Substation Supplier Selected

On 16 February 2023, Independent Power Transmission Operator (IPTO/ADMIE) announced the provisional winners of its tender for the new 150 kV GIS island substations under Cyclades Interconnection Phase D. The award was split into two sections: TERNA was named provisional contractor for the substations on Folegandros and Milos (Section A), and a NARI and Electromec partnership was named provisional contractor for the new 150 kV GIS substation on Serifos (Section B). The Serifos substation forms the island-side terminus of the Lavrio–Serifos 150 kV AC submarine interconnector, accepting the three-core XLPE HVAC cable landfall and stepping the voltage down to 20 kV for connection to the existing Serifos medium-voltage distribution network. The Lavrio mainland connection point uses IPTO's existing 150 kV GIS Lavrio substation, so the only new-build substation scope on this leg of Phase D is the Serifos facility. Per ADMIE's H1 2025 Financial Report (September 2025), the formal contracts of the High Voltage Substations for Folegandros, Milos and Serifos were subsequently signed in September 2023, putting the entire Phase D project into the construction phase. The Phase D substation budget was approximately EUR 54 million within the EUR 524 million total Phase D programme.