Peak demand on most electricity systems, including California's, is during the evening hours, typically between 18:00 and 21:00. This does not coincide with peak solar generation.
That's because residential solar is eating up the daytime peak, thus the duck curve. Residential solar is already saving the state tons of money on T&D costs.
(And becuase the Wikipedia for duck curve shows a day in October rather than a summer day where the peak is much higher, yes the annual peak does coincide with when solar is outputting a ton of power.)
You misunderstand the charts, these do not take into account residential solar. The reason the peak is getting pushed into the evening is because residential solar doesn't even show up on the chart.
Look at the difference between gross and net: this is utility scale shaving off the peak. This is what is happening with residential solar too, which is not shown.
Peak demand on most electricity systems, including California's, is during the evening hours, typically between 18:00 and 21:00. This does not coincide with peak solar generation.
You can see this even as far back as 2018 via CalISO's own data. https://www.caiso.com/todays-outlook