METLEN and Karatzis Group of Companies inaugurated Greece's largest standalone battery energy storage system (BESS) in Larissa, Thessaly.

Landmark Project Comes Online in Larissa

The facility has a power capacity of 330 MW and an energy storage capacity of 790 MWh, making it the largest standalone energy storage facility in Eastern Europe and one of the largest across the European Union.

The project was delivered through a strategic partnership between the two companies via a joint investment vehicle, in which METLEN holds a stake of 49% and Karatzis Group holds 51%.

The inauguration ceremony was attended by Prime Minister Kyriakos Mitsotakis, Minister of Environment and Energy Stavros Papastavrou, representatives of the Greek Parliament, regulatory and productive bodies, and local authorities.

Strategic Importance for Energy Security

The new facility is described as an energy infrastructure project of strategic importance. According to the announcement, storage, grid works and interconnections are essential preconditions to attract investment and strengthen the production base of both Greece and Europe.

The project is intended to enhance the flexibility and resilience of the energy system and support the more efficient use of renewable energy generation.

The Thessaly storage facility also illustrates, the companies state, the importance of mature projects, modern infrastructure and companies with the scale and expertise to turn investment plans into operational assets.

It is presented as a flagship project for the new energy era and an important step towards building the productive capacity that will underpin the next chapter of Greece's economic growth.

METLEN undertook the construction, operation and maintenance of the facility, drawing on its international experience in complex energy storage projects.

Political Endorsement at the Ceremony

In his speech during the inauguration, Prime Minister Kyriakos Mitsotakis referred to the new facility as an important step towards building the Greece of the future.

He highlighted the contribution of the investment to the energy security and competitiveness of the country and congratulated METLEN and Karatzis Group for the completion of the project.

Leadership Perspectives

Evangelos Mytilineos, Executive Chairman of METLEN, said he was particularly proud that Greece's largest standalone energy storage facility in Eastern Europe, and one of the largest across the European Union, was being inaugurated in Thessaly.

He stated that the project reflects the new reality of the energy system, as storage, alongside grids and interconnections, is essential to use clean energy efficiently and to provide businesses and consumers with a more reliable and predictable energy supply.

He thanked the partners at Karatzis Group, Antonis Karatzis personally, and everyone at METLEN who contributed to the delivery of the project.

Antonis Karatzis, Chairman and CEO of Karatzis Group of Companies, called the inauguration an important milestone for his group and for the country's energy future. He said the group's participation in a storage project of this scale reflects a strategic choice to invest in infrastructure with a long-term horizon and meaningful value for the Greek economy.

According to Karatzis, the partnership with METLEN shows how two leading Greek companies can combine strengths, expertise and willingness to invest to deliver projects to international standards, increase the use of renewable energy, strengthen grid stability and enhance Greece's energy security.

He added that for Karatzis Group, the project marks the beginning of a new era in which the company intends to play an active and meaningful role.

Delivery, Commissioning, and EU Funding Support

The successful delivery and commissioning of a project of this scale, the companies note, demonstrates the partners' technical expertise and ability to turn complex investment plans into operational infrastructure that will support the country's growth prospects for decades to come. The investment is implemented with loan support from the EU's Recovery and Resilience Facility.

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