Eles: this winter will be the toughest for power prices; Slovenia relied on imports in about 98% of hours

The director of Slovenian transmission system operator Eles, Aleksander Mervar, warns that November 2026 to February 2027 will be the most difficult period for electricity prices. “The worst will be this winter,” he said at the Energetika 2026 conference held on 3 November in Bled by the Delo media group, according to an article published by Delo on 6 November. Companies that have not yet bought power for these months are the most exposed.

The figures. According to Mervar, Slovenia relied on imports in about 98% of hours this year, and according to the latest Eles scenarios dependence will grow until the planned start of the second nuclear unit at Krško (JEK2) in 2044. Igor Koprivnikar, a GEN-I management board member, told Delo that the average Slovenian day-ahead price this year is about €20/MWh above the German one, and the Hungarian price another €7/MWh above the Slovenian, amid very poor hydrology in the region.

The grid. Mervar stressed that a lower exchange price does not automatically mean a lower final bill, because the expansion of renewables requires grid investment financed through network charges. He believes Slovenia cannot afford a significant increase in these charges in 2027, but warned: “The longer we delay the increase, the bigger it will have to be.” The director of the Energy Agency, Duška Godina, told RTV Slovenija that network charges account for about 5–6% of the final cost of energy and that she expects increases in the future.

What next. Until JEK2, Mervar proposed building several hundred megawatts of gas-fired plants to serve as reserve capacity; their financing would require a separate agreement. According to an Eles study, a JEK2 of up to about 1,100 MW would not require additional investment in the transmission grid. Mervar nevertheless said physical supply is not at risk: “There will be electricity in the sockets.”

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