The floating wind industry is still in its infancy but exciting growth potential and a close fit with aspects of offshore oil operations are starting to materialise in a pipeline of future projects.
Norway’s Equinor has led the way and is already building the world’s largest floating wind project, Hywind Tampen, which will provide an off-grid power system to the Snorre-Gullfaks oil and gas field.
The Saipem 7000 heavy lift vessel is being used for lifting and mating 162-metre wind turbine generators, each one mounted on a 91-metre concrete spar buoy, which is then anchored to the seabed.
Hywind Tampen's inner array and export cables are being installed by Subsea 7.
Markets such as California and the US East Coast, along with high-potential Asian markets such as South Korea, offer enticing prospects for growth, but floating wind is already on the move in Western Europe, where a fistful of new projects are moving toward the bidding stage in southern Mediterranean regions, north-western France and the North Sea.
"Floating wind will enter full-scale development in the second half of the decade, when it will increasingly be used for on-grid wind farm projects," says Philippe Gleize, managing director of Seaway 7, the renewables and heavy lifting arm of Subsea 7.
However, off-grid projects are in their infancy too and contractors see considerable growth in this field, targeting operators such as Eni, Total, Petrobras and Equinor in the North Sea and in Brazil, where reducing carbon intensity in deep-water production is likely to emerge as a key driver.
Both Saipem and Subsea 7 have made strategic investments in technology for floating wind, including platform design concepts.
Through its acquisition of Siem Offshore Contractors, in 2018, Subsea 7 has an equity stake in Ideol, a specialist in floating offshore wind foundation technology with demonstrator projects for its “damping pool” design in Europe and Japan.
Saipem has developed a lighter floating offshore wind substructure called Hexafloat, which uses an adjustable hanging counterweight to provide an adaptable foundation to cope with turbine sizes of up to 15 megawatts.
The structure's mooring lines and export cables will be attached to the seabed in a lazy-wave configuration, mirroring subsea methods used in the oil and gas sector.
The concept was tested in 2018 and is scheduled for a full-scale, one-year test in a hostile environment off the west coast of Ireland in 2022, as part of a project backed by the European Marine Energy Centre that aims to demonstrate the survivability and cost-competitiveness of floating offshore wind.
Equinor has also signed a two-year frame agreement with Saipem for the provision of engineering and assistance for the developer’s offshore and floating wind projects.
Although Saipem's own Hexafloat concept competes with other floating foundation designs, including barges, semi-submersibles and spar buoys, its work with Equinor does not exclude such concepts.
“We are not just a technology provider — we live off contracts and projects," says Guido D’Aloisio, Saipem’s head of offshore renewables.
"In the case of floating wind, we can bid for (contracts) involving fabrication and installation, whichever concept comes forward — whether spar, semisubmersible or tension-leg platform. We are also working hard on how to industrialise these structures, which are growing larger," he says.
"But we are also developing our own lighter concept and bringing forward the (Hexafloat) prototype. The feedback about motion from the turbine manufacturer has been very positive,” he adds.
The Saipem partnership with Equinor is not unique — Shell has forged a similar partnership with German utility Innogy and Stiesdal Offshore Technologies to develop and test the TetraSpar floating foundation concept.
Saipem also has broader ambitions for clean energy that are being carried forward by its XSIGHT business.
The company recently teamed up with Italian renewable energy developers Agnes Wind Power and Qint’X to lay the groundwork for an ambitious offshore project in the Adriatic Sea comprising offshore wind, floating solar and hydrogen technology.
The co-development will involve the installation of 56 turbines on fixed foundations on the seabed in the Adriatic Sea off the historic city of Ravenna.
Through XSIGHT — of which Moss Maritime forms a part — Saipem plans to launch similar projects in Sicily and Sardinia using floating foundations for wind turbines.
Moss's floating solar technology, designed as a flexible structure to minimise the impact of waves, can be integrated with the solution that Qint’X is studying to produce hydrogen directly from salt water.
The Agnes project was presented as the first to develop such integrated solutions, including opportunities to find alternatives to decommissioning oil and gas platforms.
“Our experience as offshore contractor gives us leverage to build on the potential synergy available from offshore wind, solar and green hydrogen,” D’Aloisio said.