Batteries don't just even out demand. They change behavior too.
Tesla has already shown that it can "kill the duck" with grid-scale batteries, by reducing the need for expensive and polluting "peaker plants." As more homes install Powerwalls too, it should also help even out residential demand by allowing homeowners to use their own solar first, and also to take advantage of off-peak rates to replenish any shortfall.
But how does it work in practice?
Robert Llewellyn recently installed a Powerwall 2 and, in one of the latest episodes of Fully Charged, he goes into typically in-depth and geeky detail to share how it's been. Here's the single biggest takeaway.
Since installing the battery pack some 3 months ago, he says he has used ZERO energy from the grid during peak hours. And that's in the not-so-sunny UK. Part of the reason for that, I believe, is hidden in the way that Robert reviews this installation: He's clearly adapted his behavior—changing when and how fast he charges his cars—in order to maximize the amount of homegrown energy he is reliant on.
The question will be, of course, whether Robert Llewllyn is normal. Or, perhaps less pejoratively, will the kinds of behavior changes we see from early adopters and tech geeks translate into behavior changes when mainstream households also start installing batteries?
The truth is that it may not matter by then. As smart thermostats and other networked devices become commonplace, they will most likely be able to coordinate directly with solar and battery systems to optimize usage. (Robert hints at this himself when he says he's installing a Zappi electric vehicle charger, which automates charging times based on greenness of electricity.)
Anyhow, check out Robert's review for the full details. And, as always, please consider supporting Fully Charged on Patreon.