HEDNO is completing one of the most significant modernization projects for the electricity distribution network by implementing the largest capacity expansion program for 150/20 kV substations ever undertaken in the country.
The program involves upgrading 14 high- to medium-voltage substations throughout Greece, adding a total of 725 MVA of new capacity to the grid. The investment creates significant additional electrical capacity, facilitating the connection of new renewable energy sources (RES) and supporting the country’s energy transition. At the same time, the necessary infrastructure is being created to connect electricity storage units to the grid, further enhancing the flexibility and reliability of the distribution grid.
The capacity increase is achieved either by installing new power transformers or by replacing existing ones with new, higher-capacity ones. At the same time, the medium-voltage side of the substations is being expanded to enable the connection of new transmission lines and additional renewable energy projects to the grid.
The project is funded by the Recovery and Resilience Facility (RRF), under Action 16899 of Axis 1.1, “Transition to a new environmentally friendly energy model.”
Of particular note is the fact that the program is being completed within an extremely demanding timeline. The selection of the substations and the project’s inclusion in the Recovery Fund took place in July 2022, and in less than four years, complex technical interventions were completed at facilities with varying characteristics and in geographically remote areas of the country.
With the completion of the project, the Distribution Network gains increased capacity to integrate clean energy, enhancing supply security, operational flexibility, sustainable development, and the achievement of national energy goals.
The following substations have already been energized and are in operation:
• Ioannina I 150/20 kV Substation – 50 MVA expansion
• 150/20 kV Florina Substation – 50 MVA increase
• Melitis Substation – 50 MVA increase
• Philippi Substation – 50 MVA increase
• 150/20 kV Eordaia Substation – 50 MVA increase
• Megara 150/20 kV Substation – 75 MVA increase
• 150/20 kV Domokos Substation – 50 MVA increase
• 150/20 kV Pylos Substation – 50 MVA increase
• 150/20 kV Oinofyta Substation – 50 MVA increase
Work has been completed at the following substations, and energization is expected within the year:
• Arachthos Substation – 50 MVA increase
• 150/20 kV Skydra Substation – 50 MVA increase
• 150/20 kV Spercheiada Substation – 50 MVA increase
• Trikala Substation – increase by 50 MVA
• 150/20 kV Magiko, Xanthi Substation – 50 MVA increase
CEO Mr. Tasos Manos stated:
"With the largest substation reinforcement program ever implemented by HEDNO, we are creating the necessary electrical capacity for more investments in renewable energy sources and electricity storage facilities, enhancing the reliability and flexibility of the grid, and accelerating the country’s energy transition.”