We use a lot of energy, and even with a radical change in the source of the energy, we aren't going to become an island. If we develop huge solar energy facilities, nuclear power plants, or start using biofuels, you really think everything in them will be coming from the U.S.?

How many of our solar power panels in twenty years might be made in China or somewhere else to keep costs down?

Even now, the only thing preventing us from getting a lot of cheap ethanol from other countries like Brazil are politically-motivated trade barriers.

We don't worry about "independence" when we trade with countries like Japan, or Canada (where most of our imported oil comes from), or other places that give us little grief in our relations with them. It's only an issue when the trade situation involves dealing with countries that are basically nuts, or hostile. With luck, maybe there won't be so many of these in the future. Nobody sits up nights wondering if Kuwait is going to do something crazy.