Statnett formally took over the Fensfjorden cable installation from BKK Nett in 2020, following completion of the Modalen-Mongstad line in 2019. The transfer was part of a wider NOK 3.5 billion agreement signed in February 2016 for Statnett to purchase BKK transmission network assets, driven by EU Third Energy Package requirements for TSO ownership of transmission infrastructure. BKK Nett (subsequently rebranded as Eviny) no longer owns any transmission network assets.
The Modalen-Mongstad 420 kV transmission line including the Fensfjorden submarine cable crossing was commissioned and placed into operation in late 2019. The cable system was built to 420 kV specification but entered service at 300 kV, consistent with the operating voltage of the wider Modalen-Mongstad-Kollsnes transmission ring. The project doubled transmission capacity in the Bergen and Nordhordland area. BKK Nett completed the project on behalf of Statnett under the terms of their 2016 asset transfer agreement.
Nexans completed installation of four 420 kV XLPE submarine cables across Fensfjorden in summer 2019 using the cable-laying vessel C/S Nexans Skagerrak. The cables were laid at a maximum depth of approximately 530 metres between Mongstad and Iledalsvagen landfalls. BEIN Engineering provided marine engineering support throughout the two-year programme including route planning, installation analysis (Orcaflex), VIV and fatigue calculations, and on-board supervision during marine operations.
BKK Nett awarded Nexans Norway a NOK 350 million (approximately EUR 37 million) contract in October 2017 for the development, manufacture and installation of the worlds deepest 420 kV XLPE submarine cable crossing Fensfjorden. The contract scope covered cable design and type-testing, manufacture at Nexans Halden plant, installation by C/S Nexans Skagerrak, and subsequent voltage testing. At the time of award the target depth of 526 metres represented a world record for a 420 kV AC submarine cable.
NVE granted construction consent (anleggskonsesjon) on 26 January 2017 for modifications and associated facilities for the 300 (420) kV Modalen-Mongstad transmission line, enabling BKK Nett to proceed with detailed engineering and construction procurement.
The Norwegian government (OED) granted consent by Royal Decree (kongelig resolusjon) on 19 June 2015 for BKK Netts 300 (420) kV Modalen-Mongstad transmission line including the Fensfjorden submarine cable crossing. The consent process from NVE recommendation to OED decision took one year and nine months.
NVE issued its recommendation (innstilling) to OED on 30 September 2013 for the 300 (420) kV Modalen-Mongstad transmission line. NVE recommended an overhead line from Steinsland (Modalen) via Haugsvaerdalen and Froyset to Iledalsvagen, a submarine cable crossing of Fensfjorden to Mongstad, then overhead line to Lindas transformer station. The total route was approximately 62.2 km comprising 55.2 km overhead line and 7 km submarine cable.
BKK Nett submitted a consent application to NVE in September 2010 for the 300 (420) kV Modalen-Mongstad transmission line, including a submarine cable crossing of Fensfjorden. The application covered approximately 62 km of new transmission line from Modalen to Mongstad, of which around 7 km would be submarine cable across the fjord. Two supplementary applications with revised route alternatives followed in May 2012 and December 2012.
| Norway | Vestland | |
|---|---|---|
| Landfall | Mongstad, Vestland, Norway | Iledalsvagen, Vestland, Norway |
| Grid Connection | — | — |
Norway
Vestland