The AEMO (Australian Energy Market Operator) website has some good data can see price of electricity in realish time. This is for the NEM (which is east coast states + South Australia), the west coast is on a separately managed grid with no interconnection.

https://www.aemo.com.au/energy-systems/electricity/national-...

You can also view the breakdown of where the grid is sourcing energy from (i.e. what portion of the grid is supplied from solar pv etc at any given time).

I know that some big industrial users (large factories etc) can optimize/spin up production lines etc based on the spot price. Although I'm not sure if they use the same public AEMO data there might be a dedicated api or similar involved.