Fusion reactors will probably never be economical.
It's the railgun problem: railguns let you trade complicated, unstable ammunition for cheap, stable slugs of metal. But the railgun imposes so much wear on its barrel, and the barrel itself is so much more expensive than in a traditional gun, that you've obliterated your cost savings.
Likewise, it's irrelevant if fusion reactors can provide infinite energy from a single gram of hydrogen, because the reactor housing itself will be an impossibly complex machine with an extremely low lifespan from dealing with the energies involved.
Is fusion possible? Probably. Will it ever be more economical than solar panels? Nope.
Solar panels would be nowhere near as effective far away from a star. Building things as far out as Jupiter or to traverse interstellar areas can't rely on them.
I like the railgun analogy. I think you can stock up on other fusion cost arguments through my article, Engineering and Economic Challenges of Fusion: https://lvenneri.com/blog/ConFusion
I know nothing about railguns, but if they are supposed to launch the projectiles with magnetic force then why do they need to impose any wear on its barrel at all? Couldn't you build a railgun where the projectile never even touches the barrel, being kept at the center by the same magnetic field that accelerates it? Or are we talking about the wear imposed by the magnetic field itself?
If I recall correctly, a "railgun" per se is one that uses the projectile to conduct electricity between the "rails" that direct said projectile. So there's contact, between parts moving hypersonically relative to each other.
It would seem that even without contact there's wear issues with both force exerted on the rails or coils from the magnetic forces and also with creating plasma as the projectile exits?
It's the railgun problem: railguns let you trade complicated, unstable ammunition for cheap, stable slugs of metal. But the railgun imposes so much wear on its barrel, and the barrel itself is so much more expensive than in a traditional gun, that you've obliterated your cost savings.
Likewise, it's irrelevant if fusion reactors can provide infinite energy from a single gram of hydrogen, because the reactor housing itself will be an impossibly complex machine with an extremely low lifespan from dealing with the energies involved.
Is fusion possible? Probably. Will it ever be more economical than solar panels? Nope.