Can Floating Turbines Save Wind Power?
The best place to build the wind farms of the future is the open ocean. While the breeze can be frustratingly variable on land, if you travel just 20 miles off the coastline, the wind blows at a consistent clip of around 33 feet per second.
But along most parts of the coastal United States, the ocean floor drops off quickly. That makes standard offshore turbines, the kind that are fixed to the sea bottom for stability, too expensive to be worth it. Two companies, Sway and Principle Power, are currently testing a new kind of technology to combat this problem: floating wind turbines.
Principle’s turbine is called WindFloat; the company has a prototype currently working in the waters off Portugal. It sits atop a base formed by three pontoons anchored to the seafloor by cables. Its 240-ton nacelle (gear housing) turns to meet the breeze, the way a land-based turbine does.
Sway’s prototype, operating in Norway, is more of a small tower. Its center of gravity lies below the structure’s center of buoyancy, which lets it stay upright even in stormy seas. With Sway, the entire tower rotates to get in the best position to capture wind.
Though these prototypes are currently in Europe, the United States is keeping a close eye. The Department of Energy, which estimates that wind power could cover 20 percent of our energy needs by 2030, has contributed funding to both systems. The hope is that offshore wind power can alleviate some of the problems hampering that energy source in America now.