

Metals and energy group Metlen and conglomerate Karatzis Group have inaugurated the largest BESS in Greece, in a ceremony attended by the country’s Prime Minister.
The companies cut the ribbon on the 330MW/790MWh Thessaly battery energy storage system (BESS) project in a ceremony this week, announced today (15 October).
The project has been deployed via a 49:51% joint venture (JV) between Metlen and Karatzis.
The inauguration was attended by Prime Minister Kyriakos Mitsotakis, Minister of Environment and Energy Stavros Papastavrou, representatives of the Greek Parliament, of regulatory and productive bodies and local stakeholders.
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In his speech during the inauguration ceremony, Prime Minister Mitsotakis said that the deployment of renewables in Greece had helped bring energy prices down.
“However, they should be accompanied by storage infrastructure, so that their production can be transported and used where and when we need it,” he said.
“This is why the project that we are inaugurating today, the project of Metlen and the Karatzis Group, is so important, this is why we supported storage overall with resources from the Recovery Fund and this is why we are still channeling 200 million euros into similar interventions.
You can see and read the full speech at the ceremony here.
The Thessaly project benefits from a loan under a BESS support scheme financed by the EU’s Recovery and Resilience Facility – NextGenerationEU funding package.
The funding scheme aimed to kickstart Greece’s grid-scale energy storage market, and its first funded projects are now starting to come online at scale. At the start of the year oil refining and petroleum supply group MORE completed three BESS projects totalling 72MW/144MWh of capacity, also recipients of funding.
However, the business case for large-scale BESS has now developed enough in Greece that projects can be realised without it. Investor ContourGlobal acquired a merchant 100MW/400MWh project, also at the start of 2026.