The Central and Eastern European (CEE) battery energy storage race has officially moved from PowerPoint slides to power lines. Two countries have emerged as the most-watched players in the region: Bulgaria and Romania.
The headlines are loud. Bulgaria recently inaugurated a 124 MW / 496 MWh facility in Lovech, declared by its Ministry of Energy to be the largest operational battery storage facility in the EU by total energy capacity. Romania, meanwhile, crossed the 240 MW operational threshold in mid-2025 and has continued to scale aggressively from there.
But milestone announcements only tell part of the story. The deeper question for investors, developers, EPCs, and grid planners is this: which market is actually positioned to win the CEE battery storage race in 2026 and beyond?
The answer is more nuanced than a single megawatt count. And once you look past the ribbon-cutting ceremonies, Romania’s structural fundamentals start to look very, very compelling.
The Headline Numbers: Where Both Markets Stand Today
Both countries have entered the EU’s top 10 battery storage markets, according to recent industry analysis featured by Aurora Energy Research and pv magazine. The pace of growth has been remarkable.
Bulgaria’s progress in 2025 and early 2026:
- Installed roughly 2.5 GWh of new battery storage capacity in 2025, ranking third in the EU behind only Germany (6.6 GWh) and Italy (4.9 GWh), per SolarPower Europe data.
- Inaugurated the 124.1 MW / 496.4 MWh Lovech BESS, developed by Advance Green Energy at a cost of around €75 million.
- Saw ContourGlobal commission the 202 MW / 500 MWh Maritsa BESS in January 2026, one of the largest standalone BESS facilities in Eastern Europe.
- Set a national target of 10 GWh of operational battery storage capacity by the end of 2026.
Romania’s trajectory in 2025 and 2026:
- Hosted 240.7 MW / 404.9 MWh of operational battery storage in mid-May 2025, then accelerated.
- Reached 494 MW / 914 MWh by the end of December 2025 (Transelectrica data).
- Crossed 599 MW / 1,130 MWh by the end of March 2026, with 31 operational storage facilities.
- Commissioned Nova Power & Gas’s 200 MW / 400 MWh Florești BESS, currently the country’s largest single facility.
- Squeezed into the EU’s top five battery markets with 2.3 GWh of annual additions, according to a January 2026 Ember chart.
If you stop reading here, the race looks tight. Bulgaria leads in headline-grabbing single facilities. Romania leads in total operational projects and pipeline diversity. So who is actually winning?
Bulgaria’s Strengths and Its Soft Spots
Bulgaria’s story is one of accelerated, subsidy-driven scale. The country leveraged the National Recovery and Resilience Plan (NRRP), heavy state aid, and a competitive tender that allocated nearly 9,713 MWh of upcoming capacity. ContourGlobal’s Maritsa project, financed by the EU’s NextGenerationEU initiative, was delivered on a coal plant brownfield site in record time.
That subsidy push has fueled impressive growth. But it has also created concentration risk. Aurora Energy Research warned in late 2025 that of Bulgaria’s roughly 5 GW of awarded BESS capacity, only around 1.8 GW is likely to be operational by the end of 2026, with capacity rising to about 3 GW by 2030.
In other words: the announcement-to-operation ratio is not as high as the awards suggest. Subsidy-led booms can deliver fast but they can also stall when project economics depend heavily on grant cycles, brownfield site availability, and regulatory tailwinds that may not all sustain through the second half of the decade.
Bulgaria also still lacks clear C&I BESS regulations and a fully developed framework for frequency regulation, as flagged by Jinko EES analysis at CISOLAR & GREEN BATTERY 2024.
Romania’s Trajectory: Slower Headlines, Stronger Structure
Romania has had fewer “largest in the EU” press releases. What it has built instead is something investors quietly value more: a structurally attractive market with multiple revenue layers, real regulatory clarity, and the deepest pipeline in CEE.
The price arbitrage opportunity is in a class of its own. According to Synertics’ 2025 mapping of Europe’s BESS potential, Romania leads the entire EU dataset in mean daily price spread. The 2-hour mean spread sat at €198/MWh, ahead of Greece (€195/MWh) and Bulgaria (€173/MWh). DNV’s February 2026 analysis found Romania’s Maximum Daily Price Spread reached €168/MWh in 2025, calling this “exceptionally high” by European standards.
The ancillary services revenue stack is exceptionally rich. DNV reported average aFRR up and down prices close to €9/MW per hour and FCR services around €70/MW per hour, the most lucrative ancillary service in the model. American grid-services player Nuvve estimates revenues of up to USD 500,000 per MW per year in Romania, which it identifies as one of the highest-yield BESS markets in continental Europe.
Total revenue potential is among the best in Europe. DNV’s PLEXOS-based modelling, optimising dispatch across wholesale and ancillary markets, yielded annualised BESS revenues between approximately €120 and €180 per kW installed, with a central estimate of about €140/kW/year.
The regulatory framework is maturing fast. In 2025, Romania eliminated the double taxation of stored electricity, exempting charging and discharging volumes from network tariffs. ANRE Order 53/2024 introduced a competitive, transparent allocation of grid capacity for projects above 5 MW, with auctions from January 2026 onward. Capacity auctions for large-scale storage are also being introduced from 2026, complementing the existing Contracts for Difference scheme.
The pipeline is deep and well-financed. A non-exhaustive snapshot:
- The Romanian government approved a €150 million scheme under the Modernization Fund (cleared by the European Commission) to install 2,174 MWh of new storage capacity, with calls for projects in Q2 2026.
- A separate €150 million municipal program is set to add 385 MW of BESS capacity.
- R.Power is building the 127 MW / 254 MWh Scornicești BESS, with GEN-I as the long-term asset optimiser.
- Belgian developers are constructing a 250 MW / 500 MWh project at Gura Ialomitei, set for mid-2026 commissioning.
- Toki Power (Renalfa Solarpro) acquired a 150 MW / 300 MWh standalone BESS in December 2025.
- ENEVO and Sungrow signed a 1 GWh deployment agreement, with 440 MWh ordered for early 2026.
- Alive Capital signed a 2.5 GWh MoU with Sieyuan Electric over four years.
- Hidroelectrica is preparing a 64 MW / 256 MWh BESS at Iron Gate 2 on the Danube.
- Electrica has initiated 15 BESS projects totalling roughly 1 GWh.
- Monsson is advancing a 2 GWh project at Stupina, valued at €540 million.
Investor returns are exceptional. Aurora Energy Research has publicly forecast double-digit internal rates of return for standalone BESS projects entering the Romanian market as early as 2026, with co-located assets potentially even more attractive post-2028.
The Verdict: Reading Between the Megawatts
Bulgaria is winning the headline race. Romania is winning the structural race.
For an investor or developer asking where to deploy capital across CEE in 2026 and 2027, the calculus is straightforward:
- Price volatility: Romania has the highest mean daily price spread in the EU. That is the single most important driver of merchant BESS economics.
- Ancillary depth: Romania’s FCR and aFRR markets offer some of the richest per-MW yields in continental Europe.
- Regulatory clarity: Removal of double taxation, capacity auctions, and competitive grid allocation create a more bankable environment.
- Pipeline diversity: Romania has utilities (Hidroelectrica, Electrica), domestic IPPs (Nova Power & Gas, Monsson, R.Power), Asian OEMs (Sungrow, Sieyuan), and global financial sponsors all active simultaneously.
- Risk-adjusted returns: Aurora forecasts double-digit IRRs for standalone Romanian BESS, while Nuvve sees up to USD 500,000 per MW per year in revenue potential.
Bulgaria’s faster start matters. But faster does not always mean further. In a maturing CEE storage market where capacity awards are starting to outrun deliverable economics, Romania’s combination of structural price volatility, deeper ancillary markets, and a more diversified investor base sets it up as the most defensible long-term BESS market in the region.
Momentum Energy’s View
At Momentum Energy, we see Romania as the most compelling battery energy storage opportunity in Central and Eastern Europe right now, and the data backs that conviction.
When we evaluate a market, we look at the same fundamentals that drive every successful BESS investment: the spread between peak and off-peak prices, the depth and predictability of ancillary services, the bankability of the regulatory framework, the maturity of grid connection processes, and the diversity of capital flowing into the pipeline. On every one of these metrics, Romania ranks at or near the top of the European league table.
What excites us most is that Romania is making the right structural moves at the right moment. The elimination of double taxation, the move to competitive capacity allocation in 2026, the expanding role of capacity auctions and Contracts for Difference, and the steady opening of FCR and aFRR markets all point to the same conclusion: Romania is no longer an emerging BESS market. It is a strategic one.
For developers, EPCs, OEMs, and institutional investors looking to allocate capital across the CEE region, the next 24 months in Romania will define a generation of grid-scale storage assets. Bulgaria will continue to deliver impressive headline projects, and we wish the entire region success. But for risk-adjusted returns, technology choice flexibility, and long-term revenue durability, our view is clear: Romania is where the smart money is going, and we intend to be a meaningful part of that story.
