Cyclades Interconnection Phase D : Santorini - Folegandros - Milos - Serifos
June 2026
Positive
Project advancing - milestone achieved
High Impact
Major milestone or critical setback
IPTO plans that the Santorini-Naxos segment of Cyclades Phase D will be completed by the end of the first half of 2026, while the remaining southwest Cyclades islands (Folegandros, Milos, Serifos) will be integrated into the High Voltage System by the end of the second half of 2026. ADMIE Holdings FY2025 annual results (published April 2026) confirm this timeline: all submarine cables have been laid and protected (completed June 2025), GIS substation construction is progressing, and the completion horizon for the Santorini-Naxos connection is H1 2026. The broader Phase D programme covering the full southwest Cyclades integration targets H2 2026. This projection represents full commercial operation of the Santorini-Folegandros-Milos-Serifos link within the H1 2026 window stated by IPTO.