The Hornsdale Power Reserve in southern Australia. Image by Google.

A recent piece at Seeking Alpha explains that Tesla’s giant installation of grid-connected batteries is doing very well financially.

For those unfamiliar, the Hornsdale Power Reserve in southern Australia is a big bank of lithium-ion batteries located next to a large windfarm. The idea is to charge the batteries when power is plentiful and release the power back into the grid when extra power is needed. This is done in two ways: by giving big boosts of power (for 10 minutes) when there’s a problem with the grid, and by load-shifting power under normal circumstances to help make renewables more reliable.

While the Seeking Alpha post goes into great detail, the important thing is this: the world’s biggest battery is not only doing well, but it’s doing well in ways that people didn’t predict. The battery is providing the services they expected when it was built, but also doing things unexpected, like allowing some peaker plants to stay off.

Because of all of this, the battery is about to be expanded 50%. With around 50% renewables in that part of Australia expected to grow further toward 100%, they’re going to need more storage not only to do what has been done already, but for new roles on the grid.

While this may seem pretty far flung from the business of replacing the batteries of vehicles like older Nissan LEAFs, that’s really not the case. Keep in mind that big batteries like the one in Australia are made up of many smaller ones, and are ultimately made of the same kinds of cells you’d find in an electric vehicle.

There have been many experiments, including in the United States, with using EVs to do the same things this big battery in Australia is doing. By allowing utilities some control over EV charging, and allowing them to take some energy from the batteries at key times, EV batteries have been able to be part of a broader solution and not just a load on the grid.