HESS inaugurates Slovenia’s largest solar complex in Brežice

State-owned Hidroelektrarne na Spodnji Savi (HESS) has officially inaugurated two new photovoltaic units at its Brežice hydropower plant, creating the largest solar complex and hybrid power plant in Slovenia. The new units, FEBR-D1 and FEBR-D2, have a combined peak capacity of 9.34 MW and consist of 14,952 bifacial modules.

Spanning 9.4 hectares, the project was constructed on sediment landfills within the Brežice reservoir to avoid using agricultural land. The expansion, which cost approximately 4 million EUR and was contracted to the Croatian company Končar, took 14 months to complete. The new segments are expected to produce an annual output of 10.5 GWh, bringing the total annual production of the entire 15.3 MW complex to 17.4 GWh, enough to supply roughly 4,550 households.

As a hybrid facility, the solar integration allows for optimized production by saving water in the reservoir for periods of peak demand. To mitigate environmental impact, HESS constructed a replacement nesting wall to preserve the habitats of the sand martin and European bee-eater.