Limiting Plant Output to Scheduled Value and Curtailing Schedules to Actual Plant Generation
October 1, 2015
I. Purpose
The purpose of Operational Controls for Balancing Reserves (OCBR) is to provide instructions on limiting plant generation to the scheduled value when there is insufficient DEC balancing reserves available to offset the over-generation of variable energy resources (VERs). OCBR also provides instructions about curtailing each plant’s schedules/e-Tags when their actual generation output is less than their scheduled amount and there are insufficient INC balancing reserves available to offset the under-generation of non-federal generators both variable and dispatchable.
II. Actions
BPA calculates the total amount of balancing reserves needed at any given time for all users (Load, DERs and VERs) within BPA’s Balancing Authority. Using this information, BPA takes action when 90% or greater of INC or DEC balancing reserves are deployed from the FCRPS. BPA will continue to establish the amount of balancing reserves available, consistent with and included in the Gen Inputs section of the BPA Rate Case.
III. Procedures for Limiting Generators to Schedule
When BPA is supplying DEC balancing reserves in excess of 90%, BPA requires generators to reduce generation. BPA Dispatchers will send generation targets and notifications to each variable generator, relative to their schedule through BPA’s Automatic Generation Control (AGC) system. An external BPA web application, called iCRS Generation Advisor, is available with additional information and graphical presentation to supplement the signals sent directly to the plants. Changes must be made by plants within 10 minutes of receiving electronic directives from BPA. The limitation remains in effect for the remainder of the hour. A plant’s failure to comply with Dispatchers directives may result in penalties as determined in BPA’s Failure to Comply Business Practice
IV. Procedures for Curtailing Schedules to Generation
When BPA is supplying INC balancing reserves in excess of 90%, BPA automatically curtails transmission schedules for each non-federal plant that is under generating. This is accomplished through the existing NERC e-Tagging system with a curtailment reason of “OCBR – Exceeding Reserve Threshold”.