The Stellarator design has proven to be stable and to produce net positive energy. We are actually only $20B away from having a fully functional nuclear fusion reactor.
Fun fact: I was skeptical of your claim that this has been proven, so I googled “stellerator proven net positive” and this very comment was the first result
Not really, unfortunately. The progress has been heartening, don't get me wrong, but it's more like $20B away from getting to the first steps of solving the next set of problems on the road to a fully functional fusion generator.
Those are fairly substantial. It's past time to stop being cynical about "ten more years every ten years", but it's also way too soon to declare victory.
And ultimately, fusion doesn't solve the hardest problem with energy today which is cost.
Solar already provides unlimited clean energy, and it took decades of development for the cost to drop to a competitive rate.
Even if we had a functioning fusion plant tomorrow, it will likely cost WAY more per kWh and require decades of iteration and improvement to become economically feasible.
I would wonder if solar plus the absolute massive battery reserves you’d need for a data center ten times bigger than the current worlds largest would still be cost effective versus a single fusion reactor
> I wonder if cooling is easier or harder in space?
It's harder. You can stop wondering.
It gets easier if you run things hotter, up to the point that there isn't much of a difference at a few hundred °C (and keeps making no difference when hotter).
