This is what I think the real benefit is, and also why I think we'll see both. I don't see the political will or financial commitment materialising for large scale energy storage in the short term because it's an upfront cost to a taxpayer whichever way you slice it.

Individuals are free to self-fund their own battery pack installations though, and can then decide if the upfront cost is worth the reduction in rates to shift energy usage to non-peak times. Once that sufficiently takes off it becomes easier to sell the public at large on the idea, and will also drive down costs, at which point I could see wide-scale grid storage becoming thing. At that point, renewables are scalable to almost 100% of energy usage (assuming vehicles and industry transition away from combustion machinery).