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.
MIT-designed project achieves major advance toward fusion energy
271–280 of 438 posts
Re: MIT-designed project achieves major advance toward fusion energy
#272Are there other cool things we can do with this magnet tech?
For instance, can I build a railgun to shoot things into orbit?
Re: MIT-designed project achieves major advance toward fusion energy
#273Earlier quoted context omitted.
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 powe…
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.
Re: MIT-designed project achieves major advance toward fusion energy
#274Earlier quoted context omitted.
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 ge…
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.
Re: MIT-designed project achieves major advance toward fusion energy
#275Plenty 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 experim…
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…
What is the downside?
Re: MIT-designed project achieves major advance toward fusion energy
#276Plenty 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 experim…
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 radio…
> 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.
Re: MIT-designed project achieves major advance toward fusion energy
#277Plenty 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 experim…
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…
> 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.
Re: MIT-designed project achieves major advance toward fusion energy
#278Could these be used to build MRI machines?
Re: MIT-designed project achieves major advance toward fusion energy
#279This 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 temper…
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.
Re: MIT-designed project achieves major advance toward fusion energy
#280Earlier quoted context omitted.
> 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…
> 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…
> 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.