A flurry of grid-scale BESS project progress totalling more than a combined 1.5GWh, from Renalfa in Bulgaria, Engie in Romania, Nala Renewables in Finland and Metlen in Greece.
Renalfa commissions second BESS in Bulgaria
Independent power producer (IPP) Renalfa has commissioned a solar co-located 65MW/260MWh battery energy storage system (BESS) in commissioned in Tenevo, Bulgaria.
The Tenevo Hybrid Renewable project is one of the largest co-located BESS projects in Europe, Renalfa said.
It was developed by Tenevo Solar Technology, a partnership between another developer and IPP Eurowind Energy and Renalfa. Solarpro Holding was project manager while the BESS and power conversion system (PCS) technologies were supplied by Chinese firms Hithium and Kehua Tech.
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It is the first phase of a total planned 238MWp solar PV and 315MW/760MWh BESS at the site, expected to be fully operational by 2026.
Hithium and Kehua also provided the technology for Renalfa (and Bulgaria’s) first large-scale BESS, a 25MW/55MWh project near the village of Razlov, put into operation in mid-2024. Renalfa then secured a first loss guarantee-backed financing from EBRD in July this year for its renewables and storage rollout.
In April, the Ministry of Energy of Bulgaria selected 82 winning energy storage projects for a share of BGN 1.15 billion (€588 million/US$670 million) in financial support as part of an EU-backed scheme.
The country has what may be the largest BESS in continental Europe, a 124MW/496.2MWh system which came online in May.
Engie to build two BESS in Romania totalling 170MWh
The Romania arm of international utility and IPP Engie has announced plans to develop two BESS in the Galați and Sibiu counties of Romania.
The first project will be built at Engie’s existing 50MW Băleni wind farm in Galați County. The 5MW/10MWh is scheduled to begin construction in Q1 2026, with commissioning expected by summer 2026.
The larger project in Șelimbăr, Sibiu County, totals 80MW of power and 160MWh of storage capacity. Engie recently acquired project rights and plans to begin construction in November 2025.
The system will occupy approximately two hectares and is ready-to-build with commercial operation targeted for Q4 2026.
The news coincides with Chinese BESS provider StarCharge’s 500MWh grid-forming energy storage order from a company called Energy Investment LLC for projects across Eastern Europe, including Romania. Other regional supply deals have been announced by Chinese rivals Hithium and Sungrow recently.
Romania is also kickstarting its energy storage market with an EU-backed scheme, reported on by Energy-Storage.news.
Greece
Meanwhile IPP and EPC firm Metlen has entered into 49:51 joint venture (JV) with industrial firm Karatzis Group’s for a 330MW/790MWh BESS in Thessaly, which would be Greece’s largest standalone storage project and among Europe’s biggest. The €170 million (US$198 million) project is targeting completion by Q2 2026.
Greece also has an energy storage financial support scheme, although had to cancel its third auction in December 2024 after confusion over the rules.
Nala buys portfolio in Finland
IPP Nala Renewables meanwhile has entered into an agreement to acquire a ready-to-build battery energy storage (BESS) portfolio of four projects in Finland from Fu-Gen AG, a Switzerland-based developer. The total capacity of the portfolio is expected to be over 250MW once operational, with construction set for 2026. Nala already acquired a 50MW BESS in the country from Fu-Gen in January 2025.
Unlike the other three countries, projects in Finland are being built on a merchant, unsubsidised basis with no large-scale EU-backed funding scheme. That hasn’t stopped a handful of IPPs and developers from reaching final investment decisions (FID) and launching construction on projects this year (see recent coverage here), but may explain why projects are generally in the lower tens of megawatts in size.
