Floating Wind Farms in the North Atlantic Could Power the World
Wind-power generation in the North Atlantic would provide three times as much power as land-based systems, but costs remain a significant challenge.
The American Midwest is sometimes called the “Saudi Arabia of wind,” thanks to the mighty, turbine-twisting gusts that blow across the plains.
But that title might better apply to the North Atlantic, according to a new paper that provides fresh support for the developing field of floating wind power.
Wind farms in some parts of the North Atlantic could produce three times as much power as land-based sites, the study found, thanks to the particularities of weather patterns over the open ocean. In fact, the smallest floating wind farm considered in the new study — with a footprint of 70,000 square kilometers — could provide all of America’s electricity for 10 months every year.
At the upper end, the study concluded, the North Atlantic could generate enough energy to meet all of civilization’s needs, provided it could be utilized economically. You read that right: enough energy for everyone on Earth.
“The road might be difficult, but the prize at the end of the road is tremendous,” Ken Caldeira, climate researcher at the Carnegie Institution for Science in California and one of the authors of the new study, told Seeker. “Making these technologies cheap enough is the challenging part.”
The traditional, fixed-bottom wind turbines that are typically found offshore stand on foundations driven into the seafloor. That places a firm limit on how far wind farms can be built from dry land. Now, the race is on to move those turbines farther out into the open water by allowing them to float on the surface.
A major milestone in the field is about to be passed: The world’s first-ever floating wind farm is gearing up to begin commercial production in late 2017 off the coast of Scotland. Known as Hywind, the project aims to power about 20,000 households from a distance of 25 kilometers (16 miles) from the shore.
Floating, deepwater wind farms in the North Atlantic would produce more electricity because the individual turbines wouldn’t interfere with each other in the way they do on land, according to the paper’s lead author, Carnegie’s Anna Possner.
“The wind farms themselves generate substantial drag,” Possner told Seeker. That drag places an upper limit of about two watts per square kilometer for a land-based wind farm, Possner said.
But windspeed can recover more rapidly over the North Atlantic, according to Possner and Caldeira’s paper, published Oct. 9 in the Proceedings of the National Academy of Sciences.
“As you extract kinetic energy near the surface from the wind farms, this energy can get replenished from upper-level wind,” Possner said.
The question now, Caldeira said, is how to handle the engineering challenges presented by constructing a large, floating wind farm many miles from the shore in a way that’s competitive with cheaper forms of energy like natural gas. One problem, Caldeira points out, is that transmission cables would likely need to be laid across great distances of the ocean floor and then rise up to meet the floating turbine, stressing cables that would be difficult to repair if damaged.
“This is an industry in its birth stage,” he said. “It really does look like the open-ocean environment can sustain a lot more power generation than on land. But making these technologies cheap enough to compete will be challenging.”
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