1. Lead from the front Texas Nodal http://nodal.ercot.com 1 Resource Node Locations 01-28-08 WMS Subgroup Meeting

2. Lead from the front Texas Nodal http://nodal.ercot.com 2 Agenda Overview of the Revised Approach [Most Resource Nodes to be located “north” of the high side of the GST (as recommended by WMS).] –Typical Configuration Description and Examples –CCP Description and Examples –PUN Description and Examples Naming Convention Ideas Open Issues with Revised Approach Is a Protocol Revision Required? Timeline for final review, release and use of updated Resource Node Names and Locations Questions

3. Lead from the front Texas Nodal http://nodal.ercot.com 3 High Level Description of Locating the Resource Nodes #1 1)Use the “First Fork Rule” to place the Resource Nodes in the model for each unit. In many cases this is “north” of the high side of the GST and is the same electrical bus with the EPS meter. Approach follows WMS recommendation. 2)Also……. Connectivity Nodes for all units are in the model. These nodes indicate where the unit is physically connected to the system (low side of GST). This info is passed to EMS and MMS. 3)More than one unit can be mapped to a Resource Node. A unit cannot be mapped to more than one Resource Node. 4)See examples. (In many cases, there is a reduction in the number of Resource Nodes as compared to previous approach.) Need naming convention.

4. Lead from the front Texas Nodal http://nodal.ercot.com 4 Typical

5. Lead from the front Texas Nodal http://nodal.ercot.com 5 Typical Complex SCED & 3PO Mw Telm HSL LSL AS etc Resource Status SCED & 3PO Mw Telm HSL LSL AS etc. Resource Status DAM EOO CRR Bids

6. Lead from the front Texas Nodal http://nodal.ercot.com 6 High Level Description of Locating the Resource Nodes #2 CCP’s 1)For CCP’s use Logical Resource Node approach. (approximately 56 Trains) 2)This Logical Resource Node is (essentially) the Resource Node for the train. There is a mapping of “Non-biddable Resource Nodes” (identified by the “First Fork Rule” for each unit) to the Logical Resource Node. Most of these Non-biddable Resource Nodes will be “north” of the GST. 3)For the CRR Auction, CRR’s at the Logical Resource Node will disaggregate to the Non-biddable Resource Nodes based on max capacity of all units in the train. 4)Resource specific offers in DAM will disaggregate to the Non-biddable Resource Nodes based on the max capacity of the units in the configuration. 5)See examples.

7. Lead from the front Texas Nodal http://nodal.ercot.com 7 Combined Cycle Plant Slide 1 SCED & 3PO Mw Telm HSL LSL AS etc. Resource Status DAM EOO CRR Bids SCADA Gross

8. Lead from the front Texas Nodal http://nodal.ercot.com 8 Combined Cycle Plant Slide 2 SCED & 3PO Mw Telm HSL LSL AS etc. Resource Status DAM EOO CRR Bids SCADA Gross

9. Lead from the front Texas Nodal http://nodal.ercot.com 9 High Level Description of Locating the Resource Nodes #3 PUN’s 1)Use the “First Fork Rule” to place the Resource Nodes in the model for each unit. In most cases this is “north” of the high side of the GST. It is usually within the PUN and also NOT where the EPS meter is located. 2)Also …… place a “PUN” Resource Node (with no units mapped to it) at the ERCOT interconnection point (usually where the EPS meter is located). This “PUN” Resource Node is where DAM Energy Only Offers and CRR bids can be made. 3)Constraints within the Private Use Network are not enforced (only monitored). 4)See examples.

10. Lead from the front Texas Nodal http://nodal.ercot.com 10 PUN

11. Lead from the front Texas Nodal http://nodal.ercot.com 11 PUN Complicated

12. Lead from the front Texas Nodal http://nodal.ercot.com 12 PUN Very Complicated

13. Lead from the front Texas Nodal http://nodal.ercot.com 13 Current Definition of Resource Node Resource Node (Current Definition) The Electrical Bus defined in the Network Operations Model at which a Resource's measured output is settled. For a Generation Resource that is connected to the ERCOT Transmission Grid only by one or more radial transmission lines that all originate at the Generation Resource and terminate in a single substation switchyard, the Resource Node is an Electrical Bus in that substation. For all other Generation Resources, the Resource Node is the Generation Resource's side of the Electrical Bus at which the Generation Resource is connected to the ERCOT Transmission Grid.

14. Lead from the front Texas Nodal http://nodal.ercot.com 14 Terms First Fork Rule Resource Node Logical Resource Node Non biddable Resource Node PUN Resource Node (PUN RN)

15. Lead from the front Texas Nodal http://nodal.ercot.com 15 Timeline 1.Send out spreadsheet with new Resource Node names and locations based on revised approach. 2.Next WMS subgroup meeting = 2/15/08 (if necessary) 3.Next WMS meeting = 2/20/08 4.When do we release new names and start using them in EDS 4?

16. Lead from the front Texas Nodal http://nodal.ercot.com 16 Questions Questions ?