Balance Responsibility

The aim of balance planning in the electricity system is to ensure that electricity generation and consumption are in balance at all times.

The balance responsible party must present their production plans, consumption forecasts and fixed supplies with other market participants for their balance areas according to the time schedule specified in the standard terms and conditions.

As TSO, Elering assesses, whether:

• the planned operations are acceptable in terms of maintaining the reliability of the electricity system;
• the balance plans presented by the balance responsible party are in balance;
• the fixed supplies presented in the trading data are in compliance with the data sent by the opposite party for the same trade;
• there is a sufficient amount of reserve capacity to ensure the electricity system’s performance.

If the submitted data is correct, the TSO confirms the balance plans. The confirmed system plan is sent to the Senior Dispatcher of the Power System Control Centre to provide a basis for real time management of the Estonian electricity system.

The rules and deadlines for balance planning, including the list of data to be presented and other information needed by the balance responsible party are provided in the standard terms and conditions of the Balance Agreement.

The aim of balance management is to ensure the balance of the Estonian power system in real time, using reserve capacity if necessary.

For market participants, intra-day balance corrections can be made either through trading on the intra-day power exchange or in trades between market participants. Trading on the intra-day power exchange (i.e. Elbas market) may begin only after the TSO has confirmed the balance plans for the next day. If the balance provider has traded on the intra-day power exchange, it must present an amended balance plan to the TSO no later than 10 minutes after the end of the corresponding trading period.

The rules for intra-day balance corrections are provided in chapter 7 of the standard terms and conditions.

The TSO can use reserve capacity to compensate for any intra-hour deviations from the balance caused by network disruption or changes in planned generation or consumption. Emergency reserves and regulation agreements are agreed upon between the Estonian TSO and power plants and neighboring TSOs offering such services (in order to ensure the balance).

If there are any intra-day changes in the cross-border transmission capacity, for example because of a network disruption, the TSO shall inform the market participants of that within an hour of obtaining the information. Market participants receive this information through UMMs (Urgent Market Message), according to the rules established by the power exchange operator.

The purpose of imbalance settlement is to determine the amount and cost of the open supply for the Estonian power system and for balance responsible party within their balance areas for each imbalance settlement period.

The balance settlement responsibility lies with the open supplier ranked higher than its preceding market participant in the open supply chain. This means that the system operator calculates the balances for the balance responsible parties. In turn, the balance responsible parties settle the balances for the market participants belonging to their balancing area. The stream of data, however, flows inversely (from individual to general). Therefore, the amount of open supply is determined when the measured supplies of every market participant for each imbalance settlement period are known.

The TSO calculates the total amount of imbalance electricity for each imbalance settlement period as the sum of:

• the total of measured supplies for the imbalance settlement period measured by the metering points in the balance responsible party’s balance area;
• the total of fixed supplies and;
• the total of deliveries between the TSO and the market participants in the balance responsible party’s balance area used to manage the Estonian power system’s imbalance

The TSO presents a imbalance report for every imbalance settlement period to the balance responsible party, containing the following data:

• the balance responsible party’s total measured supplies in the balance responsible party’s balance area;
• the balance responsible party’s total fixed supplies;
• trades between the TSO and market participants in the balance responsible party’s balance area related to the management of the national electricity imbalance;
• the amount of imbalance electricity of the balance responsible party;
• the sales and purchase prices of imbalance electricity and the total cost of imbalance electricity bought and sold, which is calculated by multiplying the amount of imbalance electricity by its price;
• amendments to the amounts and/or prices of imbalance electricity sold and purchased in preceding periods.

The imbalance energy sold in the system during the imbalance settlement period is purchased in the same imbalance settlement period from the system’s open supplier and vice versa.

If, based on balance settlement, the imbalance of a balance responsible party is negative in any imbalance settlement period, the System Operator is considered to have sold imbalance electricity to the balance responsible party during the imbalance settlement period in the amount necessary to maintain the balance of the balance responsible party during that imbalance settlement period.

If, based on balance settlement, the imbalance of a balance responsible party is positive in any imbalance settlement period, the balance responsible party is considered to have sold imbalance electricity to the System Operator during the imbalance settlement period in the amount necessary to maintain the balance of the balance responsible party during that imbalance settlement period.

Imbalance prices

The System Operator uses a uniform methodology (approved by the Competition Authority) to calculate imbalance prices for each imbalance settlement period. The sales and purchase prices for balance responsible party imbalances could be found in Imbalance prices - BTD (transparency-dashboard.eu) platform. The imbalance price methodology, which takes effect starting from 01.01.2022 could be found attached below.