...about how to extract exergy from the heat. Without that, it's a parlor trick.
I don't like to bad mouth fusion too much, since I have been attending the winter lecture series "Science on Saturday" at PPPL for well over 10 years. This said, I've lived through 50 years of "fusion power is just 10 years away."
I won't look a gift horse in the mouth.
This said, for the record, there is not enough tritium on the planet to run the ITER for six months, but...!!!!!....
Almost all of this tritium, about 50 kilos, is in Canada, an outgrowth of their use of deuterated water in their CANDU reactors, the best thermal spectrum reactors in the world in my opinion.
(There is additional tritium, small amounts in dilute concentrations, in used nuclear fission fuel from ternary fission, but it is generally not recovered during reprocessing.)
There is no evidence, none, that fusion reactors will ever be as reliable, as cheap, or as clean as fission reactors. They have a huge materials science problem, given the 14 MeV neutrons. Tungsten has a lot of issues, including embrittlement, although alloying with rare rhenium (or its congener, the fission product technetium) can ameliorate this to some extent.
It also isn't going to be simple to maintain superconducting magnets for long periods a meter away from million degree plasmas, either in Tokamaks nor in Stellators, and it's not clear there will be enough helium left on the planet to sustain those magnets on a vast scale. (Helium is not a renewable resource.) The laser based approaches are pulsed, and it's very difficult to imagine them offering a clean clear way of extracting exergy from these.
I have spent my entire adult life being less and less impressed with "fusion breakthroughs."
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