Batteries are a storage medium, the primary energy source is...

Batteries are a storage medium, the primary energy source is solar or wind. And for a plant using gas to make process energy such as steam or heat it's a continuous load.

A firmed solar PPA has a long term consistent price that can be used to power an electric boiler, the firming takes out the price swings you see in the NEM.

Below $33/MWh it becomes very attractive to replace a gas boiler with an electric boiler, because while the upfront electricity infrastructure costs are high you get it back pretty quickly on reduced turnaround costs. TBH the operating costs are so low you could almost dual operate gas (night) and electric (day) boilers and still come out on top.

These are getting lots of traction everywhere that's not Australia, like all things we're 10 yrs behind the times.

Parat high pressure electric boiler
https://www.parat.no/en/products/industry/parat-ieh-high-voltage-electrode-boiler/