I think economics is getting in the way more than politics. Storage is just simply too expensive at this time to be worthwhile for basic grid storage. It makes great economic sense for places that must be off-grid and/or mobile - the alternatives there are even more expensive/cumbersome.
Try penciling out the price delta between peak kWh and off-peak kWh and see what it takes to make a payback on that storage at pennies per kWh. Factor in start-up capital, losses in charge/discharge, maintenance (how long will those batteries last, being cycled almost daily?), and the fact that with variable power with things like wind, you won't always have an excess to store, and you can't afford enough storage to capture an excess that only happens occasionally.
Not sure what the break-point on that would be, but think of an excess that only occurs 10% of the time - it doesn't seem that you could afford storage for that. Even the 50% rate would probably not be cost effective. Still a lot of energy being wasted for want of storage.
-ERD50
Yesterday, I was doing a quick estimate of a small solar set up to run a small window A/C in the summer to supplement the big central A/C. If it worked out, I might just build it to have something to tinker with.
It turned out that even with the solar panel low current prices, no labor and installation costs, it still takes 22 summers for this to pay back. And I am not even counting capital opportunity cost and maintenance, etc...
So, where did I go wrong? It turned out that if I can make use of the produced electricity year round, then it would take 1/3 the time for payback. Outside of the summer season I do not have the A/C as a constant load to consume this free electricity. And to store this power and use it elsewhere in the home requires more equipment and creates more complication. It would be best if I could dump this power to the grid, and take credit so that I can use it later. But of course, such homemade experimental setup is not approved for a grid-tie operation, so I will not get very far with this.
Back on battery storage, in the summer I pay $0.21/KWh during peak hours, and $0.07/KWh during off-peak hours. Assuming that the difference above is due to the production cost of running "peaker" generators, then a commercial battery installation is arbitraging between the above two rates. You make $0.14 for every KWh you store during off-peak and release it when people run their A/C.
The cost of battery is around $400 per KWh right now at the retail level. It is rumored that Tesla is paying much less, but they are mum about it. But if they can get it for $200/KWh, you still need 1400 charge/discharge cycles ($200/$0.14) or 4 years to recover the cost of just the battery. Or perhaps during a power crunch, utilities have to pay even higher than $0.21 to peakers to avoid brownouts, though they cannot charge customers as much.
I am not in this business, hence only have a naive view as presented above. But it seems like they expect the battery to get a lot cheaper. If a company in the power generation business is willing to put their money into this to make money and not asking for subsidy, I surely want to stand back and watch it evolve.