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I've long been skeptical of ITER making any sense given its insane cost. I mean even it succeeds, then what? Here's the truth: there's no such thing as free en
by cletus 5y ago
I've long been skeptical of ITER making any sense given its insane cost. I mean even it succeeds, then what?
Here's the truth: there's no such thing as free energy. Even if the fuel is so abundant it's actually or effectively free (eg deuterium), the energy isn't. Say it takes $50B to build a plant that produces 1GW of power, which I'll estimate at about 7TWh/year based on [1]. Let's also say it has a lifespan of 40 years and an annual maintenance cost of $1B going to up to $2B in the last 10 years.
So that's 40 years for 280TWh at a cost of $100B, which equates to $0.35/kWh if my math is correct.
I realize ITER isn't a commercial power generation project. My point is that people need to stop getting hung up on the fuel being "free". The lifetime cost of the plant can still make it completely economically unviable.
Second, the big weakness of any fusion design is neutrons. The problem people tend to focus on is that neutrons destroy your (very expensive) containment vessel with (one of my favourite terms) "neutron embrittlement".
As an aside, hydrogen fusion also produces high speed helium nuclei, some of which tend to escape and this is a problem too because Helium nuclei are really small so can get in almost any material, which is a whole separate problem.
But here's another factor with neutrons: energy loss. High speed neutrons represent energy lost by the system.
To combat these problems we've looked for alternatives to hydrogen-hydrogen fusion, the holy grail of which is aneutronic fusion. The best candidate for that thus far seems to be Helium-3 fusion but He-3 is exceedingly rare on Earth.
I really think we get caught up on the fact that this is how stars work but stars have a bunch of properties that power plants don't, namely they're really big and they burn their fuel really slowly (as a factor of their size), which is why they can last billions or even trillions of years. Loose neutrons aren't really an issue in a star and sheer size means gravity keeps the whole system contained in a way that magnets just can't (because neutrons ignore magnetic fields).
So I hope they crack fusion but I remain skeptical. Personally I think the most likely future power source is space-based solar power generation.
[1]: https://en.wikipedia.org/wiki/List_of_largest_power_stations https://en.wikipedia.org/wiki/List_of_largest_power_stations
- sdenton4 5y agoIf only there were some way to capture and use all that power from the giant fusion reactor in the sky...
- mLuby 5y agoIt seems you're suffering from "neutron embitterment." ;P Space-based solar power generation (itself "fusion power" in the loosest sense) would be great in the inner planets. Though to open up the outer planets, Kuiper belt, Oort Cloud, and any other stars, we'll need non-solar* power: hopefully fusion, at least fission. *Unless we want to go the stellaser route, but I'd bet we'll crack fusion before getting near K2.
- ncmncm 5y agoIt won't be Tokamak fusion in any case. FRC (burning D+H-3) might work, but there is no money for it. Neutron-emission fusion eats all the fusion money. H-3 is not nearly so scarce as cletus suggests. It is uncommon, but you don't need much.
- gibolt 5y agoYour numbers sound like generation 1 numbers, after ITER. ITER is only a test facility to prove hopefully that it can be net positive. However, those maintenance costs (your estimates) would be the first thing to drop. Any company producing/operating these will be competing with wind and solar, and thus highly incentivized to improve. There should be plenty of low hanging fruit, since it hasn't happened once yet.
- ncmncm 5y agoMaintenance cost is not a place to expect major cost reductions. Those tend upward.
- snek_case 5y agoOnce we've shown this can work successfully, I think people will get excited and investment money will rush in. Ideally, we'll perfect the technology and make it cheaper and more efficient, just like any other technology. If an MIT-borne fusion startup IPOs and they have a working demonstration reactor, I would probably invest. I think the hope is that with economies of scale, we could build really huge fusion plants one day, and drive down the cost of energy to less than a cent per KWh, and of course completely eliminate our dependency on fossil fuels. If energy becomes that cheap, we could use electricity to produce hydrocarbons from CO2 and water to power airplanes and such. Currently, we can imagine short-distance flights being electrically powered, but transatlantic flights are going to be difficult to achieve with batteries.
- nickik 5y agoWhile I agree with your point about ITER. Space based power generation to me is incredibly dumb. It would be far easier to build solar on earth and transport it around with high efficiency DC lines. And if you are really looking into the cheapest possible energy a thorium breeder reactor could run for ever with no fuel cost and could be built with 70s technology. These reactor be produced in a factory at a manufacturing line and then dropped into a containment facility. How this should be more expensive then space based solar makes no sense to me.