Using optimized flow based market capacity indices in TSO investment evaluation

The current flow-based capacity calculation methodology applied in the European electricity market forces the TSOs to re-think their concepts and methodologies for network planning and investment justification. Until now, these methods have been based on methods for de-coupling of TSOs zones, based on cross-border bilateral exchanges, with reduced complexity. The main instrument of de-coupled planning is the determination of cross-zonal Net Transfer Capacity (NTC) values, as planning targets. Each TSO would thus individually plan for its own borders, where NTC targets would ensure a secure cross-zonal transmission capacity. Nowadays the market coupling has intensified the cross-zonal trade and emphasized the interdependencies between TSO borders. A more integrated planning is now required, aligning network planning and capacity calculation methodologies. The relationship between local investments and “regional” network constraints to the inter-zonal transmission capacities needs to be addressed. The method that is proposed in this paper directly relates to the flow-based market coupling methodology that is used today, complementing the assessment of network investments from a market perspective.