Ebby JohnCenterPoint Energy

Cancelling Outages During Events

• Requested by ERCOT or Initiated by Transmission Owner

• Due to Short Supply, Storms, Other

• Reliability of ERCOT Grid

• Reliability of Local Network

• Safety

Cancelling Outages During 02-02-2011 Event

• Due to forecasted extreme cold weather, CNP began cancelling next day planned outages on 01-31-2011.

• Evaluated conditions each day and cancelled outages for next day

• Canceled outages for week 02-07-2011 due to second wave of extreme cold.

Concerns with Outage Restoration

• Once an outage is cancelled, Protocols require resubmitting with at least 3 days notice.

• Delays with Equipment and Personnel mobilized in the Field

• Maintaining an outage in the OS that has been canceled in the field would produce inaccurate EMS and Market results.

Lessons Learned

• ERCOT has been working with Equipment Owners To manage Outage Coordination during Emergency Events.

• ERCOT needs to have a clearly defined process to make restoration easier and more predictable.

• Suggestions

Shorter Approval turnaround

Make use of Forced Outage process

Super User capability in OS for ERCOT Operator

New Outage Scheduler state for temporary hold.