The U.S. Department of Energy’s National Renewable Energy Laboratory (NREL, Boulder, Colo.) has released an Assessment of Offshore Wind Energy Resources for the United States, a new report that estimates the electricity-generating potential of offshore wind turbine installations off the U.S. coast.
According to NREL, 4,150 gigawatts (GW) of potential offshore wind turbine nameplate capacity (maximum turbine capacity) are available. According to the U.S. Energy Information Admin., the nation’s total electricity-generating capacity in 2008 from all sources was 1,010 GW.
The estimate does not describe actual planned offshore wind development, and the report does not consider that some offshore areas may be excluded from energy development on the basis of environmental, human-use, or technical considerations. The report’s estimate is intended only to indicate the gross energy potential of offshore wind resources.
The potential generating capacity was calculated from the total offshore area within 50 nautical miles of the shoreline, in regions where average annual wind speeds are at least 7 meters per second (approximately 16 miles per hour) at a height of 90m/295 ft. For purposes of the NREL study, it was assumed that 5 megawatts (MW) of wind turbines could be placed in every square kilometer of water that met these wind characteristics. Detailed resource maps and tables for 26 coastal states’ offshore (ocean and Great Lakes) wind resources break down the wind energy potential by wind speed, water depth, and wind farm distance from shore.