Just that this is being touted as some sort of “free” energy, when clearly it isn’t.
The ‘free’ part is a massive exaggeration.
As is any notion it is ‘infinite’.
And possible the ‘clean’ part as well - though probably (not for certain until it exists!) practical fusion would involve less carbon. Might still result in some toxic waste, depending on how we do it.
Basically, nothing is for sure until we have it and what little we can say has been greatly exaggerated, but there’s a lot of high hopes.
Just to be clear, “free” usually refers to the energy being clean and making things safe for future generations. It’s not polluting the environment or stockpiling barrels of toxic waste that we have to bury in the desert or launch into space or anything.
It’s not “free” in the sense that it costs us nothing to produce though. At least that’s my understanding.
It would seem that fusion is simply not a viable energy source to begin with. Just look at the Sun: it sheds about as much energy as a good active compost heap. I am having serious doubts about whether this is even a worthwhile avenue to pursue, other than as researching stepping stones toward to whatever might follow.
We really can build fail-safe, efficient fission reactors (EBR-II at INL showed that it could shut itself down without any intervention), and there will ultimately be a practical way to manage the waste. Fission works, and it appears to be more efficient than fusion, in the end.
Mostly, though, we should re-evaluate our “energy needs” to see how much is just pure energy waste. Probably the most abundant source of energy available is to work toward using a metric shit-ton less of it.
Don’t get me wrong. It’s certainly an important discovery, and could maybe possibly one day lead to a viable new energy source, which would be good.
I’ve just seen some rather breathless reports about this as an almost magical development in regards to getting more energy out than putting in. That’s what I meant by “free,” and where the wood fire analogy comes in. Surely the fire from burning the log produces more energy than it took to light the match - but the cost is the log. There’s always a cost.
I suppose the actual science behind this is over my head, but the attempts to dumb it down for people like me mostly came out sounding like the XKCD comic.
There is also the smoke, which is sometimes made use of but for the most part is a cost. For nuclear reactions, the log and the smoke are vastly smaller in quantity compared to a campfire, but, on the other hand, you can easily got out with a saw or ax and fetch some firewood whereas obtaining nuclear fuel is a far more involved and expensive process.
Extremely stupid and naive question, but could you theoretically feedback the gain of energy into the initial laser pulse + electrical grid energy until you reach a break even point and beyond? Or does it not scale that way? And, of course, there would be the whole problem of effeciency in getting the energy back into the input. But in a “spherical cow”/ideal world theoretical sense, does that make any sense to do?
The current approaches to physics using existing technology are probably not going to get to cost-effective fusion power production; I’ve had my reservations about ITER from the beginning because even if it does achieve Qp > 10 the enormous startup energies and technical changes probably make it prohibitive for widescale use, and the DEMO (next phase of a demonstration fusion power production reactor) will be at least half an order of magnitude larger, presumably with corresponding greater construction and operating costs. If your 2000 MW fusion reactor costs US$50B to construct and $3B-$5B per year to operate, it is never going to be cost competitive even as a baseload capability.
Which is not to say that we should not be investing in fusion technologies; it is possible that there will be some innovation in either technology or in basic high energy physics that will make it feasible to do on a practical scale. As dubious as I am at all of the fusion startups currently working, it is entirely possible that one will latch onto some means to achieve practical nuclear fusion. And the research has benefits of its own for understanding magentoplasmadynamics which is beneficial both in understanding stellar physics and potentially for high specific impulse space propulsion even if it isn’t a valid energy source. But nobody should be planning on nuclear fusion as a means to offset hydrocarbon energy sources or a magic power supply for atmospheric carbon sequestration.
The problems with nuclear fission as it currently stands are more in the implementation than the fundamental nature. Disposal of ‘expended’ fuel elements isn’t really the major issue, and in fact that it is a problem is evidence that we are making poor use of a precious energy resource by not extracting as much of the potential energy from it as possible. The once through fuel cycle of current PWR and BWR designs is extraordinarily wasteful, especially given the environmental damage wrought by uranium extraction and enrichment methods, and we should be reprocessing and developing full burnup cycle systems instead of taking ‘lightly used’ fuel elements and burying them in the ground at enormous (and mostly taxpayer) expense.
The real problems with fission are the damage and expense of the ore extraction, refinement, and fuel enrichment cycle, disposal of fuel processing waste streams that have turned nearly every enrichment facility into a Superfund cleanup site, and not accounting for cost growth in end-of-life decommissioning of nuclear plants which results in corner cutting that puts workers and nearby residents at risk. There are technical mitigations to all of these issues, but even with that nuclear fission is at best a costly baseload capability that should be used to supplement renewables rather than viewed as an all-in-one solution that many enthusiasts advocate, especially considering that high grade uranium deposits are only found in a few regions on Earth which just creates a new kind of resource control problem.
The problem is that no matter how efficient you make systems people find ways to ‘burn’ more energy. Appliances and automobiles are way more efficient than those of prior decades, and yet the per capita energy usage in developed nations has only risen due to cheap energy costs (often highly subsidized) and more energy-hungry devices and systems. I don’t think we can ever account on greater efficiency or austerity to make more than a slight and temporary dent in energy demand. That being said, we should certainly look toward reducing waste, if for no other reason than to reduce the attendant effects such as light pollution of excess artificial illumination.
Stranger
That was hilarious. You could use that comic strip and a can of coke instead of a neti pot.
Otherwise known as the Jevons Paradox - making more efficient use of a fuel source leads to increased use of that fuel, not decreased.
Eventually, yes, although NIF isn’t even set up to generate electricity and there are no plans to try.
I read about it briefly in this morning’s news. Here’s a link to what appears to be a more direct source of information:
Band name!
Ah! I haven’t noticed anything substantial about it being free energy. You’re right that it isn’t. The “more energy out than in” angle is about having passed a very early hurdle in a long long race, just a hurdle that’s not been passed before.
I think the point is that the “wood” in question is something so incredibly cheap and common (hydrogen) that it’s effectively free and limitless.
Most hydrogen fusion reactions being considered for power generation are the vastly more exotic heavy isotopes of hydrogen, so less effectively free and considerably more limited.
From what I understand, deuterium at least is fairly common (1 in 5,000 atoms?), and while refining it isn’t cheap or easy, it’s something we know how to do. Also, a little deuterium goes a long way.
Put it this way: producing enough deuterium to last the entire planned life span of a fusion reactor will cost a tiny fraction of the price of building the reactor itself.
Here is an image of some plasma (presumably D+T) in a tokamak:
Why is the color red?
It is almost certainly an IR image. The plasma itself is just the small vertical barbell line in the middle.