Battery energy storage systems are transitioning from supplementary grid-balancing assets to essential components in the South-East European (SEE) power landscape. This shift is driven by widening intraday price spreads that present lucrative arbitrage opportunities for market participants.
Recent data from the Hungarian HUPX market indicates significant volatility, with prices peaking at €278/MWh and experiencing eight hours of negative pricing within the same week. This results in an intraday price spread that exceeds €200/MWh, marking a new normal for market conditions.
The underlying factor contributing to this market transformation is the increasing disparity between peak solar generation and declining demand. Solar output has reached peaks of over 8.2 GW, while regional consumption has dipped below 29 GW. This imbalance leads to frequent midday oversupply scenarios, where prices can drop to zero or even negative levels, contrasting sharply with the evening demand that continues to necessitate reliable generation and imports.
For operators of battery storage systems, this environment fosters a clear trading strategy: charge during off-peak or negative price periods and discharge during peak demand hours. Initial projections suggest that assets in SEE markets could achieve between 1.5 to 2 daily cycles with effective spread captures ranging from €80 to €150/MWh. This translates into potential annual revenues of €120,000 to €220,000 per MW under merchant exposure conditions.
This trend is particularly evident in Romania, Bulgaria, and Serbia, where rising renewable energy penetration exists alongside limited system flexibility. Unlike their Western European counterparts—where storage revenues are increasingly diversified across ancillary services—SEE markets remain largely focused on energy arbitrage as their primary revenue driver.
<pConsequently, investment strategies within these markets are evolving. Developers are increasingly incorporating battery systems into renewable projects, notably solar installations, as a means of counteracting capture price erosion and stabilizing income streams. Additionally, standalone storage solutions are becoming more common, often integrated with trading operations or cross-border optimization efforts.
Looking forward, the anticipated growth of battery storage capacity is set to become a crucial element of the SEE power system’s evolution. Insufficient deployment could lead to heightened curtailment of renewable generation alongside increased price volatility. In this context, battery storage emerges as a vital mechanism for capitalizing on existing market inefficiencies.
