[zdragnar]

It's the only type of renewable energy. All other renewable energies depend on the heat from the sun to work. The earth's core doesn't generate enough to fully satisfy our current needs, there's a finite quantity of uranium, plutonium, coal, oil, etc.

Of course, all of this is on a scale well beyond what we need to (currently) be concerned with- we don't have the technology to fully utilize what we have to fully eliminate scarcity in the first place.