LOOKING FOR WIND IN DEEPER WATERS

Chasing the wind; Deep-water turbine farms could overshadow near-shore projects like Nantucket Sound’s
Beth Daley, July 20, 2009 (Boston Globe)

SUMMARY
After years of contentiousness, the controversial Cape Wind offshore wind installation could be emerging just in time to be too late.

It is ironic. Cape Wind has been fighting for the right to go ahead since 2001. Yet now, with the U.S. Department of the Interior (DOI) clearing up jurisdictional disputes and granting licenses for exploratory projects off Delaware and New Jersey, with states like New York and Rhode Island moving ahead on projects, with the state of Massachusetts near completion of a plan that would designate areas for offshore wind development, now all that is not so important.

Deep water technologies are becoming available that would make the objections to offshore wind’s potential intrusion on the ocean horizon moot by moving it father out to sea, beyond anybody’s view. Installations need to be 20 miles off the coast to be beyond aesthetic complaints (although they are barely visible at 13 miles). At such distances, water depths have been considered prohibitively deeper due to the need for cutting edge turbine and transmission technologies to meet the challenges.

This conceptual view - almost view - of turbines has prevented Cape Wind from becoming the first U.S. offshore wind project since 2001. (click to enlarge)

The Cape Wind site would have required the use of no new turbine or transmission technology.

Developers now have deepwater technology and will soon be able to move far offshore into waters 100-to-200 feet deep, where winds are stronger and more consistent and objections are far fewer.

Despite advances in technology, deepwater projects do not come without challenges. The farther into the ocean environment they are built, the harsher the winds, waves, storms and corrosiveness. Deeper water is also father from the onshore demand centers, requiring longer seabottom transmission cables that must, of course, also endure the demands of the pitiless ocean world.

British offshore wind. (click to enlarge)

A 2-turbine project 12 miles off Scotland’s east coast is at present the only deepwater project in the world but pilot projects are underway and the technology is expected to prove itself in the near term.

A compromise strategy is likely to be used to move offshore development ahead. Developers will look for sites that are far enough offshore to avoid controversy yet in shallow enough waters to not pose severe technological challenges.

Danish offshore wind. (click to enlarge)

COMMENTARY
The proposed New England and mid-Atlantic projects so far in the planning and exploration stages are as near in as state waters, which end at the 3-mile line, and as far out as 48 miles.

New England and Mid-Atlantic coastal waters are generally regarded as ideal for offshore wind development because the continental shelf is wide and the ocean is shallow but the winds there nevertheless blow strong and steady. Cape Wind’s chosen site is right in that sweet spot – but was subjected to controversy because locals living on Nantucket Sound objected to having a wind installation as part of their ocean view.

There is not yet any definitive rule about the locating of an installation. Interviews with thousands of coastal residents by Willett Kempton, professor of marine policy at the University of Delaware, suggest 8 miles as a hypothetically acceptable distance, where visibility diminishes to the point that installations are not objectionable. But the surveys done have been about hypothetical installations. No conclusive data can be collected until it deals with real offshore projects, of which the U.S. still has none.

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No developer wants to have to endure what Jim Gordon, Cape Wind's developer, went through. Projects now being planned or proposed, such as Deepwater Wind’s Rhode Island installation and Bluewater Wind’s New Jersey and Delaware installations, are cautiously sited. New deepwater turbine technology will facilitate such siting.

Turbines sturdy enough to endure the ocean environment of deep waters farther offshore are much more costly. It is technology pioneered for offshore oil drilling. Instead of sinking a turbine column into the seabed, pilings are driven in, a platform is mounted on them and the turbine is built on the platform.

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The technology of harvesting wind in even deeper waters, like those on the West Coast or in the Gulf of Maine, has likewise been pioneered by deepwater oil drilling rigs. It requires very expensive, floating, cable-tethered turbines. A prospective installation using such turbines, not expected to be commercially viable for several years, has been proposed by Blue H for off New Bedford, Massachusetts, in 2011.

The University of Maine has proposed a deep-water wind research center to test such floating designs in its deep Gulf.

Meanwhile, Massachusetts may soon finally approve Cape Wind. The state recently passed a draft set of offshore energy guidelines.

It appears the development of offshore wind will come sooner and later, nearer and farther.

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QUOTES
- Walt Musial, principal engineer, NREL: “People do take Cape Wind into account and try to avoid the same kind of controversy… But the trade-off is that the deeper the project is, the greater the technical risk in terms of reliability, survivability, and . . . payback.’’
- Habib Dagher, director of the Advanced Structures and Composites Center, University of Maine: “Projects in shallow waters visible from shore have been proposed in the US and many have had public support but others have had some resistance…In Maine, our goal for large-scale commercial development is to go about 20 miles offshore so you don’t see the structures from land, and to capture the best winds. But it’s a big learning curve for that depth.’’

Artist's concept of a floating deepwater turbine. (click to enlarge)

- Jim Lanard, managing director, Deepwater Wind: “Our philosophy is as far from the coastline as possible…We think wind parks are a beautiful sight, but we understand some people don’t like them. The turbines can look - even though they are not - chaotically placed near shore because they are spinning at different times and speeds.’’
- Ian Bowles, Massachusetts secretary of Energy and Environmental Affairs: “We are going to need all this and a lot more…’’