Serbia is considering two major pumped-storage projects that could add more than 2.4GW of flexible generation capacity, as the power system prepares for greater renewable penetration, coal retirements, hydrological volatility and stronger regional electricity interconnections.
- Pumped storage depends on multiple revenue streams
- Bistrica has the stronger project and financing profile
- JICA involvement adds environmental and procurement requirements
- Đerdap 3 remains at an earlier development stage
- Regional electricity markets are central to Đerdap 3
- Combined investment would approach €3.6 billion
The country already operates the 614MW Bajina Bašta pumped-storage plant, but additional flexibility is expected to become increasingly important as wind and solar capacity expands. Pumped-storage facilities can absorb excess electricity and return it during periods of scarcity, while also providing reserve capacity, frequency control and black-start services.
The two projects now under consideration occupy different stages of development. Bistrica, with a planned capacity of between 628MW and 661MW, is further advanced and has stronger financial indicators in current planning documents. Đerdap 3, modelled at 1,800MW in six units, remains at an earlier study stage and requires further work on its market, financing and regional role.
Pumped storage depends on multiple revenue streams
Pumped-storage facilities consume electricity when pumping water and generate electricity later when releasing it. Their financial performance therefore depends on the difference between lower-cost and higher-cost electricity periods, as well as revenues from capacity, ancillary services and avoided renewable curtailment. Security-of-supply value can also influence the economics of a project. A pumped-storage plant may provide important system services while remaining difficult to finance as a purely merchant asset if electricity-market rules do not compensate those services adequately.
Current Serbian planning documents give Bistrica a capacity of up to 661MW, with an official project appraisal indicating annual generation of approximately 1,600GWh. Đerdap 3 is based on an 1,800MW configuration, while alternative scenarios range from 1.2GW to 2.4GW. The combined capacity would substantially exceed Serbia’s current requirements for reserve flexibility, making the sequencing of the projects an important investment consideration.
Bistrica has the stronger project and financing profile
The Ministry of Mining and Energy ranks Bistrica as the first priority among EPS projects. Current planning assumptions put its estimated investment cost at €962.5 million, with completion targeted for around 2032. The same appraisal gives the project a €702 million net present value and a 9.92% internal rate of return. These figures represent planning assumptions rather than guaranteed investor returns, but they are stronger than the corresponding financial indicators currently reported for Đerdap 3.
Bistrica has also progressed further through project preparation. Conceptual and feasibility studies, a grid study and environmental documentation have advanced, while JICA is conducting the project’s environmental and social process. The financing structure outlined in official plans envisages approximately 70% from JICA and 30% from Serbia’s budget or another financing source. UK-backed and other financing options have also previously been considered, although the underlying plan did not establish a fully secured financing package.
JICA involvement adds environmental and procurement requirements
JICA’s involvement brings environmental and social assessment, resettlement requirements, technical review and a procurement framework into the project structure. The remaining financing and implementation arrangements would still need to be converted into executed loan and procurement documents. The project also requires an independent owner’s engineer, final demand and electricity-price scenarios, and detailed assessment of potential civil-works contingencies.
For a large hydropower project, these requirements are particularly relevant to underground construction, where geological conditions and design modifications can materially affect project execution and costs.
Đerdap 3 remains at an earlier development stage
Đerdap 3 is substantially larger but less mature. The current official base case estimates investment at approximately €2.63 billion, with completion targeted around 2036. Its appraisal reports a €464 million net present value and a 4.9% internal rate of return, compared with the stronger indicators reported for Bistrica. Đerdap 3 remains at the preliminary-study stage, with final capacity, reservoir configuration, environmental impacts and cross-border implications still requiring full feasibility work.
The Ministry’s planning documents also recognise that Serbia cannot realistically finance and execute every major infrastructure project in its investment pipeline simultaneously.
Regional electricity markets are central to Đerdap 3
The project’s location on the Danube gives Romania and regional electricity markets a significant role in its development. An 1.8GW facility would require sufficient cross-border transmission capacity, coordinated water and environmental decisions and customers extending beyond EPS’s domestic portfolio. Serbian-Romanian cooperation in 2026 is therefore relevant to the project’s development alongside any future engineering, procurement and construction announcement. Capacity contracts, balancing revenues and integration with European electricity markets would need to form part of the commercial structure before a final investment decision.
US-supported outreach during 2026 sought interest in front-end engineering and potential EPC participation. Other government-to-government proposals could combine contractors, export-credit financing and diplomatic support. Such structures could accelerate project preparation, but the financing source would not determine the engineering configuration. Engineering alternatives and lifecycle costs would need to be compared before an EPC financing arrangement is finalised. A staged development of Đerdap 3 in 600MW increments could also be maintained as an option if grid conditions and market demand support such an approach.
Combined investment would approach €3.6 billion
Serbia is expected to require additional flexibility from Bistrica in the early 2030s if its renewable-energy expansion and coal-transition plans proceed. Đerdap 3 could become relevant later under a system with higher renewable penetration and stronger regional electricity integration. That does not require both projects to receive full financing simultaneously. Their combined estimated investment is close to €3.6 billion, before cost overruns, transmission reinforcement and financing expenses are included.
EPS’s improved profitability alone would not cover that investment alongside planned spending on solar, wind, distribution infrastructure, environmental compliance and the coal transition without sovereign or concessional financing support. The current sequence places Bistrica first, supported by its higher modelled return and more advanced JICA financing route. Đerdap 3 can remain under development through additional studies while Romania, regional system operators and electricity buyers establish the commercial requirements for its flexibility.
A combination of staged construction, EU or multilateral financing and contracted capacity revenues could subsequently provide a basis for financing the larger project. Government-to-government financing competition can reduce Serbia’s funding costs, while open assumptions, independent engineering, competitive procurement and limits on sovereign debt remain relevant to both developments.
