power to run all the pumps, etc. It's generally thought that the "engineering gain" needs to be at least 5, and the "scientific gain" at least 30, for a working reactor. ITER's supposed to hit scientific gain of something like 10-20, which is close.
The amount of this we can realistically put to use is, always and forever, exactly zero.
The only useful outcome of any of this work is a generation of plasma-fluid physicists with practical experience. Pray we can find them something useful to do when the whole enterprise finally collapses.
You keep making these assertions, failing to back them up with anything other than hand-waving in the direction of entirely unrelated programs. You then respond to requests for citations, or even just an elaboration, with the near-verbatim ‘do your own research.’
Chiefly, how does that further the conversation? More pointedly, why should we listen to you?
Credentialism in this arena is valid, and what I currently see are multiple subject matter experts, albeit with a bias/incentive towards believing in themselves, versus you. Please substantiate your claims, or word them more carefully as to reflect them being conjecture.
Huh, I heard the same (tinfoil) argument about climate change, that all scientist make up the crisis to keep their jobs/funding.
Scientists are not the ones making the big bucks on fusion demonstrator construction. But, obviously, somebody is. Are. Every cent of overrun goes into a pocket. None of it evaporates.
This is the best synopsis I’ve ever seen about it, but the skepticism comes from the lack of results
A whole generation heard about it in school decades ago. Multiple generations by now, even. Its right up there with battery/energy-storage technologies. Headline after headline, enrapturing a newer and newer idealist set of people to quickly become disillusioned. People just get tired of it.
But I’m glad to understand whats going on behind the scenes now. I’ll pay attention. Looks like a real sleeper.
This is exciting. Magnetic field strength is a key component for enabling magnetic confinement fusion. This is because energy gain and power density scales to the 3rd and 4th power with magnetic field strength but only ~linearly with reactor size. See following equations for more details: https://youtu.be/xJ2h3vbOag4?t=306
So, why is this particular announcement exciting? There are 3 factors:
1. This is a high temperature superconductor. I can't find any references, but as far as I remember the substrate they are using needs to be cooled to (WRONG, it was cooled to 20degK, see reply by MauranKilom) 60-70 degK to achieve super conductivity. Compare to magnets used in ITER which need to be cooled to 4degK. This is the difference between using relatively cheap liquid nitrogen vs liquid helium.
2. Field strength of 20 Tesla is significantly higher than 13 Tesla used in ITER. Given that magnetic confinement fusion scales significantly better with field strength vs reactor size, this will enable much smaller reactor to be power positive. See following links for more details on ITERs magnets: https://www.newscientist.com/article/2280763-worlds-most-pow... https://www.iter.org/newsline/-/2700
3. Finally, the magnet was assembled from 16 identical subassemblies, each of which used mass manufactured magnetic tape. This is significantly cheaper and more scalable than custom magnet design/manufacturing used by ITER.
The kicker is how 3 of the factors above interact with the cost of the project. Stronger magnets allow smaller viable reactors. High temperature superconductors + smaller reactors allow for a much simpler and smaller cooling system. Smaller reactors + scalable magnet design further drives down the cost. Finally, cost of state of art mega projects scales somewhere between 3rd and 4th power with the size of the device. Combining all of the above factors, SPARC should be here significantly sooner than ITER and cost a tiny fraction (I would guesstimate that fraction to be between 1/100 and 1/10,000).
edit: typos + looked at the cost of ITER and refined my cost fraction guesstimate + corrected some stuff based on the reply by MauranKilom.
Appreciate the rundown of why this is important!
> This is because energy gain and power density scale exponentially with magnetic field strength but only linearly with reactor size
Nit: It scales polynomially, not exponentially. Specifically (according to those formulas) energy gain scales with the cube of field strength and power density with the fourth power. Still massive scaling indeed, but exponentially would be something else.
> as far as I remember the substrate they are using needs to be cooled to 60-70 degK to achieve super conductivity
The video in the article shows 20 K. Could of course be that higher temperature is feasible and they just played it safe (or the video is wrong).
There is a temperature dependent maximum field strength the material can take and keep superconducting. REBCO superconducts at 70k, but it can't take much current at that temperature.
You are right on both counts, I will update the comment. 2020 paper referenced 7degK magnets. I am not sure where I got 70degK number from... https://www.cambridge.org/core/services/aop-cambridge-core/c...
ITER plans first plasma for 2025 - do you think it is a coincidence that SPARC is planned for 2025 as well in that release? I think both projects will hit delays, but ITER is much further in construction, so I wouldn't bet on SPARC to win that particular race.
But they don't need to, do they? If their claim is sound, they could as well just optimize the magnets and wait for ITER to complete to offer an ITERation (pun very much intended) on the design. The fact that they focus on this weird race against an international research project makes me wonder if SPARC is mostly a vehicle to attract investors.
I think biggest downfall of ITER is also why we must do it. The downfall is thus - ITER is huge and that generally implies lots construction delays and cost overruns. But, being huge also means it will be able to study sustaining high volume of plasma for long durations.
ITERs plasma density will be comparatively low, and that is where SPARC with stronger magnets comes in. SPARC will produce data on lower volume and limited burn time, but significantly higher plasma density.
I'm curious if they can push the magnetic field even higher in the near future. For smaller magnets in NMR spectrometers 20 Tesla has been commercially available for 20 years. Of course this is more difficult for larger magnets.
The new superconductors that allow these larger magnets are also very recent, not in discovery but in actual mass production. So they don't have as much experience with using these as with the classical superconductors. So I hope there is still quite some quick improvement there on the table.
I think so far the ReBCO tape is manufactured in small quantities by a handful of suppliers. If there were million-dollar orders coming in regularly, I suppose there'd be a lot of competition to develop the highest quality product. I expect it'd be like batteries; there's a lot of incremental improvements, and then once in awhile a major chemistry change. There's probably other high-temperature superconductors just waiting to be invented.
If I remember right from one of the videos from the SPARC reactor folks, they were experimenting with not bothering with insulation between the magnet windings. The ReBCO film is bonded to a layer of stainless steel, and they figured the conductivity of the film is so much better than stainless steel that they wouldn't actually get much loss from current leaking through. That seems kind of crazy, but I guess there's a lot of things about superconducting materials that don't behave intuitively.
Maybe manufacturers can make film that's bonded to a thinner layer of stainless steel or whatever, and thus allow for more windings in the same space?
I've visited a company that produces classical and high-temperature superconductors, though this was quite a few years back. I don't know the exact market size, but the MRI and NMR markets are probably not that small, though they use almost entirely classical superconductors right now. But they have hit the physical limits of classical superconductors in NMR, and the first NMRs with high-temperature superconductors are produced and sold now. So there might be some more development there even without the fusion angle.
One purpose of the support material that isn't super-conducting is thermal protection. If your superconducter quenches, you have to dissipate the energy contained in it without destroying the magnet. In classical ones they use copper wire around them as far as I remember, and the high-temperature ones are a very thin film of ReBCO deposited on metal tape, so the actual superconductor is always a small part of the material.
These university press releases are always very positively framed. This one makes the new magnet seem incredibly promising and fusion seem like almost an inevitability now, but decades of failure have us conditioned for skepticism. What's the catch this time?
> What's the catch this time?
This is D-T fusion. Which means you have to have T. Which currently comes from fission reactor and has a half life of 15 years.
So the plan is to use a molten salt blanket with Be to breed T. But Be isn’t scalable for consumption, so maybe lead eventually. That’s probably do-able, it just slows down the rate new reactors can come online since Pb is not as good a neutron multiplier.
Once they breed extra T, they have to capture and refine it. Hydrogen is very corrosive and hard to work with… and T is radioactive hydrogen. Again, probably doable. But guess what? Refining spent nuclear waste in fission reactors is also do-able. It’s also super expensive.
And they still need a containment vessel that will withstand the wear and tear from sitting next to a mini hydrogen bomb all day.
These challenges are likely all surmountable. But are they surmountable AND cheaper than existing nuclear or other energy sources? Meh?
Tritium is a natural byproduct of CANDU fusion reactors, of which there are some 25 or so in operation globally, mostly in Canada. CANDUs use heavy water as a neutron moderator (D20 instead of H2O), making T2O a natural byproduct.
Though most of the reactors do not harvest the tritium, a small number do.
CANDU operators have long been ready to make the capital investments in tritium harvesting, once demand materializes. ITER has long been seen as a potential major source of tritium demand.
(you probably meant to write "CANDU fission reactors")
I'm wondering, fusion reactors themselves produce neutron radiation as a byproduct. Once you have a fusion reactor running, could you use the fusion reactor itself to breed tritium?
Also thinking, we target deuterium + tritium fusion because it's the least energy intensive. However, once we have working proof of concept reactors, could we just make them slightly bigger and fuse more abundant molecules/isotopes instead?
> Once you have a fusion reactor running, could you use the fusion reactor itself to breed tritium?
I'll have to find the citation, but IIRC the answer is "theoretically, yes" - the concept is that molten lithium could be used in a tokamak to absorb neutrons and produce tritium at the same time.
EDIT: Here are two citations I was able to find quickly - it looks like one of the ITER experiments will be to validate the concept [1] and that this could also be the way that heat is removed from the reactor. [2]
[1] iter.org/mach/TritiumBreeding
[2] https://www.euro-fusion.org/faq/top-twenty-faq/what-is-a-lit...
While not listed in the article, this is the design goal of the SPARC reactor.
Their plan is to use FLiBe (Google it) blanket to breed tritium. The Be acts as a neutron multiplier.
As for non D-T fusion, the next best candidate is D-He3. Unfortunately, the only large scale source of He3 is on the surface of the moon and it would have to be mined, on the moon, and sent back to Earth.
A study on feasibility of lunar He3 mining https://ui.adsabs.harvard.edu/abs/2014cosp...40E1515K/abstra...
Not as bad as I expected but not yet feasible economic wise. Assuming the fusion part exists.
According to wikipedia:
"Fusing two deuterium nuclei is the second easiest fusion reaction."
"The optimum energy to initiate this reaction is 15 keV, only slightly higher than that for the D-T reaction."
I think the SPARC guys are going to eat all the CANDU tritium before ITER ever gets a chance light up.
If we have to scale up fission reactors to produce enough tritium to scale fusion reactors, then don't need the fusion reactors.
Tritium only has a half life of 12 years. It's not like there's stockpiles of the stuff. It's constantly being produced. Also as mentioned up thread, they'll breed their own Tritium.
> But are they surmountable AND cheaper than existing nuclear or other energy sources?
DT fusion solves the two biggest arguments that are always raised by nuclear energy opponents: storage of nuclear waste (it doesn't produce high-level waste) and safety (it's not perfect but it can't explode). I wouldn't call it a "meh", even if it comes off as much more expensive than fission.
> I wouldn't call it a "meh", even if it comes off as much more expensive than fission.
It's not competing with fission, though. It's competing with renewables + storage + load shifting + efficiency. Compared to those, it might indeed be "meh".
Agreed, but grid and storage technology that will completely solve the renewable intermittence is probably as far in the future as commercial fusion reactors.
This is a gross mischaracterization of the situation. There are a wide variety of energy storage schemes that promise to make renewables + storage cheaper than fission, which in turn is likely to be much cheaper than fusion. Simply dumping excess renewable power into a resistively heated thermal mass and using that to drive a power plant is likely to be cheaper than fusion.
The only open question about large-scale energy storage is which of many viable alternatives will turn out cheapest, and when their price will bottom out. Battery storage that starts at 1/3 of lithium cost, before price begins to fall, is coming to market.
Until prices do start to bottom out, investment in storage is wasteful, so dollars go to generating capacity of known utility.
Each square meter of panel that goes online delays climate disaster by a precisely understood amount. Each panel made can go into service almost instantly. No matter how big the project, it can start delivering power anytime. There is no smallest-useful facility, right down to the residential rooftop.
Every dollar diverted to Tokamak instead brings climate disaster nearer.
I am generally in support of solar and wind. But then, people underestimate the environmental destruction those can entail, depending on the site. Yesterday, I saw a hillside in a very rural part of Appalachia covered in solar panels. Nothing grew on the hill. Because, you know, plants would cover up the panels in no-time, so you have to vigorously keep all of it in check, with herbicides. Aside from the loss of potential carbon storage from allowing trees to grow on the hillside, which very well might offset any carbon-related gains from using solar, it's just bad for the ecology (which is exceedingly rich in the vicinity). Any farm typical for the area would be multiples of times better.
This is not intended as a rant against solar (again, I'm an enthusiastic supporter), but I'd guess a landscape of fusion generators would take fewer square meters of land than the equivalent using solar. And that is nothing to scoff at.
> Aside from the loss of potential carbon storage from allowing trees to grow on the hillside, which very well might offset any carbon-related gains from using solar,
It is incredibly unlikely to offset the carbon related gains of solar, because the carbon sequestration efficiency of plants and trees is very low to begin with, far lower than solar's capacity to displace carbon emitted from coal when area is held constant.
Sure, it's better to put the solar where there is no existing tree cover, but it seems like most of Appalachia is covered in trees.
which it should be. carbon is not the only environmental issue we face. appalachia is the main channel of animal migration. its incredible. we should do all we can to protect it's integrity.
> which it should be.
Solar power will never need to remove more than a tiny fraction of tree cover from Appalachia. What's a far bigger threat to the ecosystem, including animal migration, is mountaintop removal for coal mining:
https://law.lclark.edu/live/blogs/134-de-regulation-of-mount...
Whatever. You can stop mountain removal mining for coal, and prevent environmentally sensitive land from being devastated for solar farms. Its not an either/or, since there is, in fact, plenty of other land that can be used for solar farms.
> there is, in fact, plenty of other land that can be used for solar farms.
If such land were available at an equivalent price to the hillside in question, why would anyone clear a hillside to install solar? All else equal, it's strictly more work/expense to build a solar farm on an incline. The price for the "other land" must not be right, or must have some other serious disadvantage.
Well, clearing the trees is already a profitable opportunity, if that is what happened. But my guess is we are talking about the idiosyncratic decisions of one landowner. Who knows if they did any kind of serious cost-benefit analysis. Or were you assuming that a solar company bought the land specifically to install solar. Possibly, but that's hardly clear to me. Besides, in the mountains, wind is probably the better bet.
Now .. putting solar farms on top of already strip mined mountains makes sense to me. You've already flattened them, and farming is of the question. And it ... looks like that is happening. Tjough I don't know how the Surface Mining Control and Reclamation Act plays into that.
For terrestrial operations, sure. But we need to either overcome shielding hurdles with fission or have relatively portable fusion if we're really going to explore our solar system or the stars.
Renewables are key to having a sustainable energy economy. Fusion power is what will let us do the drastic things to recover from climate disaster that is already here.
In the grid this would take role of coal or gas plants for base load, no?
Storage at sufficient scale would supply some of what we refer to as baseload today, much as hydro provides baseload power in many places today.
It sounds like the T production chain might itself be quite messy. Molten isotopes salt and lead? How much of that stuff would you need? What do you do with when it goes bad? It may not go boom Chernobyl-style, but it's still far from the birds-in-the-sky deuterium-from-the-sea fusion dream.
> It sounds like the T production chain might itself be quite messy.
It is: it's definitely the biggest challenge after plasma confinement.
> Molten isotopes salt and lead?
There are two main blanket technology in development: ceramic and liquid breeders. They're called breeders but are very different from the kind of breeders you have in a fission reactor. Both are based on converting lithium to tritium by capturing fusion neutrons, but in one case the lithium is in the form of solid pebbles, while in the other, in a molten mixture of lithium-lead (there are no salts AFAIK).
To produce more tritium than you start with you also need a neutron multiplier: beryllium in ceramic breeders and lead in liquid breeders. The problem is beryllium is rare (and also toxic): a 500MW reactor needs ~200 kg/year, which is not a lot, but there's very very little beryllium on earth. If you factor in the initial reactor inventory (170 t/reactor) it turns out ubiquitous fusion energy it's not sustainable if we choose beryllium. If you go with lithium-lead you need more material: 3 t/year (but remember lead is a lot heavier and more common too). If you plan to cover the world energy base load with fusion, you would need a lot of lead (~10% world annual production) but it's doable.
For me, the biggest problem right now is lithium: DT fusion needs lots of pure ⁶Li, which is extracted by enriching even more natural lithium. If we're not careful enough with recycling it from old batteries, we are likely to exhaust the world resources in a few decades.
> What do you do with when it goes bad? It may not go boom Chernobyl-style, but it's still far from the birds-in-the-sky deuterium-from-the-sea fusion dream.
The worst case scenario is still the loss of coolant accident (LoCA). The blanket is exposed to a ~2MW/m² heat load from the plasma (in addition to all kind of radiation), so failing to cool adequately a module means it will very rapidly turns into a (radioactive) molten mess that's not easy to handle. Yeah, it's bad but not nearly as bad as the same accident in a fission reactor.
> Both are based on converting lithium to tritium by capturing fusion neutrons, but in one case the lithium is in the form of solid pebbles, while in the other, in a molten mixture of lithium-lead (there are no salts AFAIK).
https://en.wikipedia.org/wiki/FLiBe
> FLiBe is a molten salt made from a mixture of lithium fluoride (LiF) and beryllium fluoride (BeF2).
Destroying your $300B power station is entirely bad enough.
If we are lucky enough, none will be built.
The bad zone of radioactive byproducts is the half life between 10 and 1000000 years. Shorter and you can wait it out. Longer and the activity is low enough to ignore when it's spread out. When designing a fusion reactor, you can usually choose components that won't generate these undesirable nuclides. But in fission, many products are generated, so persistent contamination is practically impossible to avoid.
Yeah, but nuclear energy opponents aren't the reason fission isn't getting built -- it's primarily about the cost.
I had heard that one of the major drawbacks of tokamaks was the incredible temperatures lead to situations where the smallest mechanical failure will lead to an explosion of hot, radioactive gas. Is that not the case?
The whole amount of gas in the chamber is just a few grams.
Tritium is not pleasant though, but veeeeeeeeery far from anything that could do real harm: https://en.wikipedia.org/wiki/Tritium#Health_risks (you'd need to leak a lot of it continuously)
Temperature is not a very good quantity to gain intuition about plasmas (or heat transfer in general): the temperature of the electrons in a incandescent light bulb is around 10000 K, which seems very hot, but since their density is much lower than the air density, the powers involved are quite small and a light bulb is pretty safe to touch.
In the same way, a fusion plasma doesn't hold that much energy because of the extremely low density (4×10^-6 that of air). An explosion (a runaway/chain reaction) is also not possible: the reactor must continuously supplied with fuel or the fusion reactions will stop in a matter of seconds.
There are situations which could result in significant damage to the reactor components, but still not a public safety concern. Distruptions are events in which the plasma confinement is lost and a large amount of heat is released that could damage all components that face the plasma, but reactors are designed to withstand this.
Another drawback, if you like, are runaway electrons, which are populations of relativistic particles that become unbound and penetrare the vacuum vessel for several mm. Again, this is not a particular issue from a safety point of view, but they can do a lot of damage: if they hit a magnetic coil and cause a loss of the superconductivity state, the coil can heat very rapidily (due to the huge current that goes through it) and potentially melt. Replacing such a coil could cost years of maintenance, for this reason reactors are build with many fallback systems.
That would be the least of its problems.
Costing hundreds or thousands of times as much as solar + storage is a more serious problem. Since it won't be built, that is a theoretical problem. But the project can absorb an unlimited amount of money first.
Very questionable if a fusion reactor is safer then a common molten salt fission reactor. I would argue that is far less likely to 'explode'.
And you can burn up the waste majority of that waste, the leftover waste after that would not really a huge issue.
Both of these are far more political problems then actual real problems a society based on modern fission would have.
The problem with fission reactors in general is that after you stop the chain reaction you've still got a tenth or so of the power output you had when it was on from decay heat for a while and you need a reliable way to get rid of that heat even in the event of a disaster. With fusion the nice thing is that the new heat stops appearing as soon as the reaction stops.
Yes and that is far easier to do then containing a fusion reaction.
There are known well understood engineering solution that have been known since the 70s and that work fine.
The real danger is the high pressure that PWR are under and the chemical instability of the elements that were put together in those designs.
Reactors that are not under pressure and do not have chemical instability that lead to explosive cases have a very contained area of effect even in a worst case.
> storage of nuclear waste (it doesn't produce high-level waste)
It does. You cannnot fuse just D+T, other trace gasses, and lighter isotopes will be present as well.
No, it doesn't in any significant quantity [1]. Besides, there are practically no high Z elements in a fusion plasma. That's because they emit bremsstrahlung radiation (power grows like Z²) and rapidly cool off the plasma. If the reaction is to be self-sustained, the plasma charge averaged over the density (Zeff) must be kept as close as possible to 1. Considering that there's only a few grams of material in a full reactor, there are virtually no heavy elements.
The radiative losses do exist, but are caused by detached atoms from the plasma facing components. Everything close to the plasma is made of light elements and specifically chosen to not produce dangerous radioisotopes when neutron activated: no high-level waste materials, meaning the half-life is lower that 10 years and they can be recycled in around 100 years.
[1]: http://www.iter.org/faq#Can_you_declare_fusion_is_really_saf...
"Hydrogen is very corrosive and hard to work with" Corrosive compared to what? You can put it in a rubber balloon and hand it to a kid.
"T is radioactive hydrogen": True, it emits low energy beta radiation, which is an electron, and is stopped by a sheet of paper. I used to have a wrist watch with a tritium dial; I haven't died of cancer yet.
Corrosive is the wrong word, but hydrogen is such a small molecule, it can leak through metals and weaken them, as I understand it. It's hard to contain.
> Corrosive compared to what? You can put it in a rubber balloon and hand it to a kid.
I've never heard of hydrogen-filled balloons (at least not the kind of balloon you can hand to a kid) - we're you thinking of helium?
It’s a high-school level laboratory experiment. Nobody’s handing them out at birthday parties[0], but mostly because hydrogen likes to go bang loudly, not because it’s corrosive or toxic or anything.
[0] unless Mark Rober is involved in some way.
I know about helium balloons, but hydrogen is really cheap compared to helium. And it's nowhere near as dangerous as it's made out to be. The Hindenburg burned, it did not explode.
> This is D-T fusion. Which means you have to have T.
For the other uninitiated, (or far enough out of secondary school and didn't take it further!) this seems to refer to Deuterium-Tritium fusion, D & T being the isotopes of hydrogen with an atomic mass of 2 (1 neutron, 'heavy' but stable) and 3 (2 neutrons, radioactive) respectively.
I'm not sure if it would be cheaper, but the potential could be there if there's enough innovation in the space. At least in happy we're exploring all paths and not betting the farm on just one.
I'm not sure it's possible for "lay people" (of which I am one) to recognize the difference between a very slow success and "decades of failure".
Very little is invested into fusion power as a project, overall. So advancements seem to come when outside influences cause breakthroughs.
I wonder how different the world would have been if it had for whatever reason been easier to produce fusion power than a fusion bomb. Military investment into the bomb would have probably pushed things forward a lot quicker. As is, the US military built thermonuclear bombs very quickly and then the appetite for advancement just dried up.
You could say that military investment into fusion and fission bombs was groundwork for everything done since. On the other hand, the fact that nuclear power started with bombs probably contributed to it falling out of favor and being regulated to irrelevance (even though hydrocarbons have been responsible for a lot more deaths and environmental damage).
Agreed. Whilst it may well be the largest, highest-field "only" high Tc superconductor design in the world, it's definitely not the highest-field high Tc superconducting magnet -- I believe that honour belongs to another bit of MIT with a 1.3 GHz NMR machine [1] (but I do remember something about Bruker collaborating with the US's National Magnet Lab and building a 30T machine -- I can't easily find a link).
I really wish that press release would put the link to the paper at the top -- I found it very hard to work out what was actually new!
The magnet with the strongest magnetic field isn't necessarily the best engineering solution for a fusion reactor. In particular, these magnets need to be cooled (plumbing can be bulky and coolant can be difficult to work with) and allow for easy servicing of the reactor components (particularly the vacuum vessel which will need replacing every ~10 years due to neutron embrittlement). This magnet design is noteworthy because of several factors: high-temperature superconductivity means they're cheaper and easier to cool, the high field strength allows for a smaller scale reactor, and the physical construction of the magnets makes them cheap to build and allows for easy disassembly during maintenance periods.
This was a 32T field created, not sure if it's the same, but similar.
https://english.cas.cn/newsroom/research_news/tech/201912/t2...
Googling "30T magnetic field" shows some papers that have apparently "pulsed" 30T.
That paper refers to a different magnet. The press release refers to milestone that was achieved a few days ago and has not yet been published. Their goal announced three years ago was to build the magnet and demo it this Summer. Let's just say they squeaked in under the wire since traditionally Summer ends in the US on the first Monday of September. (Unless you want to go with the equinox.)
I think the framing of what's happened so far as "failure" is probably the main thing responsible for this perception. It's true that progress has been slower than many had hoped and the most optimistic had projected, but "failure" sort suggests that the things the research community have been trying haven't represented meaningful progress towards the goal of power production, which isn't the case.
Q (the ratio of energy out to energy in) has improved by about four orders of magnitude since controlled fusion was first achieved, and it's been a slow, at least reasonably steady march since the middle of the 20th century to achieve that progress. The current record-holding Q for magnetic confinement is around 0.67, so we need well under one more order of magnitude to get to the point of "theoretical break-even" (Q>1) -- we're most of the way there. A plant just barely better than break-even probably wouldn't be commercially viable, though, and while estimates vary, that point is probably somewhere in the 10-30 range, so we have maybe another order of magnitude to go after break-even. I don't think there's anything to suggest that after decades of progress we'll suddenly stop being able to make more.
It's true that things have slowed down somewhat in the last 10-15 years, but most of the blame there goes to the need, in order to continue moving forward, to build bigger and bigger reactors, and the need to divert resources to that goal (mostly ITER). To the extent that promises of going faster have turned out to be hot air, it seems like they've mostly been in the form of novel approaches that do fusion in some fundamental new way that avoids the need to build an ITER-like thing. These approaches seem to often involve lots of unknowns, and end up getting bogged down in practical issues once they're actually tried (surprise plasma instabilities and so on).
Recent advances in materials science (mostly REBCO magnets) and computing, though, offer a path to progress on the regular, bog-standard flavor of magnetic confinement fusion (tokamaks) on a smaller scale -- that's what this is. The nice thing about that is that the plasma physics here are very well understood, and have been heavily researched using conventional/not-super-conducting magnets that won't ever achieve break-even, but create identical plasma conditions inside the reactor (MIT Alcator C-Mod is effectively the conventional-magnet predecessor to this project). Up until now, the only real question was whether or not they could build strong-enough REBCO magnets, and now they have, so this is all good news and reason for optimism.
Of course, commercial viability is a whole other question involving lots of questions besides physics. But the physics here seem to not be in serious doubt, unlike some of the proposals from other startups that are more exotic.
> Recent advances in materials science (mostly REBCO magnets) and computing, though, offer a path to progress ...
What sort of computing advances? Modeling? Real time controls? I'm guessing modeling, but would like to know more details.
Would stellarators see the same benefits as tokomaks from higher field strength magnets?
Potentially yes, though stellarator research in general seems to be somewhat less mature than tokamak research. There's an outfit called Type One Energy, though, that looks to me like they're essentially CFS but for stellarators (i.e., take established stellarator designs but do them with HTS magnets): https://www.typeoneenergy.com/ . Their academic heritage seems to come out of the University of Wisconsin instead of MIT.
>> What's the catch this time?
There are a bunch of issues still to be resolved. Higher magnet strength is/was just one of many.
That the most expensive parts of the plant would be quickly destroyed by neutron irradiation is another.
That it would cost overwhelmingly more than solar+storage is what will ultimately kill it. Someday. Many more $B will be spent first.
Lots of negative comments in this thread. I've been following CFS for a few years now and I honestly believe this is an historic event - probably the beginning of the "fusion age".
Yeah, any positive news on fusion progress and there always seems to be the same set of comments appear that are overwhelmingly critical of fusion development. Fusion is not well funded and imo has been let down by mismanagement of ITER, and despite this keeps making progress.
I feel that fusion is one of humanity's best shots at actively reversing climate change, and it is disheartening to see such widespread pessimism about it. Yeah it's hard. There are huge hurdles in making it economicly viable, but if we can go from first powered flight to the moon in 70 years, and put billions of transistors on a chip in 50, then maybe we can get fusion going. It's clearly possible.
> I feel that fusion is one of humanity's best shots at actively reversing climate change
Couldn't the same thing be said about current fission reactors?
I get that fusion doesn't have the downsides of fission... but I'm also worried that people will be "scared" of fusion in the same way they're against GMO vegetables and irradiated fruits, totally irrationally...
Sadly no. While I think that it would work and probably be cheaper and easier than fusion, fission has an absolutely abysmal public image.
People are terrified of radiation, even if the danger is very low. This means it becomes prohibitively difficult and hence expensive to build and run a fission plant because safety has to be prioritized so heavily. That is even if permission is granted to build in the first place.
I think it is unlikely for irrational fear of fusion to become mainstream like it has with fission.
Because of this I think the barriers to fusion power are at this point lower than the barriers to scaling up fission power.
Fusion also produces radiation. So not sure why changing one word to the other should magically change public opinion.
We can just rename fission to #goodenergy or something, that would be cheaper then developing fusion.
People don't even know that nuclear reactors use fission, so the idea that this would change anything is crazy. People opposed will call fusion reactors 'nuclear' just like they do fission.
Fusion Radiation is only immediate, ie, only in the area where the reactor is. And it can be contained with comparatively little effort, even put to use to breed Tritium for more Fusion fuel.
If a Fusion reactor blows up, the radiation risk is basically 0, aside from the lack of potential melt downs.
The amount of long lived radioactive material produced by fusion reactors is many orders of magnitude less than fission. Iirc it's about the same amount of the radioactivity released as burning coal in a coal plant of the same power output.
Yeah, I don't have much hope that the general public will understand the nuances here, especially if the greenies decide to mount a PR campaign against it. OTOH, we can call it "fusion" instead of "nuclear fusion" and that will undoubtedly help. (lol)
Fusion does indeed come with radiological hazards: a fire could release radioactive gas and dust. If designed right, the worst-case scenario would still be way less severe than for a fission plant -- and the worst-case scenario is really what stokes all the popular fears about 'nuclear'. OTOH, tritium leakage could mean that routine emissions are larger.
> even if the danger is very low
The day-to-day danger perhaps, but it's kind of hilarious in a sad way to read this right after fukushima spent god knows how long leaking radioactive shit into the ocean.
Yeah. It's these low probability events that scare people away from fission. Fossil fuel pollution kills millions of people per year. Like more than 5 million. How many has nuclear power killed in 60 years? Probably less than 100,000 as a conservative estimate. Events like Chernobyl and Fukushima are sensational and radiation is a sexy topic. People dieing of lung cancer from air carcinogens produced by coal burning is not.
There is no need worry about that. Extreme high cost will suffice. It could never come within 10x fission cost. You might notice people are not breaking down doors to build fission plants.
There is a species of environmentalism that would consider successful fusion or similar high tech mega scale energy source actually detrimental because you can't build one in your hippy community using old tractor parts and alternative ways of knowing.
Environmentally clean energy source is not enough, it needs to be ideologically pure as well.
Like Mr Fusion? runs on beer, from what I've seen.
This is projection. The irrationality is thinking that fusion is something desirable. I suspect this follows from exposure to fusion reactors as a trope in SF stories. From a hard nosed engineering point of view fusion is just terrible.
I can understand that from an enginneering perspective ITER is terrible, but fusion in general?
There are all sorts of approaches to fusion, and things such as type 2 superconductors were undiscovered 30 ago and uneconomic/unpractical 10 years ago. Timing control systems for magnetised target fusion were impossible but now are doable. Our understanding of plasma has been advancing a lot, simulations are good now, we can control plasmas much better. Chirped pulsed laser amplification is a thing now and really good at making high amplitude pulsed lasers for inertial approaches...
I could go on and on. This isn't the 90s anymore, and our technology is still rapidly advancing. What happens if we find more efficient/cheap/high power density thermocouples, or find a direct energy electrostatic power capture method?
Fusion's economic realities today may be overcome soon, we really do not know what we can do in even 20 years from now. The fundamental truth is that there is vast amounts of energy available in hydrogen, and all it takes is 100MK to ignite it.
DT fusion looks bad even if you totally ignore anything related to plasma physics or magnetic fields. Simply handling the heat flow and neutrons from the reactor looks to make the reactor too big to compete, compared to fission reactors.
And then you have the problem of having to stick sophisticated stuff in the hot zone where hands-on maintenance is impossible (compared to a fission reactor, where just the fuel and relatively simple hardware is in that zone.)
Fusion doesn’t have the stigma of fission, or a lot of the risks, and so if we can get to a point where we are actually building new fusion reactors, we should assume the technology will improve rapidly.
It's a common error to think that fission power plants aren't being built because of "stigma". The actual problem is failed economics. Fusion promises to be even more expensive, for the reasons I explained.
It's not clear why one should expect fusion to have good experience effects. Fission didn't, and the non-nuclear parts of fusion power plants will be mature technologies.
Your argument is that the stigma of nuclear meltdowns hasn’t impeded the deployment of nuclear energy?
If reactors were ten times safer but no cheaper, they still wouldn't be being built.
If reactors were ten times cheaper but no safer, we'd be building them like hotcakes.
I think Japan disabling their fission plants after Fukushima, and Germany following that path are clear manifestation of the opposite: that people fear nuclear and democratic governments act on this fear, against development of the technology.
While this is true, its a fact that the regulatory and governmental outlook on fission has prevented these changes from happening.
The western world has made development of new fission plants practically impossible. Requiring 100s of millions in development before you might get a hint if the government would actually allow you to build a plant.
Thankfully this has finally started to change. Mostly in Canada and that's where we will likely see next generation fission first.
Regulation is the scapegoat for nuclear's failure, but it's equally the case that regulation is vital to nuclear (and to nuclear getting liability caps.) If the risk of nuclear were not socialized no one would build it (or insure it).
What has also prevented changes from happening is that nuclear scales down poorly, so the cost of iterating designs is so large. Making a new kind of PV cell or module, or wind turbine, is comparatively much cheaper, because these are individually much smaller and cheaper. The replicated nature of these sources is an advantage in so many ways.
> Regulation is the scapegoat for nuclear's failure
No it isn't. If you have a regulatory structure that makes progress so expensive and counter to the government plan then progress is very hard to make.
Even the regulatory agency themselves have realized this and are changing their structures.
> What has also prevented changes from happening is that nuclear scales down poorly, so the cost of iterating designs is so large.
US regulation allows nothing between fully commercial and university research making any time of prototyping impossible.
Its in fact very possible to make smaller reactors that can teach you a lot and are not absurdly expensive and still useful. That data then could be used for to further inform regulatory agencies.
> The replicated nature of these sources is an advantage in so many ways.
Yes but even if it doesn't scale down well in terms of engineering you can still do factory construction of reactors. If we can mass produce plans, rocket engines, rockets and cars then the same could be done with reactors.
The reality is the government selected one winner and made deploying anything else practically impossible. The change in regulatory agencies has basically made progress impossible beyond marginal improvements.
Please tell me how it’s terrible, Mr Hard Nosed Engineer ?
Low power density (at least an order of magnitude worse than fission), high complexity, need to maintain large complex objects for which hands-on maintenance is impossible and for which there are many parts for which no redundancy is possible. Fusion reactors are the opposite of "Keep It Simple, Stupid".
The engineering undesirability of DT fusion has been known for decades. All the recent excitement doesn't address any of the known showstoppers.
"probably the beginning of the "fusion age"."
I wouldn't call it that, even if there would be a energy gain.
I call it beginning of "fusion age", when we solved fusion ad can build them reliable and reproducible - and if we still need them by that time, for main energy production.
More importantly, build and operate them for less than, say, 10x the best alternative.
Since any fusion plant would necessarily cost more than 10x fission, and fission is not competitive, that is well out of reach.
What makes this such a big deal? There have been many magnet advances before, what makes this one different?
It is a university press release. Literally anything can be called a big deal.
University press releases need not be peer reviewed so they can get close to saying things that would offend other scientists and get away with it. The key phrase in "the most powerful magnetic field of its kind ever created on Earth" is "of its kind." Creating a many telsa magnetic field has been done in other experiments like with lasers[0], only they are physically smaller in size and last for nanoseconds, it's just of this size, stability and with the high temperature superconductors that makes it special. If the claim is just the magnitude of the field they've already been beat.
[0] https://www.nature.com/articles/s41467-017-02641-7
Just as a note, the max B field here is 600T
I think "it's kind" refers specifically to a magnet for plasma containment. As this doesn't set the record for a REBCO magnet.
https://nationalmaglab.org/news-events/news/lbc-project-worl...
Fusion scientist here (no connection with MIT/CFS). This is in fact a very big deal. One of the chief complaints about fusion energy is the low power density (for ITER-like tokamak <<1MW/m^3, vs ~ 100MW/m^3 for a LWR fission core). The low power density is the primary reason that ITER is as large (and hence expensive) as it is.
Fusion power density scales like B^4. So if CFS can get 2x the magnetic field, then they can make the plasma volume 16x smaller, which might equate to big savings in cost and construction time. (It doesn't make sense to go much smaller than their ARC reactor design though -- the plasma already takes up only a fraction of the volume of the core at that scale, so compressing the plasma further doesn't improve the power density. If you can increase the field even more, which REBCO seems to allow, then you would rather just pack more power into a device about the size of ARC. So don't expect to put one of these on your DeLorean.)
There are definitely other challenges/limitations. For one, this approach increases the heat flux that the inner wall of the reactor will have to survive. The localized heat flux of the exhaust stream is expected to rival the heat flux of re-entry from orbit (20 MW/m^2) and could be as high as the power flux from the surface of the sun (~60MW/m^2). 20MW/m^2 is on the hairy edge of what's possible with today's technology, and that's without all the complications of neutron damage, plasma bombardment, etc. The current thinking is to spike the outer layer of the plasma with neon or nitrogen, to radiate most of the power as photons, but there are limitations & risks to that idea as well. Commonwealth's plan for SPARC (last I heard) was to oscillate the exhaust stream back & forth across the absorber plate to reduce the average heat flux.
The nuclear engineering side of fusion has been underfunded for a long time, so there's much that needs to be done on that front, in terms of demonstrating that the breeding of tritium from lithium can be done efficiently & without too much losses. Also, we should be developing better structural materials that can withstand neutron damage & not become (as) radioactive.
It's still very much an open question as to whether fusion could be made economical, even though it seems like it should be technically possible.
In the original proposal for the ARC reactor, they were proposing making the magnet separable so the top and bottom of the reactor could be separated and the vacuum vessel removed. (See pg. 5 of https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja0...)
It doesn't look like they are targeting that here. Does anyone know if that is ARC (not SPARC) specific, or if that has been abandoned?
The demountable magnets for ARC are so the blanket and vacuum vessel can be swapped out as a whole unit for replacement during maintenance. SPARC has no blanket and will only be used for some thousands of ten second shots or the equivalent of a week or two of continuous operation. The magnets being unshielded will probably fail before the vacuum vessel does.
CFS will be building a lot more magnets, not only for SPARC but for other customers, physics experiments and medical equipment, so I expect they will be working on many additional features including demountable joints for ARC.
One of the early tests they did of the VIPER cable at the SULTAN test facility in Switzerland involved a joint formed by clamping the ends of two cables to a copper bar. It does show that resistive joints are possible with HTS cables, unlike LTS cables, but the actual configuration of a joint for a large magnet is obviously a different matter. Luckily they will have a few years to work on it.
The article says this is from an "MIT-CFS collaboration" which is "on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. That demonstration device, called SPARC, is targeted for completion in 2025."
So, sounds like it's for SPARC.
Yeah, they are definitely building SPARC. I had just been under the impression they were trying to do the separable magnets in SPARC, and was curious if I misunderstood their plan or if their plan had changed.
Yeah--I misread your question. :)
I think that's ARC-specific. SPARC is a prototyping platform, they aren't designing it for long term use or to be refurbished.
Since there is no actual use planned for any power released in this gadget, no maintenance will be performed. When they finish playing, they scrap it, pocket the money, and go their separate ways.
No commercial reactor will ever be built, so this is just for showing off.
The only real good to come from these efforts is employment of plasma fluid physicists. I just hope non-military work can be found for them when this stuff fizzles. Solar Physics is fascinating and important, but has limited budget.
I've long been skeptical of ITER making any sense given its insane cost. I mean even it succeeds, then what?
Here's the truth: there's no such thing as free energy. Even if the fuel is so abundant it's actually or effectively free (eg deuterium), the energy isn't. Say it takes $50B to build a plant that produces 1GW of power, which I'll estimate at about 7TWh/year based on [1]. Let's also say it has a lifespan of 40 years and an annual maintenance cost of $1B going to up to $2B in the last 10 years.
So that's 40 years for 280TWh at a cost of $100B, which equates to $0.35/kWh if my math is correct.
I realize ITER isn't a commercial power generation project. My point is that people need to stop getting hung up on the fuel being "free". The lifetime cost of the plant can still make it completely economically unviable.
Second, the big weakness of any fusion design is neutrons. The problem people tend to focus on is that neutrons destroy your (very expensive) containment vessel with (one of my favourite terms) "neutron embrittlement".
As an aside, hydrogen fusion also produces high speed helium nuclei, some of which tend to escape and this is a problem too because Helium nuclei are really small so can get in almost any material, which is a whole separate problem.
But here's another factor with neutrons: energy loss. High speed neutrons represent energy lost by the system.
To combat these problems we've looked for alternatives to hydrogen-hydrogen fusion, the holy grail of which is aneutronic fusion. The best candidate for that thus far seems to be Helium-3 fusion but He-3 is exceedingly rare on Earth.
I really think we get caught up on the fact that this is how stars work but stars have a bunch of properties that power plants don't, namely they're really big and they burn their fuel really slowly (as a factor of their size), which is why they can last billions or even trillions of years. Loose neutrons aren't really an issue in a star and sheer size means gravity keeps the whole system contained in a way that magnets just can't (because neutrons ignore magnetic fields).
So I hope they crack fusion but I remain skeptical. Personally I think the most likely future power source is space-based solar power generation.
[1]: https://en.wikipedia.org/wiki/List_of_largest_power_stations
It seems you're suffering from "neutron embitterment." ;P
Space-based solar power generation (itself "fusion power" in the loosest sense) would be great in the inner planets.
Though to open up the outer planets, Kuiper belt, Oort Cloud, and any other stars, we'll need non-solar* power: hopefully fusion, at least fission.
*Unless we want to go the stellaser route, but I'd bet we'll crack fusion before getting near K2.
It won't be Tokamak fusion in any case. FRC (burning D+H-3) might work, but there is no money for it. Neutron-emission fusion eats all the fusion money.
H-3 is not nearly so scarce as cletus suggests. It is uncommon, but you don't need much.
Your numbers sound like generation 1 numbers, after ITER. ITER is only a test facility to prove hopefully that it can be net positive.
However, those maintenance costs (your estimates) would be the first thing to drop. Any company producing/operating these will be competing with wind and solar, and thus highly incentivized to improve. There should be plenty of low hanging fruit, since it hasn't happened once yet.
Maintenance cost is not a place to expect major cost reductions. Those tend upward.
Once we've shown this can work successfully, I think people will get excited and investment money will rush in. Ideally, we'll perfect the technology and make it cheaper and more efficient, just like any other technology. If an MIT-borne fusion startup IPOs and they have a working demonstration reactor, I would probably invest.
I think the hope is that with economies of scale, we could build really huge fusion plants one day, and drive down the cost of energy to less than a cent per KWh, and of course completely eliminate our dependency on fossil fuels. If energy becomes that cheap, we could use electricity to produce hydrocarbons from CO2 and water to power airplanes and such. Currently, we can imagine short-distance flights being electrically powered, but transatlantic flights are going to be difficult to achieve with batteries.
While I agree with your point about ITER.
Space based power generation to me is incredibly dumb. It would be far easier to build solar on earth and transport it around with high efficiency DC lines.
And if you are really looking into the cheapest possible energy a thorium breeder reactor could run for ever with no fuel cost and could be built with 70s technology. These reactor be produced in a factory at a manufacturing line and then dropped into a containment facility.
How this should be more expensive then space based solar makes no sense to me.
If only there were some way to capture and use all that power from the giant fusion reactor in the sky...
Question from a layman: how will the energy from a fusion reactor be extracted and converted into electrical energy? As far as I understand, the plasma inside a tokamak is isolated from the surroundings by the use of very powerful magnets. I assume in a reactor that is supposed to generate electricity there would be some interface between the plasma and some kind of heat exchanger that would generate steam and turn gas turbines?
Neutrons that escape the tokamak arrive in a lithium mantle around the reactor, which produces helium and some heat. The heat is extracted from the lithium mantle, and then you have a conventional gas turbine.
This is what I remember from memory, I would need to fact check that.
Yup, plain old heating water to make steam to turn a turbine.
Fusion is on my plate too. I've got a design that I really need to test, an I've finally got the funds to begin construction.
My method uses much lower magnetic fields that could be provided by permanent magnets, but should allow containment times on the order of weeks for small quantities of D-D fuel.
I have more information at http://www.DDproFusion.com
Looks like the video on your site is not working. At least from my region.
I love backyard science like this. No offense intended at all, but it's always heartening to see the Davids fighting the Goliaths.
Update: They have a press release on their website https://cfs.energy/news-and-media/cfs-commercial-fusion-powe...
In case others are wondering, looks like this is for SPARC.
FTA: This "MIT-CFS collaboration...on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. That demonstration device, called SPARC, is targeted for completion in 2025."
CFS: https://cfs.energy/technology
(edit: clarification)
The magnets are a problem to solve, but not the biggest problem by far. Solve for neutron embrittlement of the reactor parts, and then you’ll start to have some credibility.
The advances enable a magnetic field strength that would otherwise require 40x more volume using conventional technology - doesn’t the reduced volume imply the plasma temperature would also increase significantly? Or is the magnetic field strong enough to protect the walls of the chamber?
My understanding is that the volume of the magnet is smaller and thus the entire reactor size goes down significantly leading to lower cost.
ITER was designed to use weaker electromagnets and therefore needs a massive building and tons of cranes and a massive budget.
The ARC reactor design has 10x the volumetric power density of ITER.
Unfortunately, the ARC design also had 40x worse power density than a PWR primary reactor vessel.
Is that the right metric? You wouldn't need to build a huge containment structure around it like you would for a PWR, so I'd imagine the power density of the plant as a whole wouldn't be anywhere near 40x worse. Why focus just on the primary reactor vessel?
Because the rest of the power plant will be similar (or also worse for fusion; consider the tritium handling facility or the robotic equipment for maintaining the fusion reactor). You would need a confinement structure, just to keep the tritium in (which will leak all over even in normal operation). So if you swap out a cheap PWR reactor for a much larger, and hence much more expensive, fusion reactor, you get a power plant that costs more than a fission power plant.
Viewed another way: if you could make a fission reactor with a power density as low as ARC, it would have so much thermal inertia that meltdowns would be essentially impossible. You should then ask why such fission reactors are not built.
I guess I still just don't really see it... like, coal plants are also much less energy-dense than nuclear fission. So is solar, so is wind. We build all of those anyway. There are lots of things other than power density that contribute to whether or not a particular generation technology is economical.
As to why massive fission reactors aren't built: there are plenty of already-available passively-safe/meltdown-proof fission designs (many gen-IV designs qualify), and from what I can tell, the reasons they're not built are as much political as anything -- people don't like them, and the consequent regulatory regime has made any fission projects prohibitively expensive regardless of their size. None of this need be the case with fusion.
As to tritium: I think you're overstating the tritium risk. They're only dealing with grams at a time, and even if it all leaked out, it would rapidly diffuse such that risk to the public would be infinitesimal as compared to normal background radiation (plus its half-life is only something like 12 years). ITER has a safety page: https://www.iter.org/mach/safety that essentially says as much.
Power (not energy) density matters in comparison of fission and fusion because the rest of the power plant is very similar. It's not relevant to the comparison of PV solar and fusion because this is not true. But we don't need to make that comparison, since we CAN compare those directly with fission by looking at actual costs, and then conclude they should be cheaper than fusion (because that will be more expensive than fission).
Tritium will be handled in such large quantities in a fusion reactor that even small leaks will be problematic. As I like to point out, the tritium made and burned in a 1 GW(e) DT fusion reactor in one year would contaminate 2 months of the entire flow of the Mississippi River above legal limits for drinking. Even small leaks could cause serious harm to property values (sorry, your ground water can't be drunk for the next 50 years.)
Gen-IV reactors aren't built not for political reasons, but because nuclear has become such an economic orphan that there aren't stakeholders to drive the construction of these things. The money isn't there because the ROI isn't there.
If you compress something so much that its nuclei want to fuse, it must become very dense. At the core of this compression, density is intense. Unlike a thermonuclear weapon where the compression is transient, there is no release from this nuclear vise. Pressures would radically rise increasing compression even further. Would the gravitational field in the vicinity of the center of this be equally intense? Could black holes on the order of the Planck scale be created? Would such a 'Planck hole' start a chain reaction of gravitational collapse, eventually growing to consume our solar system?
The thumbnail of the youtube video made me laugh
Smaller. Smarter. Sooner. 2018
Currently 2021 where is my fusion energy? But this time must be different, after this advance we are only a few years away from fusion energy?
They seem to have made two claims. First, that they have a qualitatively different design that requires a significantly stronger magnetic field. Second, that they could build a magnet that produces such a field.
They are now claiming to have done the latter. Are you skeptical of the new design? Or do you think it does not represent as significant a departure from earlier designs as they claim?
The running joke has always been that “Fusion is 20 years away,” and has been, for the last 50 years.
I really want this to work. I am a bit concerned, with how “the old guard” will react, once we have successful, productive, fusion.
I foresee an astroturf NIMBY campaign against construction of fusion plants.
At the moment it is very far for clear that fusion will be cost effective. The article says this about the fuel of fusion: "The fuel used to create fusion energy comes from water, and “the Earth is full of water — it’s a nearly unlimited resource. [...]"
They forgot to say that it is not the H2O that comes out of your tap. The earth is especially not full of tritium.
The fuel is deuterium, lithium, and a smaller amount of beryllium or lead used as a neutron multiplier to assure a net positive tritium production. Yes, tritium is needed to start the reactor, but it can be replenished with lithium tritium breeding in the blanket.
Deuterium is plentiful in tap water.
The fuel for fission comes from rocks. The Earth is full of rocks!
That's actually a reasonable argument if you have breeders. The U and Th in an average continental crustal rock will give that rock 20x the energy output of burning the same mass of coal.
It's like saying the ocean is full of gold for anyone to pick up. It is. But not worth picking up with the very low concentration.
The plan is for them to breed their own tritium, though, so the consumables coming in the front door would just be deuterium and lithium, both of which (while less common than tap water) are not rare.
My understanding (and I am a layman) is that lithium isn't that accessibly common on Earth, and that we're doing a bang-up job of using as much of it as we can get our hands on already. Are there practical methods of extracting less accessible lithium that don't themselves have nasty side effects?
Yeah, there have been rumblings about recovering it from seawater: https://electrek.co/2021/06/04/scientists-have-cost-effectiv...
The amount of lithium required for these purposes is absolutely trivial.
It wasn't a joke, it was always based on an adequate level of funding. Everything is always off in the future if it never gets funded.
Ah yes, and how much money? The answer always seems to be “More”.
I mean, yes, obviously if the criticism is that they're getting too little money, clearly they want more. Some technologies are fundamentally expensive to develop (the Apollo program, the Manhattan project, etc.). That doesn't mean the people saying so are automatically charlatans, especially given that they've never gotten what they've asked for -- it's not like some bomber development project where they get what they want and then keep coming back for more. The relatively paltry amounts the US has been devoting to fusion energy research are lower than any of the scenarios laid out in a 1976 DOE planning document[1] about what it would take to achieve fusion power, and lower even than just continuing at 1970s levels (a plan they labeled in that document as "fusion never").
[1] https://books.google.com/books?id=KSA_AAAAQBAJ&lpg=PA234&ots...
Please consult this graphic from 1976 if you are actually interested in the answer.
Could you clarify how to read this chart? The y axis is, funding given different plans? Or.. I got the impression that this is meant to depict a relationship between when practical fusion would be developed and how much funding it receives, but I don’t see how to get that from the chart.
Also, not sure why imgur has that image marked as adult content.
These are projections made in 1976. They can be read as different project plans made at that time for different amounts of funding. For example, "if we follow the blue plan, it would require 9 billion (2012) US dollars of funding in 1982 (etc.) and we would achieve fusion by 1990."
The 1976 projection was that, assuming funding was kept at the level of 1976 (~1 billion a year), fusion would not be achieved in the foreseeable future. It further shows that actual funding has been below that level.
In short: Yes, getting fusion off the ground sooner would have required more money. Not "always more", but more than "we project no success" levels.
Those plans would not have worked, though. They were for programs that assumed tokamaks worked better than they actually do. And by the 1980s it was realized (Lidsky; Pfirsch and Schmitter) that heat transfer limits would make any tokamak power plant unattractive.
"Fusion is always 50 years away" for a reason
https://www.reddit.com/r/Futurology/comments/5gi9yh/fusion_i...
With respect to that graph: tokamaks turned out to not work nearly as well as the plans embodied there assumed (and because engineering obstacles were not sufficiently publicly acknowledged at the time). If funding has not been as high as hoped, it's because stakeholders don't really exist for fusion. The utilities have never thought much of it.
Per a comment by nielsbot, they're saying 2025. So, four years away, not 20. That's progress...
That is production of hot neutrons, not electrical power. Actual electrical power is still decades away... or would be if anybody bothered to try building it. Cost-effective electrical power from Tokamak is never.
FRC, though, maybe. But you would have to have people actually working on that.
Fusion is the Linux Desktop of energy projects.
Will fusion also occur then due to the mishandling of Windows 11?
You don't need an astroturf.
Nuclear ruined it's own reputation for generations though hopeful not as long as they'll have to care for the waste we already have.
What ruined nuclear reputation is environmentalists who don't actually care for environment.
What ruined nuclear's reputation is corruption, and being the most expensive choice. (Although coal will end up overwhelmingly more costly, in the end!) Would it be so expensive without corruption? Who can say? Corruption is wired into the process.
We are purely lucky that, for structural reasons, corruption is minimal on solar and wind projects. Probably this is because what it ought to cost is readily visible from the outset. There just isn't enough fat to attract graft.
Yeah, most expensive choice, unless you count externalities of coal.
Parroting Shellenberger will never make you look like a serious participant in this discussion.
Haven't read his books, I must have gotten his ideas by osmosis. Now reading criticism of the books on his wiki page, I think his critics are not concerned with environment any further than it aids their real case if the quote below is a representative sample:
"criticizing [The Death of Environmentalism: Global Warming in a Post-Environmental World] for demanding increased technological innovation rather than addressing the systemic concerns of people of color."
You don't have to read his books these days since the Astro-Turf he's fuelling with those phrases is all over social media.
I won't even go into this baseless bashing of "environmentalists". It's cheap and disgusting. Some of them have dedicated their whole life to the cause while a shitty anthropologist bashes them while being paid by the same companies which pollute the planet.
There will be no need for NIMBY: fusion power is necessarily 100x+ more costly than solar + storage.
The only real open question is how long the gravy train will run before the plug is pulled. F-35 and SLS have demonstrated that with careful management, that can be longer than anyone could have believed.
The company was founded in 2018. At the time they promised to demo this magnet during the Summer of 2021. What is the issue?
The goal is to get fusion power om the grid in the 2030's and scale up in the 2040's. Stop moving the goalposts.
If anyone have not seen it i recommend this video as a primer for fusion technology, it's from MIT. https://www.youtube.com/watch?v=L0KuAx1COEk
The video thouches upon magnetic fields and its relevance at this time mark ; https://youtu.be/L0KuAx1COEk?t=2880
As a society we have failed to really use fission. Fission does basically everything fusion promises to do.
Fission has a absurdly high energy density, the step from oil to fission is far more relevant then the step from fission to fusion.
Fusion would mean basically no fuel cost, but thorium is already a waste product and even uranium fuel is a tiny part of any fission plant.
Some people seem to believe the fusion is inherently prove against weapons, but this is equally not really true. If you had a working fission plant there would be ways to use it to get what you want to make a weapon.
There are some places you might want fusion, mainly in space travel but even there we are not anywhere even close to where we could get to with fission. Open gas nuclear thermal rockets anybody?
In sum, I'm not against this reseach but its not a way to solve our problems anytime soon. Fission you could get to run with 60s tech and amazing reactors could be designed within decades and often with comparatively small teams in the 60-80s and somehow we haven't managed to make it competitive.
Fusion looks to be far more complex to build in every possible way. How this will be cheaper is questionable to me.
SPARC yttrium barium copper oxide (YBCO) high temp (10-70K) superconducting magnets
SPARC is an amazing project. Congrats on this milestone! I am optimistic about SPARC and ARC. I'd love to hear legitimate critiques, though. I see a lot of negative comments on ITER, which is a very different situation. ITER will teach us a great deal btw, it isn't a waste of time.
The claim is that they have reached "a field strength of 20 tesla, the most powerful magnetic field of its kind ever created on Earth"
Haven't Tokamak Energy in the UK done better than this already back in 2019 with their 24T magnet based on similar HTS tape technology?
https://www.tokamakenergy.co.uk/tokamak-energy-exceeds-targe...
I remembered that in 2018 Japanese team manage 1200 T peak power. http://www.sci-news.com/physics/strongest-magnetic-field-ach...
In comparison, 20T does not look much, but again it is, I wonder with the Japanese technique what is the highest continuous magnetic field.
These high magnetic fields are generated using flux compression[0], in which the incompressibility of magnetic field lines means that compressing the coils generating the magnetic fields will increase the strength of the resultant magnetic field. However, the implosion process permanently destroys the magnet, which makes it highly unsuitable for continuous use and certainly shouldn't be used anywhere near your fusion reactor.
[0] https://en.wikipedia.org/wiki/Explosively_pumped_flux_compre...
1200 T has a magnetic pressure of about 5.7 megabars (about 20x the detonation pressure of high explosives). Such high fields can only be achieved very briefly in devices that explosively disassemble.
I hope the researchers behind this are proud.
And I hope the marketers pretending they'll have a commercial plant by 2025 are ashamed.
From a economical/political point of view I find very interesting and promising that CFS is participated, amongst others, by one of the largest oil company in the world (ENI), which signal a real effort to move away, or at least strongly differentiate, from fossil fuels.
It's nice to see another promising avenue. The Wendelstein 7-X (a Stellerator) design is the other one that I'm particularly interested in. I believe it met its initial goals and is now in a multi-year refit before attempting continuous operation.
Better title: Startup builds strong magnet that might be useful for a fusion plant.
Every mass-media article on fusion seems obliged to use "the fuel comes from water" line. I wonder if a "just says in mice" style harassment campaign would get journalists to stop saying this.
The journalists are saying that because the PR people tell them that. If I were doing PR for a fusion project, I'd sell that aspect hard—it's technically true, and sounds great.
Journalists quote promoters. When something has no reasonable prospect of ever producing, promoters resort to lying. Journalists are not responsible for it, although experience should make them less credulous. But pie in the sky sells better than skepticism.
A bit off-topic but it feel like the right time to ask, does anyone recommend some video or even book to understand the fusion space better as a non-physicist?
I just read an article about this tonight on Sciencex.com I believe it was. It was impressive. It reached 20 teslas in their test.
I read an article about this tonight on ScienceX.com or .org. It was quite impressive. They reached 20 teslas in their test.
Are there other cool things we can do with this magnet tech?
For instance, can I build a railgun to shoot things into orbit?
These are starting to sound like UFO pics. They’re always distant point of light.
MIT is also the origin of Transatomic Power which went belly up after they discovered that an early math mistake meant that their whole plan was bunkus, so evaluate this on its own merits rather than assigning any halo points from the MIT name.
Could these be used to build MRI machines?
so what is the most feasible approach? NIF's inertial containment or mini-tokamak?
Honestly, fission has been the solution for the past 70 years. We, as a society, have just failed to implement it.
I just read an article about this tonight on Sciencex.com I believe. It was impressive.
It's now only twenty years away!
It just a decade away!!
Ah, a university press release.
Nah.
I just read this article tonight on Sciencex.com or .org. It was quite impressive. They reached 20 teslas in their test.
Let me know when the advance comes from Elizabethtown Community and Technical College. That would probably be affordable to put in production.
Even if we can get fusion to work, it will never be economical. Just because the fuel (water) is free, that doesn't make the energy free. The fuel rods for fission power plants are already a rounding error in the cost of energy. It's the capital costs that dominate the equation, and fusion plants will be at least as expensive as fission, which is more expensive per KWh than solar.
https://thebulletin.org/2017/04/fusion-reactors-not-what-the...
You’re citing an article from 2017 talking about a reactor design from 1988 in response to an article about novel fusion technology from 2021.
I agree that the sourcing does seem off in JDDunn9's post but your comment doesn't invite further discussion much.
If we had "an inexhaustible, carbon-free source of energy that you can deploy anywhere and at any time" we'd wreck the planet faster than we already are... I guess at least a few could escape though.
I'm curious whether we could cool the planet by pulling CO2 out of the air with scrubbers powered by fusion reactors, or if their heat output would cancel it out. Removing the CO2 would have the benefit of being an exponential thermal decrease (the planet gets less hot from the sun each day), and heat output from fusion plants should scale linearly with the rate at which the CO2 scrubbers run, so it's possible the scaling properties would work out...
Unfortunately I predict that when we “stop” global warming will likely be when we stop changing the climate (at least in that way).
This is because a lot of rich countries seem to me to be well placed to benefit partially from global climate change at the moment, at least within the 1-2C range. Changing the climate past that point is likely to be controversial, since the countries who now benefit from the situation will likely not want to give those newfound advantages away.
I would think of it a lot as the end result of a war - the borders are defined by where the armies stopped ie the division of Europe and Asia after ww2. After climate change I expect whoever has benefitted from it to defend their position and reject any further alterations!
Since power from a fusion plant would cost 100x+ what solar and wind cost, no.
But every cent diverted to fusion from solar brings climate disaster closer.
Do you have a reason to believe capital deployed to fusion would have been deployed to solar? And if so, why do you think it would make a difference, given the market feedback loop going on with solar driving down costs?
Edit: also, your comments seem to be incredibly negative on fusion, would you mind disclosing if you have any solar or wind connected conflicts of interest?
I have no money invested in solar, wind, or storage enterprises. To my shame.
My beef with fusion is about long-term hucksterism and wholly-legal corruption. STS, SLS, F-35, Big Dig, 2nd Ave, Cal bullet train, fission, fusion.
Dollars are fungible. Would fusion dollars otherwise go to renewables build-out? They might be more likely to go to battery, solar panel, superconducting power transmission, or carbon reclamation research. All of those would be welcome alternatives.
Even FRC fusion would be a better use of funding.