Seafarers and beachgoers know ocean winds blow strong and often. Wind energy developers know it, too. Hundreds of massive wind turbines already dot the seas around the U.K., Denmark, Germany and other countries—and developers are preparing to install the first U.S. offshore turbines in New England waters. That’s bringing a growing source of carbon-free—though still costly—electricity to power-hungry coastal cities.
The structures that hold most of these wind turbines above the waves are not viable on the West Coast, however, where the continental shelf drops steeply just a few miles from shore. The deep water makes pounding foundation pilings into the seafloor unfeasible.
But there’s a solution to this problem—floating turbines. The world’s first floating offshore turbine was built off the coast of Norway in 2009 as a demonstration project. And now, floating platforms may be the foundation for offshore wind projects on the West Coast.
A Seattle-based technology company called Principle Power and its partner, Providence, RI-based Deepwater Wind, want to put five floating platforms, each sporting a 6-megawatt turbine in the waters off of Coos Bay, a port city on the southern Oregon Coast. The site sits at the northern edge of an area of ocean stretching south roughly to San Francisco Bay that is raked by some of the strongest offshore winds in the country. “This is an exciting moment,” said Deepwater Wind CEO Jeff Grybowski. “It is the first real opportunity for the West Coast of the United States to take advantage of what we think will be an enormous power source for both coasts in the coming decades.”
The engineering is challenging. The floating platforms must be stable enough to support a wind turbine with blade tips reaching 600 feet above the ocean’s surface. They must be strong enough to survive powerful storms and 50-foot waves. The electricity generated must reliably travel 18 miles back to shore. And the high costs of the first demonstration projects must be reduced for floating wind power to compete with traditional offshore wind turbines, and other energy sources.
But Principle Power, which has staff in Portland, OR, Berkeley, CA, and elsewhere, believes its technology is viable. It has already demonstrated as much on a smaller scale in Portugal. And in recent weeks, the project, called WindFloat Pacific, has gained momentum. In early May, Principle Power snared a $47 million federal grant from the Department of Energy—one of three awarded to innovative offshore wind projects. At the same time, the company joined forces with Deepwater Wind, which is developing a traditional fixed-foundation, 30-megawatt offshore wind project off of Rhode Island, and which also won last summer’s initial federal auction of offshore wind power leases, outbidding two competitors and taking the rights to develop wind energy in a 250-square-mile area off Rhode Island and Massachusetts. Under its agreement with Principle Power, Deepwater will be responsible for the commercial agreements, financing, and permitting for WindFloat Pacific, while Principle will be the platform technology provider. In the best case, the floating turbines could be installed in 2017.
Overall, the potential for offshore wind energy is enormous. U.S. waters, including the Great Lakes, have a “technical wind energy potential” of 4,150 gigawatts, according to a 2010 Energy Department study. That’s about four times the current capacity of all U.S. power plants.
Of course, only a fraction of that resource might realistically be developed. The Energy Department’s 2011 National Offshore Wind Strategy (PDF) calls for 54 gigawatts of wind generating capacity to be built in U.S. waters by 2030. That’s still roughly equivalent to the capacity of about 50 nuclear power reactors and is 10 times the amount currently installed globally, mainly in Europe, which is leading the way in this industry.
While offshore wind in general is more expensive than building wind farms in Iowa cornfields or on California hilltops, it has a number of advantages. The ocean winds are typically stronger and more consistent. And offshore turbines are located relatively near to coastal population centers, avoiding the need for access to crowded high-voltage transmission lines—a bottleneck for projects in the nation’s windy interior.
Floating wind turbines bring additional advantages over fixed units. Because they can
