Stationary batteries and their role in futuer power production and supply

Obviously, I'm no electrical engineer. But from what I've read about, I think this article in the NYT misses an important component of getting our infrastructure ready for an all-electric vehicle, renewable power future. And that is the role that stationary batteries will play, in every building, every house, every user of power during peak times. Battery technology is getting so good, so long lasting, so reliable, and so developed from nonrare materials that they can be installed everywhere.  Sodium ion phosphate and other new technologies that don't require large amounts of nickel, cobalt, or lithium are coming online rapidly. But, you might say, that's just storage, how does that help the shortfall of capacity? Well, it doesn't, entirely, of course. We do have to build a huge amount of renewable sourced energy plants and the transmission infrastructure to distribute power. But batteries will smooth out the curve; eliminate the need for "peaker" power plants that only come on line during periods of peak demand. Essentially, with a little margin for failures, the power system will only have to provide the average daily power consumption; the batteries will smooth out the peaks and charge to full when power demand is at its lowest. This could, I'm told, amount to as much as a 20% reduction in the peak power production levels required. This article doesn't really address this point, which is obviously crucial. This is clearly part of Elon Musk's long range strategy to turn Tesla into a critical energy company, but he is not alone in furthering this kind of technology, the advantages of which are obvious and compelling.