Summary

This page lists the exceptions to the allocation rules, namely;

• BERRP definitions when EnergyRRP is negative and when Energy CV = Energy Maxavail

• Allocation rules when OV != CV

Background

There is no unique definition of BERRP since it depends on whether or not there is a trade off with another service. (And if there is a trade off with another service then which service.) The default definition of BERRP is when the alternative scenario is unconstrained, that is to say there is no trade off with another service, by definition this is:

LowerBERRP = Utilisation * (SRMC - EnergyFRRP)

RaiseBERRP = Utilisation * (EnergyFRRP - SRMC)

This definition answers the question; what is the actual RRP required where you are indifferent to being enabled and there is no trade off with another service?

BERRP exceptions

These exceptions aim to address where there is a trade-off with the energy service. That is to say where being enabled FCAS would result in a change in energy target. In this situation (which must be inferred) the BERRP aims to reflect the value impact caused by the change in energy target.

If Lower FCAS and EnergyFRRP < 0

• BERRP for OV = 0.5 * FRRP

• BERRP for NOV = SRMC - EnergyFRRP

  • Note that this is a positive number because EnergyFRRP < 0

These exceptions ensure that NEMDE does not increase energy target in order to enable Lower FCAS unless LowerFRRP is sufficiently high.

If Raise FCAS and ‘Energy CV’ = ‘Energy maxavail’

• BERRP for NOV = EnergyFRRP * (1 - Utilisation) + SRMC * Utilisation

This rule ensures that when energy prices are high (implied by the CV = maxavail) that Raise NOV is not dispatched by NEMDE at the expense of energy target.

TP1 Exceptions

If Energy OV > Energy CV

• For Lower OV, TP1 is set to null.

TP1 is ignored in the allocation rules for Lower OV. Therefore Lower OV is allocated to PBs < FRRP. This exception aims to ensure that when Energy volume is repriced then all of the Lower FCAS OV will be enabled.

If Energy OV < Energy CV

• For Raise OV, TP1 is set to null.

TP1 is ignored in the allocation rules for Raise OV. Similar to the above, Raise OV is allocated to PBs < FRRP.