MIT-designed project achieves major advance toward fusion energy • Hacker News Board

Re: MIT-designed project achieves major advance toward fusion energy

#391

Post by ncmncm » Thu, Sep 09, 2021, 6:33 PM UTC

Edman274 wrote: post #208

ncmncm wrote: post #204

Earlier quoted context omitted.

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…

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…

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.

Re: MIT-designed project achieves major advance toward fusion energy

#392

Post by naasking » Thu, Sep 09, 2021, 7:26 PM UTC

Chris2048 wrote: post #357

ncmncm wrote: post #316

Earlier quoted context omitted.

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…

> 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.

Re: MIT-designed project achieves major advance toward fusion energy

#393

Post by ben_w » Thu, Sep 09, 2021, 8:22 PM UTC

crubier wrote: post #390

ben_w wrote: post #365

Earlier quoted context omitted.

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).

Re: MIT-designed project achieves major advance toward fusion energy

#394

Post by phscguy » Thu, Sep 09, 2021, 9:50 PM UTC

krageon wrote: post #363

phscguy wrote: post #301

Earlier quoted context omitted.

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.…

> 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.

Re: MIT-designed project achieves major advance toward fusion energy

#395

Post by danans » Thu, Sep 09, 2021, 10:00 PM UTC

jonnycomputer wrote: post #348

danans wrote: post #55

Earlier quoted context omitted.

> 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".

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 pote…

> 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.

Re: MIT-designed project achieves major advance toward fusion energy

#396

Post by nico_h » Thu, Sep 09, 2021, 10:46 PM UTC

mchusma wrote: post #112

dfdx wrote: post #34

Plenty 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…

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.

Re: MIT-designed project achieves major advance toward fusion energy

#397

Post by jonnycomputer » Thu, Sep 09, 2021, 11:07 PM UTC

danans wrote: post #395

jonnycomputer wrote: post #348

Earlier quoted context omitted.

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 pote…

> 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 cons…

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.

Re: MIT-designed project achieves major advance toward fusion energy

#398

Post by eloff » Fri, Sep 10, 2021, 12:11 AM UTC

anonuser123456 wrote: post #17

shmageggy wrote: post #7

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…

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.

Re: MIT-designed project achieves major advance toward fusion energy

#399

Post by danans » Fri, Sep 10, 2021, 12:17 AM UTC

jonnycomputer wrote: post #397

danans wrote: post #395

Earlier quoted context omitted.

> 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 cons…

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...

Re: MIT-designed project achieves major advance toward fusion energy

#400

Post by codethief » Fri, Sep 10, 2021, 12:30 AM UTC

DanielVZ wrote: post #344

codethief wrote: post #281

Earlier quoted context omitted.

> 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 (infrar…

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 fou…

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).