Serbia seeks international firms for Đerdap 3 reversible pumped-storage project

Serbia has launched a public call supported by the U.S. Embassy in Belgrade seeking companies interested in participating in the development and construction of the reversible hydropower project Đerdap 3. Interested parties are invited to submit letters of interest by 25 June 2026. The call is presented as a concrete step toward realization of the long-discussed project.

Đerdap 3 has previously been referenced mainly as a strategic concept in Serbian energy planning documents. The current phase involves direct engagement with international engineering, construction, equipment manufacturing and infrastructure companies. The move is aimed at turning technical studies and political commitments into an executable investment program.

Pumped-storage role amid rising renewable variability

The timing aligns with changes in European power systems that have emerged alongside expanding renewable generation. Solar output increasingly produces midday electricity surpluses, while evening demand peaks can trigger sharp price spikes and additional system balancing needs. Wind generation adds further volatility, particularly in markets with rapidly growing renewable portfolios.

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Pumped-storage hydropower is described as acting like large-scale energy storage. In surplus periods, water is pumped from a lower reservoir to an upper reservoir, and during higher-demand periods it is released through turbines to generate electricity. The technology is cited for long-duration storage, system flexibility, reserve capacity, frequency regulation and renewable integration services.

Serbian scenarios for Đerdap 3 capacity

Serbian planning for Đerdap 3 includes multiple development scenarios with installed capacities of 1,400 MW, 1,800 MW and 2,400 MW. Ministry officials say the smallest option would focus on national balancing needs. Larger configurations are described as enabling the facility to function as regional infrastructure supporting renewable integration across Southeast Europe.

The 2,400 MW scenario is described as among the largest pumped-storage facilities in Europe. It would also change the flexibility profile of the regional electricity market. The project’s significance is therefore framed as extending beyond storage capacity alone.

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Renewables expansion and EPS storage initiatives

Serbia’s broader energy transition includes expansion of renewable generation through utility-scale solar parks, wind farms and hybrid renewable projects. State-owned utility EPS is also advancing large-scale storage initiatives. One listed example is the Bistrica pumped-storage hydropower project, which is progressing toward construction and financing arrangements.

Within this policy direction, large-scale energy storage is increasingly treated as essential infrastructure rather than a supplementary technology. The approach links storage development to ongoing renewables deployment and system needs described in Serbian planning discussions.

Investment envelope and international engineering involvement

Government planning documents have referenced an estimated investment envelope of approximately €1.4 billion for a configuration of around 1,800 MW. Larger versions would likely require significantly greater capital commitments. Earlier assessments and industry discussions have placed potential investment requirements substantially higher depending on final design, transmission infrastructure and cross-border arrangements.

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The scale of Đerdap 3 has also been associated with international interest. American engineering group Bechtel has previously participated in studies and discussions related to the facility and has been linked with earlier exploratory phases. Serbian officials have said technical assessments and feasibility work involved cooperation with international partners due to the project’s complexity.

Danube cooperation with Romania on Đerdap 3

Đerdap 3 is positioned within the broader Danube hydropower system shared between Serbia and Romania. Both countries already cooperate through existing hydropower complexes Đerdap 1 and Đerdap 2. Discussions between Belgrade and Bucharest have intensified in recent years, including plans for a memorandum of understanding on future cooperation regarding Đerdap 3.

Romanian authorities have emphasized that new infrastructure should not adversely affect existing hydropower production along the Danube corridor. This cross-border dimension is presented as adding significance beyond national energy policy considerations for both countries.

Evolving revenue streams for storage assets

The economics of pumped-storage projects have changed over the past decade. Historically, such projects relied primarily on arbitrage between low-price and high-price electricity periods. Current market structures are described as offering additional revenue streams including ancillary services, reserve markets, congestion management, capacity mechanisms and support for renewable integration.

The increased frequency of negative electricity prices during periods of high solar output is cited as contributing to higher value for large-scale storage assets. This development is described as relevant for Southeast Europe where renewable investment acceleration and grid interconnections are expanding alongside deeper integration with European electricity markets.

From planning to commercial execution

The latest international call is described as more than a procurement exercise. It indicates that Serbia is seeking to move Đerdap 3 from strategic planning into commercial execution. After decades of discussion, studies and changing development scenarios, the project is beginning to attract institutional and industrial attention needed for realization.

The next phase will determine whether Đerdap 3 proceeds at 1,400 MW, 1,800 MW, or reaches the full 2,400 MW vision outlined in planning materials.