Krško shortfall drives replacement purchases
GEN Energija says reduced output at Slovenia’s Krško nuclear power plant is costing it at least EUR 300,000 per day. The company is turning to the wholesale electricity market to replace generation that had already been sold under forward contracts. GEN Energija had sold most of Krško’s expected 2026 electricity production in advance. With the plant generating below planned levels, replacement electricity is needed to meet contractual obligations.
Wholesale prices have averaged around EUR 180/MWh. Evening prices have increased significantly higher as regional supply conditions tighten. The higher cost of securing replacement power reflects the gap between contracted Krško volumes and current market purchase requirements.
Brestanica gas plant used more amid tighter supply
The shortfall is also increasing reliance on the Brestanica gas-fired power plant. The facility is normally used primarily as a system reserve. Higher electricity prices have nevertheless made its operation commercially viable despite elevated gas and carbon costs. Evening market prices have recently reached EUR 300–400/MWh.
Brestanica has already exceeded its expected full-year generation target ahead of the end of 2026. The plant produced 25.75 GWh by 5 August, about 3% more than its planned generation for the entire year.
Cost pressure from higher marginal generation and replacement power
The situation creates financial exposure when a large baseload unit operates below expectations after its output has been sold forward. GEN Energija is effectively exposed to the difference between the contracted price for Krško electricity and the higher cost of buying replacement power on the wholesale market. Increased Brestanica operation provides additional domestic generation during periods of tight regional supply.
This additional generation comes at a significantly higher marginal cost than nuclear production. Lower Krško output, costly replacement purchases, and increased gas-fired generation are adding pressure on GEN Energija’s finances while Southeast European electricity prices remain elevated, particularly during evening peak periods.
