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Fusion reactors: Not what they’re cracked up to be

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Re: Fusion reactors: Not what they’re cracked up to be

#181

Post by TheSpiceIsLife »

labcomputer wrote: post #58
short_sells_poo wrote: post #40

Earlier quoted context omitted.

How exactly do you propose to get that electricity from the desert to say Finland? Furthermore, you need to plaster a vast area in the desert with solar plants, which brings along all sorts of concentrated security risks. The alternative is to have many smaller plants dispersed, which results in a big loss of efficiency. I'm all for clean energy, but you seem to be handwaving away pretty huge issues as "thought exerc…

> Furthermore, you need to plaster a vast area in the desert with solar plants, which brings along all sorts of concentrated security risks This sentence seems to be at odds with itself. How does needing a large area concentrate security risks? If anything it seems to disperse them. Unlike a coal or nuclear plant, you can't just walk up to a critical part of a solar farm and blow it up. Any part that you damage is re…

You can't just walk up to coal or nuclear plant and blow it up either.

If you wanted to take a power plant offline, solar included, you would target the grid connection wiring or the high volatage transformers.

Re: Fusion reactors: Not what they’re cracked up to be

#182

Post by abrowne »

vinceguidry wrote: post #178
logfromblammo wrote: post #140

Earlier quoted context omitted.

Desalination of seawater seems a safe bet for excess solar power.

That's a horrible solution. Water is even less portable than energy, even the driest desert can't afford to import water. You're trading a highly liquid but hard to transport commodity for a highly illiquid and hard to transport commodity.

> Water is [...] highly illiquid

Do you mean ice or steam? ;-)

Re: Fusion reactors: Not what they’re cracked up to be

#183

Post by TheSpiceIsLife »

kpil wrote: post #145
logfromblammo wrote: post #140

Earlier quoted context omitted.

Desalination of seawater seems a safe bet for excess solar power.

Ah! I was going to write water pump reservoirs or at some price point electrolysis + fuel cells, but making cheap water in the daytime is also good.

By no measure is reverse osmosis or flash distillation of water cheap even if the energy is free.

Imagine building a huge water desalination plant and only running it when there is excess power available on the grid.

I can't see anyone wanting to invest in that, except maybe a financially myopic government, and they tend not to last very long.

Re: Fusion reactors: Not what they’re cracked up to be

#184

Post by TheSpiceIsLife »

extrapickles wrote: post #163
short_sells_poo wrote: post #46

Earlier quoted context omitted.

I haven't ignored the part where you mentioned overprovisioning. Where do you propose to put the excess power during sunny days? Stable baseline sources like nuclear cannot just be shut down or spun up on a moment's notice to accomodate a vast number of solar energy entering or leaving the grid. At the same time, we don't have a capability to store electricity at sufficient scale so we do need the stable baseline to…

You can do things with the excess power that otherwise would be un-economical to do during a cloudy day. Things like smelting aluminum, desalinating water, etc take massive amounts of power.

You can't just do those things when the weather is good.

Not without huge tax breaks to incentivise load following, because intermittent production of large scale industrial processes is hard and not cheap.

Re: Fusion reactors: Not what they’re cracked up to be

#185

Post by senectus1 »

politicalthrow wrote: post #72
shaqbert wrote: post #2

Mmmh, some of the claims in that article are debunked in this neat video from MIT (though over 1h long): https://www.youtube.com/watch?v=L0KuAx1COEk

That video gives a terrific overview of the landscape of the fusion field as it exists pretty much right now. It's an extremely coherent talk. It's long but worth the watch.

it was mesmerising.. this video needs to spread more.

Re: Fusion reactors: Not what they’re cracked up to be

#186

Post by MR4D »

antisthenes wrote: post #75
short_sells_poo wrote: post #63

Earlier quoted context omitted.

Sorry I worded that sentence poorly. Let's assume two scenarios: a) We create a 200 square mile solar field in the Sahara, from which cables run to Europe to supply electricity. To take this plant out, one just cuts the cables. There, you just plunged Europe into darkness. b) We create a 20x 10 square mile solar fields in the Sahara, all dispersed over a very large area. Well, this is an engineering and construction…

I'm surprised to see this kind of simplistic reductionist thinking on HN. "Just cut the cables" isn't trivial. Have you ever seen a high voltage tower? Not only are they not accessible without professional gear, it's also going to require even more expensive gear to cut multiple inch thick conductors. In all likelihood he power to Europe will be transmitted via multiple undersea cables, the effort of disrupting which…

Why cut it? Explosives would be much easier (think IEDs), and could be improvised from simple sources like gasoline and petroleum jelly. No need for a tool to "cut" a power line, regardless of it being above or below ground.

Re: Fusion reactors: Not what they’re cracked up to be

#187

Post by MR4D »

short_sells_poo wrote: post #40
Robotbeat wrote: post #26

There's nothing quite like trying to get fusion to work for a while to make you appreciate how awesome fission technology is. If we applied even half the cleverness needed for fusion to making better fission technology, we'd probably be way better off. ...and then there's solar. Why even bother with producing the energy, just capture it with a very thin solid state device! Just need to automate the planting of solar…

How exactly do you propose to get that electricity from the desert to say Finland? Furthermore, you need to plaster a vast area in the desert with solar plants, which brings along all sorts of concentrated security risks. The alternative is to have many smaller plants dispersed, which results in a big loss of efficiency. I'm all for clean energy, but you seem to be handwaving away pretty huge issues as "thought exerc…

I'm not the OP, but here's a few thoughts...

Highly distributed rotating masses would handle a large part of the storage, turning it into more of a power smoothing problem.

Secondly, I presume that at some point we'll be covering every building (rooftop and window) with some sort of solar film that converts electricity.

Why don't we have those today in large scale production? Probably for the same reason that the US builds more roads instead of mass transit - it's a bias to build what we've alway built, not a real technological limitation.

Re: Fusion reactors: Not what they’re cracked up to be

#188

Post by MR4D »

There are many good points here, but I'm dismayed at the complete lack of discussion (heck, no mention even!) of stellarators. It seems to me that computing power has made them quite viable (as shown by the German Wendelstein Stellarator), while the Tokamak design is basically an extremely old Russian design that has never performed to expectations.

So if I were stuck with his assumption that fusion = tokamak, then yes, he'd be completely right. But if stellarators achieve their promises, then he's missing the answer completely (and given the Germans success with the Wendelstein, I have a strong confidence that tokamaks will be shuttered within a decade; abandoned to the better technology of the stellarator).

Re: Fusion reactors: Not what they’re cracked up to be

#189

Post by ianai »

MR4D wrote: post #187
short_sells_poo wrote: post #40

Earlier quoted context omitted.

How exactly do you propose to get that electricity from the desert to say Finland? Furthermore, you need to plaster a vast area in the desert with solar plants, which brings along all sorts of concentrated security risks. The alternative is to have many smaller plants dispersed, which results in a big loss of efficiency. I'm all for clean energy, but you seem to be handwaving away pretty huge issues as "thought exerc…

I'm not the OP, but here's a few thoughts... Highly distributed rotating masses would handle a large part of the storage, turning it into more of a power smoothing problem. Secondly, I presume that at some point we'll be covering every building (rooftop and window) with some sort of solar film that converts electricity. Why don't we have those today in large scale production? Probably for the same reason that the US…

There's definitely a link between where it's economical to place a panel and panel efficiency. As the technology matures it will make sense to place it more places. I think at some point, ultimately, it will be in the paint of cars/buildings.

Re: Fusion reactors: Not what they’re cracked up to be

#190

Post by MR4D »

ianai wrote: post #189
MR4D wrote: post #187

Earlier quoted context omitted.

I'm not the OP, but here's a few thoughts... Highly distributed rotating masses would handle a large part of the storage, turning it into more of a power smoothing problem. Secondly, I presume that at some point we'll be covering every building (rooftop and window) with some sort of solar film that converts electricity. Why don't we have those today in large scale production? Probably for the same reason that the US…

There's definitely a link between where it's economical to place a panel and panel efficiency. As the technology matures it will make sense to place it more places. I think at some point, ultimately, it will be in the paint of cars/buildings.

Exactly. Just like Moore's law drove the price of computing power to put it practically everywhere, there is a cost curve for solar that will do the same.
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