In Greece, energy groups PPC and Metlen expect to commission the first 300 MW of their joint battery-storage portfolio in the first quarter of 2027. The initial projects are in Bulgaria and Romania. They will mark the first operational phase of a wider investment programme spanning 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, equivalent to an average duration of about two hours. The 50:50 partnership assigns development and construction to Metlen, while PPC will handle commercial operation through its regional power-trading business. The companies will share revenues equally.
Storage technology and market role
The projects will use liquid-cooled lithium iron phosphate batteries. Their role will extend beyond integrating renewable generation: the systems will charge during lower-priced periods and discharge during higher-priced hours. They will also provide grid balancing and meet other flexibility requirements.
This operating model is becoming increasingly relevant in Southeast Europe as solar and wind capacity grows and price differences widen between hours with high renewable output and evening scarcity periods. The regional joint venture treats storage not only as supporting infrastructure for renewables, but also as a tradable electricity-market asset. It is intended to capture price spreads and provide system flexibility across several interconnected SEE markets.
Established in March, the partnership initially aimed to develop 1,000 MW in its first year. Development is proceeding in stages, with the first 300 MW now expected to come online in early 2027. The initial commissioning target is the first quarter of that year.
Separate storage projects in Greece
Both companies are also developing storage projects separately in Greece. Metlen has inaugurated a standalone 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.