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NPRR #285 · Revision Request

NPRR285  Generation Resource Base Point Deviation Charge Corrections

Approved sponsor WMS posted 2010-10-12 ercot.com
ReasonThe implementation of the TWTG in the current Nodal software does not account for SCED cycles that are less than five minutes, In addition, it does not provide a clear signal to IRRs to indicate when they must curtail due to system constraints. A workaround has been put in place that requires each IRR to interpret the ERCOT Dispatch signals and its own telemetry to determine when curtailment is necessary. The changes in this NPRR provide a clear curtailment signal to the IRR and eliminate a time delay in information imposed because of the workaround. In addition, this NPRR corrects a Settlement equation error that was in the Nodal Protocols. Until the software is changed, the Base Point Deviation Charge is not calculated for IRRs. If the incorrect calculation were to remain in place then each IRR would receive incorrect Base Point Deviation Charges each billing cycle. ERCOT would be inundated with disputes. WMS submits this revision in its initial conceptual form to expedite Market Participant and ERCOT commenting. WMS will endorse the final NPRR language as soon as possible with the goal to have the NPRR in place in prior to the Texas Nodal Market Implementation Date (TNMID).
Created2010-10-21
Approved2010-11-16
Sections Affected
6.5.5.26.5.7.46.5.7.96.6.5.16.6.5.1.16.6.5.1.26.6.5.2
Summary
This Nodal Protocol Revision Request (NPRR) provides that an exception to the Generation Resource Base Point Deviation Charge for any 15-minute Settlement Interval which includes a Security-Constrained Economic Dispatch (SCED) interval that is less than four minutes in duration. Additional changes are proposed to Base Point Deviation Charges for over- and under-generation, to be effective upon system implementation. This NPRR also removes the Base Point Deviation Charge for all Intermittent Renewable Resources (IRRs) until corrections to the Nodal systems can be implemented so that the charge applies to IRRs only when there is clear indication that the Base Point received needs to be followed. A flag will be sent by ERCOT to the Qualified Scheduling Entity (QSE) for each Resource indicating SCED has Dispatched a Generation Resource below the High Dispatch Limit (HDL) used by SCED. This flag will be used by the Settlement system to determine when the IRR Generation Resource Base Point Deviation Charge will apply. In addition, the calculations are changed to apply the charge whether the Settlement Point Price is negative or positive.
Timeline