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Merged How Close is power from Nuclear Fusion

I remain skeptical. I recall the last DOE breakthrough announcement happened to be the day after mass media got wind of their "luggage thief". I only noticed because I saw the same name of the woman who runs the DOE 2 days in a row.
It was odd since I had not seen her name before then and I saw the fusion news on a friends computer, so no way of some connection to my view of the previous days story.
I sort of filed it away as 'possible deflection'. No doubt there was news to be had but the timing is suspicious.

I hope one day it does happen but I think the hype so far has been disappointing.
 
Well, as I have said before, every breakthrough is important and significant. It's just that we need an awful lot of them in order for fusion power to become a reality.
 
theprestige said:
We have a firm grasp of the fundamental principles of nuclear fusion. We're confident in the theoretical underpinnings of the work. I'm confident we'll get there sooner or later. It may be 20 years, or 200 years, or even 2000 years. But we will get there. And why shouldn't our civilization be the one to do it? Why shouldn't it happen in our lifetime?
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I hope you are right because I want to live for at least another 20 years. Unfortunately that will be too late. We need clean energy now.

Laura Ingalls Wilder was born in 1867. She died in 1957... Imagine how many opportunities she would have had to poop on some precursor technology that did not on its own represent any great leap forward.
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Difference is back then there was a lot more low-hanging fruit. Now we are getting into the really hard stuff. Just because we easily did the easy stuff doesn't mean we will easily do the hard stuff.

The center of the Sun, where fusion occurs, has a temperature of 15 million °C and pressure of 3.84 trillion psi. Despite those almost unimaginably extreme conditions, the Sun's core only produces a peak power output of ~280 watts/m3, less than the power density of an adult human. If by some miracle we were able to reproduce those impossible conditions inside the Sun in a device 1 meter across, it would produce less than 300 watts of power!

Now think about how much power the reactor needs to maintain ignition, which would need to be subtracted from the power output to keep it going. How much will be left of that 300W after all the equipment needed to power it has taken its share? Let's say by an even greater miracle you manage to get a net 'gain' of 20%, now you have around 50W of actual output, just about enough to light up the room with LED bulbs. But it gets worse. That 50W is heat energy, not electricity. At best you might be able to convert 40% of it, the rest being lost into the environment as waste heat. Now you only have 20W to light the room. Better keep the lights off while your generator is operating!

Yet the folks at Tokamak Energy tell us that by 2026 they will have a generator good enough to put in power stations producing 200MW. To do this they purportedly 'only' have to create and maintain a plasma temperature of 100 million °C, 7 times hotter than the center of the Sun, without loosing most of the energy to the environment.

But these are just numbers, right? I mean 30 years ago we only had 360k floppy disks, and now we have 12 Terabyte hard drives! If we can do that, producing a miserable 100 million °C should be a piece of cake! That's the kind of thinking that leads to unrealistic expectations. In many other areas we haven't managed to get anywhere near those numbers.

2026 is a mere 3 years away. If Tokamak Energy can demonstrate a fusion reactor that actually produces enough energy to make a 200MW power station viable I will be very surprised. I'm betting it won't even be able to power a 20W LED bulb.
 
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arthwollipot said:
Lots of scientific achievements in history can be described as breakthroughs.
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And these days almost all of them go nowhere. There's a huge difference between demonstrating an effect in the lab and producing a viable technology from it. Real breakthroughs are few and far between, especially those of the scale needed to make fusion reactors viable.

The first steam engine was produced in ~250BC, but practical steam engines didn't appear until 2000 years later. The reason is not that it didn't work, but that existing solutions were cheaper, safer, more effective and more reliable. But piston steam engines were better and became widely used. They led to development of the internal combustion engine, which then made heavier-than-air flight possible. In the same way, development of the incandescent light bulb led to the thermionic valve, which made radio communications practical and started the electronics revolution. These were mostly not scientific breakthroughs, but incremental technological developments.

The problem for fusion is that incremental development is not enough. It needs a series of huge breakthroughs to become viable. But unlike 200 years ago modern science is mature, with little room for dramatic discoveries that will be the 'game changers' required to put fusion on the map.

Even if fusion power does become viable in 20 years time, by that time other solutions will have reached a level of sophistication and ubiquity that fusion power plants may not be built simply because they are not cost effective. Incremental development of wind, solar, and batteries will probably make the fusion 'breakthrough' (if it happens at all) redundant.
 
Roger Ramjets said:
And these days almost all of them go nowhere. There's a huge difference between demonstrating an effect in the lab and producing a viable technology from it. Real breakthroughs are few and far between, especially those of the scale needed to make fusion reactors viable.
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This is a real breakthrough. And so are all the others. Many more are still needed.

Roger Ramjets said:
...The problem for fusion is that incremental development is not enough. It needs a series of huge breakthroughs to become viable. But unlike 200 years ago modern science is mature, with little room for dramatic discoveries that will be the 'game changers' required to put fusion on the map.
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No, it really doesn't. We know how to do it (by "we" I obviously mean working scientists and engineers) - we've known how to do it for decades. At this point fusion power isn't a scientific challenge, it's an engineering challenge. And the engineering is hard. There are a lot of nuts to crack, and we're cracking them, but it's taking time.

Roger Ramjets said:
Even if fusion power does become viable in 20 years time, by that time other solutions will have reached a level of sophistication and ubiquity that fusion power plants may not be built simply because they are not cost effective. Incremental development of wind, solar, and batteries will probably make the fusion 'breakthrough' (if it happens at all) redundant.
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Renewable energy does not have the capacity to provide baseline power for our energy-hungry civilisation. It's not even keeping up with the current rate of increase in the demand. We still need fusion power.
 
I'm not convinced that building a container that can survive temperatures much hotter than the sun's core and much hotter than any real substance's boiling/plasmafying points counts as merely an engineering challenge instead of a fundamental-science challenge. We'll need to design atoms that can get hit with immense amounts of energy but not do what atoms always do when hit with such immense amounts of energy.

* * *

The subject of alternatives is depressingly in fusion's favor, though. The obvious ready-to-go alternative is fission, and we're refusing to take advantage of it for "reasons" that amount to nothing more than religious superstition. :mad: :( If we do create that magical mithril-vibranium alloy for a fusion container and the other seemingly impossible inventions to go along with it any time soon, it will be quite protected from competition with fission, no matter how much more expensive & dangerous fusion is.
 
The reason above is why magnetic containment is generally used. The fissioning material never physically interacts with the container.
 
arthwollipot said:
The reason above is why magnetic containment is generally used. The fissioning material never physically interacts with the container.
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Except for neutron bombardment which weakens the structural material. Component replacements will not be straightforward and will probably require costly plant shutdown for months at a time.

I think you meant to say "fusioning", not "fissioning".
 
which is why certain types of Fusion are probably better, total cost wise, than others, when they produce no/fewer neutrons at the cost of less energy per reaction.

An ITER reactor requires the entire world yearly output of beryllium to build to capture the neutrons, and would probably have to be replaced from time to time when it becomes too radioactive. Which means that would could not possibly build more than a handful of that type, even if it turns out to be an awesome energy producer.
 
I'm confused. What is going to be "fused" to give us lots of lovely free energy, and where are we going to get it?

Actually I'm not - this is another example (like electric vehicles) where people who can't grasp basic concepts (let alone do the equations) have been convinced (or convinced themselves) that what amounts to a perpetual motion machine is possible.
 
IsThisTheLife said:
I'm confused. What is going to be "fused" to give us lots of lovely free energy, and where are we going to get it?

Actually I'm not - this is another example (like electric vehicles) where people who can't grasp basic concepts (let alone do the equations) have been convinced (or convinced themselves) that what amounts to a perpetual motion machine is possible.
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I accept that this makes sense to you. But what does it have to do with the thread?
 
Steve said:
I accept that this makes sense to you. But what does it have to do with the thread?
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"How close is power from Nuclear Fusion[?]".

We already have "power from Nuclear Fusion".

I assume the actual question is; how close are we to producing useful amounts of excess power from Nuclear Fusion?

The answer to that is ....
 
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