A recent assessment by Greek electricity distribution system operator DEDDIE shows that the national distribution network has the technical capacity to integrate a substantial volume of battery energy storage, potentially ranging between 1.8 and 2.9 GW. The study aimed to determine how much standalone storage the system can accommodate without compromising overall network stability.
The analysis focused solely on the mainland network, evaluating the performance and limitations of 230 substations and 453 power transformers. One of the key findings is that regions with strong solar penetration are the most suitable for battery connections. Because solar generation follows a predictable daily pattern, batteries can be charged and discharged to actively reduce network congestion, unlike more variable sources such as wind or hydropower.
Using these criteria, DEDDIE identified 70 substations as priority points for merchant battery projects. These locations were chosen because high levels of solar production make storage systems especially effective at smoothing electricity flows and relieving local network overloads. The study also revealed significant regional differences: Attica and Epirus have limited potential due to fewer suitable substations and lower solar density, while central Greece and central Macedonia could host almost twice the capacity, reflecting both strong photovoltaic deployment and available network space.
The study cautioned that network benefits do not increase indefinitely with larger battery installations. Beyond a certain threshold, additional storage provides diminishing returns in congestion relief. Based on this analysis, the optimal battery capacity is estimated between 1.15 and 1.7 GW, where system efficiency gains are maximized.
These findings underscore the growing role of energy storage in Greece’s electricity system, especially as solar dominates new renewable additions. By the end of 2025, the distribution network hosted around 9 GW of renewable capacity, including 7.2 GW of solar, while the transmission network had a total of 8.1 GW, of which 3.7 GW came from solar power. These trends highlight why battery storage is increasingly regarded as essential infrastructure rather than a complementary technology.
