Green light for new deep water energy platform
A prototype structure has demonstrated the potential of the floating platform at a test location off the Portugal coastline.
Floating wind turbine technology set to exploit offshore power potential
Approval in principle has been granted to a second generation floating wind turbine foundation which has been developed to produce clean, sustainable energy in previously inaccessible deep water regions.
Global classification society Bureau Veritas has given a green light to the WindFloat floating offshore wind turbine (FOWT) foundation - designed by Principle Power - following extensive tests off the Portugal coastline. Based in the United States, Principle Power is an innovative technology and services provider for the offshore deep water wind energy market.
Although wind energy is recognised as a sustainable and increasingly reliable way to produce renewable energy, the offshore industry has faced barriers and objections over its potential visual impact and transmission costs. The WindFloat concept gets round these issues with an innovative and economic approach.
Depth insensitivity means these new wind production structures can be located out of sight, far out to sea, with undersea cabling providing unobtrusive direct transmission paths to shore. A prototype version of the WindFloat technology, sited five kilometres (over three miles) off the coast of Aguçadoura, has successfully demonstrated the concept feasibility by producing and delivering more than 16GWh of electricity to the grid.
The second generation of the floating wind turbine technology, which now has technical classification approval, could have a profound impact on the industry in terms of reducing costs and the risks associated with installing and operating offshore wind turbines. This new offshore platform is scheduled to form part of a pilot array of floating wind turbines in the Mediterranean Sea, an offshore project being developed by the French multinational electric utility company Engie and the construction group Eiffage.
The floating platform supports a multi-megawatt wind turbine generator and is moored with a three-line catenary stabilising system. The unmanned three-column platform is equipped with a closed-loop ballast system to compensate for changes in average wind speed and direction.
Innovative features dampen wave and turbine-induced motion, enabling wind turbines to be sited in harsh, previously inaccessible areas of the ocean at depths of over 40 metres (130 feet) and where wind strengths are more powerful which, inevitably, increases energy production. Deep water offshore wind installations have, in most cases, not been feasible before because of economic and technological issues.
The design of the WindFloat enables the structure to be fully assembled onshore and towed to its deep water offshore location. All fabrication and qualification is completed at quayside in a controlled environment. Deployment cost savings are said to be significant in comparison with monopole and jacket support structures which require cost and time-consuming offshore heavy-lift operations.
Principle Power claims that the WindFloat foundation provides several important advantages, including:
• lower costs and reduced risks during both installation and in operation
• its design and fabrication methodology mean the entire platform, including turbine, can be assembled onshore, removing the need for specialised, expensive installation vessels
• the structure has minimal environmental and ecological impact on the seabed
• the design is ideally suited for deep water locations with varied underwater landscapes.
“FOWT technology will help exploit clean renewable offshore wind power," says Matthieu de Tugny, senior vice president and head of Offshore at Bureau Veritas. "It offers substantial advantages over fixed offshore wind turbines as the entire unit can be assembled ashore and FOWTs can be installed in deep water. There is also a much lower environmental impact from their installation."
During their assessment investigations, Bureau Veritas' engineers verified design methodologies covering hydrodynamics, structure, stability, electricity and machinery to check that the innovative design is suitable for use in all phases of operation including towing to the offshore location, installation, hook-up, commissioning and operations.
“We’re very pleased to receive this endorsement of our technology from such an esteemed body as Bureau Veritas," says Joao Metelo, president and chief executive officer at Principle Power. “It’s another important step for Principle Power as the WindFloat establishes its commercial readiness."
