Investigate the ERCOT forecast, hour by hour

Try this

Select Below forecast, then brush a high absolute-error range. The table should retain only the intersection.
Clear the error-direction chart and verify that the same error-range selection remains.
Alt-click an error point and reconcile actual minus forecast against the source row.

Limits

Actual is electricity served in each hour, not unconstrained demand. These observations alone cannot identify why consumption or supply changed. The UTC snapshot includes partial boundary dates.