An unplanned outage at Norway’s Troll gas field occurred after a failure of external power supplies, forcing operator Equinor to reduce production and natural gas exports by 34.6 million cubic metres per day and leaving only 37 million Nm³/day of the field’s 124 million Nm³/day technical capacity available. According to Norwegian grid operator Gassco, the disruption—compounded by concurrent maintenance at other gas plants—was expected to last at least until the following Tuesday, temporarily cutting Norway’s total deliveries to the EU and UK by around one third.
On 7 September 2024, Equinor and its partners began partial power-from-shore operations to the Troll B and Troll C platforms under the Troll West electrification (TWEL) project. Electricity is supplied from the Kollsnes facility northwest of Bergen through a 132 kV subsea cable via a new electro building shared with the Oseberg field, first to Troll B and then on to Troll C, where new modules adjust the voltage to onboard systems. Following this initial energisation, processing and other energy‑intensive systems on both platforms are powered by electricity from shore, while large export compressors remain gas‑driven, cutting CO2 emissions by about 250,000 tonnes and NOx by around 850 tonnes per year.
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Troll West: B&C is a shore‑power subsea transmission project that delivers onshore grid electricity from the Kollsnes area to the Troll West installations (Troll B and Troll C) in the Norwegian North Sea. Its primary purpose is to replace platform‑based gas turbine generation, substantially reduc...
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Troll West electrification, Troll West electrification project, TWEL, Troll B and C electrification, Troll Vest electrification
Construction of the new transformer substation, landfall area and related onshore cable works at Kollsnes for the Troll West electrification project were completed before power from shore was turned on to Troll B and Troll C. Equinor’s 11 September 2024 news release on reducing emissions from the Troll field confirms that power to Troll B and C now comes from Kollsnes via a new electro building and cable system, and identifies Skanska Norge AS as the main supplier for constructing the transformer substation and landfall area. This demonstrates that the Skanska Kollsnes substation and associated onshore works were completed and in service by 7 September 2024, when partial power from shore started.
System testing and commissioning of the power-from-shore solution for Troll B and Troll C, including transmission, distribution and power management systems, were effectively completed before power from shore was turned on. Equinor’s 11 September 2024 news release reports that on 7 September Troll B and C became partly powered from shore via the new Kollsnes-to-Troll B and Troll C cable system, with new electro modules and platform systems in operation. Achieving stable partial electrification implies that installation, system integration, and commissioning tests had been carried out successfully by 7 September 2024.
In 2021, Norwegian authorities approved the Plan for Development and Operation (PDO) for the Troll West electrification (TWEL) project, authorising Equinor and partners to proceed with partial electrification of Troll B and full electrification of Troll C from shore. This regulatory approval enabled investment in the subsea power cable system and platform modifications that are expected to cut around 450,000–500,000 tonnes of CO2 emissions annually and significantly reduce NOx emissions from the Troll field.
In early September 2021, Siemens Energy and Siemens AG secured a contract from Aker Solutions to supply the complete electrical transmission, distribution and power management system for the Troll West electrification project. The scope includes transformers, reactors, switchgear, static and special frequency converter systems, large-scale drive trains and the power management system for bi-directional power flow and stable AC power-from-shore operation to the Troll B and Troll C platforms.
The Troll West electrification project secured capital support of NOK 520 million from the Norwegian NOx fund, pledged to help finance partial electrification of the Troll B platform and full electrification of Troll C via power-from-shore cables from Kollsnes. The non-repayable financial support is intended to reduce CO2 emissions by almost half a million tonnes per year and NOx emissions by around 1,700 tonnes annually, improving the project’s economics and directly linking NOx taxes paid by industry to emission-reduction investments.
Equinor and its partners Petoro, Shell, TotalEnergies and ConocoPhillips took the final investment decision to proceed with the Troll West electrification project and simultaneously submitted the plan for development and operation to the Norwegian Minister of Petroleum and Energy. The decision covers partial electrification of Troll B and full electrification of Troll C with power from shore via high-voltage subsea cables from Kollsnes, representing a total investment of about NOK 7.9 billion and targeting annual CO2 emission reductions of roughly 450,000–500,000 tonnes and NOx cuts of about 1,700 tonnes.
On 23 April 2021 Equinor and its Troll partners awarded NKT a contract worth about NOK 1 billion to produce and install the high‑voltage subsea power cables for the Troll West electrification project, running from the Kollsnes landfall to Troll B and from Troll B to Troll C. The turnkey scope includes more than 110 km of 145 kV offshore AC cable with dynamic sections to connect the two floating platforms, with manufacturing in Karlskrona, Sweden and installation by the cable‑laying vessel NKT Victoria.
On 23 April 2021 Skanska signed a NOK 390 million contract with Equinor to construct the new transformer substation at Kollsnes, along with onshore cables, trenches and the landfall works, for the Troll West electrification project. The substation and associated civil works will enable power from the Norwegian grid to be delivered from Kollsnes to the Troll B and Troll C platforms, and the project was scheduled for delivery to Equinor in December 2022.
On 23 April 2021, Equinor and its partners submitted the Plan for Development and Operation (PDO) for Troll West electrification to Norway’s Minister of Petroleum and Energy. The PDO covers partial electrification of the Troll B platform and full electrification of Troll C via high-voltage subsea cables from Kollsnes, aiming to cut nearly half a million tonnes of CO2 emissions per year and substantially reduce NOx emissions from the Troll field.
On 26 March 2021, Norway’s Ministry of Petroleum and Energy granted Equinor a power concession to construct, own and operate the electrical installations needed to supply the Troll B and Troll C platforms with power from shore as part of the Troll West electrification project. The concession authorises the onshore and offshore electrical infrastructure that will transmit up to 116 MW of power from Kollsnes to Troll West, enabling significant reductions in CO2 and NOx emissions from the field.
On 15 January 2020 Equinor, on behalf of the Troll partners, awarded Aker Solutions a front-end engineering and design (FEED) contract to mature topside modifications required to supply power from shore to the Troll B and Troll C platforms as part of the Troll West electrification project. The FEED work covers how to install electrical equipment on the platforms and replace gas-turbine-driven generators and compressors with electric equipment, enabling full electrification of Troll C and partial electrification of Troll B, with expected CO₂ reductions of about 450,000 tonnes per year.
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