The determination of transmission capacities between neighbouring bidding zones (cross-zonal transmission capacities) and their allocation are of high significance for electricity trading and maintaining operational security of the electricity system under market conditions. The procedures for the calculation of Total, Net and Available Transfer Capacities (TTC, NTC, ATC), knowledge of transmission constraints, efficient allocation procedures of cross-zonal transmission capacities in short-term and long-term periods are important elements of economic and technical assessment of the transmission network under market conditions.
The indicative NTC values for winter and summer are published on ENTSO-E web site, while the bilateral NTC values are agreed by system operators of neighbouring countries.
Analyses and calculations of Net Transfer Capacities (NTC) are performed at the borders of the Croatian electricity system for the purpose of efficient use of available cross-zonal transmission capacities in addition to maintaining operational security of the Croatian electricity system. HOPS performs the calculation of cross-zonal transmission capacities in accordance with the definitions and methodologies within Synchronous Area Framework Agreement - SAFA for Regional Group Continental Europe and other ENTSO-E documents, respectively.
Net cross-zonal transmission capacities are determined for all borders of the Croatian electricity system, in the direction of import and export respectively. The transmission system operators of neighbouring countries coordinate the allocation and use of available transmission capacities on regional and bilateral level.