Utility-scale sodium-ion arrives in Romania: Renalfa plans 3.6 GWh dual-chemistry BESS

Renalfa Power Clusters has acquired two late-stage renewable energy projects in western Romania’s Arad County, with a plan for further investment. 

The first asset is the 365 MWp Horia 2 solar power plant, while the second is a nearby 400 MW / 800 MWh standalone battery energy storage system (BESS). 

Renalfa intends to combine and merge them into a single hybrid power cluster, targeting a commercial launch in 2027. The announcement said the projects are “fully derisked and in late-stage development”.

In addition to the acquisition, Renalfa plans to expand the combined Horia-Arad site in two stages, and bring in a hybrid dual-chemistry approach, mixing lithium-ion storage and sodium-ion storage, while adding in grid-forming technology as well.

The first phase will lift solar capacity to 568 MWp and increase the BESS to 669 MW / 2,000 MWh. 

A second phase will add another 400 MW / 1,608 MWh standalone BESS with the company also stating it could “potentially” be in combination with more PV. This would take the total storage capacity to 3.6 GWh. 

Renalfa CEO Ivo Prokopiev said the company had three technology innovations in mind with the recent acquisition.

“When fully built, Horia-Arad cluster will pioneer three deep-tech innovations: a hybrid dual-chemistry storage plan of lithium-Ion and sodium-Ion batteries, a grid-forming inverter technology, and a proprietary AI-driven dispatch and control platform. Together, they shall convert the wider cluster into a so-called ‘Sovereign Grid Anchor’ capable of providing the grid services previously exclusive to thermal power plants,” Prokopiev said. 

Renalfa Power Clusters is a newly formed joint venture between Vienna-based clean energy investment group Renalfa Solapro Group and Paris-based investment management company Rgreen Invest, through its Infragreen equity funds. The acquisition is the first for the joint venture, which targets Poland and Romania as its core markets. However, the pair partnered on Renalfa IPP in the past.

Nyerges and Partners advised Renalfa Power Clusters on the deal. George Tecușan, Country Manager, Renalfa Romania, pointed out where the legal firm contributed, saying “[Nyerges and Partners’] expertise in due diligence, FDI clearance, and transaction structuring helped us move this project forward efficiently. Renalfa values their support and looks forward to continued collaboration on our energy initiatives.”Last month, the European Commission approved a €150 million ($173 million) subsidy scheme for the installation of at least 2,174 MWh of standalone energy storage facilities in Romania.