The Redflow guys and similar are onto some very good ideas. If they can scale up to commercial builds then it is a good goer as compared to lithium as it is clearly longer term and larger scale than li-on.
They just need to prove they can compete with big money for commercial stuff as Musk is putting in big stuff around the USA etc. successfully.
I personally think they'll do a combination of both, would like some Australian content for sure.
These can be done in the next year.
Other solutions are years away, and you only need to look at the billions China et al are putting into renewables to know by ~2020 what the reality will be.
