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Site Characterization of Offshore Wind Energy Areas Metocean Sensors Assess Conditions, Risks and Impacts of US WEAs By Rick Cole W ith the push for alternative energy well underway in the United States, programs are ramping up with plans to begin sending megawatts of power from the coastal ocean environment along various regions of the eastern seaboard back to the beach for distribution. Wind, wave and ocean-current energy programs are making considerable advances, with wind power out in front. Wind is the world���s leading source of renewable electricity, although still considered an emerging industry in the U.S. It could help decrease greenhouse gas emissions and revitalize economic sectors of the nation. More than 90 percent of offshore wind installations are in Europe, with nearly 4,600 megawatts of power generated as of mid-2012. Outside of Europe, only China and Japan have operational wind platforms offshore. The U.S. has yet to install a single turbine along its coastal oceans. The U.S. Department of Energy���s estimate of offshore wind resource potential from state and federal waters along the U.S. and Great Lakes coastlines is in excess of 4,000 gigawatts. In November 2010, U.S. Secretary of the Interior Ken Salazar announced the Smart from the Start Atlantic wind energy initiative to hasten the responsible development of wind energy on the Atlantic Outer Continental Shelf (OCS). In early 2011, the Bureau of Ocean Energy Management (BOEM) began conducting environmental assessments to identify regions of the OCS offshore the Mid-Atlantic states of New Jersey, Delaware, Maryland and Virginia most suitable for development as wind energy areas (WEAs). Regulatory Requirements BOEM���s regulatory process consists of identifying suitable areas, issuing a lease to a company interested in developing a WEA, approving a site assessment plan (SAP) that includes meteorological (met) measurements, and approving a full construction and operation plan. An SAP must contain a proposal of any plans to construct met towers or the deployment of buoy systems and must be preapproved by BOEM before site characterization activities begin. These activities include but are not limited to hazards, geophysical, geotechnical, archaeological, biological and metocean surveys. The frst of these U.S. commercial leases was granted in 2010 when BOEM approved the construction of the Cape Wind project off Cape Cod, Massachusetts, where an es- Metocean surface-buoy system with associated data plots. (Credits: RDSEA and Down East Instrumentation; ADCP contour plot provided by the University of South Florida���s Ocean Circulation Group; met and sea surface temperature plots provided by China���s First Institute of Oceanography) timated 75 percent of the electricity needed for the Cape, Martha���s Vineyard and Nantucket Island could be generated via wind energy. A collection of measurements is necessary to analyze wind resource data and environmental conditions to determine a location���s suitability for wind energy development and the impact on biologically sensitive habitats within the WEA. The instrumentation used provides full metocean support (surface and water column physics and atmospheric studies), along with biological sampling of the bird (avian) and bat (chiroptera) populations offshore, and migrating marine mammals (cetacean) within each WEA region. Peripherally, ocean-current velocity and direction, and wave feld spectra are measured, and hydrophones are mounted on the seafoor to record marine mammal presence, and sensors are placed on buoys to listen for bird www.sea-technology.com FEBRUARY 2013 / st 21