David Appleyard, Senior Editor, Renewable Energy World
October 07, 2013 | 5 Comments
Christopher Long, Manager of Offshore and Siting Policy for the American Wind Energy Association (AWEA) described the development as "another signal of steady progress toward development of an American offshore wind industry."
With the support of a $12 million Energy Department investment over five years, at 65 feet (20 meters) the VolturnUS prototype is a 1:8th scale of the planned 6-MW commercial version.
It features a semi-submersible platform using a concrete foundation, claiming lower costs, in addition to a composite tower. As part of the five-year project, the Maine Maritime Academy helped test and conduct analysis on the design while Cianbro Corp. constructed the system.
Late last year, the University's Advanced Structures and Composites Center was also awarded $4 million by the DoE to support another deep-water floating offshore wind research project. The program, known as Aqua Ventus I, will be a 12-MW demonstration wind park using VolturnUS machines.
The $4 million will cover the first phase of a potential $93.2 million of DoE support and the Composites Center was one of seven projects selected to complete the engineering, design and permitting phase.
Up to three of these projects are expected to be selected in 2014 for follow-on phases that focus on siting, construction and installation, with the aim of achieving commercial operation by 2017. The projects will receive up to $47 million each over four years, subject to Congressional appropriations.
Several floating turbine concepts are among the seven projects chosen for the first phase of this six-year initiative. These include a project from Statoil North America, which plans to deploy four 3-MW wind turbines on floating spar buoy structures in the Gulf of Maine off Boothbay Harbor at a water depth of approximately 460 feet (140 meters), although that project was recently put on hold. On the Pacific Coast, Principle Power plans to install five semi-submersible floating foundations outfitted with 6-MW direct-drive offshore wind turbines in deep water 10 to 15 miles (16-23 km) from Coos Bay, Oregon. These projects join DeepCWind's plans to install a pilot project with two 6-MW direct-drive turbines on concrete semi-submersible foundations near Monhegan Island in the 2015-2017 timeframe.
Setting the Standard
If any clearer indication were required that floating wind turbine technology is rapidly maturing, DNV KEMA recently released its new standard for such structures.
This follows the September 2011 launch of a Joint Industry Project (JIP) focused on floater-specific design issues, such as station keeping, site conditions in relation to low frequency motion, simulation periods, higher order responses and design of structural components. DNV KEMA has been joined on the project by the likes of Statoil, Nippon Steel & Sumitomo Metal Corporation, Gamesa, Iberdrola, Alstom Wind, Glosten Associates and Principle Power.
Commenting on the new standard and effectively summarizing the evolution of deep water wind, Johan Sandberg, head of renewable energy at DNV KEMA in Norway, remarked: "As demand for wind energy increases, we predict offshore deployments will continue to move into deeper waters and, consequently, there's a need to establish design standards that will help ensure safety, reliability, and confidence in future wind turbines.
"Recent successful deployments of full-scale prototype configurations have demonstrated that floating wind turbines can be a viable alternative and the market is taking notice.
"It is now time to take the next step: standardization," he concluded.
Image: Hywind on location via Trude Refsahl, Statoil
With over 52,000 subscribers and a global readership in 174 countries around the world, Renewable Energy World Magazine covers industry, policy, technology, finance and markets for all renewable technologies. Content is aimed decision makers...