Crete-Attica Interconnection

The Crete-Attica electrical interconnection project is currentlythe largestelectricity transmission investment ever in Greece.  The project puts an end to Crete’s“electrical isolation” from the mainland grid while meeting the island’s growing needs for the future.  
 

Routing of the electrical interconnection project

The Electrical Interconnection starts at the Attica AD/DC converter Station, near Koumoundouroσ UHVC. From there, two 500 kV HVDC cables run underground to the cable landing point at Pachi, Megara.

At Pachi,  thecable system transitions into a submarine route up to the landing point at Korakia, Heraklion in Crete.

From Korakia, the cables continue to the terminal AC/DC converter station of Damasta , where the interconnection with the Cretan power grid is completed through the new Damasta GIS substation.

To support system operations, two electrode stations have been installed in order to support system operations, on Stachtoroi islet in Attica, and at Korakia, Heraklion. 

 

The project’s contractor’s are:

Nexans and Prysmian were responsible for the design, supply and installation of the submarine power cables connecting Crete and Attica. Prysmian also undertook the electrode stations subproject in Crete and Attica, as well as the design, supply and installation of the fiber optic cable system.

Hellenic Cables–NKT constructed and installed the underground cable sections linking the Converter Stations in Crete and Attica to the submarine cable system.

The Siemens–TERNA consortium was responsible for the construction of the interconnection’s Converter Stations.

 

The Crete–Attica interconnection ranks among the five most innovative HVDC interconnection projects in Europe.

 

Specifically, the project operates at 500 kV DC, using state-of-the-art Voltage Source Converter (VSC) technology.  

It is the first DC interconnection in the Mediterranean to utilise advanced Voltage Source Converter-VSC technology.

It is among the top 3 deepest submarine interconnections worldwide.

With a capacity of 1,000 MW, it is one of the highest-capacity island interconnections worldwide, along with Sardinia.

It is the only interconnection in Europe that’s brought together the largest cable manufacturers to join forces. 

Benefits
  • Economic: Annual savings of approximately EUR 500 million for all electricity consumers in Greece through reduced utilities bills.
  • Environmental: The interconnection significantly improves Crete’s environmental footprint, reducing CO2 emmisions by approximately 1.5 million tons annually, compared to current levels.
  • Social: Energy security and reliable electricity supply for the residents of Crete, along with an upgraded tourism offering for visitors throughout the year. 
Co-funded by the European Union
ΕΣΠΑ
Project's Timeline
2020

Contact signing in Heraklion, Crete

2021

-Cable manufacturing in the factories of the contractors
commences
-Marine survey is completed
-Land construction works launch
-Equipment manufacturing for the converter stations
-commence
-Optical fibers are installed
-The first section of the submarine cable is laid

2022

-Submarine cables are laid and protected
-Construction works for the electrode stations launch 
-Equipment of the converter stations is installed

2023

-The installation of the high-voltage direct current (HVDC) submarine cable system is completed
-The post-installation testing of the high-voltage direct current (HVDC) submarine cable system is completed 
-The foundation for the main converter station buildings is laid

2024

-The construction of the main buildings of the converter stations in Attica and Crete is completed
-Installation of transformers, converter valves, and primary and secondary equipment
-The GIS building and installation of all associated equipment is completed

2025

Project Completion