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Offshore wind represents a massive untapped resource and could go a long way toward addressing the approximately 4,000 TWh of electricity used in the US last year. [...]

"The reality is the platform behavior--its motions back and forth, its tilting behavior as a result of the waves--are very dynamically coupled with the behavior of the turbine, the bending of the tower, for example," Blom said. "By separately designing turbine and platform, you're essentially ignoring that coupling. That's what's driving inefficiency of overall design."

Blom and his colleagues investigated whether they could design a dynamic platform that could communicate with the turbine so the two could work together to manage the myriad forces acting on the combined structure. The researchers landed on a tension leg platform, which essentially looks like a pirate ship's anchor with many flukes instead of just two. Each of those flukes is then tethered to the seafloor.

Those tethers, or tendons, are key to the new GE design. "We're looking to make the platform active, allow it to adjust its positioning through active tendons, to ride with the waves, control the positioning as it's being moved back and forth, up and down with the waves, to ensure that it's safe," Blom said. "But we also want to ensure that all of those mechanical loads that the turbine would experience are as low as possible, while maximizing the resulting energy the turbine produces."

Wind turbines already actively manage the pitch of their blades and the torque of their generator to optimize energy production while minimizing fatigue. The new tension leg platform that Blom and his colleagues designed coordinates the turbine's responses with the tensioning or loosening of each tendon. All of this happens several times a second to continuously adjust the entire system.

The active design could trim up to 35 percent of the total mass of the platform, GE says, allowing wind developers to cut a significant driver of costs. It could also mean that a future platform may help install itself. Today, tension leg platforms require a special ship to bring the platform down to the correct depth. An active system could winch itself down, further reducing costs. How much money could be saved remains to be seen--the team has yet to do a full analysis of how the system would change the levelized cost of electricity, a key metric used to compare different sources of power, though it's in the team's plans. Currently, ARPA-E is looking to the next two-year phase of the project, which would result in a prototype that could be tested out at sea.

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