Offshore Wind Power

Using wind for power? Nothing new about that. Humans have relied on wind as a renewable resource for hundreds of years. Modern wind energy currently provides about 2% of worldwide energy use; and as clean and renewable as it is, that percentage should grow in the near future.

One of the places it may grow most lies miles from land. Offshore winds are much stronger and offshore wind farms aren’t limited to oceans—they can also be set up on lakes and rivers.

China, already a major player in the wind power game, will start its first offshore wind farm in the Yangtze River delta this month. According to an article this week on the website of Popular Science, “Energy experts predict that China will have invested $100 billion to install 30,000 megawatts of offshore wind power by 2020. Such projects would help supply energy to 40 percent of China's population that lives along the eastern seaboard.”

Europe already has around 30 operating projects but in the U.S., offshore wind farms are still just in the planning and permitting phase. The East Coast is close. According to Monday’s Technology Review, the permitting process is taking a long time, but “last week Cape Wind, which has proposed a wind farm off Nantucket, announced it had ordered 130 turbines.”

A paper published earlier this week in the Proceedings of the National Academy of Sciences may further boost wind power in that area. Scientists from the University of Delaware studied five years of wind data from eleven meteorological stations along the East Coast, trying to answer the challenge of fluctuating offshore winds in maintaining a steady power supply.

They found that if they connected proposed offshore wind farms along 1500 miles of the Atlantic, while the wind may die down in some areas, it will pick up in others. According to the paper, “The output from the entire set of generators rarely reaches either low or full power, and power changes slowly,” making it a consistent source.

And what’s happening on our coast right now in terms of offshore wind power? “Not much, yet,” according to PG&E’s Uday Mathur, a Principal in Emerging Clean Technologies. Despite the fact that Stanford came out with a report about the offshore wind potential of California at 75GW, the realities are a little more difficult to achieve.

The main hurdle? Water depth. The continental shelf off California falls off so quickly that the wind turbines that are used elsewhere would be too close to shore in California to be practical.

A floating structure to support a wind turbine could be a solution in our deeper waters, according to Mathur. In fact, he hopes it is. “PG&E would become more interested in offshore wind as floating platforms become more proven and cost-effective. We are continuing to work with industry participants to evaluate the opportunity.”  A handful of companies are currently working on the technology, one even locally.

With a little more time and technology, offshore wind power could be everywhere. Good thing Don Quixote wasn’t a sailor.



Creative Commons image by Phil Hollman