  This paper develops a novel mixed-integer linear programming (MILP) model for
optimal participation of battery energy storage systems (BESSs) in the Swedish
frequency containment reserve (FCR) markets. The developed model aims to
maximize the battery owner's potential profit by considering battery
degradation and participation in multiple FCR markets, i.e., FCR in normal
operation (FCR-N), and FCR in disturbances (FCR-D) for up- and
down-regulations. Accordingly, a precise formulation of a detailed battery
degradation model and adherence to the technical requirements of the Swedish
FCR markets are incorporated into the developed model. To achieve more
practical results, simulations are conducted based on one minute time step
realistic data for the whole year 2022. The results show a potential profit of
708 thousand Euros for a 1MW/1MWh BESS by participating in multi-FCR market.
Analyzing the impact of considering degradation in the optimization problem has
shown that the annual battery aging cost could decrease by 5%-29% without a
significant effect on profit. The proposed model can be practically used by
flexibility asset owners to achieve profitable and sustainable operation
strategies that reduce battery degradation.
