Greek energy groups PPC and Metlen expect to bring the first 300 MW of their joint battery-storage portfolio online in the first quarter of 2027, starting with projects in Bulgaria and Romania. This will be the first operational stage of a wider investment programme covering Southeast Europe and Italy.
The partners aim to develop up to 1,500 MW of battery storage capacity, with around 3,000 MWh of storage and an average duration of about two hours. Under their 50:50 partnership, Metlen is responsible for development and construction, while PPC will handle commercial operation through its regional power-trading business. Revenues will be split equally.
The facilities will use liquid-cooled lithium iron phosphate battery technology. They will be able to charge during lower-priced periods and discharge during higher-priced hours. The systems will also provide grid balancing and other flexibility services, extending their role beyond renewable-energy integration.
The partnership was established in March with an initial target of developing 1,000 MW in its first year. Development is proceeding in stages, and the first 300 MW is now expected to be operational in early 2027. The model is becoming increasingly relevant in Southeast Europe as solar and wind capacity grows and price differences widen between periods of high renewable output and evening scarcity.
Regional rollout and Greek storage projects
Both companies are also pursuing separate projects in Greece. Metlen has inaugurated a standalone storage facility at Nea Karyes near Larissa through a separate partnership with Karatzis Group. PPC plans to commission 150 MW of battery projects in Western Macedonia.
The regional joint venture positions storage as more than supporting infrastructure for renewables. Its batteries can act as tradable electricity-market assets, capturing price spreads and providing system flexibility across several interconnected SEE markets.