Battery production rates are creeping up to multiple twh/year now. This is accumulating to a lot of battery sitting around in vehicles, domestic storage, grid storage, etc. Mostly the goal of these batteries of course isn't supporting the grid but some other use case. But if it's plugged in, it could potentially be available for selling power. Right now, most EVs can't contribute power. But that's something that is starting to change. Small experiments with thousands or tens of thousands of vehicles have already been done and seem to work fine. Now imagine tens of millions of vehicles being part of the grid. That's a serious amount of stand by power for absorbing excess power or dispatching power when needed.
Another interesting aspect is that as grid demand fluctuates, a lot of cables are under utilized at least some of the time. Which means there is plenty of capacity for charging batteries provided there is excess generation and cable capacity. A lot of that power currently gets discarded instead. Batteries allow better use of this excess power. And having a lot of local battery means that cable capacity can be freed up as well when needed and then recharged when demand reduces.
And then finally battery prices are coming down. With sodium ion cell production ramping up in several places, things could get quite a bit cheaper. These don't depend on scarce metals or materials. And they last quite long as well (relative to NMC).
Another interesting aspect is that as grid demand fluctuates, a lot of cables are under utilized at least some of the time. Which means there is plenty of capacity for charging batteries provided there is excess generation and cable capacity. A lot of that power currently gets discarded instead. Batteries allow better use of this excess power. And having a lot of local battery means that cable capacity can be freed up as well when needed and then recharged when demand reduces.
And then finally battery prices are coming down. With sodium ion cell production ramping up in several places, things could get quite a bit cheaper. These don't depend on scarce metals or materials. And they last quite long as well (relative to NMC).