And as it is, utilities in the CAISO are generally too fossilized and change averse to view behind the meter aggregation as something that they can benefit from, and they will likely instead fight it. Smarter utilities would see the opportunity and approach regulators with rules changes that profit everybody. Instead, we will need legislators to impost such schemes on regulators and utilities, as there is zero innovation among leadership of utilities, and regulators have zero capability for this too.
(Perhaps I exaggerate, SMUD is tiny but they may have the vision for at least part of this. Vermont's Green Mountain Power has the leadership that we need in California, though.)
Behind the meter storage is a fundamentally different beast, because it has the potential to drastically reduce T&D costs, which are the vast majority of bills (at least mine under PG&E).
Christopher Clack has some great economic modeling of the grid at a very fine level, showing that deploying a bunch of storage and solar at the grid edge right now will greatly reduce costs and enable far more utility scale installs in the future, because the local storage and solar reduces the need for T&D peaks.
This sort of cost optimization is not incentivized but anyone in the current setup, and is impossible to achieve without direct regulation to change incentives for utilities.
In both cases, the fundamental mistake is to think of these as costs, when they are investments with rapid paybacks and so the obvious answer (and the reality) is massive expansion of battery manufacturing capacity.
The thing to do now, is increase our battery capacity.
In California, where this applies, the grid is very clean, so yes the dirties/most polluting part of the system is probably the cars.
Also, too, it's a brand new technology just being rolled out, and building more capacity at the limits of factory bandwidth. You're acting like the number of powerwall users are all we're ever going have, which seems silly.
CalISO showed a peak demand today of ~42GW. 125MW is more than nothing but nowhere close to 5% of peak usage.
Serving baseline from batteries is unrealistic and will be for quite some time. Smoothing peaks or helping with unexpected high (or low!) load however is slowly becoming viable.
https://www.caiso.com/participate/Pages/Load/Default.aspx
I think the demand response stuff adds up to about 2GW, so the same as the grid batteries at the moment, and both are set to grow at rapid rates.
Apparently, (as of 2021) Tesla has only sold about 200,000 powerwalls globally, so I guess that sort of checks out.
Annoyingly, our batteries are set to minimize our bill, but didn't get the memo about the special rates today (they are not powerwalls). They stopped selling back to the grid just before 6pm, and are almost half full as I write this.
More annoyingly, every morning they aggressively charge themselves during the precommute CO2-intensive demand spike, since power is cheap then (due to a policy setting, they normally only charge from solar)
I wish I could forbid them from charging before 10am or that PG&E would fix their rates.