Non-Qualifying Facility Over-Generation Threshold Determination Process
/ 05/06/2004Page 1 of 2
Purpose:
This business practice describes the process whereby the Entergy Transmission System Operations Center (SOC) shall determine the allowable aggregate Non-Qualifying Facility over-generation threshold (NQFOGT). When the aggregate generation from Non-Qualifying Facilitiesis in excess of the aggregate Schedules, Start-Up Periods, Shut-Down Periods, and Test Periods for Non-Qualifying Facilities by an amount greater than the current NQFOGT, the SOC shall invoke the following provision of the Generator Imbalance Agreement (GIA):
Entergy reserves the right to order non-qualifying facility Delivering Parties to cease over deliveries in excess of 10% of the Schedule for the clock hour from the Facility and 20 MWh to avoid causing a Low-Load Event or causing the system to be unable to meet NERC operating criteria. The Delivering Party will be notified within a reasonable time to allow it to cease such over deliveries.
Background:
Non-Qualifying Facilities generating in excess of their aggregate Schedules, Start-Up Periods, Shut-Down Periods, and Test Periods disrupt control area balancing operations by:
- shifting ramping obligations to the Entergy generators supplying control area ancillary services and
- causing those generators to be unable (because of minimum-run levels) to reduce their generation in order to accommodate the unscheduled energy.[1]
This significantly hinders the Entergy control area’s ability to meet NERC performance standards such as CPS2.
Responsibilities:
- SOC
- MonitorNon-Qualifying Facilities’ Schedules and Output
- Calculate NQFOGT
- Implement internal procedures for invoking the above GIA provision
Process:
- At the beginning of each month, the NQFOGT shall be set to the lesser of the average of the adjusted values from the previous month or 600 MW. For the first month of implementation of this practice, the beginning of the month value will be 400 MW.
- The NQFOGT will be revised during the month so that the effects of Non-Qualifying Facility over-generation will not significantly hinder the Entergy control area’s ability to meet NERC performance standards for the current period. Computed values will be rounded to the nearest 50 MW. See Table 1.
NERC Current Monthly CPS2 / Week 1 / Week 2 / Week 3 / Week 4
(Remainder of Month)
CPS2 95% / Average NQFOGT
for Previous Month / 1.25 * NQFOGT for Previous Week / 1.25 * NQFOGT for Previous Week / 1.25 * NQFOGT for Previous Week
92.5% < CPS2 < 95% / Average NQFOGT
for Previous Month / No change / 1.25 * NQFOGT for Previous Week / 1.25 * NQFOGT for Previous Week
90.5% < CPS 2 92.5% / Average NQFOGT
for Previous Month / No change / No change / No change
CPS2 90.5% / Average NQFOGT
for Previous Month / 0.75 x NQFOGT for Previous Week / 0.5 x NQFOGT for Previous Week / 0.5 x NQFOGT for Previous Week
Table 1
- The SOC, in consultation with the Fuel and Generation Operations (FGO) group, will reviseTable 1 as needed in order to ensure compliance with NERC performance standards. The SOC will also periodically consider whether adjustments are required more frequently than weeklyin order to ensure compliance with NERC performance standards.
Attachments:
- None
References:
- Generator Imbalance Agreement
- NERC Operating Policies
[1] Although the GIA outlines actions that can be taken when a low-load condition is foreseen, the low-load condition can occur suddenly and without warning.