This Market Driver Alert (MDA) investigates the Energy Emergency Alert 2 issued by ERCOT on September 6th, 2023, and the response of wind and thermal generation in the south and coastal zone.
On September 6, 2023, ERCOT experienced the tightest grid conditions since Winter Storm Uri when physical response capability (PRC) hit a minimum of 2.1 GW at 19:40. PRC dropped rapidly enough that ERCOT blew through an Energy Emergency Alert 1 (EEA1) and went directly into an EEA2, reigniting post-Uri concerns as to how the grid ended up in emergency conditions with lower load and net load levels than seen in August.
Live Power 60-second wind generation in the coastal and south zones shows wind output drop 761 MW in 30 minutes across 12 facilities. Shortly after, frequency began to decline, reaching a minimum of 59.77 Hz at 19:25.
Live Powerwind data also shows that the dip in generation was not correlated to weather-related wind decreases and was not the result of economic curtailment as location marginal prices (LMP) were >$1000.
Instead, the drop appears to be correlated to CALAVERS-PAWNEE 345KV PAWNEE_SPRUCE_1 constraint with contingency DELMSAN5 (Elm Creek-San Miguel), of which Live Power monitors both transmission lines.
Figure 1: Live Power 60-second Coastal/South wind generation vs. ERCOT frequency, HE 18-HE 24 on Sept. 6, 2023
Digging into the 60-second generation and transmission data from Live Power, we will uncover how different resource groups responded to the EEA2 and what their link is to congestion in the area.