To estimate the earth's capacity for wind power, the researchers first sectioned the globe into areas of approximately 3,300 square kilometers (2,050 square miles) and surveyed local wind speeds every six hours. They imagined 2.5 megawatt turbines crisscrossing the terrestrial globe, excluding "areas classified as forested, areas occupied by permanent snow or ice, areas covered by water, and areas identified as either developed or urban," according to the paper. They also included the possibility of 3.6 megawatt offshore wind turbines, but restricted them to 50 nautical miles off the coast and to oceans depths less than 200 meters.
Using this criteria the researchers found that wind energy could not only supply all of the world's energy requirements, but it could provide over forty times the world's current electrical consumption and over five times the global use of total energy needs."
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