Subsea Substations Float New Thinking for Offshore Wind

This is certainly the view of Aker Offshore Wind. In October, the company outlined plans to develop, manufacture, and supply Scotland’s first offshore wind underwater substation under the Scotwind licensing program. Installing substations on the seafloor, according to Aker Offshore Wind, could bring considerable advantages to offshore operations. Notably, seawater could be used as a natural cooling system —stable temperatures ultimately mean greater reliability and reduced maintenance costs—and undersea substations would require fewer components and rotating parts.

Aker Offshore Wind has teamed up with Ocean Winds to submit a series of floating bids which could deliver up to 6,000 MW—enough energy to power millions of homes—in the Outer Moray Firth, in the North Sea. The substations would be produced by Aker Solutions, a sister company of Aker Offshore Wind and a key supplier to UK wind projects.

Floating wind technology is still in its infancy, but its potential is staggering. Most offshore wind turbines have fixed foundations and so, due to lateral loads and other environmental factors, can only be installed in depths of up to approximately 50 meters. Floating turbines, however, are tethered to the seabed by mooring lines and so can exploit deeper waters, where winds tend to be stronger and more abundant. Estimates suggest that 80% of potential offshore wind is found in deeper waters.

So, with falling technology costs and the fact that positioning floating turbines further offshore mitigates the NIMBY (Not-In-My-Back-Yard) sentiment, it is little wonder why offshore developers are so interested in technological breakthroughs like Aker’s proposed subsea substation.

Technologies that essentially champion the scalability of floating offshore wind will be of huge interest to investors in the US energy mix. The current Administration’s pledge to deliver more than 30 GW of offshore wind by 2030 will hinge somewhat on the viability of floating wind infrastructure. In fact, The Department of Energy has reportedly already invested more than $100m in researching and developing floating offshore wind technology in an attempt to establish itself as a leader in the sector.

SCALING UP

Back in Scotland, the hope is that Aker Offshore Wind and Ocean Winds can bring world-leading innovation to scale:

“Both the Aker group and Ocean Winds have the necessary heritage and experience to deliver this at scale. We know the benefit is there—it will revolutionize how energy is produced and present Scotland with the opportunity to export genuinely innovative technology to the rest of the world,” said Sian Lloyd-Rees, managing director of Aker Offshore Wind UK.

“Through innovation, we have the opportunity to implement new technology in the ScotWind leasing round, making Scotland and the UK a global leader in subsea solutions for floating offshore wind and exporting the technology around the world.”