Fortuitous timing from my perspective. I was just thinking in the past day or two about fiddling with numbers in the more mundane 'replace current energy use' w/ 'renewables' realm. The impetus being simply having an extra moment for my mind to regale me w/ impending potential horrors in light of Exxon's release only days ago of their "ha ha, we're definitely sailing right past CO2 etc. required to stay under 2C of global average temp increase by 2050, M'Fers!" report ...

I thought, of course, of the always attractive "breakthrough" possibility, but ... in particular, fusion isn't it.* So, deployment of renewables is the obvious solution ... and, solar, in particular, has made massive strides in the past decade+.

What you're talking about is actually much more attractive, though. Sounds like a potentially great implementation / execution. And, all of this - much more rapid deployment for (electric) power generation, or, even better, as you propose, I think - seems like exactly the context in which a new "TVA" (Tennessee Valley Authority) or similar (maybe even "Apollo Project") would be the way to actually get it done with the urgency that seems warranted.

Of course, the US coffers have been so raided, it may take the kinds of "national pain" experienced around a century ago to generate the political "housecleaning" required to, well really, "right the "USS USA". As usual, it's not clear the will is there in the electorate. But, I'd say this much for sure: as old as I am now, the behavior of people older than me has disgusted me in many ways for years, and anyone younger than me should be thoroughly pissed off, I think. I don't want to veer into more of a rant - suffice it to say ... if you look at the benefits a certain generation enjoyed, then consider their voting for policies / tax breaks likely to deny such benefits to future generations (already happening, of course - take a look at college tuitions in the US, for just one example), it's a travesty.

In any case, I think another commenter raised a good point regarding the materials requirement. I'd imagine that would be "paid back" many times over very easily by the scheme overall, but don't know for sure ... I know there have been issues with having enough of the right type of sand to make high (enough) purity silicon wafers for chip manufacture ... but, my knowledge is very limited in these areas in general. If anyone has a real handle on what the materials side of this type of scheme looks like, I'd be interested...

* It was always such an attractive idea ... sounds so perfect ... until you know about neutron generation / flux and realize that something like a "tokamok", in particular, is just not likely to be economical AT ALL (the problem being that without some method to contain neutrons or method for preventing generation, you bombard your materials and end up having to replace / "decontaminate" / etc. far too quickly ... at least, based on my sense of best methods available around 10 years ago ... last time I was involved in any work even marginally related to anything in that field). In any case, even if we have or can determine ways of further reducing neutron generation or ... doing something w/ Higgs or something to deal better w/ the neutron problem, seems like it'd take more like a "miracle" than a breakthrough at this point for it to have any bearing on the climate problem on the timescale relevant.

Edit: realized couple oversights / clarifications (not that it's likely to matter, but, prefer to put in anyway): I have nothing against fission apart from its merits. It's been expensive and track record hasn't been good - plus waste, proliferation, etc. concerns. Practically, it's the cost issue (generally related to the other issues I mentioned, of course). I keep waiting for the advanced / modular / "standard design" reactors we've been promised for years... the track record vis-a-vis AP-1000 (already rather old, but, at least deploying) is not confidence inspiring.

Regarding "certain generation", I've known too many from that generation who sat in taxpayer funded jobs essentially not fulfilling THEIR responsibilities as they RAILED against taxes and the POOR. I have a dim view based on personal experience - too many I knew were spoiled and hypocritical to an unbelievable degree. Of course, that doesn't mean there aren't plenty who were decent etc. So, obviously, I don't mean to blanket condemn any generation ... usual qualifications etc. apply.