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> You seem to be implying that comparing by volume is unfair to fusion I am pointing out an obvious logical fallacy. If it really isn't obvious, try substituti

by T-A 7y ago

> You seem to be implying that comparing by volume is unfair to fusion I am pointing out an obvious logical fallacy. If it really isn't obvious, try substituting "Tesla cars" for "fusion" and "bars of gold" for "fission reactors". Here's what you get: "Tesla cars are MUCH more complex than bars of gold. So, just comparing volume is being very favorable to Tesla cars." Which of course is utter nonsense. A Tesla Model 3 occupies roughly 10 m^3 (order of magnitude, mind you); that volume of gold would weigh about 19.3e4 kg, which at the current price of $45.6e3/kg would be worth about $8.8 billion. Clearly, the MUCH more complex Tesla Model 3 costs quite a bit less than the same volume in gold. > So, instead, let's compare by mass. That would be equally pointless. Instead, how about taking a moment to look up a serious economic analysis? Here is a fairly recent one, open access and all: https://www.sciencedirect.com/science/article/pii/S0360544218305395 https://www.sciencedirect.com/science/article/pii/S036054421... It compares existing power plants with four tokamak conceptual designs which "span a range from relatively near-term concepts, based on limited technology and plasma physics extrapolations, to a more advanced conception". Upon reading it, you will be happy to learn that it finds Total Cost Of Electricity (TCOE) produced by those fusion reactors to be slightly higher than the lowest cost alternative, fission reactors. All other options considered (combined-cycle gas turbines, open-cycle gas turbines, coal plants, solar large photovoltaic plants, onshore and offshore wind plants) turn out to be more expensive.

pfdietz 7y ago
It's amusing you believe those projections, especially when projections of the cost of fission power plants -- a much simpler and more mature technology -- keep coming in 3x over estimates, and when ITER blew through its initial lowballed cost estimates. Think about the motivations for the people making estimates of the economics of fusion. They have little external motivation to be honest. The worst they could suffer if they were caught cooking the books was to lose their professional positions: but that is the same thing that would happen if fusion turns out to be seen as unaffordable and work is shut down. And really, a fusion power plant is so far in the future that they aren't likely to be caught on any but the most blatant dishonesty anytime soon. And who is being funded to check on their estimates? So what might they do in that situation, even if they didn't flagrantly lie? They could tweak the assumptions going into the estimates, and keep tweaking them until they get results that are acceptable. If some source gives an input to their cost model that seems too good to be true, they might not question it too much. It's not "lying lying", they might tell themselves. They might even rationalize it's only a venial sin to bend things a bit, since fusion is so obviously a good thing to work on, right? Motivated reasoning can be a powerful thing. All those failure modes are there, and there's incentive for them to occur, and there's little real world feedback to keep them in check. So you should take any estimates like the ones you linked to with more than a few grains of salt, especially when they fail a "smell test" by giving better economics than simpler, smaller fission. In contrast, costs for renewables face the harsh test of actual experience, many times a year. Renewable cost estimates are, as a result, highly grounded in real evidence, and typically come in within 10% of the actual values. There is no room for lying -- to oneself or to others -- there.
- T-A 7y ago
  > It's amusing you believe those projections The paper explains the methodology and lists references to the data. You can go through them and check the calculations yourself. > Think about the motivations for the people making estimates That's another logical fallacy, a classic one known as "ad hominem". Their motivations are utterly irrelevant to the question whether their results are correct. If you think their work is in error, show how.
  - pfdietz 7y ago
    > If you think their work is in error, show how. That's now how it works. If they put together a big, complicated cost model, it's up to them to provide evidence it's valid. Otherwise, it's just an exercise in "believe us, we're honest". For example, they could apply the same model to fission reactors and show it accurately predicts what they end up costing. Oddly, I don't recall fusion cost modelers ever doing that. Hell, I don't recall fission cost models being terribly accurate. You like this result because it's telling you what you want to hear, not because it's intrisically believable. More motivated reasoning.
    - T-A 7y ago
      > That's now how it works. Yes it is. They presented their work, their sources and conclusions. If you believe it's wrong, but can not explain why, all you have is a prejudice. If you want anyone to take you seriously, you need to provide a rational argument explaining exactly how they are wrong, not just why you want to believe that they are.

by T-A 7y ago

pfdietz 7y ago

It's amusing you believe those projections, especially when projections of the cost of fission power plants -- a much simpler and more mature technology -- keep coming in 3x over estimates, and when ITER blew through its initial lowballed cost estimates. Think about the motivations for the people making estimates of the economics of fusion. They have little external motivation to be honest. The worst they could suffer if they were caught cooking the books was to lose their professional positions: but that is the same thing that would happen if fusion turns out to be seen as unaffordable and work is shut down. And really, a fusion power plant is so far in the future that they aren't likely to be caught on any but the most blatant dishonesty anytime soon. And who is being funded to check on their estimates? So what might they do in that situation, even if they didn't flagrantly lie? They could tweak the assumptions going into the estimates, and keep tweaking them until they get results that are acceptable. If some source gives an input to their cost model that seems too good to be true, they might not question it too much. It's not "lying lying", they might tell themselves. They might even rationalize it's only a venial sin to bend things a bit, since fusion is so obviously a good thing to work on, right? Motivated reasoning can be a powerful thing. All those failure modes are there, and there's incentive for them to occur, and there's little real world feedback to keep them in check. So you should take any estimates like the ones you linked to with more than a few grains of salt, especially when they fail a "smell test" by giving better economics than simpler, smaller fission. In contrast, costs for renewables face the harsh test of actual experience, many times a year. Renewable cost estimates are, as a result, highly grounded in real evidence, and typically come in within 10% of the actual values. There is no room for lying -- to oneself or to others -- there.

T-A 7y ago
> It's amusing you believe those projections The paper explains the methodology and lists references to the data. You can go through them and check the calculations yourself. > Think about the motivations for the people making estimates That's another logical fallacy, a classic one known as "ad hominem". Their motivations are utterly irrelevant to the question whether their results are correct. If you think their work is in error, show how.
- pfdietz 7y ago
  > If you think their work is in error, show how. That's now how it works. If they put together a big, complicated cost model, it's up to them to provide evidence it's valid. Otherwise, it's just an exercise in "believe us, we're honest". For example, they could apply the same model to fission reactors and show it accurately predicts what they end up costing. Oddly, I don't recall fusion cost modelers ever doing that. Hell, I don't recall fission cost models being terribly accurate. You like this result because it's telling you what you want to hear, not because it's intrisically believable. More motivated reasoning.
  - T-A 7y ago
    > That's now how it works. Yes it is. They presented their work, their sources and conclusions. If you believe it's wrong, but can not explain why, all you have is a prejudice. If you want anyone to take you seriously, you need to provide a rational argument explaining exactly how they are wrong, not just why you want to believe that they are.