Energizing the “Themelio” project is a significant step for the country’s energy transition
Our first Battery Energy Storage System (BESS), with the commercial name “Themelio”, has been energized, aiming to enhance the flexibility and the electrical system. The project, for which construction began in April 2025 and was completed in September of the same year, is located in Polygyros, Chalkidiki.
A milestone for the energy transition
“Themelio” is a 49 MW energy storage project, with a total installed storage capacity of 127.04 MWh and a guaranteed storage capacity of 98 MWh. The project infrastructure includes 26 battery containers, 13 generation substations and 2 medium voltage terminal substations, elements that work in combination to store and manage energy, ensuring smooth interconnection with the grid.
As the penetration of renewable energy sources increases, the ability to store the generated energy and reintroduce it into the grid when needed becomes crucial. With its electrification, the “Themelio” plant contributes to the better utilization of green energy, supporting the stability of the system and facilitating the further development of RES in Greece.
Circular economy included in construction
During the construction of the “Themelio” project, waste was generated from the plastic covers of the battery containers, weighing a total of 962 kg. Using 74 kg of these materials, we created, in collaboration with Fabric Republic, waterproof utility backpacks, which we offered to our colleagues. Through this initiative, 150 families gained access to clean clothing, while at the same time 150 kg of CO₂ were not released into the atmosphere - demonstrating in practice the power of the circular economy.
Looking to the future
The operation of the project confirms our strategic focus on technologies that enhance the transition to a more resilient and more efficient energy model. Energy storage is now an integral part of the new energy reality: it acts as a catalyst for integrating a greater percentage of clean energy into the system, providing power during peak hours and ensuring the stable operation of the grid.
With “Themelio” now in operation, we are practically strengthening our contribution to shaping a more modern energy future for the country, through projects that combine technological excellence, operational reliability and a clear orientation towards sustainable development.
