Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

thebulletin.org

Post reply on HN
Print view View original

151–160 of 222 posts

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

#151

Post by ChuckMcM »

abalone wrote: post #149
ChuckMcM wrote: post #121

This is an interesting article from Dr. Jassby who has both patents and papers on Fusion going back to 1977 at least. And there are at least two things that stand out for me, the first is that he goes out of his way to craft a narrative that is negative, and the second he doesn't mention the half dozen or so fusion efforts that are on going beside the NIF and ITER projects. The interesting thing about the narrative i…

> While it is absolutely true you could design a fusion reactor whose purpose was to create fissile material for bombs, that design would look nothing like a power reactor This directly contradicts the article: "The open or clandestine production of plutonium 239 is possible in a fusion reactor simply by placing natural or depleted uranium oxide at any location where neutrons of any energy are flying about. The ocean…

I challenge you to find anywhere in the ITER facility or NIF facility where you can insert, leave, or remove any amount of natural or depleted uranium oxide at all, much less where it could be exposed to neutron flux. There is a wealth of information on the iter site you can read to understand just how difficult it would be.

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

#152

Post by patsplat »

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…

https://en.wikipedia.org/wiki/Hydrogen_fuel

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

#153

Post by gsnedders »

lucaspiller wrote: post #134
sfifs wrote: post #111

Earlier quoted context omitted.

The danger is political risk, not necessarily theft or vandalism. Any dependency on territory not under your own societal control can be used to hold you hostage and cannot be depended upon. Forget the solar farm, easiest is to cut power lines. (explosives?)

Europe imports around 30% of its oil and gas from Russia. The pipelines between the east and west were originally setup during Soviet times. Given how stable that has been it seems unlikely that a small African country, who will be getting a big chunk of cash from Europe, would do anything stupid.

They haven't been perfectly stable, though. We've seen since 2005 a few cases of oil and gas prices surging upwards as part of the Russia-Ukraine dispute (in 2005, 80% of all gas from Russia to the EU went through Ukraine).

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

#154

Post by trhway »

Recurecur wrote: post #33
_rpd wrote: post #27

Earlier quoted context omitted.

There are a whole bunch of options for aneutronic fusion ... https://en.wikipedia.org/wiki/Aneutronic_fusion

True, but there are many engineering tradeoffs. Any of the listed reactions involving deuterium produce some neutrons, so those aren't desirable (plus deuterium and tritium are rare). Of the other reactions, neither Li-6 or N-15 are readily available, plus lithium is highly chemically reactive. The proton-boron reaction requires the lowest input energy (temperature) of the desirable aneutronic reactions, so it's the…

>neither Li-6 or N-15 are readily available, plus lithium is highly chemically reactive.

your laptop battery (100wh) has something like on the scale of 1 grams of Li6, and the separation is pretty easy.

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

#155

Post by desdiv »

dkirtley wrote: post #102
Robotbeat wrote: post #65

Earlier quoted context omitted.

I said a fifth or a tenth of the land in the US used for ethanol production. NOT a fifth or a tenth of our deserts. More like 1%. And my point is we can install solar on land that has no other use. Like land contaminated by industrial waste, etc.

1% of all deserts is only correct if you are talking about only today's electricity use. Even moderate growth and actually solving energy, not just the electricity subset drives these percentages much higher. To get US centric again, NREL published an optimistic 2016 report suggesting that the maximum rooftop solar capability could ever meet is 40% of electricity. That's 15% of today's energy use in an electricity he…

>1% of all deserts is only correct if you are talking about only today's electricity use. Even moderate growth and actually solving energy, not just the electricity subset drives these percentages much higher.

U.S. electricity usage has been flat for the past 10 years[0] despite a cumulative GDP growth of 34% over the same period. I'm not saying the same trend will continue to hold, but you are overestimating future electricity usage growth.

[0] https://www.statista.com/statistics/201794/us-electricity-co...

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

#156

Post by ekun »

sfifs wrote: post #111
theptip wrote: post #81

Earlier quoted context omitted.

> How exactly do you propose to get that electricity from the desert to say Finland? High voltage DC transmission works fine for this problem. All of the engineering challenges have been credibly worked out and priced ( https://en.wikipedia.org/wiki/Desertec ). The main problems with this approach are political, in that it requires massive cooperation between many countries over very long time scales (decades). Why i…

The danger is political risk, not necessarily theft or vandalism. Any dependency on territory not under your own societal control can be used to hold you hostage and cannot be depended upon. Forget the solar farm, easiest is to cut power lines. (explosives?)

So we resolve all regional conflicts and unify the world under one country. It's not hard.

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

#158

Post by rtx »

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.

We already have a solution to all our energy needs. Funny to see people come up with outlandish suggestions. I am not sure what I am missing. Because logic points to only one direction.

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

#159

Post by rtx »

robotresearcher wrote: post #99
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…

> How exactly do you propose to get that electricity from the desert to say Finland? You don't. No one said it has to be all solar everywhere. > there are many difficult issues that remain to be solved before they can become a core part of the energy production. Wind and solar are already core sources in some places. In many places, a decent solution to the night-time solar problem is natural gas power stations. We b…

Are even thinking about pollution from storage technologies.

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

#160

Post by rtx »

scriptkiddy wrote: post #60
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…

Spoken like someone who has never visited a desert. As a Southern California native, I am intimately familiar with the Mojave, Anza Borrego, and Sonora deserts. I will tell you that these deserts are far from "crappy land that nothing can grow on" as you put it. The North American deserts are areas of huge ecological and geological diversity. They are also some of the most beautiful and awe-inspiring landscapes that…

Thanks for writing this. I am not sure from where this solar lobby sprung up suddenly. If people are so eco conscious, that they support solar. I am not sure how they are ok with have huge parcels of land be covered with panels. We are not even talking about pollution from storage technologies.
Post reply on HN