Serbia and Romania have signed a memorandum of understanding covering the proposed Djerdap 3 pumped-storage hydropower plant. The agreement is intended to revive preparations for what is described as one of Southeast Europe’s largest prospective electricity-storage projects. The two governments will set up joint working groups to exchange technical information and coordinate project development.
Serbia expects work on the spatial plan and technical documentation to begin during 2026. Six expressions of interest submitted through an earlier public call remain under review. The governments’ cooperation framework is focused on aligning project development steps through the joint working groups.
Djerdap 3 design concept and operational role
The proposed facility would have an installed capacity of approximately 2,400 MW. Current planning envisages an upper reservoir on the Serbian side of the Danube. That reservoir would be connected by large pipelines to the existing Djerdap reservoir.
Under the concept described, electricity would be used to pump water uphill during periods of low demand or abundant renewable production. Stored water would then be released to generate power during high-price and system-stress periods. The project is positioned as a tool for shifting generation and demand balancing across operating conditions.
Serbia’s flexibility position is expected to be materially affected by Djerdap 3 at this scale. Serbia is developing a pipeline of wind and solar projects but continues to rely on lignite generation, hydropower and imports to manage variations in demand and renewable output. Pumped storage is described as capable of absorbing surplus production, providing balancing capacity and reducing exposure to expensive evening imports.
Financing framework within Serbia-US strategic cooperation
Djerdap 3 is also being advanced within Serbia’s Strategic Energy Cooperation Agreement with the United States. This places the project within a broader financing and geopolitical context, according to the memorandum coverage. The eventual project structure could involve international contractors, equipment suppliers, development institutions and commercial lenders.
Procurement, ownership and financing arrangements are not yet defined in the planning materials referenced. Bankability is described as depending on multiple revenue components rather than conventional electricity sales alone. These include peak–off-peak arbitrage, balancing services, capacity value and potentially regulated system-support payments.
Romanian requirements for Danube operations
Romanian participation is described as essential because the development would affect the shared Danube system. It would also influence operation of the existing Djerdap 1 and Djerdap 2 hydropower plants. Bucharest has indicated that the new facility must preserve navigation and protect riverbank areas in Romania and Bulgaria.
Bucharest also requires that the operational regime of Djerdap 1 and Djerdap 2 not be disrupted by Djerdap 3 development. These conditions place environmental and hydraulic modelling at the centre of project preparation. Coordinated environmental assessments and operating rules acceptable to both countries are required for the upper reservoir, pumping cycles and downstream water management changes.
Technical studies, cross-border framework and investment timing
The project’s financial profile is described as demanding due to its scale. A 2,400 MW pumped-storage scheme would require several billion euros of investment, along with a long construction period. Revenue streams are expected to extend beyond conventional electricity sales.
The size of the development is also described as requiring phased technical progress before an investment decision can be reached. Spatial planning, geological investigation, hydraulic modelling and grid studies are among the elements that need to advance. An agreed cross-border operating framework must also be developed before a credible CAPEX envelope can emerge .
