The last stages of equipment testing and inspection are now underway at the Damasta Converter Station near Heraklion, paving the way for the launch of trial operations that will, for the first time, directly link the island of Crete to mainland Greece’s high-voltage power grid through Attica.
The interconnection is being developed by IPTO (Independent Power Transmission Operator), Greece’s transmission system operator, in collaboration with its dedicated project subsidiary, Ariadne Interconnection. Company leadership recently visited the Damasta site to review the completed installations.
The station is expected to be energized next week, beginning with the controlled injection of reactive power into Crete’s grid—a key step in stabilizing the system ahead of full-scale operation.
On the mainland, testing is also progressing rapidly. In Attica, engineers are conducting trial energization of the 400 kV cable system linking the Koumoundourou Converter Station with the adjacent Extra
High Voltage Center, which connects the new link to Greece’s broader transmission network. Full system trials are scheduled to begin later this month.
This interconnection is the largest and most technically complex power transmission project ever built in Greece. Its completion will allow Crete—currently reliant on localized, fossil-fuel-based generation—to import electricity from the mainland, enhancing energy security, reducing emissions, and supporting the island’s growing renewable energy sector. According to IPTO, active power transfer from Attica to
Crete is expected to begin by the end of May, signaling the start of the interconnection’s operational phase.
The project has advanced rapidly over the past several months. Since early 2025, extensive testing has been conducted at both converter stations, including the 150 kV GIS substation in Damasta, which was successfully integrated with Crete’s power system. The full suite of 500 kV cables—both submarine and underground—has also undergone comprehensive testing.
Adding to the momentum is a recent regulatory approval for a new 150 kV transmission line between Chania and Damasta. This line is considered essential for the coordinated operation of Crete’s two mainland interconnections: one via the Peloponnese and the other via Attica. It will allow for more flexible and robust electricity flows across the island and to the mainland.
