Operating Procedure
Attachment
Load Shed Calculation Guideline (Formerly E-508A)
Procedure No.
4510A
Version No.
10.2
Effective Date
4/20/16
Distribution Restriction:
None
Fixed Pro Rata Shares
UDC / MSS
Anaheim
Azusa
Banning
Corona
Lassen
NCPA
Pasadena
Pacific Gas & Electric
Port of Stockton
Riverside
SCE
SDG&E
VEA
Vernon
Fixed Pro-Rata Share
1.20%
0.13%
0.08%
0.03%
0.06%
2.08%
0.63%
41.79%
0.0080%
1.18%
42.29%
9.93%
0.23%
0.35%
Pro Rata Load Shedding
CAISO System Operator Actions
If fixed pro rata Load-Shedding by all UDCs and MSSs is required, then determine the
amount and location of Load to be reduced, and, to the extent practicable, allocate a
portion to each UDC/MSS based on the results shown in the Load Shedding Tool.
Calculation used in the Load Shedding Tool
Load Shedding Responsibilities = UDC or MSS demand at the time of the CAISO BA
annual peak for the previous year/ Total BA annual peak Demand for the previous year
taking into account system considerations.
Example: When a sudden multiple Contingency or an ISO Grid reserve deficiency
requires Load-Shedding assistance from the entire CAISO Balancing Authority to
Stabilize the grid.
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Operating Procedure
Attachment
Load Shed Calculation Guideline (Formerly E-508A)
Procedure No.
4510A
Version No.
10.2
Effective Date
4/20/16
Distribution Restriction:
None
Version History
Version
10.0
10.1
10.2
Change
Updated load shedding Fixed Pro-Rata Share
% based on 2013 CAISO BA peak load data.
Clarified Instructions in "Calculation Without
RA" and "Calculation With RA" tabs to
identify instructions implemented in the Excel
formulas vs. instructions to be car...
Updated the percentages to reflect Peak
Loads in 2014. Changed instances of prorata to pro rata.
Updated the percentages to reflect Peak
Loads in 2015.
By
Date
4/9/14
4/14/15
4/20/16
Technical Review
Reviewed By Content
Expert
Operations Procedures
Real-Time Operations
Signature
Date
4/04/16
4/15/16
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