Yes, the Berkeley report says that California is worse off than the national average in terms of electrical generating supply to support EVs. But there is a region that is worse off than California. Yet some other regions could accommodate 100% EV adoption with generating capacity to spare. The point is, the 74% national average is not necessarily meaningful. Each region needs to be looked at.
The map you posted suggests 23% for CA (or most of it) with 24-hour valley filling. However, the graph you posted earlier shows that much more is easily achieveable.
To me, the CA curve actually looks quite good, once you do away with the report's arbitrary 6pm - 6am restriction, and the misguided assumed absence of intelligent load balancing. (See discussion below.)
Also, the report suggests that to achieve the 74% national average assumes that EV charging demand is managed to perfectly fill in the low demand periods throughout a 24 hour day, so everything matches daily peak demand. It assumes a flat demand cycle across 24 hours a day. No juggling of the TOU periods and TOU rates can accomplish that.
This is wrong, I think. Of course, at the point at which the EV adoption will be *exactly* 74%, at that point it would require achieving a perfectly flat demand curve, to avoid even the smallest additional generation.
However, while the EV adoption is less than that, as well as once it will be more than that (meaning most of the time), it will *not* require a perfectly flat demand curve to make optimal use of the currently existing off-peak capacity.
The report seems to assume that all load-balancing would have to be achieved with fixed TOU rates. It does away with grid communication more or less by calling it "hype" and making a list of difficulties which apparently the authors imply are unsolvable.
They seem to forget, for example, that each car built by Tesla has an internet connection, and knows exactly how much electricity it consumes. And is able to lower and raise its charging rate by remote control.
The report is simply wrong in thinking that these things are that difficult.
If EV charging is managed so that the 6 pm to 6 am period is filled in to match peak demand, the study found that the feasible national average EV adoption rate drops to 43% with our current generating capacity.
The restriction to charging only in the period 6 pm to 6 am is justified with nothing more than the following sentence (as far as I can tell):
Assuming electric vehicles can be recharged at any time of day is probably unrealistic, as most recharging will occur at home in the evenings and overnight. As such, a second scenario was considered whereby valley filling could occur only between the hours of 6 p.m. to 6 a.m.
What's wrong with charging at work, after the morning commute, which in many cases is half the day's consumption? What about delivery trucks, taxis, buses, and many other business-related vehicles which can (or even have to) be (re-)charged during the day? Those things are not unrealistic, they are more of a practical necessity.
To support high adoption rates for EVs, energy storage might be needed in a big way. Or a Smart Grid. Or more generating capacity in many regions. The problem can be solved of course. Generating capacity has grown a lot in the last 50 years. It can keep growing if needed.
We already have a smart grid: The combination electric car and internet connection, courtesy of Elon.
It would have been interesting to model the case where 39% of EV owners have rooftop solar, which I understand is the norm in California.
Now that sounds more like it.
I think that report is, to summarize it, wrong.
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I have trouble with this assertion. For me, for example, my plug-in time (at night, or early morning) is far more random than my unplug time (morning for work). Furthermore, I would argue most employed folk have similar unplug time (between 7 and 10 am) so it doesn't seem like it's very randomizing at all.
The idea is to avoid a big spike at midnight (or whenever the local off-peak time/rate starts), which many use to set the start time.
With more sophisticated software (which currently isn't really necessary), setting a need-by time would allow the on-board computer to do something fancy, including randomizing both start and stop time. Given cooperation between Tesla and utilities, the car could even get real-time info about the charging time and rate that is best for the grid. All within the confines of making sure the charge is complete at the specified need-by time. Of course, the driver should still have a charge-ASAP option when needed.