You posted the Texas grid, I posted the California grid. Here's the NW grid which includes Nevada. Same thing, demand peaks around 6PM when people get home and turn on their houses.
https://www.eia.gov/electricity/gridmonitor/expanded-view/el...
https://www.eia.gov/electricity/gridmonitor/expanded-view/el...
https://www.rte-france.com/en/data-publications/eco2mix/elec...