A consortium led by Siemens Gas and Power has been awarded a turnkey contract for two converter stations for the HVDC link that will connect Crete, Greece’s largest and most populous island, with the mainland of Greece. The project will enable an exchange of electricity of up to 1000 MW to enhance reliability of the power supply and facilitate integration of renewable energy sources in the power grid. The customer is Ariadne Interconnection S.P.S.A., a wholly owned entity of the Greek independent power transmission operator IPTO. Commissioning of the interconnector is scheduled for mid-2023. Total order volume for the consortium is €370 million.
Siemens will co-operate in a consortium with Greek construction company TERNA S.A. The EPC turnkey contract comprises design, supply and installation of a 1000 MW converter system at a direct-current voltage of ± 500 kV, and a gas-insulated switchgear (GIS) substation on Crete including 10-year service contracts for the GIS and Control and Protection systems of both the HVDC stations. The two converter stations – one located in the Attica region near Athens and the other near Damasta in the north of Crete – will be linked by a 330 km DC power cable. Terna will be responsible for the HV distribution systems, the entire civil works and the erection of all equipment of the HVDC project.
Currently, Crete’s energy supply mainly relies on old fossil-fuelled power plants that will be shut down by the end of 2022. The interconnector will facilitate the transmission of energy from renewable resources generated on the Greek mainland to the island and will therefore reduce carbon emissions – by 500 000 tons in its first full year of operation.
Both converter stations will use HVDC Plus voltage-sourced converters in a modular multilevel converter arrangement (VSC-MMC). The system is said to combine the advantages of HVDC transmission with benefits like AC voltage control, black-start capability, minimised power transmission losses, grid stabilisation and high availability.