To use wind turbines as an example, more than 50% of the various bits are manufactured here in the US. For turbines destined US wind farms, at least.

What's the evidence that there's "flooding the market" going on? It seems to me wind turbine prices have followed a plausible looking downwards hill and there's no sign of dumping excess inventory or otherwise unsustainably low prices.

> How much would it cost if China turns off that supply?

Buy them while they're selling cheap. They're good for at least 20 years. Plenty of time to stand up domestic manufacturing if they cut you off.