PivotBuoy project receives funding to advance cost-competitive floating wind

By X1 Wind / Michael Rogers

X1 Wind aims to make a step change in the weight and costs of floating wind, using a weathervaning downwind design and a single point mooring system – PivotBuoy®
X1 Wind aims to make a step change in the weight and costs of floating wind, using a weathervaning downwind design and a single point mooring system – PivotBuoy® (illustration: X1 Wind)

PivotBuoy®, X1 Wind’s novel, single point mooring system platform, which could significantly reduce the cost of floating offshore wind, to receive EUR 4 million of EU Commission Horizon 2020 funding. A consortium of nine partners, led by X1 Wind, will deploy a prototype of the PivotBuoy, at a test site at the Oceanic Platform of the Canary Islands (PLOCAN).

Once proven, the technology stands to reduce platform weight by as much as 80% and costs by 50%, turning floating wind competitive. The project aims to validate the benefits of the PivotBuoy system and other key innovations to reduce installation, operation and maintenance costs, paving the path to achieve EUR 50/MWh in commercial scale wind farms.

Proven technologies
First backed by EIT InnoEnergy, Europe’s sustainable energy innovation engine, the platform can operate at an increased water depth, compared to other floating solutions, opening up hundreds of sites, which were previously technically or commercially inaccessible.

The system combines advantages of Single Point Mooring systems (SPM) with those of Tension-Leg Platform systems (TLP) and a more efficient downwind structural design, enabling a radical weight reduction in floating wind structures compared to current spar and semi-submersible systems.

Alex Raventos, CEO at X1 Wind, says, “In the last decade, a number of prototypes have successfully proven floating wind is technically feasible, but costs need to be reduced by at least 50%. Technology disruption is required to achieve large-scale competitive floating offshore wind. Together with a consortium of nine cutting edge R&D institutions and industry partners, we plan to demonstrate the advantages of our innovative PivotBuoy system. We are delighted to receive this important support from the European Commission.”

Part-scale prototype testing
The consortium will integrate a part-scale prototype of the PivotBuoy into a downwind floating wind platform designed by X1 Wind at PLOCAN’s test site. The system will be installed by 2020, where other innovations related to assembly and installation will be validated.

The project consortium combines experienced industry partners and R&D organisations from the offshore wind, naval and oil and gas sectors, and is formed by nine partners from six different countries: X1 Wind, ESM, WavEC, PLOCAN, EDP, INTECSEA, DTU, DNV GL and DEGIMA. The project will officially start on April 1 and will last for 36 months.

X1 Wind CEO and cofounder, Alex Raventos
X1 Wind CEO and cofounder, Alex Raventos (photo: X1 Wind)

Positive feedback
To find out more about X1 Wind’s plans for the PivotBuoy, Energy Northern Perspective queried Alex Raventos, CEO and cofounder of X1 Wind, who responded via email.

To give us an idea of the scale and scalablility – has the manufacturer/model of the wind turbine been decided? Will it use a full-sized “off-the-shelf” offshore wind turbine?

“We are in contact with several turbine OEMs who have shown strong interest in our disruptive technology, but technology disruption also brings challenges in a historically traditional sector. One of the challenges that we face is that, in order to maximise the cost reduction potential of floating wind, we propose a downwind turbine configuration, and most turbine OEMs currently offer only ‘upwind’ turbines. There is however increasing interest in downwind rotors, in particular due to the benefits they bring for larger rotors in offshore conditions with very strong winds.”

“For instance, there are a few OEMs that have recently installed already downwind turbines between 2 and 6 MW and working on 10- to 12-MW designs, and several leading R&D institutions such as NREL, DTU or CENER are working on larger downwind designs of up to 25 MW in the medium term. For this particular project, we are going to proof the technology at part-scale, converting a Vestas V27 225-kW ‘upwind’ turbine in a ‘downwind’ configuration.”

Could you describe the installation of the PivotBuoy prototype platform on site?

“The mooring system and electrical connection will be pre-installed on site, while the floating platform and turbine will be fully assembled at port and towed to site as a whole with a simple tug boat, eliminating the need of using large offshore vessels in the installation process.”

Are you considering “winterised” options for less temperate locations?

“Yes, we are working on a number of platform ‘types’, optimised for different climates, e.g. more temperate locations like the Canary Islands, Mediterranean or North Sea or extreme climates like the North-Atlantic or Pacific.”

What sort of feedback have you had from offshore wind farm operators/developers?

“We have received very positive feedback and letters of interest from a number of European utilities and developers. In particular, some experienced utilities in the offshore wind have raised the need of developing integrated floating solutions like ours instead of combining traditional ‘tower – turbine’ designs on the top of floating platforms in order to bring the costs of floating wind to the same level or lower than fixed solutions.”

“With this project, we want to demonstrate the performance, installability and maintainability of our solution, bringing critical learning and de-risking the technology before moving into full-scale projects.”