IN Brief:
- Terna is due to begin operational participation in the European MARI mFRR platform on 25 November.
- GME will conduct market participant testing of new IPEX functions from 28 September until 13 November.
- MARI enables participating transmission operators to exchange balancing energy from manually activated frequency restoration reserves across Europe.
Terna will begin operational participation in Europe’s MARI balancing platform on 25 November, connecting the Italian transmission system to the common European mechanism for exchanging balancing energy from manually activated frequency restoration reserves.
Gestore dei Mercati Energetici, Italy’s electricity market operator, will run test sessions with Terna and market participants from 28 September to 13 November. The exercises will cover new functions added to the IPEX platform so that Italian balancing activity can interact correctly with MARI before the live connection begins.
MARI, the Manually Activated Reserves Initiative, is the European implementation project for the mFRR platform established under the EU Electricity Balancing Regulation. It has been operational since October 2022 and has progressively added transmission system operators as national balancing arrangements have been adapted to the common technical and market framework.
The platform allows participating system operators to exchange balancing energy from frequency restoration reserves with manual activation instead of relying only on bids within their own control areas. Standardised bids are brought into a common European process in which available resources can be ranked and activated while cross-border capacity and system security limits are respected.
For a transmission operator, the arrangement widens the pool of balancing energy that can be considered when scheduled and actual system conditions diverge. National operators remain responsible for the security of their own networks, while the common platform provides access to additional bids where interconnection, congestion, and market conditions allow them to be used.
Italy’s November entry comes as the country is also expanding storage and other forms of flexibility. Terna has scheduled its second MACSE storage auction for 24 November, one day before the planned MARI go-live, with the procurement targeting 16GWh of battery capacity for 2029 delivery. The two mechanisms serve different purposes, but both increase the range of controllable resources available to the system.
Balancing requirements become more variable as the generation mix contains a larger share of wind, solar, and converter-connected resources. Forecast errors, plant outages, and unexpected movements in demand can leave the system with too much or too little power relative to scheduled positions. Frequency restoration reserves are among the tools used to correct those imbalances after the immediate response to a disturbance.
The pre-launch testing period has an operational purpose. Market participants need to verify order submission, validation, timing, data exchange, and settlement-related functions before live balancing energy is routed through the European platform. The IPEX changes must also interact correctly with Terna’s control systems, because the market transaction ultimately results in a physical change in generation or demand.
Physical network constraints remain in force even when the market pool becomes larger. A balancing bid may be competitively priced but unusable if the relevant cross-border capacity is unavailable or if activating it would aggravate congestion. MARI can widen access to resources, but it cannot bypass the electrical limits of the transmission system.
The platform also increases the importance of consistent technical products and data exchange. Participating operators and market parties need common definitions for bid characteristics, activation, and timing if balancing energy is to move reliably across several national systems. That standardisation is one reason European balancing integration has progressed in stages rather than through a single launch.
MARI is one part of a wider set of European balancing platforms intended to make reserve procurement and activation more consistent across interconnected systems. Each accession requires national market arrangements, control systems, and data exchanges to be aligned closely enough for cross-border activations to work within operational timescales. Italy’s testing programme is the final practical stage before that integration moves from market preparation into live dispatch.
Italy is a significant addition because its system combines large electricity demand, substantial interconnection, and rapidly growing renewable generation. Joining MARI will place more of its mFRR activity inside the common European process, while domestic resources continue to respond through national market arrangements and Terna’s operational requirements.
GME plans to publish further details of the test timetable and procedures through its test platform. The first milestone is the 28 September start of market participant testing, followed by several weeks in which systems and procedures can be checked before live use.
If that programme remains on schedule, 25 November will mark the point at which Italian mFRR balancing energy becomes part of MARI’s operational exchange. The connection adds another national system to Europe’s common balancing architecture, while the practical value will depend on available interconnection, bid liquidity, and the physical limits of the grid at the time each activation is requested.