Issues

NPRR282

Summary
Action
Voting Record
Background
Key Documents

Summary

Title	Dynamic Ramp Rates Use in SCED
Next Group
Next Step
Status	Approved on 01/18/2011
Effective Dates	07/26/2011

Action

Date	Gov Body	Action Taken	Next Steps
01/18/2011	BOARD	Approved
12/06/2010	TAC	Recommended for Approval	ERCOT Board consideration of NPRR282
11/18/2010	PRS	Recommended for Approval	TAC consideration of NPRR282
10/21/2010	PRS	Recommended for Approval	PRS Impact Analysis review

Date

Gov Body

Action Taken

Next Steps

01/18/2011

BOARD

Approved

12/06/2010

TAC

Recommended for Approval

ERCOT Board consideration of NPRR282

11/18/2010

PRS

Recommended for Approval

TAC consideration of NPRR282

10/21/2010

PRS

Recommended for Approval

PRS Impact Analysis review

Voting Record

Date	Gov Body	Motion	Result
01/18/2011	BOARD	To approve NPRR282 as recommended by TAC in the 12/6/10 TAC Report.	Passed
12/06/2010	TAC	To recommend approval of NPRR282 as recommended by PRS in the 11/18/10 PRS Report.	Passed
11/18/2010	PRS	To endorse and forward the 10/21/10 PRS Report and Impact Analysis for NPRR282 to TAC and to assign NPRR282 a priority of Critical.	Passed
10/21/2010	PRS	To recommend approval of NPRR282 as amended by the 10/18/10 Luminant Energy Company LLC comments.	Passed

Date

Gov Body

Motion

Result

01/18/2011

BOARD

To approve NPRR282 as recommended by TAC in the 12/6/10 TAC Report.

Passed

12/06/2010

TAC

To recommend approval of NPRR282 as recommended by PRS in the 11/18/10 PRS Report.

Passed

11/18/2010

PRS

To endorse and forward the 10/21/10 PRS Report and Impact Analysis for NPRR282 to TAC and to assign NPRR282 a priority of Critical.

Passed

10/21/2010

PRS

To recommend approval of NPRR282 as amended by the 10/18/10 Luminant Energy Company LLC comments.

Passed

Background

Status:	Approved
Date Posted:	Sep 28, 2010
Sponsor:	Calpine
Urgent:	No
Sections:	2.1, 6.5.7.1.12, 6.5.7.2
Description:	This Nodal Protocol Revision Request (NPRR) proposes revisions that are intended to result in more reasonable Dispatch of Generation Resources when a telemetered Base Point requires the Resource to employ technologies that in turn change the Resource’s ramp rate. For example, when Security-Constrained Economic Dispatch (SCED) generates a new Base Point for a unit that is currently at baseload, SCED uses a static ramp rate found in the Resource Parameters database that does not accurately reflect the dynamic ramp rate that the unit can deliver as it leaves baseload status (ten MW/min. for some units) and goes into duct burners (one MW/min. for some units) or through duct burners into other technologies such as certain forms of power augmentation. Instead of using the declared static ramp rates at designated output levels, SCED should use a dynamic ramp rate that can be telemetered by the Qualified Scheduling Entity (QSE) to ERCOT using the Inter-Control Center Communications Protocol (ICCP) database with an update rate of two or four seconds, which will better match the unit’s ramp rate capability during the SCED execution. The up and down ranges of this telemetered dynamic ramp rate are best defined by ERCOT based on its experience in the Nodal Market trials and its view of the SCED Base Point outcomes and its analysis of the Generation Resource Energy Deployment Performance (GREDP) scores and Regulation Service deployed.
Reason:	Market trials demonstrate that plants are Dispatched at levels that are unachievable during the five-minute SCED intervals. These situations occur when SCED uses a declared static ramp rate for an output level that does not apply over the output range implicated by the new telemetered Base Point.