Study warns against overnight charging

I recommend reading the original:
Scalable probabilistic estimates of electric vehicle charging given observed driver behavior - ScienceDirect

Abstract
To prepare for rapid growth in global electric vehicle adoption, grid and policy planners depend on detailed forecasts of future charging demand. In this paper we propose a novel holistic, scalable, probabilistic framework to produce large-scale estimates of electric vehicle charging load for long-term planning that capture real drivers’ charging patterns. Our framework captures the uncertainty and stochasticity in charging demand by taking a graphical modeling approach. It has three core elements: driver groups, charging segment choices, and charging session time and energy requirements. The framework uses hierarchical clustering to group drivers by their charging histories, capturing their heterogeneous behaviors and preferences across different segments or types of charging. The framework uses probabilistic mixture models for each driver group’s sessions to identify the unique charging behaviors observed within each segment. We illustrate its application with a large data set from California, profiling the charging patterns and unique driver clusters it identifies. Using the model knobs representing drivers’ battery capacities, behavior, and segment access we present scenarios for California’s charging demand in 2030 with 8 million passenger electric vehicles. Peak charging demand ranged from 3.3 to 8.7 GW across scenarios. Each was calculated in under 45 s on a laptop computer.​

I highlighted the problem I have with this "novel holistic, scalable, probabilistic framework." The paper PDF is behind a 'paywall' for $38. I'm skeptical of the value of this paper because of the cyclical nature of daily electrical usage.

For example: U.S. Energy Information Administration - EIA - Independent Statistics and Analysis



As long as we see such daily load changes, it is a simple task to change to 'Time of Day' rates, even discounted for EVs, and even out the load.

Bob Wilson

 

If this is primarily a problem where most electric cars exist in the USA (California) - then that's on them & their poor infrastructure. How is it on SoCal's 90° nights it's okay to run lots of juice for the central AC (all the while putting up more homes along every Hillside) but not a lower draw in many instances to recharge a car. Oh the ironies.
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@tochatihu will suggest writing the author for a copy of the study.

I recall posting info on when Californians actually charge their EVs, but no love finding it again. What I recall was that they charged at night, and that the time of use rates for EVs encouraged that. So regulations and rates can work for encouraging another charge schedule. I have a suspicion that installing enough work place chargers will cost more than grid storage for peak shaving.

These cover actual charging times.
https://www.nber.org/digest/202105/what-charging-habits-owners-reveal-about-electric-vehicle-use
Distribution grid impacts of electric vehicles: A California case study - ScienceDirect

The model wasn't about grid stability, but about best time for EVs to charge for lower emissions and maybe costs.

 

TOU rates do favor charging after a certain hour. I switched us back to Domestic rate meaning simple fee not based on TOU, per SCE who provides annual estimates on which plan would cost what, (Domestic predicted lowest). We now have a $2xx credit which I believe will cover electricity cost for the entire year.

I'll charge at any time when we get a new plug-in/EV, unless SCE says to cut back for whatever reason...