Prices for imbalance The prices for imbalance in application on January 1, 2008, as stipulated by the decision of the CREG of December 13, 2007, are established on the basis of costs incurred by Elia for maintaining balance between generation and consumption in the Belgian control area, at the considered quarter. 1. Definitions The Imbalance of a given Access Responsible Party is the quarter-hourly difference between:
his total injections within his balance perimeter, namely injections at injection points within the Elia Grid, injections in the Elia Grid coming from any other system belonging to the balancing zone operated by Elia, imports, purchases from other Access Responsible Parties; and his total offtakes within his balance perimeter, namely offtakes at offtakes points within the Elia Grid, offtakes from the Elia Grid made in any other system belonging to the balancing zone operated by Elia, exports, sales to other Access Responsible Parties, the losses attributed to this Access Responsible Party.
The Losses for the considered period of this document that are attributed to a Access Responsible Party are the losses in the 380-150 kV grid and are set at 1 % of the sum of: the measured offtakes at offtake points attributed to this Access Responsible Party and; the Distribution Offtake Positions (in case of net offtake) attributed to this Access Responsible Party. The Net Balancing Volume (hereafter ‘NRV’) is, for a considered quarter, the difference between : − on one hand, the sum of upwards activations as ordered by Elia, for the considered quarter, for maintaining the balance in the Belgian control area, expressed in MW, and − on the other hand, the sum of downwards activations as ordered by Elia, for the considered quarter, for maintaining the balance in the Belgian control area, expressed in MW. When, for a given quarter, Elia exclusively orders upwards activations, the Net Balancing Volume has a positive value and is referred to as « upward regulation ». When, for a given quarter, Elia exclusively orders downwards activations, the Net Balancing Volume has a negative value and is referred to as « downward regulation ». When, for a given quarter, Elia orders both upwards and downwards activations with a greater volume of upwards activations, the Net Balancing Volume has a positive value and is referred to as « upward regulation ». When, for a given quarter, Elia orders both upwards and downwards activations with a greater volume of downwards activations, the Net Balancing Volume has a negative value and is referred to as « downward regulation ». The weighted average price for upward regulation (hereafter ‘GGO’) is, for a given quarter, the average price of all upwards activations ordered by Elia for
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maintaining the balance in the Belgian control area ; activated volumes serving as the weight factor. The resources ordered by Elia for upwards regulation are : − secundary control; − tertiary reserve, including activation of incremental bids and activation of mutual reserve between TSO’s; − load shedding. The weighted average price for downward regulation (hereafter ‘GGA’) is, for a given quarter, the average price of all downwards activations ordered by Elia for maintaining the balance in the Belgian control area ; activated volumes serving as the weight factor. The resources ordered by Elia for downwards regulation are : − secundary control; − activation of decremental bids and activation of mutual reserve between TSO’s. The marginal price for upward regulation (hereafter ‘MO’) is, for a given quarter, the highest price of all upwards activations ordered by Elia for maintaining the balance in the Belgian control area. The resources ordered by Elia for upwards regulation are : − secundary control; − tertiary reserve, including activation of incremental bids and activation of mutual reserve between TSO’s; − load shedding. The marginal price for downward regulation (hereafter ‘MA’) is, for a given quarter, the lowest price of all downwards activations ordered by Elia for maintaining the balance in the Belgian control area. The resources ordered by Elia for downwards regulation are : − secundary control; − activation of decremental bids and activation of mutual reserve between TSO’s. The gross volume of upward regulation (hereafter ‘BOV’) is, for a given quarter, the sum of upwards activations ordered by Elia for maintaining the balance in the Belgian control area. The resources ordered by Elia for upwards regulation are : − secundary control; − tertiary reserve, including activation of incremental bids and activation of mutual reserve between TSO’s; − load shedding. The gross volume of downward regulation (hereafter ‘BAV’) is, for a given quarter, the sum of downwards activations ordered by Elia for maintaining the balance in the Belgian control area. The resources ordered by Elia for upwards regulation are : − secundary control; − activation of decremental bids and activation of mutual reserve between TSO’s. The market price is set equal to the day-ahead clearing price on the Belpex.
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2. Setting prices for imbalances in application on January 1, 2008 The prices for quarterly imbalances are established on the basis of computations formulas in the table below. These prices relate to the quarterly imbalance of one given Access Responsible Party (ARP), for one given quarter. Prices for negative Imbalance are always positive, meaning a payment from the Access Responsible Party to Elia. Prices for positive Imbalance can either be positive or negative. A positive price for Positive Imbalance means a payment from Elia to the Access Responsible Party and a negative price for Positive Imbalance means a payment from the Access Responsible party to Elia. Net Balancing Volume (NRV)
Imbalance of the ARP
Positive Negative
Negative (downward regulation)
Positive (upward regulation)
Min[γ*GGA;GGA+δ*(MA-GGA)] (1)
0,92 * market price
1,08 * market price
Max[α*GGO;GGO+β*(MO-GGO)] (2)
where:
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(1) the price (0,92 * market price) is an upper bound for the price for imbalance (2) the price (1,08 * market price) is a lower bound for the price for imbalance γ = 0,92 if GGA > 0 and γ = 1,08 if GGA < 0 δ = min (1;BAV/450) α = 1,08 β = min (1;BOV/450).
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