METLEN and Karatzis Group sign agreement for standalone energy storage unit

METLEN and Karatzis Group are entering into a new strategic partnership, through a joint venture with ownership stakes of 49% and 51% respectively, for the development, construction, operation, and energy management of a battery energy storage system (BESS) with a capacity of 330 MW/790 MWh in Thessaly, Greece.

This will be the largest standalone storage unit planned to date in Greece and one of the biggest in Europe. The partnership builds on the existing co-operation between the two companies in the sale and absorption of green energy, which, since August 2024, has involved the implementation of a portfolio of solar stations with a total capacity of 262 MW in the same region.

The total investment for this project, which is expected to be completed within 2Q26, amounts to around €170 million. No further grants or tax reliefs are expected for this project.

By investing in this pioneering project for the Greek energy market, METLEN undertakes the full construction, operation, and maintenance of the unit through M Renewables. The M Renewables segment of METLEN’s energy sector has proven experience in implementing complex BESS projects, with presence and projects on five continents. In 2024 alone, METLEN completed storage projects with a total capacity of ~0.7 GWh and is in the final stages of agreements for third-party projects totalling 2.2 GWh.

Through strategic partnerships such as this one with Karatzis Group – which has seen excellent co-operation in recent years – METLEN reaffirms its leading role in strengthening energy security and advancing the green transition, building the next-generation utility.

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Read the article online at: https://www.energyglobal.com/energy-storage/10102025/metlen-and-karatzis-group-sign-agreement-for-standalone-energy-storage-unit/