The Gjøa field, located off the Norwegian coast includes the world’s first dynamic high-voltage (HV) cable system. The floating oil and gas platform located at 380 m deep water depth is energized through a 98 km long 115 kV AC power cable which was laid from shore at depths of down to 540 m.
One of the greatest challenges, and one which made Gjøa the world’s first of its type, is the dynamic section of the cable that rises up from the sea floor to the floating platform. The power link was put in operation in 2010 and is designed to accommodate extreme environmental conditions and the platform’s movement during a full lifetime.
Proven reliability by a decade in operation
The development and qualification work performed within the cooperation in the Gjøa project, combined with that the link has been in service more than a decade, has proven that dynamic cables are robust and reliable solutions. We have continued to build on that experience with the electrification of the Goliat FPSO, Martin Linge and in the ongoing Troll project. Dynamic cables are now a serious candidate for high voltage applications for the electrification of floating platforms, vessels and offshore wind application.
Important success factors for the Gjøa project included a proactive verification of the transmission concept as well as an early validation of the technology. A development in close collaboration with the customer, interface partners and cable manufacturer has been paramount for the success both in the development and execution phase.
Existing dynamic technology to support renewable energy targets
In addition, the dynamic cable system technology developed to energize floating oil and gas platforms with power from shore is foreseen to serve also in floating wind applications, where power needs to be transmitted to shore by export cables. This is also in line with the ambitious targets from the European commission (the European Green Deal) that Europe shall be carbon neutral by 2050. The interconnected offshore wind strategy for EU implies that the amount of offshore wind power to be transferred by submarine cable systems is to increase from today’s 16 GW to 300 GW by 2050.