The Danube reached 10 cm in Budapest on August 4 - well below the previous all-time low of 33 cm set in 2018. Serbia's Djerdap I is running at about 20% of capacity and Djerdap II at about 30%, per Energy Minister Djedovic Handanovic. The two plants supply roughly 18% of Serbia's electricity. Romania shut down one reactor at Cernavodă and deployed its navy to blast rock to redirect cooling water. Bulgaria warned of potential Kozloduy curtailment. Solar and BESS are the only generation assets unaffected by the drought - and suddenly the most valuable on the grid.
| Country | Project | MW / MWh | Status | Note |
|---|---|---|---|---|
| 🇧🇬 Bulgaria | Total operational BESS | 4,800 / 14,000+ | Operational | Capital ranking: 4,800MW / 14GWh+ by mid-June 2026. Largest BESS market in CEE. |
| 🇧🇬 Bulgaria | IPS Battery Factory (Sofia) | 3,000 MWh/yr | In Production | Production started. Expanding to 5 GWh/yr capacity by Q2 2027. |
| 🇷🇴 Romania | Premier Energy (Iași) | 200 / 400 | Under Construction | On track for Q4 2026 / Q1 2027 COD. €100M ČSOB financing. |
| 🇷🇴 Romania | PNE Romania - 2 standalone (Constanța) | 272 / 544 | Permits secured | 165MW/330MWh + 107MW/214MWh. Grid connection at 110kV. |
| 🇷🇴 Romania | PPC - Fântânele-Vest + Corugea | 86 / 172 | Development | 45.7MW/91.4MWh + 40.1MW/80.2MWh. Modernisation Fund co-financed. |
| 🇷🇸 Serbia | 7 standalone (EMS contracts) | 724 / n/a | Grid contracts signed | Djerdap I at 20%, Djerdap II at 30%. BESS urgently needed for grid stability. |
| 🇲🇰 N. Macedonia | Ministry BESS grant scheme | TBD | Public call open | Ministry launched public call for standalone BESS grants - first in country. |
| 🇬🇷 Greece | 3 tender programmes | 900 / n/a | 0 MW connected | 2026 curtailments forecast 3.3-3.7 TWh. BESS still unfinanced. |
The Danube crisis is the most important stress test SEE's energy infrastructure has faced in a decade. Record-low water at 10 cm in Budapest. Serbia's largest hydro plant at 20% of capacity. Romania deploying its navy to blast riverbeds. Bulgaria's nuclear plant on watch. And in the middle of all this - solar panels keep generating, batteries keep charging and discharging, and Bulgaria emerges as a net exporter to the region. This is not a coincidence. It is the structural argument for the energy transition made visible in real time.
Bulgaria's BESS fleet - 4,800 MW / 14+ GWh - has changed the country's grid role. In the old model, Bulgaria exported baseload coal power. In the new model, it imports cheap midday solar from across the region, stores it, and re-exports it in evening peaks when neighbours are desperate for supply. Romania was paying €340/MWh on August 4. Bulgaria's batteries were buying at near-zero and selling into that spread. The business model works. The infrastructure investment thesis is validated.
Greece remains the cautionary tale. 12 GW of solar installed, 3.3-3.7 TWh forecast to be curtailed in 2026, zero operational BESS from 900 MW tendered, and now relying on Bulgarian imports during the regional crisis. The country that built solar fastest is least prepared to benefit from it. The connection between curtailment, BESS deployment failure, and import dependency is not accidental - it is the predictable result of a financing framework that never resolved the bankability of storage.
The drought exposes a structural vulnerability that the energy transition was supposed to solve. Hydro was supposed to be the flexibility provider. At 10 cm of Danube, it provides nothing. The lesson for the next decade of infrastructure planning in SEE is that flexibility cannot depend on a single resource - and that BESS is not optional for any grid with serious renewable penetration. The countries that understood this early (Bulgaria, Romania) are weathering the crisis. The countries that didn't (Serbia, Greece) are in emergency mode.