Fusion: Hope For The Future?

Achieving fusion ignition is a well fought over (scientifically) accomplishment. Congrats to the National Ignition Lab.The story, however, is far over hyped. [shocked look]First, this ignition lab device was not built as a power station but to make controlled fusion explosions for bomb research.The story’s hype, though, is in the math. There is something called the Q value for gauging progress in fusion research. Q is the ratio of energy output over energy input. For the last couple generations world labs have slowly climbed from Q = 0 to this latest announcement of Q = 1.5+. This is just a bit above the break-even point where the amount of energy produced would equal the amount put in. Here, the energy out from the fusion system exceeded, for the first time, the amount of energy they were pumping in: 2.05 megajoules (MJ) of laser energy in, 3.15 MJ of fusion energy out. That fusion flame wasn’t much, lasting a mere split second, but it was the first flame with everything else up to this being sparks.But that Q value is misleading. There are 2 of them.The one everyone is so hyped about is Q_p: Q(plasma). That has to do with the energy delivered into the target, not the total energy required to generate and deliver that amount of laser power.The other measure is Q_t: Q(total). That is the whole energy budget for this one shot (powering the lasers, splitters, tracking assemblies, plus Q_p, etc.)On this project, for this device to produce more total power than consumed, they need to generate at Q_t = 100+. They are barely at Q = 0.01. But, again, this ignition lab device was not built as a power station but to make controlled fusion explosions for bomb research.To be commercially viable, so the fusion buzz goes on the internet, Q_t of any fusion device (tokamak, stellarator, etc) needs to be at 1000++ and sustainable for years.We are not even there yet. Just like in every generation since they started, viable fusion energy for public use is still a generation away. And when we get there expect it to still be only a generation away.