Massive waves, howling winds test turbines in ‘mini ocean’

Source: Christa Marshall, E&E reporter • Posted: Monday, November 30, 2015

The University of Maine is opening a first-of-its-kind “miniature ocean” today that can demonstrate how everything from floating wind turbines to coastal cities may react to “some of the worst storms possible anywhere on Earth.”

The impetus for the $13.8 million project — which involves a massive wave pool tied to a rotating wind machine — is to accelerate the development of renewable ocean energy technologies like offshore wind and tidal devices, said Habib Dagher, director of the university’s Advanced Structures & Composites Center in Orono, Maine, which will operate the new Harold Alfond W² Ocean Engineering Lab. It also can prepare local communities for more intense storms associated with climate change by simulating future conditions, he said.

“There are wave basins out there, there are wind tunnels out there, but no one to our knowledge has put a rotating wind tunnel on top of a wave basin, particularly one that can produce extremely high-quality winds, including modeling wind shear,” he said in an interview.

The engineering lab — which has been in the works for six years — is 100 feet long and 30 feet wide with a fluctuating depth that can increase by up to 15 feet. “The bottom floor of the basin can be moved up and down to simulate changing ocean water depth,” said Dagher. Models of coastal cities could be used with the simulator to assess the effects of rising sea levels.

The W² Ocean Engineering Lab has just completed testing of a new wave energy device, Dagher said, and there are a “few more wave energy clients lined up.” They also are readying the device for testing of a floating offshore wind turbine technology, and there has been interest from companies in boatbuilding, coastal construction and aquaculture, as well, he said. There also is a role for testing oil and gas structures and infrastructure like bridges and ports vulnerable to powerful storms, according to the university.

At scale, the basin can model wind speeds of more than 200 mph and waves more than 100 feet high, he said. The structure is designed so that the wind and waves can come from any direction, paralleling the dynamics of the ocean.

Maine Sens. Susan Collins (R) and Angus King (I) and officials from the Department of Energy and U.S. Economic Development Administration are expected to attend the dedication of the project, which was funded by the National Science Foundation, U.S. Department of Commerce, Economic Development Administration, National Institute of Standards and Technology, Maine Technology Institute, state bonds, and the Harold Alfond Foundation.

“The world-class research capabilities this lab will provide in ocean engineering and advanced composites manufacturing will help secure Maine’s place as a national leader in the ocean economy of the future, help advance our industrial competitiveness in boatbuilding and renewable energy such as offshore wind and help ensure the resiliency of our coastal communities,” Collins said in a statement.

Currently, there are no full-scale, multiple-device commercial deployments in the United States of marine and hydrokinetic technologies, which convert the energy of waves, tides and ocean currents into power, according to DOE. The harsh conditions of the ocean — along with high costs — have been a significant deployment barrier. The waters near Maine, however, are considered one of the prime spots to test marine technologies, and DOE estimates the recoverable ocean-based energy potential in U.S. waters is 2,195 terrawatt-hours per year (Greenwire, Nov. 11, 2014).

Tidal stream power — which has strong potential in the United Kingdom, France and Canada — is further along than wave power, said Angus McCrone, chief editor of Bloomberg New Energy Finance, which forecasts 19 megawatts of wave power installed worldwide by 2020. There have been several company failures with tidal power in the past two to three years, McCrone said, but “it could be a huge market one day,” in the late 2020s or 2030s.