TNG holders might be interested in this, page-4

Is there anyone in Australia that is capable of providing batteries at the scale required for a project of that size?

From what I know about government tenders, they are determined on the basis of merit. Often you will see contracts awarded to foreign companies, even though Australian companies are bidding.

A collaboration of SEI, TNG and EMC has a lot of Australian involvement anyway. It is possible they would need to bring in a major energy company (like AGL or Origin, or an infrastructure company like Lend Lease).

In WA EMC has worked with WesternPower, Horizon Power and Synergy. They would probably need to work with whoever the grid owner was in the state where the project was to be built.