What is the storage time typically? 30 GW is how many GWH? around 50-70? When i ran the numbers last time it looked like less than 200GWH won't make a visible dent in renewables' intermittency. 2TWH will be enough to massively deploy solar and replace everything with it. So about 7x the annual rate of installation is needed (assuming 3000 cycles lifetime and daily usage)
It depends on the application, but four hours of duration is typical.
You'll find that most new solar installs in states with a lot of existing solar will include storage already, so that they shift some of their power to times of higher power proces.
I would agree that it's meaningful. It will only expand to higher amounts as time goes on, and more chemistries enable longer duration (such as iron air for 100h duration)
However all these batteries are driven by economics. The first megawatts are useful for frequency regulation, for which they get reimbursed handsomely, but those batteries are only 15-30 minute duration usually.
Once there's lots of cheap solar and wind on the grid, and it's grid that embraces time based reimbursement, that's when the four hour batteries come on. The 100h batteries start to become economical at about that time too. But all time arbitrage depends on having a high enough difference in prices.
There won't be 100h batteries i believe. Rather, there will be a lot more of 2-3 hour ones. To consume and then output power of lots and lots of solar (which is nearing 10 cent/watt threshold)...
You may very well be right, but in wind heavy generation markets, intuitively it feels like there's a good potential fit. And startups like Form Energy claim to have done extensive market modeling such that they think their air-iron battery can come in at the right cost.