February 19, 2009 ERCOT Follow up on questions from 2/11 discussion on proposed Expedited Switch rulemaking changes…

2 ERCOT’s understanding of the proposed rulemaking: –Currently there are 2 types of Switch transactions: On-Cycle – ERCOT sends the First Available Switch Date (FASD) to the TDU Out-of-Cycle – ERCOT sends the FASD and the Special Read Date Requested by the Rep to the TDU –After the rule making ERCOT believes the Expedited Switch will replace the On-Cycle Switch: Expedited – ERCOT sends the FASD to the TDU. TDU returns a Scheduled Meter Read Date (SMRD) for the Switch within the 6 calendar day window. Out-of-Cycle – ERCOT sends the FASD and the Special Read Date Requested by the Rep to the TDU

3 Two or Three Types? If with proposed rulemaking the Expedited Switch replaces the On- Cycle Switch: –ERCOT believes we may have to make minor system changes. –No TX SET version change foreseen. –Cancels inside the window(s) to be managed with the MarkeTrak process. If proposed rulemaking has 3 types of switches – Off-cycle, On-cycle and Expedited: –ERCOT would work with the market to add the expedited switch processes into the stacking logic. –TX SET change would be required to accommodate the expedited switch transaction. –ERCOT believes we may have to make major system changes and facilitate a flight test with the market prior to implementation.

4 Parking Lot / Questions for follow up? What other questions would MPs like ERCOT to research to bring back to future meetings? 1.Show trans flow of priority MVI with switch 2.Show trans flow of permit pending MVI with switch 3.Review impact to ERCOT system/stacking logic if change evaluation / cancellation window for switches from 5 day to 2 day 4.Review impact to ERCOT system/stacking logic if change FASD date from EPD+3BD to EPD+1BD, EPD+2BD 5.Review impact to ERCOT system/stacking logic if change FASD to equal the 6 calendar days out (TDSP bounce back the FASD as the SMRD)

5 Scenario 1 - Priority Move In received day before a scheduled Switch –ERCOT will accept the Move In and cancel the Switch, same as standard MVI scenario Follow up #1 – Trans Flow of Priority MVI with Switch REP C is Rep of Record REP A submits Expedited Switch Saturday 02/07 Monday 02/09 Thursday 02/12 Sunday 02/15 Wednesday 02/18 Saturday 02/21 Switch FASD is calculated at 3 Business days TDSP schedules Switch within the 6 day window Switch for REP A is Scheduled for 02/17 Rep B submits priority MVI for 02/17 Switch for 2/17 will be Cancelled

6 Scenario 2 - Priority Move In received same day as scheduled Switch –ERCOT will accept the Move In. The Switch will not be cancelled on receipt of the Move In. –Switch will be cancelled upon receipt of the 814_04 on the Move In Follow up #1 – Trans Flow of Priority MVI with Switch REP C is Rep of Record REP A submits Expedited Switch Saturday 02/07 Monday 02/09 Thursday 02/12 Sunday 02/15 Wednesday 02/18 Saturday 02/21 Switch FASD is calculated at 3 Business days TDSP schedules Switch within the 6 day window Switch for REP A is Scheduled for 02/17 Rep B submits priority MVI for 02/17 Switch for 2/17 will be Cancelled upon receipt of the 814_04 on the Move In

7 Scenario 1 Permit Pending Move In received prior to Switch. –ERCOT will accept the Switch. Switch is not cancelled. Follow up #2 – Trans Flow of Permit Pending MVI w/Switch REP C is Rep of Record Rep B submits MVI requesting 2/16. TDSP responds with 814_28 PT Saturday 02/07 Monday 02/09 Thursday 02/12 Sunday 02/15 Wednesday 02/18 Saturday 02/21 Switch FASD is calculated at 3 Business days TDSP schedules Switch within the 6 day window Switch for REP A is Scheduled for 02/17 REP A submits Expedited Switch

8 Scenario 1 Cancel & Notification changed to 2 business days –ERCOT would accept the 814_08 from the CR until 2 business days prior to the Scheduled Meter Read Date of the Switch. –ERCOT would have to make system changes. Similar to MVI logic. –No TX SET version change foreseen. –Cancels inside the 2 day window to be managed with the current MarkeTrak process. Follow up #3 – Trans Flow / Impact of 5 day to 2 day for evaluation / cancellation window

9 Scenario 1 - continued Cancel & Notification changed to 2 business days –ERCOT will accept the 814_08 from the CR until 2 business days prior to the Scheduled Meter Read Date of the Switch. Follow up #3 – Trans Flow / Impact of 5 day to 2 day for evaluation / cancellation window REP C is Rep of Record Rep A submits Expedited Switch Saturday 02/07 Monday 02/09 Thursday 02/12 Sunday 02/15 Wednesday 02/18 Saturday 02/21 Switch FASD is calculated at 3 Business days TDSP schedules Switch within the 6 day window Switch for REP A is Scheduled for 02/16 REP Cancel will be accepted through 2/11 2 business day cancel window 814_06 Notification will be sent 2/12

10 Scenario 2 Cancel & Notification changed to 2 business days –TDSP determines the Switch can be worked prior to Scheduled Meter Read Date. ERCOT send 814_06 after the Switch completes in ERCOTs system Follow up #3 – Trans Flow / Impact of 5 day to 2 day for evaluation / cancellation window REP C is Rep of Record Rep A submits Expedited Switch Saturday 02/07 Monday 02/09 Thursday 02/12 Sunday 02/15 Wednesday 02/18 Saturday 02/21 Switch FASD is calculated at 3 Business days TDSP schedules Switch within the 6 day window Switch for REP A is Scheduled for 02/16 TDSP determines they can work the switch early and completes for 02/11 814_06 is not sent till after the Switch Completes in ERCOTs system or at 2 Business Prior to the SMRD of 2/16

11 Follow up #4 and #5 4.Review impact to ERCOT system/stacking logic if change FASD date from EPD+3BD to EPD+1BD, EPD+2BD 5.Review impact to ERCOT system/stacking logic if change FASD to equal the 6 calendar days out (TDSP bounce back the FASD as the SMRD) If proposed rulemaking changes the FASD timeline –ERCOT would work with the market to adjust the new FASD timeline along with other expedited switch changes into the MIMO stacking logic business rules –TX SET change would be required to accommodate the expedited switch transaction. –ERCOT believes we may have to make major system changes and facilitate a flight test with the market prior to implementation.

12 REP / TDSP Questions for follow up? What other questions were brought up for MPs to review and bring back for next time? –All MPs – review slide deck and determine impacts, gaps, questions –TDSPs asked Are REPs open to the use of estimates? How will the expected switch date of an expedited switch be communicated to the customer? –REPs asked What additional changes have to occur at the TDSP level if FASD remains at 3BD but the evaluation window shrinks from 5BD to 2BD What if the 6 th calendar day is on a non-business day? Will the TDSP go back to the last BD to determine the scheduled date?

13 Parking Lot / Questions for follow up? What other questions were brought up for MPs to review and bring back for next time? –Obviously any rulemaking changes then result in corresponding PRR, RMGRR that the market and ERCOT would need to review. Do we need another workshop?