It's better and cheaper to use locally, but unless you find a plant that is unable to sell capacity, you're taking it from something else.

True, it doesn't make sense to move the power all the way around the world, but that's also not really how things like the synchronous grid of Continental Europe works, where power is traded across 24 countries on a single grid.

If your have cheap renewable energy, when you start selling, excess non-renewable capacity and more expensive plants in general powers down in nearby areas and countries.

Any power taken from a renewable plant there when power price is positive means increased non-renewable output.