Bulgaria | Battery Storage Capacity Doubles to 6 GW as Bulgaria Strengthens Its Position in Europe's Energy Market

Bulgaria has rapidly expanded its battery energy storage capacity to approximately 6 GW, doubling its installed capacity within one year and emerging as an important battery storage market in Southeast Europe.

Supported by approximately €700 million in European Union grants and regulatory reforms, the country has attracted significant private investment into battery energy storage systems.

The expansion has enabled Bulgaria to store surplus solar electricity generated during daytime hours and discharge it during periods of higher evening demand, improving the flexibility of its electricity system.

According to figures from the Association for Production, Storage and Trading of Electricity (APSTE), Bulgaria's electricity exports increased by 62% year on year to 3.5 TWh in 2026.

The additional electricity supply also supported neighbouring countries during the summer, when extreme heat and drought conditions placed pressure on regional power systems.

Romania, for example, received electricity exports from Bulgaria after drought-related restrictions forced a nuclear reactor shutdown in August. Increased battery deployment also helped reduce Romania's dependence on hydropower during the period.

However, the rapid expansion of storage capacity presents several challenges.

The country's electricity grid will require further investment to accommodate additional battery installations. Meanwhile, narrowing electricity price spreads could reduce the profitability of conventional energy arbitrage, in which batteries charge during low-price periods and discharge when electricity prices are higher.

Bulgaria's Energy Ministry has therefore emphasised the importance of expanding battery participation in balancing markets and providing additional grid services.

The country's experience highlights a broader trend in Europe's energy transition: battery storage is increasingly being valued not only for electricity trading, but also for energy security, cross-border electricity supply and grid stability.