Atlantic Wind Power

November 11, 2010

The forces of nature were very important to the ancients; so much so, that they were deified. The Greek god of the wind was Aeolus, and his minions were the four winds that were identified with the four geographical locations. As is the case today, the winds were identified by the direction from which they came, rather than the direction to which they were blowing. Boreas was the North Wind, Notus was the South Wind, Eurus was the East Wind and Zephyrus was the West Wind. Several of their names survive today, since we have such things as the Aeolian harp and the Aurora Borealis. In the future, there may be a new wind god named Google.

Portion of Hesiod's Theogony (ll. 378-380) dealing with Zephyr, Boreas and Notus (Scan of author's copy [1])

As I wrote in a previous article (Cool Data, October 4, 2010 ), server farms consume a tremendous amount of electrical power. Because of this, companies such as Google are becoming very interested in alternative energy sources. Google's headquarters consumes about 22 megawatt-hours of electricity daily, but it strives to derive about a third of that electrical requirement from more than 9,000 solar panels on the headquarters roof.[2-3] Now, Google has greater ambitions in alternative energy with a huge investment in an electrical transmission backbone for wind farms along the Atlantic Seaboard. Construction for this venture, called the Atlantic Wind Connection, could start as early as 2013.[4-8]

Google Energy is a 37.5% stakeholder in a consortium of companies that invested in the planning stage of this $5 billion project that would construct an undersea transmission cable about twenty miles offshore. This venture was the brainchild of Trans-Elect, a Maryland transmission line company. An initial phase would connect southern New Jersey and Rehoboth Beach, Delaware; and a later stage would connect Norfolk, Virginia, to the south; and northern New Jersey and New York City in the north. The entire 350 mile transmission system, as shown schematically in the figure, could be completed by 2021. Although the eventual objective is a transmission means for offshore wind farms, the cable will initially be used to bring cheaper electricity from Virginia to the New York metropolitan area. The cable will have a six gigawatt capacity. For comparison, an average US household consumes about 920 kilowatt-hours per month (1.28 kW average consumption), so the transmission line is capable of serving about four and a half million homes. A nuclear reactor has about a gigawatt of power generation capability.

"X" marks the spot. Potential wind farm locations are marked with an X on this map of the Atlantic Seaboard. The proposed transmission line, shown in red, sits midway between the coastline and the edge of the continental shelf. Landfall distribution hubs are shown as red circles. (Map: USGS)

There are quite a few selling points for this system. Wind turbines that far offshore will not be visible, which eliminates the major objection to the Cape Wind project of similar wind turbines in the waters off Cape Cod, Massachusetts.[4] Even environmental groups like the concept. The undersea transmission line eliminates the need for each wind farm to lay its own transmission line to shore. Furthermore, placing the cable beyond the three mile limit eliminates any problems with state approvals. All that's needed is approval at the federal level, from the United States Department of the Interior. According to the New York Times, government officials have praised the idea as ingenious. Jon Wellinghoff, chairman of the Federal Energy Regulatory Commission, is quoted as saying, "Conceptually, it looks to me to be one of the most interesting transmission projects that I've ever seen walk through the door."[4]

Every part of this wind system is larger than its land counterpart. Typical land wind turbines have a 1.5 megawatt capacity. The coastal wind turbines, which would have ninety meter hubs and sixty meter blade lengths, will generate anywhere from 5-10 megawatts. One production problem is that there are no US manufacturers that make such turbines. They're made in Denmark and Germany.[6] The transmission system would be high voltage DC , rather than land-use high voltage AC, so they will require less copper. Even so, the cables will be huge, six inches in diameter, weighing thirty pounds per foot, with about two inches of outer insulation and mechanical shields.[6]

One advantage of this extended configuration of wind farms is that it mitigates the problem of the inherent variability of winds. A study by scientists at the University of Delaware and Stony Brook University analyzed five years of wind data along the East Coast. Since storm tracks usually follow the seaboard from south to north, the wind power will transit from southernmost stations to those to the north, thereby reducing variability.[4] Dana Veron, a meteorologist, and an assistant professor at the University of Delaware, says that research has "demonstrated there [are] very few periods of time with little or no power."[5] The U.S. Department of Energy estimates that the project could create more than 43,000 permanent jobs by 2030.[6]

References:

1. Hugh G. Evelyn-White, Translator, "Hesiod: The Homeric Hymns and Homerica," Loeb Classical Library (The Macmillan Company, New York, 1914), p. 104.
2. Robyn Beavers, "Corporate solar is coming," Google Blog, October 16, 2006.
3. Google Inc. Builds Massive Rooftop Solar Panel Array, Solar Panel Dot Com, May 21, 2009.
4. Matthew L. Wald, "Offshore Wind Power Line Wins Backing," New York Times, October 12, 2010.
5. Rick Needham, "Official Google Blog: The wind cries transmission," Google Blog, October 11, 2010.
6. J. Okray, "Banking on Connections to Spur Offshore Wind," National Geographic News, October 13, 2010.
7. Matthew L. Wald, "An Undersea Trench for Wind Power?" New York Times Blog, October 12, 2010.
8. Juliet Eilperin, "Google helps finance 'superhighway' for wind power," Washington Post, October 12, 2010.
9. Anders Bylund, "Google Enters the Solar Industry," Fool.com, September 11, 2009.