When the reserves drop below 2,300 megawatts, Emergency Energy Alert 1 is activated. That’s when ERCOT communicates to the public and to power generators that the situation is deteriorating.
At this time, ERCOT will import power from other states and from Mexico. This regularly happens during peak summer months and is not new. But right now, because prices are so cheap, and unrelated to the weather, ERCOT was already importing power from Mexico and other power grids.
Rotating outages do not happen during this stage.
EEA2
When the electric reserves drop to 1750 megawatts, other steps are taken to bring on additional capacity, but rotating outages are still not yet activated.
EEA3
When the reserves get to 1,000 megawatts and they are not expected to recover within 30 minutes, ERCOT will then ask electric suppliers like Oncor and Reliant to begin rotating outages to reduce load on the system.
ERCOT said the location of outages would be determined by each provider like Oncor and Reliant.
The DC ties represent <1.7% of current load. About the size of a single large generating station. ERCOT, by policy (to avoid certain federal regulations), keeps it that way. I guess you're technically right that they can import power, but that is far from the design intent of the system. (Which is stark contrast to the eastern and western interconections, and their internal multistate ISO's.)
Following up on this, I checked ERCOT status this morning and none of the DC ties are moving energy (at a moment when you might expect they'd really like to):
From ERCOT's own Q&A:
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EEA1
When the reserves drop below 2,300 megawatts, Emergency Energy Alert 1 is activated. That’s when ERCOT communicates to the public and to power generators that the situation is deteriorating.
At this time, ERCOT will import power from other states and from Mexico. This regularly happens during peak summer months and is not new. But right now, because prices are so cheap, and unrelated to the weather, ERCOT was already importing power from Mexico and other power grids.
Rotating outages do not happen during this stage.
EEA2
When the electric reserves drop to 1750 megawatts, other steps are taken to bring on additional capacity, but rotating outages are still not yet activated.
EEA3
When the reserves get to 1,000 megawatts and they are not expected to recover within 30 minutes, ERCOT will then ask electric suppliers like Oncor and Reliant to begin rotating outages to reduce load on the system.
ERCOT said the location of outages would be determined by each provider like Oncor and Reliant.
https://www.wfaa.com/article/weather/texas-power-outages-fre...