North American Windpower reports that a team of researchers that includes Sanjay Arwade and Don DeGroot from the Civil and Environmental Engineering Department at UMass Amherst is developing a new mooring system for floating offshore wind turbines which uses an integrated network of anchors and lines to hold dozens or even hundreds of turbines in place for ocean-based, industrial-scale, offshore, wind farms. See News Office release.
The team, which includes Charles P. Aubeny from Texas A&M University and Melissa Landon of the University of Maine, is conducting the research with a three-year, $497,341 grant from the National Science Foundation. The research team is working with Vryhof Anchors, an international industrial partner that is a world leader in producing offshore anchoring systems, including the one used by the world’s first floating offshore wind turbine in Norway.
“This project is an exciting opportunity to bring together structural dynamics and geotechnical engineering in new ways to support national renewable energy goals by potentially lowering capital costs associated with offshore wind development,” Arwade says.
The team is also looking at the best designs for the mooring lines, the connections between the floating wind turbine and the anchors, says Arwade. They will develop three-dimensional models for measuring the behavior of the anchors on the sea floor and the best designs for the multiple cables attached to each anchor.
“At each level, the floating structure and the anchor, there are challenging nonlinear and dynamic issues that force this research to work at the cutting edge of geotechnical engineering and offshore structural engineering,” Arwade says. “For that reason it also provides a perfect opportunity to educate the next generation of researchers in the area of offshore wind energy, and is supporting a doctoral student towards that end.”
According to the North American Windpower article, the principal goal of the research is to develop projects in which floating turbines are moored using a networked series of anchors and cables to hold the entire wind farm in place. With current projects, each floating wind turbine has its own individual anchoring system. However, according to the researchers, their proposed system would save money and require fewer anchors and geotechnical site investigations.
In order to accomplish this goal, the researchers plan to evaluate the feasibility and design implications of highly variable soil conditions on the ocean floor for securing the anchors, the layout of the wind farms, and the complicated dynamics that cause loads on the anchors. In addition, the scientists will be developing wind and wave models for the best placement and orientation of the wind farms. (March 2016)