Serbia’s Ministry of Mining and Energy has launched a procurement procedure worth approximately €5.3 million for planning and technical documentation for the proposed Đerdap 3 pumped-storage hydropower plant. The tender is aimed at moving the project from an early concept stage toward structured development. Bids are due by 20 August 2026.
The contract scope includes general design, a preliminary feasibility study, a special-purpose spatial plan, and a strategic environmental assessment. The resulting documentation is intended to support decisions on whether one of Serbia’s largest proposed energy investments can proceed into detailed development.
Design scope and key technical parameters
Current concepts for Đerdap 3 envisage installed capacity in the range of 1,200 MW to 2,400 MW, with an elevation difference of approximately 400 metres. The existing Đerdap 1 reservoir on the Danube is proposed as the lower reservoir. For the upper reservoir, options under consideration include Pešča or Brodica on the Severni Kučaj mountain.
The project would require intake and outlet structures on the Danube, reversible pump-turbine units, tunnels, and pressure pipelines. Additional elements listed for the scheme include an upper-reservoir dam, substations, switchgear, and a high-capacity transmission connection.
The proposed location is in the Đerdap Gorge between Golubac and Donji Milanovac, about 65 kilometres upstream of Đerdap 1. This siting would place the upper-reservoir option within the broader area covered by the project’s environmental review requirements.
Pumped-storage role in daily power balancing
If developed at the upper end of the capacity range, Đerdap 3 could be positioned as one of the largest flexibility assets in south-east Europe. The scheme is described as absorbing electricity during periods of low prices or renewable surplus and returning power during peak demand. The services referenced include balancing, reserve capacity, and system restoration.
The documentation work also reflects market conditions shaped by additional wind and solar in Serbia and neighbouring markets. Midday prices are described as increasingly exposed to solar-related price effects, while evening prices remain supported by thermal generation and imports. Pumped storage is noted as able to shift large electricity volumes across this daily cycle more effectively than short-duration batteries when storage hours are sufficient.
Cost range, cross-border studies and environmental assessment
The project remains at a very early stage, with a broad preliminary capital envelope for a technically complex 1.2–2.4 GW pumped-storage scheme estimated at approximately €2 billion to more than €6 billion. The range would depend on final capacity, geology, tunnel length, reservoir design, and environmental mitigation measures. The €5.3 million documentation contract is intended to narrow that spread and identify a realistic configuration.
Cross-border coordination will be essential, given that Đerdap 3 would interact with the existing Serbia-Romania hydropower and navigation system. Studies are required to examine changes in river flows, navigation conditions, and the operation of Đerdap 1 and Đerdap 2. Serbian authorities would need to coordinate technical assumptions with Romania.
Protected-area constraints and revenue model considerations
The strategic assessment must account for environmental sensitivity because the project lies within Đerdap National Park. The scope referenced includes protected habitats, cultural assets, landscape effects, construction spoil, water regimes, and the footprint of the upper reservoir. Environmental constraints could influence which upper-reservoir option—Pešča or Brodica—is selected.
The tender also points to commercial considerations tied to project bankability through a defined revenue model. Energy arbitrage alone is described as potentially insufficient to support multibillion-euro investment levels. Capacity remuneration, ancillary services, strategic-reserve payments, or regulated cost recovery may be required to provide predictable cash flow.
Tender outputs feeding long-term financing decisions
The procurement is described as moving Đerdap 3 from a long-discussed concept toward structured project development . The decisive outputs identified for that transition include preferred capacity, reservoir location, an environmental pathway, connection design, and a commercial framework capable of supporting long-term financing.
