Sumitomo acquisition, page-10

Sumitomo are in the business of financing new infrastructure, long life cycle assets.
The WA investment as I read it, in order to supply power 24/7 will require investment in energy storage.
Sumitomo have 30+ years of operational & maintenance data on Vanadium Redox Flow batteries. In the Engineering world that is pretty damn important to eliminate risk. Tesla large scale stationery storage is a different beast, so far many of their projects backed by public funds.
Sumitomo have the resources to finance & develop the entire Vanadium battery industry on their own, independent of government support, if they so wish. 
And there is plenty of reason even back at home for them to do so with the deregulation changes in the Japanese energy market.
https://www.engerati.com/article/energy-transition-japan-disrupt-TEPCO-deregulation