ERCOT Posts Final Seasonal Assessment Of Resource Adequacy For Fall 2021

ERCOT has posted the Final Seasonal Assessment of Resource Adequacy (SARA) for the Fall 2021 season.

After the Fall 2021 SARA, ERCOT will publish only a single, final SARA for each season and will no longer publish a preliminary SARA.

"The ERCOT region is expected to have sufficient installed generating capacity to serve peak demands in the upcoming fall season, October – November 2021, under normal system conditions and several of the capacity reserve risk scenarios examined," the SARA states

"Based on expected fall peak weather conditions, the preliminary fall SARA anticipates a seasonal peak demand of 62,662 MW, which is unchanged from the preliminary SARA released on May 6th. This demand forecast has been adjusted downward by 120 MW to account for the load reduction impact of incremental forecasted rooftop solar capacity," the SARA states

Reserve capacity is projected as 27,771 MW under normal system conditions

"ERCOT is projecting a decrease in reserve capacity of 868 MW since the release of the preliminary fall SARA in May, based on data provided by resource owners and developers. The decrease is mostly due to an extended outage for a coal unit. Planned resource capacity totaling 5,277 MW is expected to be available to meet the fall peak demand. The planned projects are comprised of gas-fired units, wind and utility-scale solar. Another 644 MW of battery energy storage capacity is also expected to be available, although this capacity is currently assumed to provide Ancillary Services rather than sustained capacity for meeting system peak loads," the SARA states

"The report includes a thermal outage forecast of 14,774 MW based on historical outage data from the past three fall seasons (starting with 2018). Due to a change in categorizing a type of outage called an Unavoidable Extension, unplanned outages (previously called forced outages) increased while planned outages (previously called maintenance outages) decreased by a like amount. This change resulted in greater unplanned outage amounts for the high and extreme unplanned outage cases. The Background tab now includes more outage accounting information as well as details regarding the change in categorizing Unavoidable Extension outages," the SARA states

"Starting with this SARA report, ERCOT expanded the low wind output scenario adjustment to include low solar output as well. Similar to the preliminary fall SARA report, the final fall SARA includes a tab that provides a set of extreme scenarios. These extreme scenarios assume that multiple severe system conditions occur simultaneously, resulting in very low probability, high impact system outcomes," the SARA states

See the SARA here