At RENPOWER Greece 2026 in Athens on 8 July 2026, D.TRADING, the trading division of our energy company DTEK, set out how battery storage economics, cross-border trading and market integration will shape Southeast Europe's energy transition. Stanislav Dudka, Head of Power Desk Europe, joined the panel "Scaling Beyond Borders", examining how battery revenue models evolve, why early market entry matters, and why national storage markets across Greece, Bulgaria and Romania are moving at very different speeds.
Why does battery storage now define the region's energy agenda?
The question in Southeast Europe is no longer how to add renewable generation capacity, but how electricity markets can absorb rising volumes of variable output. The European Commission estimates that flexibility needs in the EU electricity system will reach 288 TWh by 2030, around 24% of total EU electricity demand, and that Europe will require more than 200 GW of energy storage by 2030 and 600 GW by 2050, up from roughly 89 GW in 2024.
Battery storage absorbs surplus midday solar generation and releases it during evening peaks, reducing curtailment and stabilising revenues for renewable producers. Greece shows the cost of not having it: in 2025 the country curtailed around 1,867 GWh of renewable generation, about 6.6% of total renewable output, while hours of zero or negative wholesale prices more than doubled to 483.
How do battery revenue models evolve as deployment grows?
Battery projects typically stack revenues from ancillary services such as frequency regulation, arbitrage between low and high prices in day-ahead and intraday markets, and balancing market participation. The weight of each stream shifts as installed capacity grows. Early entrants capture strong ancillary service margins; saturation then compresses those margins, and returns migrate to energy trading across multiple market segments. Structured offtake and revenue solutions, from tolling agreements to floor structures, allow investors to manage this transition without carrying full merchant risk. As Mr Dudka put it:
"Battery projects need to enter the market as early as possible to capture the highest value from ancillary services before these revenues become increasingly competitive. As battery deployment accelerates, project economics will gradually shift towards day-ahead, intraday and balancing markets. Long-term success will depend on diversified revenue strategies and effective risk management"
Why are Greece, Bulgaria and Romania moving at different speeds?
National storage markets are scaling at different rates. Bulgaria's National Energy and Climate Plan sets a 2030 target of 1.28 GW, yet state-backed auctions have already awarded capacity well beyond that level, and Romania continues to commission merchant projects at pace. Greece targets 4.3 GW by 2030, but grid connection queues and financing delays hold back a permitting pipeline that has grown to roughly 12 GW. These trajectories can no longer be assessed in isolation: storage commissioned in Bulgaria flattens the price spreads that Greek and Romanian assets rely on, and interconnector flows transmit those effects across borders within hours.
What will unlock the next investment wave?
Four factors will determine whether investor appetite converts into commissioned projects: faster battery deployment, expanded grid infrastructure, stronger regional interconnections, and market frameworks that give investors long-term certainty. Greece holds the fundamentals of a regional energy hub, but the pace of grid connections will decide how much of its pipeline reaches operation. For D.TRADING, deepening its presence across European power markets reflects a wider commitment to building the partnerships and integrated trading capabilities the region will need.
"Developments in one country increasingly affect neighbouring markets. Growing battery capacity and renewable penetration across Southeast Europe will influence pricing and trading opportunities throughout the region. Greater market integration and new cross-border trading products will be essential to unlocking the full value of renewable investments," Mr Dudka commented.
