ERCOT Conditions Yesterday Prompt Oncor to Call Curtailable Load

ERCOT yesterday entered Energy Emergency Alert Level 1 for about an hour and a half, which prompted Oncor (independently of the ERCOT process) to initiate its first unscheduled curtailment order under the voluntary Commercial Load Management program.

ERCOT entered an Energy Emergency Alert Level 1 at 3:30 p.m. local time when responsive reserves dropped below 2,300 MW due to the unexpected loss of about 2,000 MW of generation and high temperatures. The alert was cancelled at 4:55 p.m. local time.

LMPs did reach the $3,000 cap in several intervals yesterday

ERCOT demand peaked at 62,762 MW between 4-5 p.m. local time, lower than the earlier forecast of more than 65,000 MW.

ERCOT's forecasted demand for today is 64,400 MW, but units that failed Monday are expected to be available today, in addition to other capacity that was not available Monday.

During the emergency alert, Oncor ordered a curtailment of resources participating in its Commercial Load Management program. The curtailment was not directed by ERCOT, but did result in response to grid conditions.

This is the first curtailment of resources under the Oncor program, outside of tests, according to a program participant.

The Oncor program is separate from ERCOT-run curtailment programs, and is part of Oncor's "standard offer" energy efficiency programs. The Oncor program pays $20 per kW for unscheduled curtailments, as well as $10 per kW for scheduled curtailments during testing.

Oncor may call up to four unscheduled curtailments during the one-year contract term. Oncor notifies service providers of an unscheduled curtailment with at least one-hour advance notice of the start-time for the curtailment.

The duration of an unscheduled curtailment is a minimum of one hour and a maximum of four hours.