Fusion Power - Is it worth banking on?

[ZunarJ5]

In a previous thread I proposed fusion power as a possible alternative to nuclear powered space-craft of the future and as a solution to powering vehicles that would leave our solar system. The response I received made me question whether fusion power will ever be a likely reality, or whether I will ever see it at all (assuming I'm alive 50 years from now).

http://www.ccfe.ac.uk/index.aspx

The above link seems to be a fairly legitimate authority on fusion power... unless I've been taken in, which is entirely possible.

I'm never without a critical eye, I always question my sources of information... but of course I do this in degrees. So, just how skeptical should I be of the information on that website?

What are your best guesses on the fusion time line? What are the best sources of information that you have found on the subject?

[Ara Pacis]

Fusion is nuclear power.

[ZunarJ5]

Fusion is nuclear power.

Sorry, by nuclear I meant fission, as in the form of nuclear power available to us today. Thank you for the constructive reply.

[ZunarJ5]

With the impending power crisis this planet is facing I would think there would be more interest in fusion power. It seems like the one true "out" we have from this approaching disaster.

Is there reason to think that fusion power is a dead end?

Or is it the inevitable next step in energy generation?

[noncryptic]

With the impending power crisis this planet is facing I would think there would be more interest in fusion power. It seems like the one true "out" we have from this approaching disaster.

Since we don't yet have fusion power, it's primarily a research interest.
Other alternatives are already available and are being implemented.

Is there reason to think that fusion power is a dead end?

Given the research in fusion that's going on, more than a few scientists seem to think it's not a dead end.

Or is it the inevitable next step in energy generation?

Maybe, but with the (ongoing) global power crisis, we can't afford to wait for fusion.

[mutleyeng]

there was a wonderfull bbc horizon documentary back in 2009, called "can we make a star on earth".
The tentative conclusion was that the experiments and trials going on at that time should at least show whether it will be possible (practically viable) or not within the next 4 years -- not long to go now then

[Swift]

Is there reason to think that fusion power is a dead end?

Or is it the inevitable next step in energy generation?

I claim no expertise on this topic, but it seems to me the reality is somewhere between those two positions. The running "joke" for the last 50 years is that practical fusion power is 50 years in the future, and it still seems to be true. I think fusion has turned out to be a lot harder than anyone ever thought. I think it probable that the technology will eventually be made to work, but I don't think it will be any time soon, nor may it be as much the magic solution people imagined it would be.

But I also don't think it is the "one true 'out'" we have from "this approaching disaster".

[Jens]

Fusion is a funny thing, because we know it works. But it's just very hard to achieve technically. Even the sun is from what I understand not very efficient at it at all. But there are lots of people who believe it is achievable, and there are many well funded projects that are trying to achieve commercially viable fusion, so I'm cautiously optimistic.

[mutleyeng]

But I also don't think it is the "one true 'out'" we have from "this approaching disaster".

It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.
We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back

[Swift]

It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.
We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back

Maybe, but I'm not convinced of that. Depending on how complex or dirty the technology turns out to be, it might be extremely expensive for example. If can only use deuterium or tritium, you are going to have to separate those out from hydrogen.

[Ara Pacis]

It might be useful to point out that we do have fusion. It's done all the time. It can even be commercialized as a novelty, if we wanted to do it. However, it's not useful for electrical power generation because it takes more electricity to make than it produces. And then there's that whole radioactivity thing. Doing aneutronic fusion is even harder than doing regular fusion. If people weren't worried about radioactivity, then maybe we'd have a lot of breeder fission reactors by now.

[HenrikOlsen]

It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.
We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back

It's been demonstrated with positive energy output decades ago.
It wasn't in a sustained reaction though and it wasn't in a power plant, to it's been demonstrated to be theoretically viable rather than practically viable.

That "change everything", "too cheap to meter" stuff was exactly what was claimed of fission before it was realized how large installations are needed to do it effectively, and how many extra costs environmental hysteric can pile on top of things.

[mutleyeng]

[QUOTE]

It's been demonstrated with positive energy output decades ago.
It wasn't in a sustained reaction though and it wasn't in a power plant, to it's been demonstrated to be theoretically viable rather than practically viable.

I know, that was the context of what i meant by viable.

That "change everything", "too cheap to meter" stuff was exactly what was claimed of fission before it was realized how large installations are needed to do it effectively, and how many extra costs environmental hysteric can pile on top of things.

no claims of too cheap to meter, i wouldnt assume it would be any cheaper at the meter.
The rest comes under viable.
If it turns out that the cost to build the plants is on a par with fission, then it will be of limited help.
I dont quite see why it would when the major cost of fission is as you say safety related. I dont see anything like the scale of that problem with fusion, but i admit im not much of an expert on the subject.
We already know we couldnt build the numbers of fission reactors needed even if we had a mind to.
The point really being, it is the only solution i know of that has the potential to satisfy our current demand, provide the exta to facilitate moving to hydrogen ecconomies, and allow for the developing world to have access to the same energy levels as the developed world. But i do stress, potential

[HenrikOlsen]

It it's going to allow the developing world to have access to the same energy levels as the developed world, it really does need to be "too cheap to meter" otherwise they wouldn't be able to afford it.

[mutleyeng]

i dont think thats the point, they will build up their ecconomy the same as we did, gradually over time in various way (as they are in india and china right now). The point is that we have to allow for them doing that and demanding the energy that goes with it, as in generating capacity

[John Mendenhall]

I find the link in the OP to be much too optimistic. The Wiki article is much more realistic, and is here:

http://en.wikipedia.org/wiki/Fusion_power

Regards, John M.

[kzb]

Apparently, ITER will eventually work up to a positive energy balance, in other words there is more energy released in the fusion reaction than was put in to make it happen. This is being built now. It won't produce a commercially viable energy source though, because you need to produce several times the energy input as useful energy output before it is viable. The machine to do that will be the generation after ITER.

So you can imagine what kind of time line we are on before it could become commercially viable. I won't see it in my lifetime. It also seems to be the case that a fusion reactor along the lines of these machines would be described by the term power amplifier. They need a huge energy input, exceeding the capacity of the national grid, to deliver a fusion pulse.

In the meantime, fission technology, in the guise of a fast breeder and reprocessing fuel cycle, is a proven technology and could supply power for centuries to come.

[cjameshuff]

It would change everything though.
I think the moment the research demonstates its viable, things will move very quickly.

It's been demonstrated to be physically possible, with several reactors demonstrating the needed plasma containment. ITER is expected to eventually produce 500 MW of thermal power, and is under construction now...and yet, all the international partners together are only spending ~$13 billion on it, spread over ten years.

Funding of fusion research has been pathetic. If we were seriously interested in an alternative to fossil fuels and fission, the US alone would already be running multiple ITER-scale projects in parallel on accelerated timetables, and not constantly cutting and canceling much-smaller research projects. (Instead, the closest thing we've got is NIF, which is more about nuclear weapons research than power production.)

We will all move over to hydrogen ecconomies .. and maybe i can have my 100w light bulbs back

If the only thing needed for a "hydrogen economy" was energy sources, we could have it now with nuclear power. The truth is that hydrogen's just a rather poor way to store or transport energy.

[Swift]

<snip>
... and how many extra costs environmental hysteric can pile on top of things.

Not to mention, legitimate environmental concerns.

[mutleyeng]

i would be really interested to see what the american multi laser approach manages to achieve when they finally fire it at a fuel pellet.
192 laser beams producing 400 trillion watts for 23 nanoseconds aimed at a 1mm target.
what could possibly go wrong

[mutleyeng]

Funding of fusion research has been pathetic. If we were seriously interested in an alternative to fossil fuels and fission, the US alone would already be running multiple ITER-scale projects in parallel on accelerated timetables, and not constantly cutting and canceling much-smaller research projects. (Instead, the closest thing we've got is NIF, which is more about nuclear weapons research than power production.)

If the only thing needed for a "hydrogen economy" was energy sources, we could have it now with nuclear power. The truth is that hydrogen's just a rather poor way to store or transport energy.

I dont know what US funding is like, but by european standards the funding it gets seem to suggest they at least do take it seriously, which is quite significant for a technology that at best is still a long way from generating power into peoples houses.
I agree there are problems to be solved with hydrogen storage and transportaion.

[Grashtel]

i would be really interested to see what the american multi laser approach manages to achieve when they finally fire it at a fuel pellet.
192 laser beams producing 400 trillion watts for 23 nanoseconds aimed at a 1mm target.
what could possibly go wrong

It failing and breaking the experimental equipment is really the worst plausible outcome. 400 trillion watts sounds like a lot of energy but if you actually work it out the fact that it is applied for only 23 nanoseconds means that its really not that much, a few tens of megajoules at most (for comparison a litre of gasoline contains 35 megajoules). If the fusion reaction succeeds really well then I could just about see it managing to blow up the lab, but I doubt that even if fully fused the fuel pellets would contain enough energy for that and would think its likely that the test chamber is going to be designed to survive even the largest possible energy release from one.

[mutleyeng]

i meant to have a successful test, and was a back handed compliment at the technolgy they are using ( i think its kinda impressive thing they got going there)
dont worry, i didnt think it would create a black hole over California or anything.

[Grashtel]

i meant to have a successful test, and was a back handed compliment at the technolgy they are using ( i think its kinda impressive thing they got going there)
dont worry, i didnt think it would create a black hole over California or anything.

Ah cool. Text isn't good for transmitting tone so I had misinterpreted what you said. Glad to see that you aren't one of the alarmist types who freaks out about big numbers without realizing what they mean

[whimsyfree]

It's been demonstrated to be physically possible, with several reactors demonstrating the needed plasma containment.

That's great! how many years have they kept it contained?

If the only thing needed for a "hydrogen economy" was energy sources, we could have it now with nuclear power. The truth is that hydrogen's just a rather poor way to store or transport energy.

Gee it only seems like yesterday that Very Important People were making Serious Announcements about the "hydrogen economy" being the solution to the world's problems (at least so far as energy and climate change are concerned). The idea was, for the reason you give, obviously naive and irrelevant to the problems it was supposed to solve. It made me wonder about the quality of advice our VIPs get from the highly respected (and paid) Distinguished Scientists who advise them on such matters. Or do they just ignore them?

[John Mendenhall]

i would be really interested to see what the american multi laser approach manages to achieve when they finally fire it at a fuel pellet.
192 laser beams producing 400 trillion watts for 23 nanoseconds aimed at a 1mm target.
what could possibly go wrong

Don't worry. The designers say the ship is unsinkable.

[cjameshuff]

That's great! how many years have they kept it contained?

Assuming you mean "how many years have they had the ability", JT-60 was able to contain a deuterium plasma (as a plasma research system, they don't actually run it with anything it can fuse) under conditions that would produce a power gain of 1.25 in D-T plasma back in 1998. Fusion benefits from large scales, but we haven't been funding new large scale devices...JT-60 was built in 1985, and is still one of the largest (and used resistive magnets, though it's being upgraded to use superconducting ones). ITER is to be about twice as large, with superconducting magnets, and to achieve peak gains of 10 with steady state operation at a gain of 5.

If you mean actual containment time, why would you require years of containment? Apart from that not being anything close to a requirement for fusion power, when and why would an experimental device have had time set aside for doing this? And why would funds be spent on equipping it with the cooling and other equipment needed for such a stunt, and the power needed to run it? It's just not a reasonable expectation, for anything up to and probably including a fully operational fusion power plant.

[cjameshuff]

It failing and breaking the experimental equipment is really the worst plausible outcome. 400 trillion watts sounds like a lot of energy but if you actually work it out the fact that it is applied for only 23 nanoseconds means that its really not that much, a few tens of megajoules at most (for comparison a litre of gasoline contains 35 megajoules). If the fusion reaction succeeds really well then I could just about see it managing to blow up the lab, but I doubt that even if fully fused the fuel pellets would contain enough energy for that and would think its likely that the test chamber is going to be designed to survive even the largest possible energy release from one.

Vastly more energy goes into the equipment that produces the pulse. Producing precise, ultra-short pulses of high quality laser radiation is not an efficient process, and produces far more heat than it does laser radiation. They start off with 422 MJ of electrical energy and end up with about 1.8 MJ delivered to the target. The NIF is trying to get the cooldown period short enough to do multiple shots a day. A cooling failure following a shot could lead to thermal damage to quite a bit of equipment that's not normally exposed to the waste heat. We're probably talking "slowly melting plastic bits", though, not a spectacular explosion.

[whimsyfree]

ITER is to be about twice as large, with superconducting magnets, and to achieve peak gains of 10 with steady state operation at a gain of 5.

If you mean actual containment time, why would you require years of containment? Apart from that not being anything close to a requirement for fusion power,

I may be confused and have not understood the terminology. I'm confused by some of your statememts. How can a fusion reactor be "steady-state" if it only operates for a few seconds at a time? I don't know much about containment times, so I defer to ITER partner General Atomics. According to their website the goal is 4s confinement and the best achieved is about 0.8s. I also checked out the ITER website. Seems they're just coming to the end of the digging big holes in the ground phase. The new headquarters building looks nice though. SciAm has a distinctly downbeat assessmemt of the project.

[cjameshuff]

I may be confused and have not understood the terminology. I'm confused by some of your statememts. How can a fusion reactor be "steady-state" if it only operates for a few seconds at a time?

It's just what it says, if the state's not changing, it's in steady state. Some processes take place in constantly changing events where such a condition is never reached, others go through a startup transient and reach a region of stable operation, which can be maintained as long as you maintain the conditions that produced it.

I don't know much about containment times, so I defer to ITER partner General Atomics. According to their website the goal is 4s confinement and the best achieved is about 0.8s.

Energy confinement time. They're not talking about how long the reactor can maintain a plasma, they're talking about how fast heat is lost to the reactor walls, which determines things like how hot the plasma gets and how much fusion occurs, and particularly whether ignition occurs (heat being generated fast enough to maintain fusion on its own).

I also checked out the ITER website. Seems they're just coming to the end of the digging big holes in the ground phase. The new headquarters building looks nice though. SciAm has a distinctly downbeat assessmemt of the project.

ITER's an international project with rather too many parties involved. Its resulting problems are not unique to fusion power. That article has no specific technical criticisms as far as I can tell, just vague doom and gloom and a rather ignorant claim that ITER is taking money from wind and solar power...which will never be able to handle the base load power supply that fusion power is intended to provide.