1. December 8, 2006 PUCT DR Workshop Status of LaaR Participation in RPRS

2. PUCT DR WorkshopDecember 8, 2006 Background: In early 2006 ERCOT identified three problems within our network model related to LaaR modeling which were impacting the RPRS process and resulting in incorrect solutions. In an effort not to delay the migration of the RPRS code into production ERCOT elected to temporarily disable LaaRs from participating in RPRS until these problems were solved.

3. PUCT DR WorkshopDecember 8, 2006 Status: ERCOT believes that a change to model LaaRs as negative generation will correct these problems. A patch (modified code) is expected to be migrated into the test environment in early December. If all test results return positive ERCOT plans to migrate patch into production during the January update.

4. PUCT DR WorkshopDecember 8, 2006 LaaRs are only considered in Step 2 of the RPRS process (zonal congestion & system balance) Online, available, but not active in the Resource Plan RPRS Bid required Eligible LaaR’s Max Capacity will be set to the lesser of RPRS Bid Capacity or the difference in the Resource Plan Max and Min Things a QSE should know/prepare for to Participate in RPRS

5. PUCT DR WorkshopDecember 8, 2006 QSE can submit RPRS bids by: 1.Access through the Texas Market Link (TML) 2.XML Submission Things a QSE should know/pre ….

6. PUCT DR WorkshopDecember 8, 2006 Day – The Operating day for which the bid is submitted FIRSTHOUR – The first hour the bid is active LASTHOUR – The last hour the bid is active CAPACITY – The capacity in MW for the RPRS bid RSRC_ID – ID of Resource RSRC_TY – Type of Resource (GEN, UFR, CLD) CMZONE – Zone where the Resource is located STARTUP_PRICE – Capacity Price per MW PERHOUR_PRICE – Operational Price per MW EXPERATION_DATE – Date which bid expires EXPERATION_TIME – Time which bid expires BES_BIDPOINT – Procured RPRS MW will be bid at or under this price What makes up an RPRS Bid?

7. PUCT DR WorkshopDecember 8, 2006 Things a QSE should know/pre …. Deployment Electronically Transmitted via XML Hours of Capacity Dispatch included What does a QSE do when RPRS is procured from the QSE? Receive and XML Message Update Resource Plan Accordingly Add entire capacity of RPRS Resource into Up Balancing Energy Bid Stack Ensure Resource Ready for dispatch for specific hours