For several months now, there has been extensive discussion about a major construction undertaking of national significance: the building of the Bistrica pumped-storage hydropower plant (PSHPP), which the Public Enterprise Electric Power Industry of Serbia (EPS) describes as a "strategic energy project crucial for the future".
It will be the first pumped-storage hydropower plant Serbia has built in 35 years, and it is also announced as the "largest new energy capacity of around 650 MW".
As EPS emphasises for our portal, "its importance is also reflected in the estimate that the Bistrica PSHPP should enable the integration of an additional 1,500 MW of renewable energy sources in the future." At the same time, the project is fully compatible with European goals related to increasing the share of renewable energy sources, system flexibility, development of energy storage, and reduction of CO₂ emissions. It is also part of Serbia’s broader energy strategy to reach a 49.6% share of renewable energy by 2040.
Since the Bistrica hydropower plant has been in operation since 1960, it needs to be rehabilitated, especially given Serbia’s commitment to harmonising its regulations with EU environmental legislation.
The modernised hydropower plant would support wind and solar power plants, enabling greater integration of renewable energy sources into Serbia’s electricity grid.
It should be noted that the PSHPP and the existing Bistrica hydropower plant are two separate hydroenergy systems. The machine hall of the PSHPP will be located around three kilometres downstream from the existing machine hall of the Bistrica plant. The existing Bistrica hydropower plant is a conventional storage-and-diversion facility. It uses water from the Radoinja reservoir, which, after electricity generation, is discharged into the Lim River, i.e. into the Potpeć reservoir.
The new facility will be located between the Uvac and Lim rivers, and on the Uvac, 7.5 kilometres downstream from the existing Radoinja Dam, the construction of the Klak dam is planned. According to EPS, the total capacity of this reservoir will be 108 million cubic metres of water, while the existing Potpeć reservoir on the Lim will serve as the lower reservoir in the PSHPP system.
"The energy community agrees that with the increasing share of variable sources such as wind and solar energy, there is also a growing need for stable and reliable systems that can ensure balance at all times. That is precisely why, for EPS, the construction of the Bistrica PSHPP is the most important investment, without which there can be no safe integration of renewable sources such as wind and solar into the power system.
Both experts and scientists agree that this new capacity is essential for Serbia’s future. The importance of pumped-storage hydropower plants - secure energy storage facilities - is measured at the moments when energy is most needed and most in demand," it adds.
The Bistrica hydropower plant is the third stage in the hydroenergy utilisation system of the Uvac River and is the largest plant in the system of Lim hydropower plants built in the 1960s.
In what phase is the construction of the Bistrica PSHPP?
Rehabilitation involves maintaining the same installed capacity of the plant while increasing efficiency by replacing old units with new ones, as well as reducing breakdowns through the replacement of auxiliary equipment. Higher efficiency of units with the same capacity means better utilisation of water resources. It is estimated that efficiency will increase by 3–5%, which will directly raise annual electricity production to around 350 GWh, while also reducing harmful gas emissions.
Construction has not officially begun yet; all preparatory works are currently underway.
“The project is entering one of the most important phases of its implementation. The Government of Serbia has confirmed the public interest for land and property expropriation. Location conditions for the main facility, i.e. the power plant, have recently been obtained, which forms the basis for further project development. The technical documentation for preparatory works is also in its final stage; these works represent an important introduction to the realisation of the investment itself. The start of preparatory works is planned for the second half of 2026, and will include the reconstruction of existing infrastructure as well as the construction of missing infrastructure. The first tender for the reconstruction of three bridges on state road 191 has also been issued. Much has been done so far, and the documentation is very extensive. The conceptual design is undergoing technical review by the State Revision Commission, and a draft of the project documentation for obtaining a construction permit has also been prepared, in line with the planned schedule. Activities are underway to define the scope and content for the Environmental Impact Assessment Study, in accordance with the highest environmental protection standards and sustainable development principles. At the same time, intensive work is being carried out on securing project financing with the Japan International Cooperation Agency (JICA). It is important to emphasise that the construction of such a large energy and infrastructure facility is a complex and multidisciplinary undertaking, and that every energy investment is long-term and requires detailed preparation, analysis, and extensive works,” EPS stated for EUpravo Zato.
What other works are planned – relocation of water supply networks, road changes…
Before construction can begin, a series of preparatory infrastructure works must be carried out, including the reconstruction of bridges and the relocation of key water supply infrastructure in the municipalities of Priboj and Nova Varoš.
Adjustments to roads, drainage systems, the construction of retaining walls, as well as the installation of traffic signage and equipment are also mentioned.
It is stated that reconstruction is necessary in order to adapt existing infrastructure to its new function, given that after the construction of a road diversion of around 2.5 kilometres, this section will become an internal road within the Bistrica PSHPP system.
According to tender documentation, part of the municipal infrastructure must also be relocated, including the water supply system serving Priboj and Pribojska Banja, as well as certain transmission lines.
Later, construction is planned for a new water supply network of around 4.5 kilometres, with pipelines ranging from 225 to 500 millimetres in diameter.
The existing water supply system relies on the karst springs Čelice, Bjeličkovica and Saračevina, as well as the Radoinja reservoir within the Bistrica hydropower system. Water is transported through an approximately eight-kilometre tunnel to the facility, and then further to the “Mihajlovac” water treatment plant. Part of the pipeline route runs through the planned construction zone of the Bistrica PSHPP, making its relocation necessary.
The new water pipeline route will be placed along existing forest roads and the state road, and accompanying structures are also planned, such as break chambers, sludge outlets, air valves and connection shafts. The aim is to ensure full independence of the water supply system from the future hydropower plant and uninterrupted water supply for the local population.
We asked officials from the municipalities of Nova Varoš and Priboj about these planned works and other project details, as all activities will take place in this area, but have not yet received responses.
What makes pumped-storage hydropower plants special?
Pumped-storage hydropower plants are specific because they can both generate and store electricity. Unlike conventional hydropower plants, which “only” use water flow to produce electricity, pumped-storage plants have two reservoirs, upper and lower, and operate in two modes: when there is surplus electricity in the system, it is used to pump water from the lower to the upper reservoir; when consumption is high or there is insufficient generation from other sources, water is released back through turbines to generate electricity.
In a sense, they function as large “batteries” of the power system.
“In the Bistrica PSHPP system, alternating intake and discharge of water from the future Klak reservoir is planned. In turbine mode, water is taken from the upper Klak reservoir, then directed to the hydropower plant and discharged into the lower Potpeć reservoir, generating electricity. In pump mode, the cycle is reversed: water is taken from the lower Potpeć reservoir and, using energy, pumped through the same machinery and discharged into the upper Klak reservoir,” EPS explained.
In Europe, pumped-storage hydropower plants are one of the key drivers of energy decarbonisation. Countries such as Austria, Switzerland and Norway have a large number of such facilities precisely due to the development of renewable energy sources.
Serbia already has one pumped-storage hydropower plant, Bajina Bašta, and planned projects such as Bistrica are therefore considered strategically important, as they enable greater integration of solar and wind power plants and reduce the risk of grid instability in the future.
Seventeen households and ten holiday homes to be flooded
“It is planned that the facilities of the Bistrica PSHPP system, including the land to be flooded by the new Klak reservoir, will cover an area of around 700 hectares. In accordance with legal provisions and procedures, and according to pre-prepared resettlement plans, there are 17 active households, 10 holiday homes, and three abandoned households within the expropriation area,” EPS told our portal, although it was not specified exactly how the process will be carried out or what will happen to the people whose homes will be submerged.
This article is part of the special feature on energy: “Serbia in Times of Global Uncertainty”.
