Here's raw table data to look at 15 min spot price per mWh http://www.ercot.com/content/cdr/html/20210220_real_time_spp

Here's overall grid conditions in real-time http://www.ercot.com/content/cdr/html/real_time_system_condi...

You can see the massive excess capacity which is why pricing has gone negative now, total opposite of earlier in the week, grid may fail now from overload instead of brown out.