How close is nuclear fusion power?

Mandatory video by Sabine Hossenfelder: ▶ this video So they probably are talking again about Q_plasma, not Q_total .

everyone should watch ▶ this video to put this into perspective. for some reason, all the news articles are extremely misleading. previous output ratio for this fusion method was something like 70%, now it is 150%. it's a useful improvement, but not a major breakthrough. the whole system still consumes 100x more energy than it produces. 100MJ of energy is needed to power the laser. the laser generates only 2MJ of energy that powers fusion. fusion generates 3MJ of output energy. so all the articles are saying "they put 2MJ energy and got 3MJ energy back". no, they put 102MJ and got 3MJ.

According to Sabine Hossenfelder, published numbers are frequently mis-stated on purpose. When you look at frequently reported Q Plasma (or plasma efficiency) we are not that far from it being > 1. However, we should look at Q Total (total efficiency), which is still way below < 1, even in the best plans. ▶ this video For years, I was hoping fusion is close. After watching Sabine's video, I'm not so optimistic anymore.

It’s true that ITER will not produce net power and that the administrators have misled the public about the difference in Q factors. You can have a reactor which produces more thermal power than you put in to it that is still a net power drain when you factor in the rest of the plant operations to keep it going. All clearly explained in this great video. ▶ this video There is a real risk that by focusing on the wrong Q factor you sink all your budget in to plants which can never work as a real power plant. Still I am hopeful that ITER will be sufficiently valuable as a research system that we do move closer to commercial fusion power.

Neither. From TFA: "While the latest experiment still required more energy in than it got out, it is the first suspected to reach the crucial stage of ‘ignition’, which allowed considerably more energy to be produced than ever before, and paves the way for ‘break even’, where the energy in is matched by the energy out." Here [1] is an excellent video by Sabine Hossenfelder about why you should not get too excited about this result. [1] ▶ this video

The question is, in terms of energy input, are we talking about Q-total or Q-plasma? Based on the video by Sabine Hossenfelder, my guess would be, the announcement references Q-plasma. That would mean that the announcement is a motte-and-baily miscommunication, as it promises much more than people are lead to read into it. Motte: We got more energy out than we put in. Bailey: Oh, what we really meant is, more energy was produced, than was put into the plasma, though we didn't actually capture any energy and also, there was actually a great deal of energy also needed to run all the ancillary systems to keep the plasma confined. How close is nuclear fusion power? ▶ this video

▶ this video explains the difference between Qplasma and Qtotal. I hope this presentation will be as forthright.

I hope you win! I usually get my reality checks from Sabine Hossenfelder, who a while back explained that all these fusion claims are wildly optimistic. You can find her video here: ▶ this video I am no scientist, so it is hard for me to know if team optimistic or team pessimistic is right. But even if it is the latter, I think we should put more money and research on it!

This video details some of the ways that nuclear fusion energy reporting gets done (both media, but also the industry) : ▶ this video We are not near a viable fusion reactor yet. Not close.

Skeptical. This video by Sabine clearly explains why a lot of these fusion research claims are dubious with a focus on ITER and JET: ▶ this video

There is quite some misleading terminology being used in the field of nuclear fusion (see excellent overview here [1]). So I was genuinely curious what kind of Q is used in this paper, so here it is: > In this regime, self-heating from α-particle deposition exceeds the external heating input into the DT8; this ratio is denoted Qα, where the self-heating is taken relative to the heating power to the plasma—for inertial fusion this is the PdV compressional work on the fuel and not the total laser energy (P, pressure, dV, volume change). Qα > 1 is a burning plasma. So as far as I understand such Qα > 1 can be reached without sustaining neither pressure or volume, so one can think about it as an explosion rather that intuitive burning (somewhat continuous process). To summarize: Q_total = total_energy_out / total_energy_in is what matters, not any Q related to plasma energy. Since to build a power plant we just care what it consumes in comparison with what it produces. For this particular case even though Qα > 1 you likely can extract just a tiny fraction of that energy stored in plasma, while spending huge amounts of energy to heat it in the first place. 1. ▶ this video or as an article link Edit: I'm a big proponent of nuclear fission and fusion since both are the best (current and future) way of getting carbon neutral energy, which can cover the spikes in the grid and sun/wind-less days. It is just important to be careful with the terminology, which can be used to make research r

Can anyone tell me if this is a net + like the lay person would understand it or something like the net + qplasma thing often misleadingly used when talking about tokamaks? Sabine Hossenfelders explains here: ▶ this video