Sweden’s power grid faced an exceptionally strained operational situation on Monday, June 8, 2026. People climbed high-voltage pylons near Bollnäs, prompting the grid operator to shut down a key transmission line. Shortly thereafter, the 500-megawatt Swe-Pol Link connection to Poland also failed. As a result, the grid frequency dropped to 49.80 Hertz. At the same time, Svenska kraftnät utilized all available reserves in southern Sweden. However, four gas turbines and electricity supplies from Norway and Lithuania prevented a system collapse. Authorities reported no power outages, injuries, or material damage.
Collapse Averted After Double Grid Disturbance
Svenska kraftnät received initial reports around 2:20 p.m. of people on electricity pylons outside Bollnäs. Consequently, the operator disconnected the affected high-voltage line from the grid at 2:33 p.m. However, the shutdown significantly reduced transmission capacity between northern and southern Sweden, forcing other lines to take on a larger share of the power flow.
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The grid operator initially increased exports to Finland via the Fenno-Skan link. This relieved the load on vulnerable lines within the Swedish transmission grid. However, the measure reduced the margin available to handle a further outage. Precisely this scenario occurred less than an hour later.
At 3:16 p.m., the Swe-Pol Link tripped while importing 500 megawatts. Sweden thus abruptly lost a significant power supply from Poland. At the same time, the frequency in the Nordic synchronous grid dropped well below the target value of 50 hertz. Although a total system collapse was averted, the operator had to immediately procure additional power.
All upward reserves in the south activated
Between 3:30 p.m. and 3:45 p.m., Svenska kraftnät activated 701 megawatts of balancing energy in bidding zone SE3. An additional 255 megawatts were activated in the southernmost zone, SE4. In total, the operator mobilized 956 megawatts of manual frequency restoration reserve. Following this, no further standard upward bids were available in either zone.
Consequently, Svenska kraftnät started up two gas turbines in Halmstad and two units at the Barsebäck site. Additionally, Norway and Lithuania each supplied 200 megawatts of extra power. At 3:43 p.m., the operator declared a heightened operational status. This classification signaled an impending power shortage but did not yet imply a lack of electricity supply for consumers.
The situation subsequently stabilized gradually. Three gas turbines shut down by 3:55 p.m., while the fourth unit continued running until 4:10 p.m. The special supplies from Norway and Lithuania ended at 4:30 p.m. The Swe-Pol Link resumed operation around 5:15 p.m.
Extreme imbalance prices retroactively corrected
The activation of reserves caused the initially published imbalance prices to surge. For the 15-minute period starting at 3:30 p.m., the settlement system initially reported a price of 10,000 euros per megawatt-hour for zones SE3 and SE4. Values ranging from 2,500 to 5,500 euros also appeared in subsequent intervals. Such prices would have placed a significant financial burden on parties responsible for balancing.
Svenska kraftnät later corrected the figures to approximately 87 to 110 euros per megawatt-hour. The operator justified this move by citing the specific reason for the activations: the deployment was triggered not by poor planning on the part of individual market participants, but by disturbances in the transmission grid. Consequently, Svenska kraftnät applied the respective spot market prices for settlement purposes.
The incident highlights the importance of rapidly available power plants and cross-border interconnectors. At the same time, technical emergency measures remained available even after regular market-based offers had been exhausted; thus, the situation was not on the verge of an imminent, unavoidable collapse. Nevertheless, two independent disturbances were sufficient to deplete all market-based upward reserves in southern Sweden.
Author: Blackout News
Sources: Teknisk Ukeblad (12.06.26) – Svenska Kraftnät (11.06.26) – Montel News (11.06.26) – Trading View (10.06.26)