Not all of Australia. Just South Australia.

South Australia is a world leader in renewable electricity, possibly the OECD world leader, averaging 70% currently. The balance is gas peakers.

Unlike the rest of Australia SA has no coal and no gas so all energy had to be imported. Usually as coal because they are over 1,000km from anywhere so transmission lines are expensive.

They always had lots of reliable wind and solar. So it isn't surprisingly they started their "renewable revolution" as soon as the technology became available, well over a decade ago.

They have to import the gas for their peakers so replacing them with storage is more attractive than elsewhere. But they are flat, so no hydro. So it's not surprising it's one of the first places where grid scale batteries make economic sense.

Their electricity prices always have been expensive by Australian standards. However despite the investment of billions replacing coal and gas with wind and solar, those prices have dropped a little. They expect to complete the transition and be 100% renewable this decade.

I wish this was driven by "incredible vision and foresight", but all they have done is chosen the cheapest option at each step. The only incredible thing about it is they took on the risk of adopting new technologies very, very early, wearing the (sometimes considerable) political pain of abandoning existing plants, capital investments, and jobs.