Low Load Process

David L. PlantMarch 2006

Objectives

Describe the three stages of the Low Load Process and their time requirements

Discuss Where to Locate Information Needed to Complete Worksheet on GMS

References

Low Load Procedure 2.6 Entergy Generator Imbalance

Agreement

Low Load Procedure Each Control Area has a commitment to

control its generation in a manner so as not to burden the interconnected systems.

To the extent possible, Entergy will make every effort to provide advance notice of low load conditions. However, even if the Low Load stage warnings have not been issued, Entergy will implement the applicable actions contained in this procedure as required to meet NERC standards.

The System Dispatcher is

responsible for implementing the actions in this procedure necessary to mitigate Low Load conditions.

If the margin to regulating minimum calculated in Attachment 1 is less than 500 MW, the System Dispatcher will declare a Low Load Alert.

1.1 The EMO System Dispatcher will notify the SOC System Operator of a Low Load Alert condition and the start time.

1.2 The SOC will implement the appropriate notification steps.

If the margin to regulating minimum calculated in Attachment 1 is 0 MW or less, the EMO System Dispatcher will declare a Low Load Event for the applicable start time.

3.1 The EMO System Dispatcher will notify the SOC System Operator of a Low Load Event condition and the start time.

3.2 The SOC will implement the appropriate notification steps.

3.3 Suspend hourly economy purchases (including reducing our share of Big Cajun 3 Unit 2 output and requesting that AECC reduce purchases as needed to avoid a Low Load Emergency).

3.4 Cease or reduce hydro generation

(Arkansas units & Toledo Bend) if water levels allow, if possible initiate hydro pumpback operations as needed.

3.5 Notify any EMO units coming on line to not synchronize (if possible) until the dispatcher notifies them there is room available.

3.6 Contact the on duty next day marketer to see if any pre-scheduled purchases can be reduced.

3.7 Reduce Nelson 6 output as needed to regain regulating margin.

3.8 Determine the reduction in QF “put” energy needed to regain an appropriate regulating margin to be exercised during a Low Load Emergency.

If conditions occur such that the

EMO System Dispatcher can no longer match the decreasing load (using normal generation minimum limits and a margin for regulation) then the EMO System Dispatcher will declare a Low Load Emergency for the applicable start time.

4.1 The EMO System Dispatcher will notify the SOC System Operator of a Low Load Emergency condition and the start time.

4.2 The SOC will implement the appropriate notification steps.

4.3 To the extent possible, the actions in Step 3

will be verified complete. 4.4 The following steps will be performed in the

order listed until sufficient margin is regained: a. The SOC will determine if unilateral inadvertent

payback is appropriate, if in such a manner as to mitigate the condition (based on time error and accumulated inadvertent). The SOC will inform the EMO System Dispatcher if inadvertent payback is initiated.

b. Reduce Nelson 6 output if not already done.

c. Initiate hydro pump back operations if possible or not already started.

d. Initiate emergency sales, if not already performed in the previous stage. (These sales are made for reliability purposes and it is understood that due to market conditions these sales may be at a zero profit or a loss when compared to system generation cost).

e. Determine the reduction in QF “put” energy needed to

regain an appropriate regulating margin (if not performed in the previous stage) and notify the SOC System Operator the amount of QF “put” relief needed.

1. The SOC System Operator will implement the applicable steps to acquire the requested reduction in QF energy.

f. Contact fossil units to see if units can be dispatched below normal minimum load on an emergency basis.

g. Reduce nuclear unit output (consult with Operations Superintendent if time permits).

h. De-commit generation (consult with Operations Superintendent if time permits). i. Request the SOC to direct IPPs to cease any activities

(e.g. over generating) that are contributing to the control area NERC CPS2 violations.

Generator Imbalance Agreement

Low-Load Event - Any period during which Entergy EMO may be required to take a Facility off-line due to low-load conditions based on criteria such as load profiles and generating schedules, to maintain minimum stable operating levels based on prudent utility practice. Entergy shall provide notice via e-mail to all Delivering Parties that have provided Entergy with a current e-mail address, as soon as possible, but in no event less than two hours prior to the occurrence of a Low-Load Event. Entergy shall also provide notice of a Low-Load Event by broadcast fax, but for purposes of the two hour prior notice period, the email notification controls. If Entergy fails to provide two hour prior notification of a Low-Load Event, no penalties shall apply.

Over Deliveries During A Low-Load Event

Any Facility that is a Qualifying Facility under

PURPA shall receive Entergy’s Avoided Cost for all Excess Energy.

Non-Qualifying Facility Delivering Parties - In the event that Entergy is experiencing a Low-Load Event, then any Excess Energy delivered in the clock hour beginning two hours after the notice of the Low-Load Event, shall not be purchased and shall be assessed a charge

Entergy will provide 2 hour prior notice of Low-Load Event by email and broadcast fax This 2 hour notice will also be provided to Qualifying Facilities as an indicator that a Low Load Emergency will occur in 2 hours if nothing changes on the system.

Over Deliveries During A Low-Load Emergency

Entergy will cease PURPA purchases from Qualifying Facilities when, due to operational circumstances, purchases from Qualifying Facilities will result in costs greater than those which Entergy would incur if it did not make such purchases

Entergy will notify Qualifying Facilities via email and broadcast fax prior to the termination of purchases.

Cancellation of a Low-Load Event/Emergency

Cancellation of each stage will occur in reverse order when the actions of this procedure are no longer necessary to maintain system control. Note that per the GIA, the Low Load Event

end time is not required to occur until all of the test energy can again be accommodated.

Document Retention Requirement

The printed document and any supporting information is to be retained in a binder in the current day room.