Karatzis, Metlen to install Greece’s largest battery in joint venture

Karatzis Group of Companies and Metlen are establishing a joint venture for a standalone battery energy storage system (BESS) of 330 MW and 790 MWh. It is the biggest project in Greece so far and one of the biggest in Europe.

Metlen said it is entering into a new strategic partnership in Greece with Karatzis Group of Companies, through a joint venture with ownership stakes of 49% and 51% respectively, for the development, construction, operation, and energy management of a BESS with 330MW in operating power and a capacity of 790 MWh. The site is in Thessaly.

The two Greek companies are building upon their cooperation in the sale and purchase of green energy. Since August 2024, it has involved the implementation of a portfolio of solar power plants with a total capacity of 262 MW in the same region, the update adds.

The partners value their BESS investment at EUR 170 million

The BESS would be the largest standalone storage unit planned to date in Greece and one of the biggest in Europe, Metlen said. Total investment amounts to some EUR 170 million.

Karatzis and Metlen expect to complete it in the second quarter of next year. The partners expect no further grants or tax reliefs for the project, according to the announcement.

Metlen is tasked with full construction, operation, and maintenance of the unit through its M Renewables segment. It has presence and projects on five continents, the company pointed out. In 2024 alone, Metlen said it completed storage projects with a total capacity of 0.7 GWh and is in the final stages of agreements for third-party projects totaling 2.2 GWh.

Karatzis, based in Crete, manufactures a variety of netting products. It has five plants. In recent years it expanded to the construction of photovoltaic plants. The Metlen conglomerate produces metals and has a vertical presence in the energy market, being one the largest producers and suppliers in Greece.