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Spinning reserve (margin peak and off peak), load rejection reserve and system restart (cost_LR)

Spinning reserve is generation capacity that is held in reserve but ready to respond quickly if another generator suffers an unexpected outage. This helps maintain an uninterrupted supply of electricity to customers. Margin Peak and Margin Off-Peak parameters are used in the Ancillary Service settlement calculations to compensate Synergy for the costs it incurs in providing spinning reserve.

The value of the Ancillary Service Cost_LR parameter covers the payment to a market generator for the costs of providing the Load Rejection Reserve Service and System Restart Service.

The “L” component in the "Cost_LR" parameter relates to Load Rejection Service. This ancillary service is used to maintain power system reliability in the event of an unforeseen reduction in customer demand.

The “R” component in the “Cost_LR” parameter relates to System Restart Service. This ancillary service is used to restore power to the electricity system in the event of a localised or system-wide blackout.

Synergy is the default provider of the Spinning Reserve and Load Rejection Reserve Ancillary Services in the Wholesale Electricity Market in the South West Interconnected System. Multiple generators provide the System Restart Service.

The ERA must determine the margin values and cost_LR parameters to apply in 2021/22 by 31 March 2021.


Date Documents File type
31-Mar-21 Determination
Adobe PDF 913 kB

12-Mar-21 Addendum to Issues paper
Adobe PDF 223 kB

09-Feb-21 Issues paper
Adobe PDF 3 MB

09-Feb-21 AEMO revised proposal
Adobe PDF 76 kB

09-Feb-21 AEMO proposal
Adobe PDF 280 kB

Public submissions

Date Documents File type
24-Mar-21 Bluewaters Power
Adobe PDF 658 kB

24-Mar-21 NewGen Power Kwinana
Adobe PDF 318 kB

24-Mar-21 Perth Energy
Adobe PDF 269 kB

24-Mar-21 Synergy
Adobe PDF 306 kB

12-Mar-21 Australian Energy Market Operator (AEMO)
Adobe PDF 284 kB

Page last updated: 31 Mar 2021