The mFRR Process is executed as a mixed integer linear programming model for each mFRR Time Period.

The objective function for resolution of mFRR minimises the cost of covering zonal imbalances for all Bidding Zones using upward and downward mFRR Energy Offers submitted by Balancing Service Entities. The cost of covering HETS zonal imbalances arises from the mFRR Energy Offers that are accepted.

The constraints on mFRR problem resolution shall include at least:

a) the zonal Imbalance constraint for each Bidding Zone,

b) the constraints on electricity flows between the Bidding Zones,

c) the technical constraints of the Balancing Service Entities,

d) the constraints ensuring that the overall HETS requirements for ISP Balancing Capacity and aFRR are maintained,

e) any restrictions on mandatory injections, and

f) any constraints on maximum daily electricity injection from Dispatchable Generating Units.

In the event that the offer prices of two or more Balancing Energy Offers pertaining to the same mFRR Time Unit are identical, and, at the same time, the respective Balancing Energy quantities of the above offers are not included in their entirety in the mFRR Process results resolution, the offer segments shall be selected in the following order of priority: (a) Dispatchable RES Units Portfolio, (b) Dispatchable hydro Generating Units, (c) Dispatchable Load Portfolio, and (d) Dispatchable thermal Generating Units. Among bidding segments that belong to the same category, priority shall be given to the segments of the offers corresponding to the Balancing Service Entity with the highest Ramp Up Rate. For bidding segments that come into the same category and have the same Ramp Up Rate there will be random selection.

In the event that no feasible result is produced for a mFRR Time Unit under the mFRR Process resolution, that is, covering the short-term forecasted imbalances by observing the constraints in paragraph 3 of this Article is unfeasible, the HETS Operator shall repeat the mFRR Process having indicatively undertaken to:

a) include Balancing Energy Offers from Contracted Generating Units;

b) relax the constraints indicated in paragraph 3 (4) of this Article in order to reach a feasible solution.

If, after following the above steps, there is still no feasible solution, the manual FRR process shall be performed once again in accordance with the provisions on Emergency Situations, as defined in the HETS Grid Code.

When resolving the manual FRR Process, mFRR Balancing Energy Offers that may have been submitted by Dispatchable Intermittent RES Units Portfolios or Dispatchable Load Portfolios are not taken into account if they are supplying aFRR during the specific manual FRR Time Unit.

When resolving the mFRR Process, optimisation may be executed for three consecutive 15-minute periods, so that the impact of HETS conditions during the subsequent mFRR Time Units are effectively taken into account for each mFRR Time Unit. In this case, only the results of the first mFRR Time Unit shall be binding. Results related to subsequent mFRR Time Units shall be indicative.