Front-and behind-the-meter storage needs of the Greek power system under high RES penetration levels

This paper assesses grid-scale battery energy storage system (BESS) requirements for the Greek power system, in addition to already scheduled storage projects, aiming to attain upgraded renewable energy penetration targets for 2030. Two alternative BESS integration routes are analyzed, namely front-of-the-meter (FtM) BESSs and behind-the-meter (BtM) BESSs coupled to photovoltaics (PVs) undergoing power output limitations, examining a wide set of storage configurations regarding incurred system benefit. System operation is optimized employing the state-of-the-art unit-commitment and economic dispatch problem, formulated as a mixed-integer linear programming algorithm. The cost-benefit analysis evaluates variable system operating cost reduction due to introduction of storage, as well as the benefit emanating from contribution of additional BESS to system resource adequacy. After deducting annualized cost of additional storage to ensure its economic feasibility, the annual net system benefit is calculated. Energy capacity of introduced BESS configuration is proven determinant of total delivered system benefit. In both storage pathways, similar maximum net benefits can be attained reaching 62-64 million € per annum. Both 1-1.5 GW – 4h of FtM BESSs or BtM BESSs coupled with PVs with 7-10 GWh and 0.5-2 equivalent hours of energy storage capacity deliver similar savings in the vicinity of maximum net benefit.