MARI (Manually Activated Reserves Initiative)
MARI is the European platform for the cross-border exchange of mFRR balancing energy under Article 20 of EBGL Regulation (EU) 2017/2195. Connected TSOs submit standard mFRR bids into a common merit order list; every 15-minute market time unit the platform clears the cheapest combination of bids needed to meet aggregate mFRR demand, at a marginal price per direction. Elering joined MARI on 9 October 2024.
MARI (Manually Activated Reserves Initiative) is the European platform for the cross-border exchange of mFRR balancing energy. It is implemented under Article 20 of the Electricity Balancing Guideline (Commission Regulation (EU) 2017/2195) and operated by ENTSO-E member TSOs.
How it works
Each connected TSO submits its standard mFRR bids into a Common Merit Order List (CMOL). Every 15-minute Market Time Unit, MARI runs an activation optimisation that respects available cross-zonal capacity, selects the cheapest combination of bids needed to meet aggregate mFRR demand, and clears at a marginal price per direction. Direct activation (intra-MTU) handles fast-response situations.
Estonia and the Baltic TSOs
Elering joined MARI on 9 October 2024, alongside AST (Latvia, 4 October) and Litgrid (Lithuania, 8 October), ahead of the 9 February 2025 Continental synchronisation. Eesti Energia was the first Estonian BSP to forward bids from day one. Since accession, Baltic mFRR scarcity events have repeatedly cleared at the platform price cap of ±10 000 €/MWh.
Energy not capacity
MARI is a balancing-energy platform — the activation marketplace, not the procurement market. mFRR balancing capacity is procured separately, in the Baltics through joint mFRR auctions run by Elering, AST and Litgrid. The companion PICASSO platform plays the same role for aFRR energy.
Sources
ENTSO-E: MARI · EBGL Article 20 · Elering: Balancing service · Eesti Energia: MARI go-live