Balancing energy

Balancing energy is the electricity the TSO buys or sells in real time to keep system frequency at 50 Hz. Estonian regulation splits the concept into two: Bilansienergia (imbalance energy settled between TSO and BRP) and Reguleerimisenergia (activated balancing energy from BSP bids). EU EBGL collapses both under one label.

Balancing energy is the electricity the Transmission System Operator buys or sells in real time to keep system frequency at 50 Hz. The EU EBGL (Commission Regulation (EU) 2017/2195, Article 2(11)) treats it as a single concept; Estonian regulation splits it into two distinct terms whose distinction matters for settlement.

Bilansienergia (imbalance energy)

Bilansienergia is the energy settled financially between the TSO and a BRP under a balance agreement. At the end of every imbalance settlement period, the TSO measures the BRP's actual flows, compares them against schedule, and bills the BRP at the imbalance price for any deviation. This is the cashflow that reconciles forecasts with physical reality.

Reguleerimisenergia (activated balancing energy)

Reguleerimisenergia is the physical energy activated from a BSP's balancing-reserve bid. When the TSO needs to ramp generation up or down to clear an imbalance, it dispatches aFRR or mFRR bids in merit order; the energy that flows is reguleerimisenergia. The BSP earns the activation price; the imbalance price billed to BRPs is derived directly from these activations.

Why the distinction matters

Operationally the two flow through the same kilowatt-hour at delivery time, but they hit different ledgers: reguleerimisenergia is BSP revenue (paid by TSO for activation); bilansienergia is BRP cost (paid to TSO for being out of position). The same MWh that earns one party reguleerimisenergia simultaneously prices another party's bilansienergia. EU EBGL papers over the distinction; Estonian operators do not.

Live data

Estonian mFRR clearing prices — the per-MTU activation prices that drive both BSP revenue and BRP imbalance settlement — are charted hourly: mFRR clearing price chart.

Usein kysyttyä

What is balancing energy?

Balancing energy is the electricity the TSO buys or sells in real time to keep system frequency at 50 Hz. It comes from activated FCR, aFRR or mFRR bids submitted by BSPs. EU EBGL Article 2(4) defines it as the energy used by TSOs to perform balancing — distinct from balancing capacity, which is the right to call on the energy.

What's the Estonian-specific terminology distinction?

Estonian regulation splits the EU concept into two terms. Reguleerimisenergia is the energy activated from BSP bids (the supply side); bilansienergia is the imbalance energy settled between the TSO and BRPs (the demand side). The two are equal in volume per settlement period but represent the two sides of the same trade — what the TSO bought from BSPs equals what it sells to short BRPs.

What's the difference between balancing energy and balancing capacity?

Balancing capacity (reguleerimisvõimsus) is the right the TSO procures from a BSP to call on flexibility — paid as a €/MW availability fee, procured day-ahead on the BBCM. Balancing energy (reguleerimisenergia) is the actual MWh delivered when the bid is activated — paid as a €/MWh activation fee through MARI (mFRR) or PICASSO (aFRR). A BSP earns both streams: capacity for being available and energy for actually delivering.

Where does Estonian balancing energy clear?

Through the EU activation platforms since 2024–2025: mFRR through MARI (Estonia joined 9 October 2024), aFRR through PICASSO (Estonia joined 9 April 2025). Both clear at a marginal cross-border price per direction per Market Time Unit; the area-specific local marginal price applies when cross-zonal capacity binds.