Page - 126 - in Water, Energy, and Environment - A Primer

markets for their outputs (note: 50%ofAmericans livewithin50 milesofaUScoast).Oceansitesalsoallowdeploymentof larger wind turbines (improving theeconomicsofpowergeneration), as wellas reducedonshorevisualandnoise impacts.Thetrade-off is thatOSWfarms, subject to harsh ocean conditions, canbemore expensive, difficult to build, and maintain than onshore wind farms. Offshore wind resources are abundant, many countries are exploring its potential, and by the end of 2017 nearly 19,000 MW of capacity had been installed in 17 markets around the world. Almost 16,000MW (84%) were installed in the waters off the coasts of 11 European countries. The remaining 16% was located largely in the waters off China, followed by Vietnam, Japan, South Korea, the US and Taiwan. The US, which is today far behind other countries in deploying offshore wind, sited its first offshore wind turbines in the waters off Rhode Island in 2016. Nevertheless, on a global basis, the potentialUSOSWenergy resources are second only to those of China. China has a very long coastline and the US has a broadly distributed OSW resource associated with four coastal regions (East Coast,West Coast, Gulf Coast, Great Lakes), and thirtyUSstates border anoceanor aGreatLake. In its report ‘2016 Offshore Wind Energy Resource Assessment for theUnited States’ (49) theNREL estimated the US potential ‘net technical resource capacity’ to be 2058GW. This was calculated by estimating the US’s potential gross OSWenergy capacity out to 200nautical miles (the outer edge of the US Exclusive Economic Zone), excluding ocean areas with water depths greater than 1000m and wind speeds less than 7m/sec (15.7miles per hour), water deeper than 60m in the Great Lakes (to avoid damage from winter ice), and other exclusions for shipping lanes and marine protected areas. The net resultwas that the gross resource potential areawas reduced by 75% to arrive at the technical resource potential area (after exclusions), and the gross energy resource numberwas reduced Water,Energy, andEnvironment–APrimer126