Negative
Setback or risk materialised
Medium Impact
Significant progress or notable issue
On 4 April 2025 an unplanned power outage at the Kollsnes onshore facility cut electricity supply to Norway's Kollsnes gas processing plant and the offshore Troll A platform. The outage occurred during maintenance work on a substation transformer, according to Norway's electricity transmission system operator Statnett. The Kollsnes substation is the TWEL onshore grid interface built by Skanska and equipped by Siemens Energy, supplying power-from-shore to Troll B and Troll C as well as the original Troll A 2005 HVDC link. The incident triggered a brief precautionary evacuation at Kollsnes in line with procedure and curbed Thursday's gas processing capacity at Kollsnes by approximately 39 million cubic metres according to Gassco's transparency portal. Equinor and Gassco confirmed power supply restoration the same day and entered a normalisation phase ahead of a safe restart of gas exports. The event illustrates the cascading impact of TWEL substation availability on Norwegian gas exports now that the Troll complex's three platforms share onshore power feed at Kollsnes.