Really a couple of key points. The first is that the US isn't "incapable" of producing renewable energy infrastructure, we've just largely chosen not to for various reasons and are certainly capable of doing so if there was a good reason to.
But the second and more important point is that relying on another country to produce renewable energy technology is not analogous to relying on another country to supply your actual energy. If I bought solar panels from China and tomorrow a US-China war started, my solar panels keep producing energy just fine. I might have imported the panels from China, but that's not where the actual energy is coming from. Sure, eventually I'll need to replace them, but that's not for decades. Assuming a conflict with China lasts long enough to prevent me from ever buying Chinese solar panels again, that's plenty of time to develop US capacity to produce them. And in the meantime, my solar panels keep importing energy from the Sun, which I'm told is very hard to blockade, embargo, or tariff.
Renewable energy tech actually has another major advantage over fossil fuels in a conflict situation. As the current Middle Eastern unpleasantness has demonstrated, fossil fuels are a global commodity and their price everywhere is impacted by restriction on their trade anywhere. Sufficient domestic production of fossil fuels may prevent a country from literally running out in a war, but that's unlikely to actually keep the country's economy healthy. China obviously isn't sitting on top of a fossil fuel producing region the way Iran is, but it seems pretty obvious a US-China war will dramatically impact fossil fuel energy prices given that blockading fossil fuel trade will be an obvious weapon in such a conflict.
When it comes to the impact conflicts have on the price of your energy, you might be better off relying on your Chinese solar panels than American oil. Especially if you can replace them with American solar panels when the time comes. China clearly understands the strategic value of renewable energy, which is why they've invested so much in becoming the major source of that technology.