Northern Aegean Interconnection Phase C : Chios - Samos

In January 2025 IPTO commenced the final phase of its framework tender for submarine cable projects for the Dodecanese and North Aegean electrical interconnections, and on 26 February 2025 participating companies submitted their binding financial and technical offers. This framework, with an initial budget of €1.7 billion plus VAT and a planned six‑year duration, will underpin award of cable contracts for all included links, among them the Northern Aegean Interconnection Phase C: Chios–Samos.

By December 2024, IPTO had completed the marine route surveys for both the Dodecanese and Northeastern Aegean electrical interconnections, covering all planned submarine cable corridors, including the future 150 kV AC Chios–Samos link that forms part of Phase C of the North Aegean Interconnection.

In October 2024, IPTO advanced the submarine cable procurement for the Dodecanese and Northeast Aegean interconnections by moving to Phase B of the framework tender, in which prequalified contractors submitted their technical and economic offers. Evaluation of these offers is in progress and the resulting framework will be used to award cable supply and installation packages, including for the Northern Aegean Interconnection Phase C: Chios–Samos.

The Phase A expressions‑of‑interest stage of IPTO’s framework tender for submarine cable projects for the Dodecanese and Northeast Aegean electrical interconnections, which will also procure the cables for the planned Chios–Samos interconnector, was completed in July 2024 after submission of participation applications by interested contractors.

In April 2024, IPTO launched Phase A of a framework tender for the submarine cable works of both the Dodecanese and Northeast Aegean electrical interconnections, by posting a call for expressions of interest for the cable interconnections. This framework covers the submarine cable scope for all phases of the North Aegean scheme, including the future Northern Aegean Interconnection Phase C: Chios–Samos link.

On 3 February 2022, RAE Decision 611/2021 approving the Hellenic Electricity Transmission System Development Plan 2021-2030 was published in the Greek Official Journal, formally endorsing IPTO's ten-year plan. The decision specifies that the interconnections of the Dodecanese and the North Aegean Islands must be completed within the second half of 2029, thereby confirming at regulatory level the schedule and investment authorisation for the North Aegean Interconnection including this Phase C Chios-Samos link. For Greek regulated TSO transmission projects, the RAE Decision approving the TYNDP plays the same project-level planning consent role that the BNetzA NEP confirmation plays for German offshore grid connections (see EventType planning_consent_awarded description): it creates the legal basis for IPTO to plan, procure, and construct the listed transmission system under Law 4001/2011. Created during manual audit review by analogy to the same RAE Decision already recorded for Phase A Limnos-Lesvos — the decision is programme-wide and applies equally to all North Aegean phases.

IPTO adopted the mixed HVDC/HVAC "Scenario B" configuration for the Dodecanese and Northeast Aegean island interconnections, confirming that the Chios–Samos section will be implemented as a 150 kV AC single‑circuit submarine interconnector of about 100 km length and 250 MVA capacity using one three‑core cable. This system‑level design decision superseded the earlier 220 kV double‑circuit option and defines the technical concept for the Northern Aegean Interconnection Phase C: Chios–Samos ahead of detailed engineering and procurement.

IPTO (ADMIE) confirmed that the Chios–Samos 150 kV AC interconnection, as part of Phase C of the North Aegean Islands Interconnection, was included in its preliminary Ten‑Year Network Development Plan (TYNDP) 2021–2030, with Phase C defined as closing the interconnection loops via the Lesvos–Skyros and Chios–Samos links by 2030.

On 3 January 2020, IPTO formally launched the North Aegean Islands Interconnection project within its preliminary Ten-Year Network Development Plan 2021–2030, defining three sub‑phases in which Phase C specifically includes the Chios–Samos interconnection as part of the loop‑closure works to be completed by 2030.