> The big downside to decentralising residential power is that's variable demand–precisely the sort of demand you can net out against other parts of the grid.
Residential is variable but for the most part not all that amenable to time shifting, at least at present. Isn't a grid most efficient with a constant load, with the next best being something that varies only slowly over time and is highly predictable?
Then there's EVs. I'm under the impression that replacing a notable fraction of the ICE cars on the road with EVs would at present place the grid over capacity most places in the US.
When it comes to unit cost doesn't the ultimate benefit here lie with the consumer's pocketbook? I don't see why residential considerations should make much (or even any) difference to dense commercial or extremely high capacity industrial users. Given that solar plus battery is reasonably affordable for a large chunk of the US population it doesn't really seem like much of a downside when framed as a voluntary expense. I still see people building it out where I'm at (suburbs) despite (AFAIK) the subsidies ending.
> not all that amenable to time shifting
That’s fine. A solar system specced to a house has to meet its max drawdown. A house connected to a grid can effectively pawn off its unused power to another user. That’s the efficiency of a grid.
> doesn't the ultimate benefit here lie with the consumer's pocketbook?
Yes. The NPV of a blended system (solar, maybe battery and grid) almost always beats going all in on one or the other. You spec to your base load and put the uncertainty on the grid. That way you don’t have to overprovision solar and battery. (And you’re good with your essentials if the power goes out.)
This is almost universally true unless you have super-subsidized solar (bonus points for an expensive grid, e.g. California) or stupidly-cheap and reliable grid power (until recently, the Gulf).