Hmmm, edit appears to have disappeared. Forgive me if this shows up twice.

> [[Citation needed]] - "all the time" is not a mathematical statement and therefore cannot be included in your (pseudo) mathematical reasoning.

https://en.wikipedia.org/wiki/Riggatron - was about 50%
http://books.google.ca/books?id=KSA_AAAAQBAJ&pg=PA203 - calls for 80%, gives no reasons (maybe dup)
aries.ucsd.edu/HAPL/MEETINGS/0511.../SheffieldApproachFusion.ppt - 20% first year, 50% after
http://books.google.ca/books?id=5A51AgAAQBAJ&pg=PA139 - "70 to 80% [...] These values cannot be achieved today..."
http://hifweb.lbl.gov/public/Sharp/HIF_documents/Perkins-future%20fusion.pdf - makes fun of IFE predicted cap factors, says ICF would be 80% in order to work but doesn't really argue for that number

> [[Citation needed]] - not to mention that since the system is not under significant pressure,
> the containment building (if actually needed) will be far simpler and far cheaper than that needed by a nuclear power plant.

The magnets are under significant pressure, and represent a serious physical risk. A failure of the blanket releases tritium. To ensure that one doesn't lead to the other getting into the environment, you need a very strong containment vessel and building on the same level of size and strength as a fission version. You *have* seen the ITER containment building, right?

http://fire.pppl.gov/fusion_science_parkins_031006.pdf - breaks it down in detail
http://dotearth.blogs.nytimes.com/2012/10/19/a-veteran-of-fusion-science-proposes-narrowing-the-field - Hirsch says "it is virtually certain that the regulators will demand a containment building for a commercial tokamak reactor that will likely resemble what is currently required for fission reactors"
http://www.osti.gov/scitech/servlets/purl/7117740 - this is a very old study, but you can get a feel for the buildings as part of the overall system costs. They flatline it at 10% of the overall project cost, but they estimate that to be as low as 35 cents/kWt.
http://books.google.ca/books?id=iuC3IFwk5ZsC&pg=PA342 - no dollar figures, but this shows you why you need a big expensive building

That last one is pretty good overall if you're interested in this stuff. It's based on the UWMAK-1, which was a study carried out by Bechtel and WISC. Using current figures you get CAPEX numbers like $1.8 for the blanket, which you can scale using the second-last ref to suggest building costs on the order of $6/W. If you want to understand why all of this starts adding up, go to the UWMAK home page and look at the image. See the *little person* at the bottom? Now scale that thing out to a complete torus:

http://fti.neep.wisc.edu/studies/UWMAK-I

For comparison, wind turbines are currently going in at $1.50 to $2.00, and NG combined-cycle plants around $1 to $1.50.

http://gallery.mailchimp.com/ce17780900c3d223633ecfa59/files/Lazard_Levelized_Cost_of_Energy_v7.0.1.pdf

> but then substitute FUD for actual numbers

Which you could have shown me up by posting some numbers to show why I'm full of FUD. But you didn't. So first, pto, meet kettle. Secondly, now you have some reading to do.

> I won't fault any of your numbers, but failure to acknowledge the role of serendipity in the history of science and technology is just a statement of your own ignorance, not a convincing argument.

Right in the message you are replying to"

"'Now wait' you say... what if advancement X causes the price of fusion to fall? Well sure, but what if advancement Y causes the price of peanut turbines to fall."

This clearly acknowledges the role of serendipity. It is entirely possible that there will be a technical breakthrough and suddenly everything I said about fusion moot. But it is just as likely there will be a breakthrough in some other power source that renders fusion moot. That's the problem with serendipity, it's random.

Found a better link to the one article:

http://fire.pppl.gov/fusion_science_parkins_031006.pdf

> and here's why I've bet my career on solar

I don't work in solar. I do have panels on my garage roof though.

> They agree that fusion is challenging

Of course; just challenging enough that a little more money will definitely, totally fix the problem.

> with childhood classmates, neighbours and professional colleagues now decades into their work in both next-gen
> fission and current fusion reactor design

Excellent, I'd love to debate them. Feel free to set something up.

> the worst kind of bad science is advocacy that overreaches your expertise

No, the worst is when someone starts attacking the messenger while hiding behind an alias and making claims of great expertise.

> Anyone posting on /. ought to be well aware of the long, long history of technical prognostications
> of exactly the kind you are posting here that turned out to be utterly, absolutely wrong.

Yes, *technically*. But this isn't about the *technical* side. This is about the *economics* side. Fusion reactors will be, forever, more expensive than a fission reactor. There is no way around this. And even today, fission reactors are too expensive to build. And that's that.

Look, someone might indeed invent a totally new way to build a fusion reactor that is actually simpler and cheaper than a fission one. If that happens, then we'll use fusion reactors.

But that's just playing dice. It's exactly as likely, or much more likely actually, that someone will come up with a way to 1/2 the price of PV. And if that happens, then even a 1/2 as expensive fusion reactor still won't get built.

> What was the usefulness of general relativity in the early 20th century ? Nothing before artificial satellite (i.e. GPS).

Bzzzt. GPS would work perfectly without GR. The only difference would be one less correction factor.

> What was the usefulness of galois theory in the 19th century ? Nothing. Now we have got major applications (coding theory...).

Galois theory was invented to solve a well known problem in mathematics of that era.

> What was the usefulness of Fast Fourier Transform (known since ~1800) ? Nada Now everywhere.

I think you are confusing the discrete form, not the FFT. The version of the FFT used today is from the 60s IIRC. Fourier analysis in general was invented in order to greatly simplify heat transfer equations.

Let me guess, this list came from a page supporting one or another wild-eyed idea and used arguments like these to suggest why the fact that the system didn't actually work should not be a reason to doubt it?

> To some degree, I still like the idea of plug-in hybrids for the time being

Especially when the hybrid is this:

http://www.cbc.ca/news/technology/electric-car-with-massive-range-in-demo-by-phinergy-alcoa-1.2664653

Take a Tesla S. Remove 2/3rds of the li-ion. Add one of these. Car loses 500 lbs. One-way range increases to ~1600 km. Refuelling for short trips is about 5 minutes. Longer ones takes a swap, just like now.

> Your argument appears to be "we haven't solve the technical and practical challenges yet, so we never will."

What?!? I said the *exact opposite* of that.

I said that even if they get it working, there's no reason to build it.

Here, let me put this in crayon for you. Right now I can go and buy a turbine from GE, hook that up to a food dryer system from some hippy store, and use it to dry out peanut butter and feed them into the turbine. I *guarantee* you this will actually work, and produce net energy. What, you don't believe me? Fine, read this:

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

Better yet, it's carbon neutral, because the CO2 you release by burning it is sucked back into the next tree. Now of course the power coming out would cost ten times what you'd get by burning bunker oil, and bunker oil produces power at ten times the rate of a wind turbine, but *it will work*, for sure. Fusion? Meh, maybe by 2050. Maybe not. And of course, fusion will likely cost even more.

So what problem does a fusion reactor solve that a peanut turbine doesn't? None. So why isn't anyone racing to built peanut turbines? Because they cost too much. And fusion costs more than that.

And THAT is my argument.

"Now wait" you say... what if advancement X causes the price of fusion to fall? Well sure, but what if advancement Y causes the price of peanut turbines to fall? And when you look at all the research in the world, there's a lot more going into making cheaper peanuts than fusion.

I am being a bit facetious here, but not that much. I've been looking at this problem for three decades now, and it's not getting any better. Quite the opposite, fusion is getting more and more expensive. Its just not going to happen. You need to spend your energy on something that will actually happen, even if it's not as good in theory.

> Because thorium isn't easier or cheaper to use in the US

Nor India, who imports all the fuel they need. And as the supply from Africa and Australia remains solid for the foreseeable future, the economic argument is unlikely to work for anyone, including India.

> You said you where aware of India working on this, but I guess not aware that they want it running in less than a decade, not decades.

I'm perfectly aware of this. I'm also aware that they said the same thing a decade ago. And the decade before that. And I'm also aware that they laid out this plan *in 1954*.

None of this inspires confidence, especially in a market where PV and wind will almost certainly (we're talking 99.9% here) cost less. You are aware, I'm sure, that India currently has plans to install more PV than nuclear, right?

> Your assumption of course is that all other factors stay the same

Exactly the opposite, I'm taking into account the changing market at every turn.

Right now commercial PV is around 8 cents and is expected to fall in 6 to 7 cents by the end of this year.
Right now wind turbines are producing power for between 4.5 and 9 cents, and it is expected the price will collapse to the 5 cent mark over time.
These numbers include factors for intermittency, transmission upgrades, and anything else you might think of.

So, thorium. In spite of multiple decades of ongoing research, we still have no working thorium reactor. In fact, that's true in spite of the fact that the reactor just down the road from me can run on it. So if we have reactors right now that can use it, and they're not, surely there is a reason for this, right?

And the reason is that the price of building the infrastructure needed to commercialize the fuel pipeline is enormous, and at current U2 prices, utterly pointless. As I'm sure you're no doubt aware, the price of the U2 fuel cycle development was paid for by WWII, which provided a large subsidy to plants in countries with military needs. That leaves only Germany as a country that had to develop a fuel cycle *without* an interest in bombs, and look how well that turned out for them.

So basically people that actually work in the power industry, especially the nuclear power industry, see that this is not a technical problem (well, it is) but a practical one. One that is *not* getting solved any time soon. Perhaps this is simply a chicken-egg problem, and anyone that cracks one side will produce a reason to attack the other. But to date that hasn't happened, and there you have it.

> was wondering the same thing... perhaps spiking up for major experiments/phases?

Correct. The assumption in that graph is that applying more money means you need to do less experiments. The super-funded option has an initial series of experiments, followed by a testing phase, followed by a second round of construction and testing. The dot represents commercialization.

The problem is that all predictions about the "amount of science" left have been wrong, every time. In 1953 Spitzer predicted commercial systems by 1970 and outlined a four-step path for stellerator development, culminating in the D model that would be a production prototype. In fact, the system plateaued in the B model, and the C model was never completed in its original form because it was clear that approach would never work and they should move to tokamaks instead.

Every device has gone through a similar evolution, or much worse. There were dozens upon dozens of designs in the 1950s and 60s, not in terms of machines, but entirely different approaches to building a reactor. Most of these have proven to have plateau points well below any sort of break-even, technical or practical. Mirrors, picket fences, astrons, bumpy toruses, electron-beam ICF, zeta-pinch, theta-pinch, etc etc etc etc etc. Today we are left with two approaches, laser ICF and tokamak.

So explore the tokamak for a second. With each generation of machine the cost of staying in the game increases another order of magnitude. Today, we can only afford to build one machine. Originally ITER was going to be the testbed for a design known as DEMO. DEMO would be the testbed for a commercial reactor. The end was in sight.

Oh well, not any more, because now DEMO is the testbed for PROTO. PROTO will be the testbed for a commercial reactor. Time frame for PROTO? 2050 at the least.

I will not be alive in 2050. Many of the people reading this won't be. However, long before that, other forms of power will commercialize. We'll keep sinking money into this pit throughout though, because, as this article notes, that's the way the pork works.

> there is some truth

There's *all* truth to that. Let me put this simply; there is almost zero chance that fusion, in its current form, will *ever* be a practical power source.

Now when people read a statement like that they get their backs up about the future, and progress and science and all that. But that's not the issue. The issue is that *fusion isn't the only power source on the planet*. As long as one of these is "better" that fusion, then fusion won't happen. That's all there is to it.

So why do I state my conclusion so forcefully? Because math.

The Levelized Cost of Electricity is the key determinant in telling you whether or not a system will be built. The formula basically tells you what you have to charge for the power coming out of your system in order to break even. Anything above that number is gravy.

The formula, which you can read in depth here:
http://matter2energy.wordpress.com/2012/01/24/your-own-grid-parity-pv-system/

basically boils down to five numbers. The first is the amount of money you pay for the plant, and more specifically, the amount of interest you pay on the loans you took out to build it. The second is the cost of fuel to produce a given amount of power. The next is the peak power that the plant can produce, and next is the percentage of time that the plant actually does produce that. Finally there's the lifetime of the plant, which feed into all of the others. It's something like this:

price of your power = (all the money you put into the plant over its lifetime) / (all the power that you exported to the grid)

We measure money in dollars and cents. We measure power in kWh. This is why your power bill lists a figure in cents/kWh, and why the grid operators measure in $/MWh.

Ok, so fusion. So the price of fuel for a fusion reactor is low, about the same as a fission plant. So we can eliminate that figure for a rule-of-thumb calculation, and leaves us with the lifetime cost of the plant, the CAPEX+OPEX. Now we look at the other side, and we see two figures, the peak power and the percentage of time it runs. We can simplify by listing our CAPEX/peak power as a single number, dollars per watt.

So basically the entire cost structure comes down to the cost of the reactor, and the amount of time it spends running. The rest we can scale out linearly against other power sources.

So what do we know about these two factors?

Well in terms of percentage power, or capacity factor as we call it, fusion reactors are not competitive. Because of neutron embrittlement, they need to be shut down all the time so the reactor core liner can be removed and replaced. Newer designs place lithium-infused blocks inside the containment vessel; this means the vessel itself lasts longer but you still need to open it up all the time to get at those blocks. Generally we might expect a fusion plant to have a capacity factor on the order of a good hydro plant, on the order of 60%. For comparison, a fission plant is around 90%, a wind turbine is 30%, a solar panel is about 15%.

Ok, now the CAPEX. Any fusion reactor of practical output is going to be one of the most fantastically complicated devices ever made. They are utterly crammed with high-end materials, poisons, huge electrical and magnetic systems, high-end vacuum pumps, etc. Depending on the design, it's also flammable, and the fire will cause radioactive rain, so you still need a complete containment building. Now on top of this all, the energy density of a fusion system is *tiny*, so you need to build *enormous* reactors.

And that's where it falls apart. There is simply no way, under any reasonable development line, that the cost of building the plant, and servicing its debt, can possibly be made up by the electricity coming out. PV, one of the worst power sources in terms of cents/kWh, is currently running at about 15 to 20 cents/kWh. A fusion reactor almost certainly cannot be built that will produce power at under ten times that cost. And that's assuming it ever "works", which it doesn't.

This has nothing to do with the technology, it's inherent to the entire concept. Simply put, using a fuel that's widely described as a "very good vacuum" isn't going to produce a lot of total output.

Fusion research along the current lines is a colossal waste of money, and *everyone* knows it. It's entire existence relies entirely on fooling politicians - either by claiming that the system is needed for weapons research, or by the sorts of jingoistic arguments you see in this article.

Now someone will complain that we need to do this just in case it ever works. No, that's is absolutely wrong. The Soviets spent a huge amount of money making sure they had the best vacuum tubes in the world. How did that work out for them?

> Still, though, both fission and fusion are much better than the alternatives (fossil fuels).

Fallacy of the excluded middle. There is no way fusion will ever compete with this:

http://gallery.mailchimp.com/ce17780900c3d223633ecfa59/files/Lazard_Levelized_Cost_of_Energy_v7.0.1.pdf

> I'm pretty sure the Soylents will be against any energy program

So you're worried that a group of people you don't even know will scupper this effort?

> imagine if we could build big fusion plants that could power cities... would they be all over that?

Imagine if there were unicorns...

It's quite a bit more likely that someone will DNA-soup you a unicorn before you die than fusion will be in commercial use.

> much more realistic about its short/medium term viability then the hopefuls

Let's not mince words. The short/medium-term viability of thorium is exactly zero. None of the players, even the hopefuls, expect a production plant in anything less than decades.

I doubt even that, given the extremely slow pace of development to date. Yes, I'm very much aware that India and China are working on this, and I'm also away that India has been doing that for longer than China has even had nuclear power and still have nothing to show for it.

Of course thorium might actually work and be practical. The same cannot be said for any current approach to fusion, which simply will not ever be practical. This story is about more pork being dumped down a very deep hole.

http://matter2energy.wordpress.com/2012/10/26/why-fusion-will-never-happen/