Interconnection of Crete with the Peloponnese

The interconnection of Crete with the Peloponnese constitutes the first phase of the interconnection of Crete with the Hellenic Electricity Transmission System (HETS)

The System of Crete is characterized by:

  • Very high variable production cost due to the use of oil at the local production Stations, which is reflected as a steep charge for consumers in their Utilities bills (more than €300 million a year).
  • High annual increase rate for the Island’s load. It should be noted that local Stations marginally manage to cover the load during the summer months.
  • Great difficulty, or even inability, to find spaces and obtain the licensing for reinforcing local Stations or developing new ones.
  • The constantly increasing interest in the utilisation of the rich local RES potential, penetration of which into the island’s power production mix is limited due to technical constraints (mainly major stability issues which a high penetration of RES may cause in an autonomous electricity system such as Crete’s).
  • Low supply reliability level, particularly in cases of faults in the production system.

These characteristics render the interconnection of Crete with HETS a necessary project as regards the feasibility of its implementation.

In more detail, the interconnection of Crete with the Peloponnese consists of the following separate projects:

  • Upgrade of existing Megalopoli I - Sparti II - Sparti I - Skala - Molaoi Transmission Line.
  • Construction of a new 150 kV Transmission Line bay at the existing Megalopoli I Substation, to connect the second circuit of the upgraded TL mentioned above.
  • Upgrade of two simple 150 kV TL bays into fully equipped ones at the existing Sparti II Substation
  • Construction of three new 150 kV TL bays at the existing Molaoi Substation, to connect the second circuit of the above upgraded TL and the two new circuits towards Crete.
  • Construction of a new 150kV double-circuit Transmission Line, of a rated 200 MVA transferring capacity, from the Molaoi Substation to the landing point in SE Peloponnese. 
  • Construction of a new 150 kV Switching Substation in SE Peloponnese (Compensator Terminal), where the new overhead TL from the Molaoi Substation will end and the cable sections towards the Chania Substation will begin. 
  • Construction of new double submarine 150kv line from the SE Peloponnese landing point to the Western Crete landing point, with a length of 132 km.
  • Construction of a new double underground 150 kV line from the Western Crete landing point to the Chania I Substation, with a length of 34 km.
  • Construction of two new 150 kV Transmission Line bays at the existing Chania I Substation, for connection of the two cable circuits from SE Peloponnese, as well as 7 new 150 kV / 40 MVAr self-inductances.
  • Herakleion III Substation for installation of the STATCOM.
  • Reliable and stable operation of the Cretan grid, with significant benefits for tourism and the general economic activity.
  • Reduction of environmental burden on Crete due to the gradual reduction of thermoelectrical power plant generation.
  • Reduction of energy production cost.
  • Reduction of Utilities bills for all consumers.
  • Development of Wind, Solar and other RES potential of Crete.
  • Reduction of necessity for Reserve Units.
  • Reduction of greenhouse gas emissions.
  • Reduction of the country’s dependency on oil.
Project's Timeline
Estimated completion time
Molaoi ΟTL - Terminal NAP & STATCOM
Upgrade of Grid from Megalopoli to Molaoi
Terminal Compensator Stations
Underground & Submarine Cables