It started with a solar boom, many small home scale solar roofs popping up everywhere. Australia has a free trade agreement with much of the world, including China, and solar panels have literally dropped to 1/50th of the price they were in 1990 ($10/W to $0.2/W today). A shout out to the work that was done to establish dynamic grid pricing too.

Anyway that caused power prices to reliably go negative during the day as the solar boom led to too much energy being produced. So everyone started buying batteries (you can even get live feed in/out pricing as a consumer). In fact the government even today will pay you a $3000 subsidy to go install a battery. This is in a country where people can buy cheap batteries with no tariffs (free trade's amazing, seriously!). So everyone who could started doing it. For those in apartments etc. that couldn't easily install solar and batteries they won too since the entire power grid is now half the price.

Another consequence of all this, aside from the cheap power prices during a datacenter boom and Hormuz blockade is that fossil fuel usage is plummeting. Particularly gas https://ieefa.org/resources/slump-eastern-australia-gas-dema... . No need for a gas peak power plant when the grid is packed with batteries. Which is helpful since one of the main issues with the current blockade is a lack of gas globally.