Greece is reinforcing its position in the Energy Storage and Renewable Energy sectors after two pumped storage hydropower projects in the north of the country received the required environmental approvals, marking a key regulatory milestone.
As part of a broader pipeline of proposed pumped storage investments, the Flampouro and Trani Rachi projects have reached a pivotal stage in their development. The approvals signal tangible progress in Greece’s strategy to position itself as a regional hub for renewable energy generation and power transmission across the Mediterranean and Europe.
The Flampouro project is designed with a capacity of 450 MW in both generation and pumping modes, while Trani Rachi is expected to reach 594 MW in generation and up to 600 MW in pumping. Located near the Ilarion dam in Western Macedonia, the projects are being developed through special purpose vehicles Aliakmonas 1 and Aliakmonas 2 by investors from the Katselis family. Together, the two facilities are estimated to deliver around 1.34 TWh of annual output.
Both projects will include upper and lower reservoirs, underground tunnels, power stations, and high-voltage grid connections to the national transmission network, forming fully integrated long-duration storage assets.
The development comes amid growing investor interest in energy storage, which is increasingly viewed as a critical enabler of the energy transition. Long-duration storage solutions play a central role in integrating higher shares of renewable generation, enhancing grid flexibility, and balancing supply and demand as solar and wind capacity expands.
From a market perspective, securing environmental approvals significantly reduces regulatory risk, strengthens investor confidence, and improves decision-making visibility. These projects underline that energy storage is becoming a core component of a broader energy ecosystem that supports system reliability, energy security, and long-term market attractiveness.
Beyond their immediate impact, the projects are widely seen as a signal for further storage development. They help establish a clearer and more flexible regulatory framework, opening the door for additional investments and reinforcing Greece’s appeal as a destination for clean energy capital. Storage is expected to reduce curtailment, enable higher renewable penetration, and improve overall system flexibility.
In practical terms, the two projects are expected to deliver a combined 6.2 GWh of storage capacity, representing a step change in the power system’s ability to support variable renewable energy. This added flexibility is expected to benefit not only Greece’s electricity market, but also the wider Balkan and Southeast European region.
Greece’s National Energy and Climate Plan (NECP) further underscores this direction, setting a target of 1.74 GW of pumped storage capacity by 2030. The goal reflects a strategic shift toward long-duration storage as a core pillar of the country’s power system. As renewable capacity continues to expand, large-scale storage is expected to play a decisive role in maintaining grid stability, reducing curtailment, and enabling higher levels of clean energy integration, supporting Greece’s ambition to become a regional energy hub.
