ERCOT Moves From Three to Five Under-Frequency Load-Shed Stages on 1 November

ERCOT told transmission operators on 20 October that Nodal Operating Guide revisions NOGRR226 and NOGRR247 take full effect on 1 November. The standard under-frequency load-shed scheme goes from three stages to five, with a 59.1 Hz stage added, a minimum delay of six cycles (0.1 seconds), and each stage shedding a further 5 per cent of a transmission operator's load. Five steps of 5 per cent put automatic relief at 25 per cent of that load by the last stage, measured at the moment frequency reaches 59.5 Hz. NOGRR226 adds anti-stall firm load shedding at 59.5 Hz.

The PUCT approved NOGRR247 on 12 October 2023, so the final piece arrives just over three years later. Most of its text went in on 11 March 2024; the remaining table language was held for a date no earlier than 1 October 2026.

Two market changes land a few days earlier, on 29 October. NPRR1198 creates Extended Action Plans, which let a transmission reconfiguration stay in place for a set period to manage congestion that SCED can otherwise resolve; participants may submit proposals from that date. NPRR1281 and NPRR1327 automate how ERCOT counts availability for Firm Fuel Supply Service resources when an alternate unit stands in for the primary, with settlement changes applying from the 15 November operating day.

ERCOT has warned of intermittent interruptions to its market information system, dashboards and outage scheduler during the 28-29 October release.