First (monthly) imbalance settlement represents monthly financial settlement for the imbalances made by the balance group managers.

Imbalances are calculated on the hourly basis (settlement interval “i”) and the settlement period is a month (settlement period “j”).

Imbalance of the balance group (E_{imbalance, BG,i})
In the first (monthly) settlement the imbalance of the balance group represents the difference between the total realization and the market position of the balance group for each settlement interval (hour). It is calculated in [MWh] in accordance with the following formula in:

E_{imbalance BG,i} = E_{realization BG,i} – E_{market position BG,i}

Where:
E_{realization BG,i}                –       is the total quantity of imbalance for the balance group at the settlement interval „i“ [MWh]
E_{market position BG,i}             –       is the market position for the balance group at the settlement interval „i“ [MWh]

Realization of the balance group member (E_{realisation member BG,i})
Realization of the balance group member represents the difference between the total quantity of intake and the total quantity of offtake on the transmission system. It is calculated in MWh in accordance with the following formula:
 
E_{realisation member BG,i} = E_{intake member BG,i} – E_{offtake member BG,i}
 
Where:
E_{intake member BG,i}         –       is the total quantity of intake on the transmission system made by the balance group member at the settlement interval „i“ [MWh]
E_{offtake member BG,i}        –       is the total quantity of offtake on the transmission system made by the balance group member at the settlement interval „i“ [MWh]
 
Market position of the balance group (E_{market position BG,i})
Market position represents the difference between the sale (including export) and purchase (including import) of electricity of the balance group at the settlement interval „i“ and it also includes a correction of the market position. It is calculated in MWh in accordance with the following formula:
 
E_{market position BG,i} = E_sale,ug,i – E_{purchase,ug,i} + E_sale,ur,i – E_{purchase,ur,i} + E_{sale,correction,i} – E_{purchase, correction,i}

Where:
E_sale,ug,i                        –       is the total quantity of electricity sold by all balance group members according to schedules, at the settlement interval „i“ [MWh]
E_{purchase,ug,i}                 –       is the total quantity of electricity purchased by all balance group   members according to schedules, at the settlement interval „i“ [MWh]
E_sale,ur,i                         –       is the correction of market position for the sold electricity as a result of balancing energy activation and other system services provided by all balance group members, at the settlement interval „i“ [MWh]
E_{purchase,ur,i}                  –       is the correction of market position for the purchased electricity as a result of balancing energy activation and other system services provided by all balance group members, at the settlement interval „i“ [MWh]
E_{sale,correction,i}              –       is the correction of market position for the sold electricity as a result of activated balancing energy and other system services when the balancing service provider and/or other services provider is the direct end user of the transmission or distribution system or independent aggregator, at the settlement interval „i“ [MWh]
E_{purchase,correction,i} –             is the correction of market position for the purchased electricity as a result of activated balancing energy and other system services when the balancing service provider and/or other services provider is the direct end user of the transmission or distribution system or independent aggregator, at the settlement interval „i“ [MWh]