IPTO/ADMIE: upgraded Ionian interconnections now operational

The Independent Electricity Transmission Operator (IPTO/ADMIE) put into operation, as announced on Monday 28 September 2026, the upgraded electrical interconnections between Zakynthos and Cephalonia, as well as between Cephalonia and Leucada. These are submarine alternating current cables with a voltage of 150 kV, which carry embedded optical fibers. According to IPTO/ADMIE, the cable connecting Zakynthos to Cephalonia is 20.4 kilometers long, while the cable between Cephalonia and Leucada extends for 14.8 kilometers. The announcement of the commissioning of the two interconnections was reported on Monday 28 September 2026 by pelop.gr and by Ta Nea, at 11:56.

The upgrade project of the two submarine interconnections is part of IPTO/ADMIE’s broader infrastructure program for electricity transmission to the Ionian islands. According to the operator, the construction contract was signed in November 2024, while its completion was recorded in September 2026. The total cost of the project reached 99.8 million euros, as stated by IPTO/ADMIE. More information about energy transmission infrastructure in the country is recorded in the infrastructure section of the publication.

The two interconnections concern the electrical grid of the Ionian islands, connecting Zakynthos to Cephalonia and Cephalonia to Leucada via upgraded submarine cables. IPTO/ADMIE’s announcement describes the upgrade of the existing interconnections with 150 kV voltage cables and embedded optical fibers, but does not clarify the transmission capacity of the new cables in megawatts. The operator provides no information on how the upgraded interconnections affect the grid operation in the three islands, nor does it mention any potential changes in electricity prices or in the frequency of outages, matters for which no data is provided. The announcement is part of broader activity around energy transmission networks, which the publication monitors in the economy section.

IPTO/ADMIE’s announcement does not mention the transmission capacity in megawatts of the new interconnections, nor the technical specifications of the older cables. It also does not clarify whether the old cables remain installed as backup, who was the construction contractor for the project and what was the source of financing for the 99.8 million euros. The same applies to the use of the embedded optical fibers and which body will manage them, as well as whether further upgrade projects for interconnections in the Ionian Sea are planned. It also has not been clarified whether the announcement concerns other submarine connections in the Ionian region beyond these two. IPTO/ADMIE has not yet announced additional information on the above matters.