Peak demand is 6 PM when everyone gets home from work and turns on the air conditioning.
EDIT: Your chart shows the same thing? Demand is highest at 6 pm, not noon.
People regularly use the demand being supplied by solar to argue that solar isn't delivering when people need electricity.
The yearly peak grid demand in California is moving later in the day and later in the year due to this effect.
https://www.eia.gov/electricity/gridmonitor/expanded-view/el...
https://www.rte-france.com/en/data-publications/eco2mix/elec...