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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

#91

Post by Retric »

opo wrote: post #78
Robotbeat wrote: post #52

Earlier quoted context omitted.

This really is not a big technical problem. You simply don't output the power. This is trivial with any kind of decent power-optimizing inverter setup commonly available today. Solar PV isn't spinning a turbine that needs to find a load. If you disconnect a solar panel, it doesn't damage itself, it just sits there. But I'm sure we'd eventually find uses for this extra energy. Like producing ammonia for agriculture.

No one I know is opposed to renewable energy, but advocates really do everybody a disservice when they try to argue that an intermittent power source without storage is a reasonable replacement for base load power. As Bill Gates said in an interview "…They have this statement that the cost of solar photovoltaic is the same as hydrocarbon’s. And that’s one of those misleadingly meaningless statements. What they mean i…

The term Baseload power is not a goal, it's a Problem with some types of power not being flexible. In that context, soar is closer to Baseload power than peaking power plants. Yes, it currently better matches demand than Baseload power, but as you ramp it up the supply / demand miss mach will simply shift around the day.

Turning on some peaking power plants at night vs the day is not a significant issue. Further, the solution is excess capacity not long term storage.

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

#92

Post by scythe »

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…

Energy storage is easier than fission or fusion. We've just been working on the other two problems for ten times as long. Grid energy storage became financially viable maybe five years ago and there are already startups in compressed air and sodium-ion batteries (which can be potentially much larger/cheaper than lithium-ion at the cost of being less space-efficient). Nuclear energy has been financially viable forever and it took an existential crisis for the richest nation in the world to devote all of its resources to it for years to make it happen.

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

#93

Post by Dylan16807 »

FiatLuxDave wrote: post #77
mrfusion wrote: post #7

It's weird to consider "parasitic" loss a problem. You just factor that into the total output. If it's high enough you're good.

Large parasitic losses are indeed an engineering challenge. In theory, you are correct. However, you are making the assumption that efficiency is a static number. In reality, parts age, get dusty, out-of-alignment, etc. Let's say you are building something that makes 10 units of power, but 8 of those units are needed to keep it running (when working as designed). Say that the part that uses the 8 units of power is no…

It's a challenge, yes, but there's nothing special about it. Getting that machine from 3 units of output to 10 took a lot of work, and nothing stops them from getting to 25 units of output with a similar amount of work. At which point it's safe from marginal losses in output.

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

#94

Post by leephillips »

Spare_account wrote: post #57
leephillips wrote: post #45

Earlier quoted context omitted.

'This is a step short of the lab's stated goal of "ignition", where nuclear fusion generates as much energy as the lasers supply.' Which is just what I was pointing out. And it's a large step from honest break-even, where you count the energy input into the laser system (it's not 100% efficient). And a huge step from practical break-even, where you count the energy required to run the plant.

I was attempting to build on your contributions, but I decided to do it the same level as your comment because it made more sense to address SomeStupidPoint directly. Attempt at constructive criticism: I think your answers were a little too concise for some members of this audience and I decided to help out by expanding on your points a little. I've factored your comment about input energy into the lasers in my reply…

Thanks. I was probably too concise, but only had a couple of minutes.

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

#95

Post by antisthenes »

tonyarkles wrote: post #86
antisthenes wrote: post #75

Earlier quoted context omitted.

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…

I'm not 100% positive that this is the right video, but I think it is. As part of the "overthrow a nation" plan, he talks specifically about destroying critical infrastructure, like electricity. The solution for taking out high voltage powerlines? A pair of Skilsaws hanging under a quadcopter. Drop down onto it and... something bad's going to happen! edit: I also missed the link: https://www.youtube.com/watch?v=m1lhG…

Absolutely. The infrastructure is very fickle, but also enormous on the scale of countries.

Since we're talking about hypotheticals, I could say these things are also true:

1. There are counter-drones deployed and patrolling air space above the towers.

2. There are hundreds of independent power lines with 2N redundancy, so cutting 5-10 high voltage lines would do nothing.

3. The undersea cable points are protected by state agents and have good security for amateurs to compromise.

4. Europe will have 24-48 hours worth of storage even if ALL the lines are cut from the Solar Generation plants.

5. Europe will have backup power generation capacity in the form of locally stored and operated fossil fuel plants.

____

In other words, there's absolutely no evidence that the future hypothetical solar installation is going to be more vulnerable than the infrastructure that already exists today, and surprisingly Europe doesn't plunge into darkness every week.

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

#96

Post by jcranmer »

Robotbeat wrote: post #71
short_sells_poo wrote: post #59

Earlier quoted context omitted.

Ok so you are saying that the new solution isn't any worse in terms of security than the current one, so it's fine? In any case, you cannot compare this to oil pipelines directly because we can stockpile oil. Even if all the pipelines are taken out, many countries stockpile oil that can bridge them over until an alternative solution is found. If a considerable part of the electricity comes from some remote site in a…

I'm the classic US-centric American. Northern Europe can solve its own problems, they have all the tools (nuclear, hydro, wind, geothermal). The rest of the world (i.e. the vast majority of people) is closer to the equator and doesn't need a cable running to the Sahara.

About a decade ago, there was a book written which looked at the ability of Great Britain to become self-sufficient entirely in renewable energy (https://www.withouthotair.com/ looks to be the URL).

It concluded that there is literally not enough renewable energy potential in Great Britain (e.g., cover every square millimeter of space with solar panels) to do so at then-current energy consumption rates. It also pointed out problems with approaches like "giant solar fields in the Sahara" (the requisite solar fields are, well, roughly the size of Germany in terms of required area). Nuclear is technically not a renewable energy resource, but it does have requisite power generation capabilities--and very staunch anti-nuclear activism that makes expanding nuclear difficult.

All in all, quite an eye-opening read.

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

#97

Post by Arizhel »

theptip wrote: post #81
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? 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…

So you think northern African nations are going to let European nations station troops there and take over a big chunk of their land? That doesn't seem realistic, and seems rather imperialistic actually.

Letting the northern African nations provide the security is just plain folly, and also makes Europe completely dependent on these economically backwards and frequently hostile nations.

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

#98

Post by Robotbeat »

scythe wrote: post #92
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…

Energy storage is easier than fission or fusion. We've just been working on the other two problems for ten times as long. Grid energy storage became financially viable maybe five years ago and there are already startups in compressed air and sodium-ion batteries (which can be potentially much larger/cheaper than lithium-ion at the cost of being less space-efficient). Nuclear energy has been financially viable forever…

Energy storage for a few hours is easier than fission. Seasonal energy storage, on the other hand, is much more difficult.

This is why I think a mix of clean power sources (including some nuclear) is going to be optimal.

I am of the firm belief that there are MULTIPLE feasible ways to solve the clean energy problem that we, as a society, could probably do if we put as much effort into it as we did a world war. Examples:

nuclear France (ultimately using breeders of uranium or thorium)

hydro/geothermal Iceland

over-built intermittent renewables buffered with grid storage and perhaps either a little hydrogen seasonal storage or a mega-grid connecting north to south

even exotic solutions like

inertial or magnetic confinement fusion

space-based solar power (which is easier than fusion)

But the optimal (both in time and money) solution is to use a mix of clean energy sources (solar, wind, hydro, geothermal, nuclear) and some storage and some demand-response (smart meters are a pretty obvious solution, here) and some increased geographical grid interconnection (UHVDC power lines).

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

#99

Post by robotresearcher »

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…

> 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 built them already.

Finland will use Finland-appropriate solutions. That has very little to do with the appropriateness of solar in Mumbai or Phoenix.

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

#100

Post by gregmac »

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…

> "Just cut the cables" isn't trivial.

Well, how many towers do you have to knock down using explosives before the lines fail?

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