Slovenia’s state-owned power generation company, Holding Slovenske Elektrarne (HSE), is developing a 140 MW floating solar power plant at Lake Dru?mirje, near Šoštanj in northern Slovenia. The lake, formed from decades of lignite mining, will have up to half its surface covered by the Dru?mirje floating solar power plant (PSE Dru?mirje), which is set to become Europe’s largest floating solar project upon completion.

Simon ?i?mek, project manager for the floating solar plant, told pv magazine: “The agreements with local authorities are underway, we are very positive on the outcome and hope to be able to see the financial and other benefits being shared with the local population, in all sorts of different ways.” Spatial planning activities are ongoing, with the spatial plan decree expected in the fourth quarter of 2025. A public consultation was held earlier this week to engage the community.

The project, with an estimated cost of €100 million ($116.6 million), will be financed through HSE’s own funds, loans, and support from the European Union’s Just Transition Fund. HSE will fully own the project, with operations managed by its subsidiary, HSE SaŠa. Construction is scheduled to start in the third quarter of 2026, with electricity production expected to begin in the first quarter of 2027. As a state-owned initiative, the project will adhere to EU public tender regulations.

Once operational, PSE Dru?mirje is projected to generate 140 GWh of electricity annually, sufficient to power approximately 35,000 Slovenian households. The lakeside area will also be transformed into a recreational and social space for the local community, enhancing regional benefits. The project surpasses the current largest floating solar array in Europe, a 74.3 MW facility in France inaugurated in June 2025.

PSE Dru?mirje represents Slovenia’s largest solar project under development, as the country’s solar market is primarily driven by residential and commercial installations, with utility-scale projects still emerging. Slovenia’s total solar capacity reached 1.5 GW by mid-2025, following the addition of 85 MW in the first half of the year, 298 MW in 2024, and 400 MW in 2023. Another notable project, a 30 MW ground-mounted solar facility approved in May 2025, is being developed by HSE’s subsidiary, Dravska elektrarna Maribor, marking progress in the utility-scale sector.

The Dru?mirje project underscores Slovenia’s commitment to expanding renewable energy, supporting local communities, and advancing sustainable development through innovative solar solutions.