ERCOT Increases Minimum Reserves
November 06, 2023
ERCOT has announced an increase in the minimum operating reserves requirements for emergency operations for each of its three Energy Emergency Alert (EEA) levels.
ERCOT periodically studies the level of online reserves that must be preserved to maintain system reliability during emergency conditions. The level of reserves has increased as the resource mix has changed, with more wind, solar, and battery storage resources supplying power during emergency conditions.
ERCOT now requires a baseline minimum operating reserve for EEA 3 of 1,500 MW, which automatically increases EEA 1 and EEA 2 reserve levels, as follows:
- EEA 1 will occur if reserves reach 2,500 MW (previously 2,300 MW) and are not expected to recover within 30 minutes. When operating reserves drop below 2,500 MW and are not expected to recover within 30 minutes, grid operators can call on all available power supplies, including power from other grids, if available.
- EEA 2 will occur if reserves reach 2,000 MW (previously 1,750 MW) and are not expected to recover within 30 minutes, or if frequency has dropped below 59.91 Hz for 15 minutes (previously 30 minutes). When operating reserves are less than 2,000 MW and are not expected to recover within 30 minutes, ERCOT can reduce demand on the system by interrupting power from large industrial customers who have contractually agreed to have their electricity turned off during an emergency. ERCOT can also use demand response resources that have been procured to address tight operating conditions.
- EEA 3 occurs if reserves drop below 1,500 MW and are not expected to recover within 30 minutes, or if frequency drops below 59.8 Hz for any period of time. If either situation occurs, ERCOT would require Transmission and Distribution Service Providers (TDSPs) to implement controlled outages, which impact residential, commercial, and industrial users. Previously, an EEA 3 was issued when ERCOT’s operating reserves dropped below 1,430 MW. When operating reserves dropped below 1,000 MW, and were not expected to recover within 30 minutes, controlled outages were activated.