The proposed reconstruction of the Formin hydropower plant has been moved into the public-review stage of the integrated construction-permit process in Slovenia. The Ministry of Environment and Spatial Planning has published documentation covering the plant reconstruction and work on the adjacent Markovci dam. The materials will remain available for public inspection until 24 August.
Permitting documentation for Formin and Markovci
The project is led by Dravske Elektrarne Maribor (DEM), which plans a comprehensive replacement of the plant’s mechanical and electrical equipment. The scope also includes rehabilitation of the intake canal using a new geocomposite lining. Additional works comprise construction of a protective wall and repairs to the discharge canal and stone embankments.
Capacity and generation targets after modernisation
Formin entered operation in 1978 and is the last hydropower station on Slovenia’s section of the Drava River that has not undergone a full overhaul. Modernisation is intended to extend the operating life of the plant and align its hydraulic performance with the rest of the Drava cascade. Installed capacity is expected to increase by 12.6%, from 116 MW to 130.65 MW.
Average annual production is forecast to rise by about 7%, from 548 GWh to 588.6 GWh. Overall, the investment would add approximately 14.65 MW of capacity and 40.6 GWh of annual generation. The project’s capacity increase relative to energy output is described as reflecting operational flexibility, higher peak capability, and improved reliability rather than baseload production alone.
Construction schedule for units and canal works
Work on the intake canal and the first generating unit is scheduled to start in August 2027. Reconstruction of the second unit is planned for late 2027. The modernised plant is expected to return to operation by the end of 2028 or early 2029.
The integrated permitting process is positioned as central to maintaining that timeline, given the need to coordinate canal works, dam interfaces, equipment replacement, and staged unit outages. Coordination is required without compromising water management or operations across the wider Drava cascade.
Market context for dispatchable hydropower in Slovenia
Formin’s modernisation aligns with growing value for flexible hydropower in Slovenia. The rapid expansion of solar generation has widened the difference between midday and evening prices. Regional drought is also increasing the strategic importance of dispatchable hydro assets in the system.
