Cyclades Interconnection Phase D : Lavrio - Serifos
Approximately June 2026
Positive
Project advancing - milestone achieved
High Impact
Major milestone or critical setback
According to IPTO’s 2025 financial disclosures, the fourth and final phase of the Cyclades electrical interconnection—which includes the 150 kV Lavrio–Serifos submarine and underground link as part of the Serifos–Milos–Folegandros–Thira chain connecting the Lavrio GIS substation to the new Naxos GIS substation—is planned to be completed with the integration of the island cluster into the High Voltage System by the end of the first half of 2026, at which point the Lavrio–Serifos interconnector is expected to be in full commercial operation.