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

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

#381

Post by godelski » Thu, Sep 09, 2021, 5:27 PM UTC

tuatoru wrote: post #234

godelski wrote: post #224

Earlier quoted context omitted.

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.

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.

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

#382

Post by [deleted] » Thu, Sep 09, 2021, 5:31 PM UTC

codethief wrote: post #380

gghyslain wrote: post #374

Earlier quoted context omitted.

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.

[deleted]

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

#383

Post by tsimionescu » Thu, Sep 09, 2021, 5:39 PM UTC

ajdegol wrote: post #296

tsimionescu wrote: post #277

Earlier quoted context omitted.

> 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).

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

#384

Post by tsimionescu » Thu, Sep 09, 2021, 5:40 PM UTC

dsign wrote: post #276

tsimionescu wrote: post #265

Earlier quoted context omitted.

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 disca…

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.

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

#385

Post by godelski » Thu, Sep 09, 2021, 5:41 PM UTC

brazzledazzle wrote: post #228

godelski wrote: post #223

Earlier quoted context omitted.

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…

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 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.

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

#386

Post by Krasnol » Thu, Sep 09, 2021, 5:45 PM UTC

UnFleshedOne wrote: post #368

Krasnol wrote: post #247

Earlier quoted context omitted.

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 address…

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.

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

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Post by el_nahual » Thu, Sep 09, 2021, 6:01 PM UTC

ziotom78 wrote: post #321

drexlspivey wrote: post #313

Earlier quoted context omitted.

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?

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

#388

Post by TrainedMonkey » Thu, Sep 09, 2021, 6:08 PM UTC

choeger wrote: post #279

TrainedMonkey wrote: post #35

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 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…

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.

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

#389

Post by ncmncm » Thu, Sep 09, 2021, 6:17 PM UTC

liamwire wrote: post #300

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…

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…

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.

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

#390

Post by crubier » Thu, Sep 09, 2021, 6:30 PM UTC

ben_w wrote: post #365

baq wrote: post #266

Earlier quoted context omitted.

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.