APPENDIX B
GRID OPERATIONS CHARGE COMPUTATION
B 1	Purpose of charge
The Grid Operations Charge is a charge which recovers redispatch costs incurred due to Intra-Zonal Congestion pursuant to Section 7.3.2 of the ISO Tariff.  The Grid Operations Charge is paid by or charged to Scheduling Coordinators in order for the ISO to recover and properly redistribute the costs of adjusting the Balanced Schedules submitted by Scheduling Coordinators.
B 2	Fundamental formulae
B 2.1	Payments to SCs with incremented schedules
When it becomes necessary for the ISO to increase the output of a Scheduling Coordinator’s Generating Uniti or System Resourcei or reduce a Curtailable Demandi in order to relieve Congestion within a Zone, the ISO will pay the Scheduling Coordinator.  The amount that ISO pays the Scheduling Coordinatorj is the price specified in the Scheduling Coordinator’s Day-Ahead or Hour-Ahead Adjustment Bid (or Imbalance Energy bid as appropriate) for the Generating Uniti or System Resourcei or Curtailable Demandi multiplied by the quantity of Energy rescheduled.  The formula for calculating the payment to Scheduling Coordinatorj for each blockb of Energy of its Adjustment Bid curve in Trading Intervalt is:

B 2.1.1	Total Payment for Trading Interval
The formula for calculating payment to Scheduling Coordinatorj whose Generating Uniti or System Resourcei has been increased or Curtailable Demandi reduced for all the relevant blocksb of Energy in the Adjustment Bid curve (or Imbalance Energy bid) of that Generating Unit or System Resource or Curtailable Demand in the same Trading Intervalt is:

B 2.2	Charges to Scheduling Coordinators with decremented schedules
When it becomes necessary for the ISO to decrease the output of a Scheduling Coordinator’s Generating Uniti or System Resourcei in order to relieve Congestion within a Zone, the ISO will make a charge to the Scheduling Coordinator.  The amount that the ISO will charge Scheduling Coordinatorj is the price specified in the Scheduling Coordinator’s Day-Ahead or Hour-Ahead Adjustment Bid (or Imbalance Energy bid) for the Generating Uniti or System Resourcei multiplied by the quantity of Energy rescheduled.  The formula for calculating the charge to Scheduling Coordinatorj for each blockb of Energy in its Adjustment Bid curve (or Imbalance Energy bid) in Trading Intervalt is:

B 2.2.1	Total Charge for Trading Interval
The formula for calculating the charge to Scheduling Coordinatorj whose Generating Uniti or System Resourcei has been decreased for all the relevant blocksb of Energy in the Adjustment Bid curve (or Imbalance Energy bid) of that Generating Unit or System Resource in the same Trading Intervalt is:

B 2.3	Not Used

B 2.4	Net ISO redispatch costs
The Trading Interval net redispatch cost encountered by ISO to relieve Intra-Zonal Congestion is the sum of the amounts paid by the ISO to those Scheduling Coordinators whose Generation or System Resource was increased or Curtailable Demand was decreased during the Trading Interval less the sum of the amounts received by the ISO from those Scheduling Coordinators whose Generating Units or System Resource were decreased during the Trading Interval.  The fundamental formula for calculating the net redispatch cost is:

Note that REDISPCONGt can be either positive or negative.  This means that it is possible for the ISO to generate either a net cost or a net income, for any given Trading Interval.  In the event the ISO does not make use of equal amounts of incremental and decremental dispatched MWHs, then the net redispatch cost becomes the sum of the amounts paid (or charged) by the ISO to those Scheduling Coordinators whose Generation or System Resource was increased (or decreased) or Curtailable Demand was decreased (or increased) during the Trading Interval less the sum of the amounts received by the ISO from Scheduling Coordinators through the Imbalance Energy Market.
B 2.5	Grid Operations Price
The grid operations price is the Trading Interval rate used by the ISO to apportion net Trading Interval redispatch costs to Scheduling Coordinators within the Zone with Intra-Zonal Congestion.  The grid operations price is calculated using the following formula:

B 2.6	Grid Operations Charge
The Grid Operations Charge is the vehicle by which the ISO recovers the net redispatch costs.  It is allocated to each Scheduling Coordinator in proportion to the 
Scheduling Coordinator’s consumption in the Zone with Intra-Zonal Congestion and Exports from the Zone with Intra-Zonal Congestion.  The formula for calculating the Grid Operations Charge for Scheduling Coordinatorj in Trading Intervalt is:

B 3	Meaning of terms of formulae
B 3.1	INCbijt - $
The payment from the ISO due to Scheduling Coordinatorj whose Generating Uniti or System Resourcei is increased or Curtailable Loadi is reduced within a blockb of Energy in its Adjustment Bid curve (or Imbalance Energy bid) in Trading Intervalt in order to relieve Intra-Zonal Congestion.
B 3.2	adjincbijt - $/MWh
The incremental cost for the rescheduled Generating Uniti or System Resourcei or Curtailable Loadi taken from the relevant blockb of Energy in the Day-Ahead or Hour-Ahead Adjustment Bid curve (or Imbalance Energy bid) submitted by the Scheduling Coordinatorj for the Trading Intervalt.
B 3.3	incbijt - MW
The amount by which the Generating Uniti or System Resourcei or Curtailable Loadi of Scheduling Coordinatorj for Trading Intervalt is increased by the ISO within the relevant blockb of Energy in its Adjustment Bid curve (or Imbalance Energy bid).
B 3.4	PayTIjit - $
The Trading Interval payment to Scheduling Coordinatorj whose Generating Uniti has been increased or System Resourcei or Curtailable Loadi reduced in Trading Intervalt of the Trading Day.
B 3.5	DECbijt - $
The charge to Scheduling Coordinatorj whose Generating Uniti or System Resourcei is decreased for Trading Intervalt within a blockb of Energy in its Adjustment Bid curve (or Imbalance Energy resource).
B 3.6	adjdecbijt - $/MWh
The decremental cost for the rescheduled Generating Uniti or System Resourcei taken from the relevant blockb of Energy of the Day-Ahead or Hour-Ahead Adjustment Bid curve (or Imbalance Energy resource) submitted by Scheduling Coordinatorj for the Trading Intervalt.

B 3.7	decbijt - MW
The amount by which the Generating Uniti or System Resourcei of Scheduling Coordinatorj for Trading Intervalt is decreased by ISO within the relevant blockb of Energy of its Adjustment Bid curve (or Imbalance Energy resource).
B 3.8	ChargeTIijt - $
The Trading Interval charge to Scheduling Coordinatorj whose Generating Uniti or System Resourcei has been decreased in Trading Intervalt of the Trading Day.
B 3.9	Not Used
B 3.10	Not Used
B 3.10.1	Not Used
B 3.10.2	Pxt - $/MWh
The zonal Hourly Ex Post Price, for Uninstructed Imbalance Energy, for Trading Interval t in Zone x.
B 3.11	REDISPCONGt - $
The Trading Interval net cost to ISO to redispatch in order to relieve Intra-Zonal Congestion during Trading Intervalt.
B 3.12	GOPt - $/MWh
The Trading Interval grid operations price for Trading Intervalt used by the ISO to recover the costs of redispatch for Intra-Zonal Congestion Management.
B 3.13	GOCjt - $
The Trading Interval Grid Operations Charge by the ISO for Trading Intervalt for Scheduling Coordinatorj in the relevant Zone with Intra-Zonal Congestion.
B 3.14	QCHARGEjt – MWh
The Trading Interval metered consumption within a Zone for Trading Intervalt for Scheduling Coordinatorj whose Grid Operations Charge is being calculated.
B 3.15	EXPORTjt – MWh
The total Energy for Trading Intervalt exported from the Zone to a neighboring Control Area by Scheduling Coordinatorj.