Regional market coupling aligned much of Hungary, Romania, Slovenia, Croatia, Serbia and Albania around €150/MWh on 11 August. The 12 August fifteen-minute curves show that convergence is much weaker when analysed at the interval level.
Hungary reached almost €265/MWh, Romania €310/MWh and Bulgaria about €199/MWh. These differences indicate that available cross-border capacity could not fully equalise the evening scarcity price.
Romanian emergency restrictions further weaken the assumption that purchased capacity guarantees physical delivery. During an adequacy event, transmission-system operators can reduce commercial exchanges to preserve system security.
The Montenegro–Italy corridor retains a different value profile. Recent daily auction prices in the export direction averaged approximately €8.59/MWh, supported by Italy’s persistent premium over the Adriatic markets. Montenegro’s own dry-summer deficit can reduce the electricity available for export even where Italian prices remain attractive.
The submarine cable can simultaneously support Montenegro through imports during domestic scarcity and provide access to Italy when EPCG has surplus hydro or wind production. Its economic value therefore lies in optionality rather than a permanently fixed direction.
Intraday coupling reliability has become another pricing input. Repeated cancellations and partial decoupling of European intraday auctions during early August reduced traders’ ability to correct cross-border positions. That operational weakness matters when fifteen-minute prices move from zero to €300/MWh.
A portfolio with forecast solar output but no dependable intraday route can incur balancing costs far above the revenue earned during the original day-ahead sale. Storage reduces the physical imbalance but cannot fully compensate for an unavailable or illiquid market interface.
