• A 202 MW / 500 MWh stand-alone battery energy storage system now fully operational and actively participating in Bulgaria’s day-ahead and intraday electricity markets.
• The plant represents one of the biggest stand-alone BESS installations in Eastern Europe and among the first in Bulgaria, designed to enhance grid flexibility, reliability, and system stability.
• Located within the Maritsa East 3 coal plant complex and benefiting from existing grid infrastructure, this project demonstrates how battery storage technology is a viable and rapid solution to help meet the country’s energy needs and sustainable transition targets.

ContourGlobal today celebrated the commissioning of one of the biggest Battery Energy Storage System (BESS) projects in Eastern Europe in the Stara Zagora region, a major industrial and energy hub in central Bulgaria, with a ribbon-cutting ceremony.

The event was attended by ContourGlobal’s CEO, Mr. Antonio Cammisecra, the Minister of Energy, Mr. Zhecho Stankov and the Deputy Mayor of Galabovo, Eng. Mr. Planen Barakova, as well as local authorities and representatives from the electricity sector, underscoring the strategic importance of the project for Bulgaria’s energy transition.

The 202 MW stand-alone BESS plant developed by ContourGlobal, one of the largest battery energy storage projects in Bulgaria and Eastern Europe with a total storage capacity of 500 MWh, has recently commenced operations. The facility is actively participating in both the day-ahead and intraday national electricity markets, supporting optimized power dispatch, improved balancing of electricity supply and demand, and the integration of renewable energy sources, while enhancing overall system stability and flexibility.

“ContourGlobal Maritsa BESS” project is funded by the European Union–NextGeneration EU through the National Recovery and Resilience Plan. Located on a 25,000 m² area inside the fence of the Maritsa East 3 (ME3 TPP) coal-fired power plant, the BESS facility leverages existing grid infrastructure, enabling rapid deployment and seamless integration into Bulgaria’s electricity network. The two remaining operational coal units of ME3 TPP continue to supply electricity during periods of peak demand, ensuring the country’s energy security.

“The commercial operation of our 202 MW/500 MWh BESS plant represents a significant step forward for battery storage development in Bulgaria and underscores ContourGlobal’s ability to deliver large-scale storage solutions across different markets and technologies. We have built a sizeable presence in battery energy storage, with this project in Bulgaria representing a key contribution to our 3 GWh portfolio of operating BESS projects,” commented Antonio Cammisecra, CEO of ContourGlobal. “The successful commissioning of the plant in record time, led by local teams and supported by re-skilled personnel from the coal power plant, further strengthens our position as a leading operator in battery energy storage. Bulgaria has played a central role in achieving this milestone, and we look forward to continuing our growth in the country alongside local partners, while further investing in renewable energy and BESS projects”.

“The commissioning of this facility marks a decisive step in Bulgaria’s energy transformation,” said Minister of Energy Zhecho Stankov, noting that such projects signify how innovation and existing industrial infrastructure can work together to strengthen grid stability, improve flexibility, and accelerate the integration of renewable energy sources. “By combining advanced storage technologies with a strategic location in one of our key energy regions, Bulgaria is sending a clear signal that is at the forefront of the energy transition in Southeast Europe,” Minister Stankov added. He emphasized that the investment enhances energy security, supports market-based operation, and creates a sustainable pathway for the evolution of traditional energy hubs such as Maritsa East.

The BESS facility’s advanced technical features allow it to provide advanced grid services. It is equipped with the most recent battery technology, including 110 battery skids supplied by BYD and 28 combined Power Conversion System (PCS) and Transformer units, converting direct current (DC) from the batteries into alternating current (AC) for the grid. This represents BYD’s largest project in Eastern Europe to date.

The new BESS facility in the country also stands out for its exceptional execution timeline, having progressed from Final Investment Decision to COD in less than nine months, with construction and commissioning completed in just seven months and installation finalized in October 2025. This accelerated deployment reflects ContourGlobal’s ability to execute complex energy infrastructure projects at speed while maintaining high technical, health & safety, and operational standards, supported by the strength and expertise of its local BD and Engineering teams in Bulgaria, with a multi-contract approach with over 15 contractors and suppliers committed.

Leveraging these same capabilities, the company is now developing a second 202 MW BESS on the same site as part of Phase II of a broader strategy to leverage on the thermal asset site to develop an integrated renewable energy hub. This approach enables ContourGlobal to further unlock the strategic potential of Stara Zagora’s major energy hub while advancing additional hybrid renewable projects, including photovoltaic generation combined with battery storage solutions, and reinforcing its long-term commitment with Bulgaria.