>Either way, 20 year lifetimes where you build once and reap the rewards for 20 years is sufficient to put to rest the kind of argument being made about dependancies.

It's not sufficient. We have had plenty of time to start making all of the critical things we import, and that never happened. In most cases, these things used to be made in the West in the first place. Just because you CAN make a thing doesn't mean it makes sense. The economics of solar would be totally different if you had to pay 5x more for solar panels to replace Chinese-subsidized slave-labor-backed imports.

There are other arguments to be made against mega-scale solar. Don't get me wrong, I love the idea of solar because it is on a small scale one of the best ways for an individual to get a bit of electricity without reliance on fuel supplies. But it has a lot of disadvantages at scale which make it unsuitable for many regions. Hail, snow, dust, vandals, and strategic vulnerability all make it look precarious. The supply chain concern is that much worse.