Two major Greek energy companies, PPC Group and METLEN, are expanding their presence in the regional storage market through a cross border partnership focused on large scale battery energy storage systems.
PPC Group and METLEN have signed a joint venture agreement to establish a new company that will develop, construct, and operate a portfolio of battery energy storage projects with a combined capacity of up to 1,500 megawatts and 3,000 megawatt hours. The projects will be located across Romania, Bulgaria, and Italy, three markets where renewable generation is expanding rapidly and where grid operators are increasingly seeking flexible balancing resources.
Under the agreement, each partner will hold a 50 percent stake in the joint venture. The companies intend to accelerate development quickly, with approximately 1,000 megawatts of battery capacity expected to be implemented within the next twelve months. The scale and timeline reflect the growing role of battery systems in supporting power system stability as coal generation declines and variable renewables expand across Southern and Eastern Europe.
Electricity markets in the region have experienced significant structural changes in recent years. Romania and Bulgaria are both expanding solar and wind capacity as part of broader European decarbonization targets, while Italy already operates one of Europe’s largest renewable fleets and continues to integrate additional generation capacity. As renewable penetration increases, power systems require greater short duration flexibility to manage fluctuations in supply and demand.
Battery energy storage systems provide several operational functions that are becoming increasingly valuable in these evolving markets. Grid scale batteries can store excess electricity during periods of low demand or high renewable output and release it during peak consumption periods. They can also support frequency regulation, reduce curtailment of renewable generation, and improve grid reliability in markets where transmission infrastructure remains constrained.
The joint venture reflects a broader strategic alignment between project development expertise and engineering capability. PPC Group brings an established operational presence in the targeted markets, with existing activities across Romania, Bulgaria, and Italy that can support project permitting, grid integration, and electricity market participation. METLEN contributes engineering and construction capabilities developed through decades of experience in energy infrastructure projects.
Combining these capabilities may allow the partnership to move projects from development to construction more rapidly than independent developers operating in unfamiliar regulatory environments. Speed of deployment has become an important competitive factor in European storage markets, where project economics often depend on securing grid connection capacity and participating in emerging flexibility markets.
The proposed storage portfolio would represent a significant addition to battery capacity in parts of Southeastern Europe where grid scale storage remains limited compared with Western European markets. Many countries in the region are only beginning to integrate battery systems into their electricity systems, even as renewable installations accelerate. Expanding storage capacity could therefore play a critical role in stabilizing power markets and reducing reliance on gas fired generation for balancing.
At the same time, battery storage projects face evolving regulatory frameworks and revenue models. In several European markets, developers rely on a combination of income streams including wholesale electricity arbitrage, ancillary service markets, and capacity mechanisms. The long term bankability of projects often depends on regulatory clarity regarding these revenue sources.
Romania, Bulgaria, and Italy are each developing policy frameworks to support energy storage deployment, though the structure and maturity of these markets vary. Italy has been among the most advanced in creating mechanisms to procure storage capacity through grid operator tenders, while Southeastern European markets are still refining their regulatory approaches as renewable penetration increases.
By targeting multiple markets simultaneously, the joint venture may diversify regulatory and market risks while positioning itself in regions where storage demand is expected to grow as coal generation phases down and renewable capacity expands. The planned scale of the portfolio also suggests that both companies view battery systems not as niche assets but as core infrastructure within the evolving European electricity system.
