ABSTRACT
Offshore wind energy is one of the most promising and largest potential energy sources for many countries. Strategically speaking, offshore wind can become one of the main sources of energy in some northern European countries, such as the United Kingdom, which has identiŽed a potential offshore power capacity of 48 GW in its coasts. The European Wind Energy Association has identiŽed a target for the EU members of 40 GW offshore wind power to be installed by 2020 and 150 GW by 2030.339
Additionally, the estimated potential offshore power capacity in the United States, in a band extending out to 50 nautical miles from the coastline (including the two coasts and the Great Lakes), has been distributed in three depth categories: about 1070 GW in shallow water (up to 30 m in depth), 620 GW in medium water (30-60 m in depth), and 2400 GW in deep water (deeper than 60 m). According to NREL, the target for offshore wind power installed in the United States by 2030 is between 54 and 89 GW.318,342
In comparison with onshore systems, some advantages for offshore wind energy include more reduced wind turbulence and higher mean wind speed; reduction of the turbine size constraints due to transportation limitations and visual concerns; less noise limitations, which brings the possibility to operate at higher blade tip speed, with better efŽciency and lower torque-associated costs, etc.
