The offshore wind-industry trends are just taking shape, but they seem to center around the turbines, their foundations, and the equipment and vessels needed to place them. That an offshore industry is testament to the persistence of Cape Wind developers (10 years of persistence) and finally, an accommodating administration that has opened the doors to more wind plants in U.S. waters. Building offshore presents a range of possibilities and new challenges to developers.
The location is attractive because it lets developers place turbines where NIMBY (not in my backyard) complainers should be fewer and capacity factors higher. A spokesman for a Finnish developer says capacity factors for their offshore farms average 40%, significantly better than the 30% of a well functioning land based wind farm. And for Europe’s one floating turbine, he reported a capacity factor of an enviable 60%.
Trends to keep costs down are particularly evident. The cost of erecting turbines in water is so expensive—at least twice that of land based development –that it’s most cost effective to erect the largest turbines available designed for the salt spray and stronger wind. To date, candidate machines have included 3 to 5-MW turbines for Cape Wind and others on the East Coast, and 4-MW units for the first installation in Lake Erie.
At a recent offshore technology conference, American Superconductor’s Senior Vice President John Collett suggested several conditions that must take shape if the U.S. is to compete effectively offshore. For one, the Federal government must provide long-term incentives and goals for renewable energy such as the Production Tax Credit and Renewable Electricity Standard. Collett suggests educating the masses on how offshore wind can benefit our economy and energy independence. The U.S. industry must stop focusing on the tried and true, and adopt a leapfrog mentality. The wind industry is currently fielding 5-MW turbines in small volumes, while larger turbines are required to reduce cost.
To float or not to float? That is another question for offshore developers. In relatively shallow water, less than 30-m deep, a monopole can be driven into the seabed to support turbines while tripods work better in depths from 25 to 50m. Cape Wind and projects in Lake Erie will likely use monopoles. In deeper water, a floating platform makes more sense. Several have been proposed, each with tradeoffs. However, without pilings, acoustic disturbances during installation are minimal. Also, there should be less disturbance to wildlife there because the level of biodiversity typically decreases with water depth due to lack of sunlight and nutrients.
The entire effort will call for more marine equipment, which could start a building boom along the East Coast. A news story in this issue tells of one type of jack-up barge under construction that will be useful.
Discussions of offshore construction eventually reach the issue of jobs and the Jones Act. The 1920 Merchant Marine Act calls for all goods transported on water between U.S. ports carried in U.S.-flag ships, constructed in the U.S., owned by U.S. citizens, and crewed by U.S. citizens and permanent residents.
Global Marine Energy Inc. is one emerging company in offshore cable installations. CEO Joel Whitman says the crew of one vessel requires about 60 men who have been certified for their jobs. If work in the North Sea is any indication, at season’s peak he tallied up to 40 vessels at work on one construction job.
Whitman says the company’s goal in North America is to educate developers, investors, and anyone interested in the market. That will let his company put Europe’s lessons to use here.
Filed Under: Construction, Offshore wind, Projects