On the battery front, a major patent on lithium iron phosphate expired just a couple weeks ago. I don't know what the long term consequences of that will be, but if it means being able to buy LFP batteries at $100/kwh or less outside of China, that could change the economics of utility-scale battery storage quite a bit.
In the long run I hope to see high capacity transcontinental HVDC lines linking continents so we can buy solar power from the other side of the Earth when it's night where we are, and sell our surplus when the sun is shining -- no batteries needed. That's hard and expensive. (Supposedly China is working on a deal with Chile where China can buy solar power that gets sent across a proposed trans-Pacific power line. I think that's the kind of megaproject that every industrialized country should be thinking about.)