The major project to connect the Dodecanese islands to mainland Greece’s electricity transmission system is moving forward, with Kalymnos included in the Kos–Kalymnos autonomous power network.
According to the Independent Power Transmission Operator’s new Ten-Year Network Development Plan for 2027–2036, the first major section of the project—the Corinth–Kos interconnection—is scheduled to enter operation during the first half of 2029. The entire Dodecanese interconnection is expected to be completed in the second half of 2030.
The project carries an estimated budget of approximately €2.96 billion. The operator notes that this figure may be revised as planning advances, particularly during the tendering process.
The new development plan will remain open for public consultation until October 10, 2026.
Kalymnos and neighbouring islands included
The Dodecanese interconnection will be implemented in two phases and will cover six autonomous electricity systems:
- Karpathos and Kasos
- Rhodes and Chalki
- Symi
- Kos–Kalymnos, including Pserimos, Telendos, Nisyros, Tilos, Leros, Lipsi and Gyali
- Patmos
- Arki and Marathi
Kalymnos’ inclusion in the Kos–Kalymnos system places the island within one of the largest and most technically complex energy infrastructure projects ever planned for Greece’s island regions.
A 420-kilometre subsea connection
At the heart of the project is the Corinth–Kos link, which will use two high-voltage direct-current subsea cables with a combined capacity of 1,000 MW and a total length of approximately 420 kilometres.
The planned capacity has been increased from the original 900 MW to 1,000 MW, while the connection will operate at 320 kV.
The project includes:
- a 1,000 MW AC/DC converter station near the Corinth Extra-High Voltage Centre,
- a second 1,000 MW converter station near the Mastichari substation on Kos,
- two subsea HVDC cables linking mainland Greece with Kos,
- three 150 kV subsea alternating-current cables between Rhodes and Kos,
- the Karpathos–Rhodes interconnection,
- two new indoor GIS substations on Karpathos and Kos.
Connection with the Northeastern Aegean
The Northeastern Aegean interconnection, designed as a continuation of the Dodecanese project, is also scheduled for completion in the second half of 2030. Its total estimated budget stands at €1.425 billion.
It will cover the autonomous electricity systems of Lemnos, Agios Efstratios, Skyros, Lesvos, Chios and Psara, Samos, Fournoi and Thymaina, Ikaria and Agathonisi.
A key part of this wider network will be the approximately 100-kilometre Samos–Kos subsea cable. It will terminate at the Mastichari substation, close to the converter station planned for the Corinth–Kos link.
Once completed, the programme will integrate the Dodecanese and Northeastern Aegean into an extensive interconnected electricity network, giving Kos a central role and making Kalymnos part of the islands’ new energy infrastructure.
Source: Marina Xypnitou https://ypodomes.com/
