When Equinor announced at ONS 2018 that it was exploring the possibilities of supplying two of its oil and gas platforms with power from floating offshore wind, it marked an important step in the evolution of reducing the carbon footprint of producing hydrocarbons. The forecast is that it would result in a reduction of CO2 emissions of more than 200,000 tonnes per year, equivalent to the emissions from 100,000 cars.

If approved, the project will mark the first time an offshore wind farm is directly connected to oil and gas platforms.

“A lot of hard work remains. We must further mature the concept and reduce cost, have a regulatory framework in place and get sufficient financial support from Enova before a potential FID [final investment decision] next year,” said Pål Eitrheim, Equinor’s executive vice president for New Energy Solutions.

“This is an innovative project that demonstrates what we want to achieve on the NCS [Norwegian Continental Shelf], while at the same time it may pave the way for technology development and new industrial opportunities for Norway, Equinor and Norwegian supplier industry within profitable renewable energy.”

The project is part of Equinor’s quest to reduce the carbon footprint of its oil and gas production. Earlier this year the company said the giant Johan Sverdup Field will be powered from the onshore grid.

The Snorre and Gullfaks fields, located in the Tampen area of the northern North Sea, were selected for the project after extensive work to evaluate which oil and gas installations on the NCS were suitable for power supply from a floating offshore windfarm.

“We have assessed the CO2 reduction potential as well as cost and technical feasibility,” Eitrheim added. “Power cables from the wind farm will be connected to Snorre A and Gullfaks A. Both will distribute power further to the other installations on the field. The existing gas turbines will then work as backup power.”

The plan is to install 11 8-MW Hywind turbines, Equinor’s floating offshore wind concept. The 8-MW turbines will have a combined capacity of 88 MW and are estimated to meet about 35% of the annual power demand of the Snorre A and B and Gullfaks A, B and C platforms. In periods of higher wind speed this percentage will be significantly higher.

The floating wind turbine design features a single floating cylindrical spar buoy that is moored to the seabed by three cables or chains that have 60-tonne weights hanging from the midpoint of each cable to provide additional tension. The construction is ballasted so the turbine floats in an upright position. The arrangement allows the turbines to be placed in deep water, something that would have not been possible with traditional offshore turbines that are secured to the seabed. Each turbine is controlled onboard, so the pitch of the blades can be altered to dampen the motion of the tower and maximize production.

Eitrheim explained that the task of reducing the use of gas turbines by supplying platforms with power from floating offshore wind was a challenging and innovative project.

“The Hywind Tampen project is contributing to further developing floating offshore wind technology, reducing costs and making the solutions more competitive,” he added.

The expected capital and development expenditures for the project are about $590 million, but the aim is to reduce that over the lifetime of the project. Investment of $67 million for the project will come from the industry’s NOx fund, the Norwegian fund that supports efforts to reduce nitrogen oxide (NOx) emissions.

In addition, Norwegian authorities have, through their offshore wind strategy and Enova, offered financial support for innovative offshore wind projects associated with the oil and gas industry. The Snorre and Gullfaks partners have applied for support from Enova’s program for full-scale innovative energy and climate measures to realize the project.

Equinor’s partners at Gullfaks include Petoro and OMV, while it is joined at Snorre by Petoro, Exxon Mobil, Idemitsu Petroleum, DEA Norge and Point Resources. The seven Snorre and Gullfaks partners in the Tampen area in the North Sea will mature the project toward a possible investment decision in 2019.

“This is still a groundbreaking and challenging project that requires optimization of the technical solutions and further cost reductions before the partners can make a potential investment decision,” said Olav-Bernt Haga, Equinor’s project director.