MARI Platform Goes Live in Estonia Tomorrow: What to Expect

On 9 October 2024, Estonia officially joined the MARI (Manually Activated Reserves Initiative) platform, marking a major step in its integration into Europe’s electricity balancing market. Alongside Lithuania, Estonia led the Baltic region through this transition, aimed at strengthening grid stability, improving the efficiency of balancing energy exchanges, and providing access to a larger pool of reserves for energy balancing.

What is MARI?

(Chart: MARI implementation project as of February 2024. Source: ENTSO-E)

MARI is a European platform built to optimise the use of manual frequency restoration reserves (mFRR). By joining MARI, Estonia gained access to a pan-European system where resources are shared across borders to help keep electricity supply and demand in balance. The system allowed for faster, more efficient responses to grid imbalances, cutting mFRR activation times from 15 to 12.5 minutes.

What changed for market participants

MARI brought several key changes to how energy balancing works in the Baltic region:

• 15-minute bidding units on MARI. MARI operates on 15-minute market time units (MTUs), allowing for more precise bidding and faster responses to imbalances.
• Nord Pool stayed on 60-minute MTUs, at first. Estonia’s Nord Pool day-ahead market continued using 60-minute MTUs for a while after MARI went live, creating a mismatch between the two systems’ time resolution.
• Nord Pool has since moved to 15-minute MTUs too. Nord Pool made that switch in February 2025, aligning the day-ahead and balancing markets onto the same time resolution across the Nordics and Baltics. That shift brought more volatile, faster-moving prices — and with them, more opportunities for market participants able to react quickly.
• A move toward a nodal-based system is still ahead. Estonia and its Baltic neighbours are expected to eventually move to a nodal-based approach, where the balancing system is based on local nodes rather than a region-wide system, helping optimise resource distribution and improve efficiency in energy trading.
• More frequent bidding means more flexibility. The 15-minute MTUs on MARI let market participants adjust their bids and energy schedules more often, offering greater flexibility than the previous hourly cycle allowed.

The road since

MARI’s integration gave Estonia early practice operating in a faster, more granular balancing environment before Nord Pool’s own move to 15-minute pricing arrived a few months later, in February 2025. That sequencing gave companies time to adapt to MARI’s more dynamic system before they had to navigate faster-moving day-ahead prices too.

For energy market participants, Estonia’s entry into MARI was a step toward greater efficiency: enhanced access to a larger pool of European resources to help stabilise the grid, optimise reserves, and ultimately reduce costs for consumers.

Want help navigating 15-minute settlement and MARI participation? Talk to Fusebox →