this post was submitted on 09 Apr 2024
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Enter nuclear fusion… unlimited energy always and forever.
It's pretty easy to imagine fusion being great - but it's still just in our imaginations. No one has yet been able to build a working fusion power plant. There has been progress over the decades that people have tried, but its still a way to go yet. So although we can imagine that it could produce clean and plentiful energy, we just comparing sci-fi tech to current tech. The future reality might not be so great, and the current reality is that fusion power isn't possible at all.
To illustrate my point, lets imagine solar power from a 'theoretical' point of view, like fusion is described. Solar power uses no fuel; gets its power from sunlight. There is enough energy coming from the sun to meet the whole world's energy needs with just reality small amount of area. Solar power produces no waste biproducts... So if we just imagine the benefits of solar power, it sounds pretty much perfect. In in reality though, although solar is very good, it is still far from perfect. Construction, maintenance, and disposal of the panels are where the costs are. And so to compare to fusion, we'd need to know what it would take to build, maintain, and disposal of the fusion power plants. Currently we can't do it at all - so the costs are basically infinite. But even if our tech improves to the point where it is possible... it's hard to imagine it will be easy or cheap - especially because there will be radioactive waste. (Radioactive waste not from the fuel, but from the walls and shielding of the reactor, as it absorbs high-energy particles produced by the operation of the power plant.)
Every previous adoption of technology has taken - what, 50 years? - between having the technology and being set up to make use of it. Gasoline did not immediately have car engines to put into, nor kerosine a whole city's worth of lamps set up to receive them, etc.
Though at first, if fusion could power up the existing electrical grid then it could e.g. make electrical cars more efficient in the net/overall sense, even if vehicles operating directly on fusion power themselves would take many more years. So fusion really might be different than those that came before, if we are anticipating and more ready for it than previous technical advances?
Though yeah, it will have its own challenges e.g. the radioactive wastes, so fusion would not begin to replace greener energy approaches such as solar, wind, and geothermal, only perhaps supplement them.
afaik, this isn't a thing for nuclear fusion. fission, to a very limited degree. yes, but fusion, no, not really.
Not for the direct reaction itself but I thought there was something about spraying the container down or some such... I am probably entirely BSing here:-). In any case, whenever someone figures out a method to make it practical, then we'll see whatever downsides there may be to that:-P.
Just 20 more years of research. At least text was predicted 1990. And 2000. And 2010. And 2020. And last year.
my pet theory on the "nuclear fusion is coming in the next 20 years" thing is that science journalism has reported on every minor breakthrough related to fusion technology. being able to theoretically confirm it, being able to actually accomplish a test run, being able to use some other forms of nuclear fusion (like a tokamak vs a stellarator), being able to very recently, break even. Earlier on, in the optimistic post-war nuclear period, some dipshit probably gave an estimate that we'd have it in the next 20 years because everyone was so optimistic, and ten it stuck around. so every time someone brings up nuclear fusion, which happens a decent amount, the "it's only been 20 years away for the last 80 years" remark gets popped off and spreads around without any really clear origin point. I think probably also the sheer number of breakthroughs reported over time means that people are going to be skeptical, since everyone interprets science journalism as always reporting on the one life-changing breakthrough, rather than just being a kind of steady background noise, like any journalism.
I'm personally very excited about how it does seem to be finally making progress if slowly, but realistically, I'm less convinced that it'll be the solution to all our energy needs than many are. The physics of the process itself is very efficient, sure, but the kinds of machines needed to harness it are literally among the most expensive and complicated things built by humans, and they don't even produce net energy yet. Granted, the cost of such things should be reduced once they are industrial machinery and not exotic scientific instruments loaded with experiments, but I'd bet that the reactors themselves will still be incredibly expensive and complex (and therefore have expensive maintenance). This doesn't say good things about the actual cost of the resulting energy, even if the fuel is quite abundant. We could get abundant energy with a similarly high if not quite as much fuel efficiency with advanced fission reactors and fuel breeding, but the cost of those kinds of plants has been relatively prohibitive, and the costs of renewables has been falling. I could certainly see it possible for fusion to reach net energy, only to get used only on specialized roles or for base load power because solar panels end up being cheaper. In a sense this has already happened. It is theoretically possible, if not practically desirable, to use fusion energy in a power plant already, by detonating fusion explosives in a gigantic underground chamber full of water to heat it up, and harnessing the steam. Such ideas were considered during the cold war, but never developed, at least in part because it was calculated that they wouldn't be cost competitive compared to other power options.
FYI https://www.theguardian.com/environment/2023/aug/06/us-scientists-achieve-net-energy-gain-second-time-fusion-reaction
That's not really net energy gain from a practical standpoint. Technically yes, they get more energy than was present in their lasers, but those those lasers aren't created perfectly efficiently, and so the actual electricity needed to create them still is much higher than the energy output of the reaction
I agree with you, but I don't think it means we stop the pursuit. It won't be viable or cheap enough in time to help in the transition off fossil fuels. If it does pay off the way some people think it may be a viable energy source for carbon sequestration to undo some of our stupidity though. I think it's worth that moonshot.
Oh I wasn't suggesting we should stop the pursuit. I just think it won't be a magic bullet for solving our energy needs the way some proponents seem to suggest it will be.
not exactly but for all practical purposes might as well be
Solar power is just really inefficient nuclear fusion