Texas Staff Updates Estimate of ERCOT Capacity Used for Small Fish Swim Free Rule

Staff of the Public Utility Commission of Texas have filed an updated estimate of the installed generating capacity in ERCOT.

For purposes of the 5% "small fish swim free" market power exemption under Subst. R. 25.504(c), Staff's estimate of ERCOT installed capacity is 81,597 MW

For purposes of the 20% capacity limit (PURA Sec. 39.154), Staff's estimate of installed capacity is 83,747 MW.

The installed capacity value for Subst. R. 25.504(c) is slightly smaller than the value used for the 20% capacity limit because the former does not include uncontrollable renewable capacity or import capability.

The definition of installed generating capacity includes capacity that is currently not available to the ERCOT market, such as mothballed capacity and "behind-the-fence" capacity. Therefore, the estimate should not be used for purposes of resource adequacy, Staff said.

Consistent with PURA § 35.152, the installed generation capacity now includes energy storage facilities that were identified in the ERCOT Capacity Demand & Reserves (CDR) report.

Docket: 39870