Comment by uwuemu | Hacker News Reader

Comment by uwuemu | Hacker News Reader

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Good luck trying to "scale up" (at least in the near future). Tokamaks are only getting to be "scaled up" now, after pretty much decades, and basically only thanks to ITER (factor of ten plasma volume compared to the second largest tokamak). And ITER is a megaproject comparable (both in budget and time) with the SLS program. Maybe even more expensive (depending on if you believe the official number, 22bn EUR, or the unofficial estimate, 40bn EUR) and DEFINITELY more complex with far more cutting edge science (plasma physics, material science...), technology, and engineering required.

If ITER succeeds (proves that fusion in a magnetic confinement device can be used to produce net electricity and it's "just" a matter of scaling things up that is holding fusion back), then sure, investors are going to line up, even for alternative designs. Fusion will be all the rage. But until then, I doubt anyone is scaling anything fusion-related up. Well and if ITER fails, then we are all fucked, and we can turn the fusion "are we there yet" clock back 50 years.

Have you taken a look at MITs SPARC reactor? I’m always skeptical of comments that only reference ITER, since it’s very old news at this point, and there have been a plethora of innovation beyond ITER in just the last few years. The REBCO tape, and being able to get 10x magnetic field strength compared to ITER in a 3x smaller diameter seems like fairly significant progress to me.

> I’m always skeptical of comments that only reference ITER, since it’s very old news at this point, and there have been a plethora of innovation beyond ITER in just the last few years.

Seeing as ITER doesn't even exist yet, I fail to understand how it can be old news or how we can innovate beyond it.

Isn't total cost per reactor more constraining than cost per Wh for these mega projects? Say you spend $10B on a reactor that produces essentially free energy. You're still limited by plant lifetime, maintenance and crucially transportation of that energy – just breaking even would be a challenge in many locations. Thus, we have to have many plants distributed, similar to today's fission, at somewhere in the 500MW range per reactor (give or take an OOM).

In short, we have diminishing returns for giant reactors, and instead need to have plants that can be mass produced, fast.

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