ELES and Terna, the Slovenian and Italian electricity transmission system operators, have signed an agreement to upgrade the cross-border electricity interconnection between the two countries. The planned developments, which include three major upgrades, will increase cross-border transmission capacity by 600 megawatts, representing a more than 50 per cent increase.
400 kV Divača–Sredipolje
The phase-shifting transformer at the Divača substation will be upgraded, and a new third unit will be added, enabling the full capacity of the 400 kV line between Divača and Sredipolje to be utilised. The current capacity of 1200 MVA will increase to 1800 MVA.
220 kV Divača–Padriče
The phase-shifting transformer at the Padriče substation and the conductor on this 220 kV connection will be upgraded using low-voltage conductor technology. The current capacity of 350 MVA will increase to 700 MVA.
220 kV Padriče–Sredipolje
On the Italian side, the 220 kV Padriče–Sredipolje connection and the Sredipolje substation will be upgraded by installing a new transverse transformer within the Italian grid. This will be key to managing internal power flows.
Work is expected to begin in 2029, with completion planned by the end of 2031. The total value of the investment is estimated at approximately 250 million euros. ELES intends to apply for European funding to support the investments on the Slovenian side.