[zardo]

> But maybe I'm missing something important about the economics?

I think you've understood it.

Imo fusion is never going to be able to compete with renewables+storage with the energy being captured from neutrons. Maybe reactions that release energy in charged particles or photons could, but they're even harder to do.

[Analog24]

Could you elaborate on your point a bit more? If you're talking about utilizing the weak force vs. the residual strong force then I'm not sure this argument holds up.

Also, when comparing to renewable+storage you have to consider how much land has to be dedicated to energy use in these scenarios. Wind and solar require orders of magnitude more than a potential fusion reactor (or an existing fission reactor).

[zardo]

Just referring to what particles the released energy is carried in.

The easiest fusion reactions to make happen release most energy as neutrons. But neutrons are, from a practical standpoint, a huge pain in the ass to deal with. They just fly off until they hit another atomic nucleus.

They irradiate the structure of reactor, making it radioactive and weakening it, neccesating periodic replacement. This means handling radioactive materials, which as the existing nuclear power industry demonstrates, is hard to make cheap.

Reactions that release excess energy as charged particles, though all harder to actually do, leave you with charged particles that can be directed by electric or magnetic fields and can be used for direct enerergy conversion.

Yes solar requires a lot of surface area, but fusion power is just not looking like it will be anywhere near cheap enough for the real estate savings to matter.

[Analog24]

Neutrons aren't that hard to capture. They are certainly harder to capture than charged particles but there are plenty of materials that are dense enough to reliably capture neutrons. This is how heat is extracted from the reaction to use in a generator. The activation of the containment material is a problem but it's not even close to the level it is for fission reactors where you're forced to deal with spent fuel rods.

At the moment fusion is obviously not cheap but no one is planning on using the technology in its current form for actual power generation. The processes involved will all get more efficient and given the astronomical upper limits of energy output from fusion it doesn't take a big stretch of the imagination to think that it will eventually be preferable to solar and wind power. There's no guarantee that will happen but hopefully this breakthrough will trigger more investment and momentum to make it a reality. I also want to add that I'm very pro solar and wind, especially in the short term.