Offshore wind farms being proposed for the Atlantic Ocean and Gulf of Mexico sit in hurricane paths and as a result, almost half of the planned turbines for these farms could be destroyed over a 20-year period.
The U.S. Department of Energy has proposed 20 percent of the nation’s energy by 2030 will come from wind, with one-sixth of that amount coming from shallow offshore turbines in known hurricane tracks.
Pittsburgh’s Carnegie Mellon University conducted a study on four proposed offshore wind farm sites and their connection to hurricane risks, and found maximum turbine wind speeds are not designed to meet maximum wind speeds created by hurricanes, but advanced planning could help reduce these risks.
“The U.S. Department of Energy has estimated that if the U.S. is to generate 20 percent of its electricity from wind that some 50 GW (gigawatts) of power will have to come from offshore turbines that may be vulnerable to hurricane damage,” said Paulina Jaramillo, in a university news release. “While no offshore wind farms have been built in the U.S., there are several in advanced stages of planning.”
The study, published in the Feb. 13 edition of Proceedings of the National Academy of Sciences (PNAS) focused on near-offshore areas of the Atlantic and Gulf where the most accessible wind resources are available and found more than 90 hurricanes hits these areas between 1949 and 2008.
A multimillion-dollar lease for a wind farm site near Galveston, Texas is “the riskiest location to build a wind farm of the four locations examined,” said Stephen Rose, a researcher on the team, New Scientist reports.
There are currently around 1,200 wind turbines along the coasts of China, northern Europe and Japan. In 2003, Typhoon Maemi destroyed seven turbines near Okinawa, Japan and Typhoon Dujuan damaged several turbines in China.
In their PNAS paper, the research team recommends developing reasonable safety measures, including increased design requirements and backup power for turbine motors which would allow wind tracking, thereby reducing serious hurricane damage.
Each of these wind farms could cost $175 million. “We want these risks to be known now before we start putting these wind turbines offshore,” said Jaramillo, NS notes. “We don't want any backlash when the first one goes down and it costs a lot to replace.”