HELLENiQ ENERGY has commissioned a 100 MW/200 MWh battery energy storage system at its Thessaloniki industrial complex, marking a significant step in Greece’s shift from expanding renewable generation towards developing the flexible infrastructure needed to integrate it efficiently.
Developed by HELLENiQ Renewables, the project represents an investment of approximately €50 million. The facility comprises three lithium iron phosphate battery systems, supported by a new 33/150 kV substation and approximately five kilometres of underground high-voltage connections.
With a power capacity of 100 MW and an energy storage capacity of 200 MWh, the installation is designed to complete at least one full charge-discharge cycle per day. It can therefore store electricity during periods of abundant supply and release it when demand and wholesale prices increase.
Unlike many battery projects still progressing through permitting, financing or construction, the Thessaloniki facility has entered operation, providing a tangible example of Greece’s growing investment in large-scale energy storage. As the market develops, the distinction between announced capacity and operational assets is becoming increasingly important for investors, electricity traders and lenders.
Greece’s increasingly volatile wholesale electricity market is strengthening the commercial case for battery storage. Periods of high solar and wind generation can push daytime electricity prices towards zero or below, while tighter supply conditions in the evening can drive prices significantly higher.
These price differences create opportunities for battery operators to purchase or store electricity when it is inexpensive and discharge it when market prices rise. Storage systems can also participate in balancing services and help reduce renewable energy curtailment, improving the overall efficiency of the electricity system.
The Thessaloniki project is entering operation as flexibility becomes an increasingly valuable component of Greece’s power market. The growth of solar and wind capacity is changing the timing of electricity supply, increasing the need for assets capable of shifting energy between periods of surplus and scarcity.
For HELLENiQ ENERGY, the investment also supports the diversification of its business beyond its traditional refining and petroleum activities. Through HELLENiQ Renewables, the company is expanding its presence in renewable generation, energy storage and electricity-market services.
Battery storage could strengthen the links between these activities by enabling more flexible electricity management and creating additional opportunities to participate in wholesale and balancing markets. The commercial performance of the Thessaloniki installation will nevertheless depend on market price spreads, charging costs, operating availability, battery degradation and the revenues available from different electricity-market services.
The project was selected through Greece’s first competitive battery-storage tender and benefits from support under the country’s recovery and resilience framework. Its operation provides a practical reference point for future storage investments, allowing developers and lenders to assess operating performance rather than relying exclusively on projected revenues.
As more battery capacity enters the Greek market, competition is likely to put pressure on the most attractive trading opportunities. Projects that initially benefit from pronounced price volatility may face narrower spreads as storage deployment increases, making efficient dispatch and diversified revenue strategies more important.
HELLENiQ ENERGY’s Thessaloniki facility therefore represents more than an additional storage installation. Its long-term value will depend on how effectively it converts electricity price volatility into sustainable operating revenues while supporting Greece’s integration of renewable energy. As the country’s battery pipeline moves towards commercial operation, performance and market participation will increasingly determine which projects deliver the strongest returns.
