Important to have some perspective on scale, though. All powerwalls acting together can source 125MW, max. Yesterday, grid-scale batteries in California discharged a peak 2751MW. The powerwall tricks are cool, but I’m not sure it solves a problem the ISO actually faces.
But the number of power walls is not fixed, and going from 125MW to 12,500MW is only going to happen there are proper incentives from the grid.
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.)
Regulated market participants went from zero to 3000MW/12000MWh of capacity in only 2 years. That's 100x faster than powerwall installations. I don't see how you can conclude from these facts that CAISO or the CPUC are stuck in the mud.
Central installations are perfect for the current incentives: they use the same amount of T&D, for which utilities can always charge their profit margin, as long as they can convince regulators that the expenditure is justified.
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.
I don't disagree with any particulars of your analysis except one omission: powerwalls compete with electric cars for relatively scarce high-tech batteries. It is globally optimal for the time being for those batteries to all be used to electrify transportation, while utility power can be enhanced with large, fixed installations using whatever kind of battery they can get. Lead-acid or anything else, it doesn't really matter. But nobody is selling turn-key residential power packs using anything but lithium-ion batteries.
Note this same argument is used against EVs. Saying the batteries should be used for hybrids instead.
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 hybrid thing is true though. With the same number of batteries you can cut carbon emissions from cars by either 50% with hybrids or 2% with electrics. It makes perfect sense as the thing to do now with the capacity we actually have.
I thought a lot of these were recycled from vehicles when their energy density doesn’t meet the needs of a vehicle anymore but make sense in a house since the house doesn’t move?
Not all parts of the energy grid are as “clean” as a gas cars’ ICE unfortunately. You’re better off driving an ICE in those regions than charging an EV. Globally we’re better off creating a sustainable carbon-free grid in regions with poor grid generation first.
In California, where this applies, the grid is very clean, so yes the dirties/most polluting part of the system is probably the cars.
Seems like having an available 5% bonus on peak (!) usage is a huge deal, actually. Buffering shortfalls have an exponential frequency curve. I wouldn't be surprised if 5% extra generation would have been enough to cover, what, 60-90% of all brownout/failure conditions on the grid over the past few decades.
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.
The baseline is not zero GW. If the grid planned for 35 to 40GW of demand for today and then sees 42GW load, the 0.125GW are over 5% of the excess load.
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.
And solar was providing about 3GW less than it was about a month ago. Lower solar output but spiking fall temperatures. It's sort of a "coffin corner" for the state, currently.
I think they meant that if grid batteries are a good thing (which they are), then distributed batteries equal to 5% of their peak contribution, isn't nothing. (125MW/2751MW)
Regulated market participants are adding the equivalent capacity every month. That's where the progress is coming from, and where you should expect most future progress to occur. Long-tail stuff just isn't efficient enough to really make a dent.
I'm surprised it is so low. Our pack discharges at at least 10kw (max averaged by hour over the last two weeks; didn't look up specs). That means we're over 1/12,500th of the state wide pilot's footprint.
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.
Many of these devices do let you set 'fake' time of use details if you want to further restrict them. Not ideal, but a quick way to make your energy use greener if you consult one of the APIs that tells you when your local grid is greenest (which probably roughly, but not quite matches their time of use rate structure since they have to simplify, possibly averaging over a year when it various seasonally)
