A major electrification project for a quartet of North Sea oil and gas platforms has set a December 2028 target for first power.
Further details of the Central North Sea Electrification (CNSe) project, from Harbour Energy (LON: HBR), TotalEnergies (XPAR:TTE), Shell (LON: SHEL), and BP (LON: BP) have been disclosed in a scoping report from consultancy Xodus.
These include landfall locations and details of new infrastructure to be built – such as a 60-metre offshore converter, and new bridge-linked platforms which may be added to the existing oil and gas installations.
The project will be one of the first in the UK to power platforms with electricity, rather than diesel or gas generators – which are the main pollutants offshore.
Xodus said in the report that CNSe “will deliver a significant reduction in greenhouse gas emissions” at the four production hubs: BP’s ETAP, TotalEnergies’ Elgin, Harbour Energy’s Judy and Shell’s Shearwater.
North Sea electrification – infrastructure and power
According to the scoping report, the project secured a grid connection offer in September 2022.
CNSe is targeting Q1 2027 for the start of onshore construction and offshore installation, and “it is anticipated that the CNSE Project will be ready for first power in December 2028”.
The work will see major new infrastructure placed, including installation of a new platform sitting between the Elgin, Judy, ETAP and Shearwater; potential additions to those existing assets, and hundreds of miles of cable laid down.
The 62-metre tall Offshore Converter Station will sit equidistant from them, supported by a piled-jacket foundation.
It may also be required that two of the four existing oil and gas hubs have new bridge-linked platforms installed in order to handle the power conversion infrastructure – though the report does not specify which of the four.
The topsides would be up to 52 metres high, on 27 metre tall jackets.
CNSe is a power-from-shore project which will require hundreds of miles of cables to supply electricity to the platforms.
According to the report, up to two bundled High Voltage Direct Current (HVDC) cables will be required, up to 139 miles-long each, and five High Voltage Alternating Current (HVAC) cables of up to 115 miles-long will be needed.
Three potential landfall sites for the cables have been identified in Aberdeenshire: one at Sandford Bay, Peterhead, and two at Longhaven, chosen following an “extensive review of technical engineering, commercial, planning and socio-environmental factors”.
A single location will be selected as the environmental impact assessment progresses following further surveys.
The ultimate landfall design will be subject to an Aberdeenshire Council planning application.
The scoping report also assesses impacts on areas like wildlife and shipping – as well as potential overlap with other energy developments.
Green Volt – an INTOG offshore wind project from Flotation Energy and Vargronn – is one such project, while the study notes a “potential” impact to shipping and navigation.
To mitigate that, a navigational risk assessment will be carried out.
Fighting North Sea emissions by 2030
The North Sea electrification scheme comes as the industry attempts to meet targets agreed with the government, which include a 50% cut in emissions by 2030 (against a 2018 baseline)..
For assets which will be producing beyond that time, electrification is seen as vital to hit those goals.
Xodus highlights that 71% of total UK upstream emissions in 2018-2020 were attributable to power generation, with the remainder mainly from flaring and venting.
Replacing fuel gas combustion for power generation with national grid power from shore is therefore “essential” to hit the 2030 target.
The report does not go into detail on the expected CO2 reduction for the specific platforms.
The project will also be eligible for subsidy from the UK Government under current legislation via the Energy Profits Levy (EPL), otherwise known as the windfall tax.
A revision in November 2022, which widened the scope of the levy, introduced an electrification sweetener.
Firms spending £100 on such decarbonisation projects will receive £109.25 back.
Petroleum economist Alex Kemp noted the “superdeduction”, adding that is “could be justified on the wider grounds of getting emissions down”.