Greek energy groups PPC and Metlen expect to commission the first 300 MW of their joint battery-storage portfolio in the first quarter of 2027, starting with projects in Bulgaria and Romania. These facilities will form the first operational stage of a wider investment programme spanning Southeast Europe and Italy.
The partners ultimately plan to develop up to 1,500 MW of battery storage capacity, with around 3,000 MWh of storage. The portfolio would have an average duration of about two hours.
Partnership responsibilities and battery technology
Under their 50:50 partnership, Metlen is responsible for development and construction, while PPC will manage commercial operations through its regional power-trading business. The partners will share revenues equally.
The projects will use liquid-cooled lithium iron phosphate battery technology. Their commercial role will go beyond integrating renewable energy, with the systems able to charge during lower-priced periods and discharge during higher-priced hours.
The batteries 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 periods of high renewable generation and evening scarcity.
Regional rollout and separate Greek storage projects
Established in March, the partnership initially aimed to develop 1,000 MW during its first year. Development is proceeding in stages, with the first 300 MW now expected to come online in early 2027.
Both companies are also expanding independently in Greece’s storage sector. Metlen has inaugurated a standalone facility at Nea Karyes near Larissa through a separate partnership with Karatzis Group, while PPC plans to commission 150 MW of battery projects in Western Macedonia.
The regional joint venture positions storage both as infrastructure supporting renewables and as a tradable electricity-market asset. Its batteries are intended to capture price spreads and provide system flexibility across several interconnected Southeast European markets.