A sophisticated new study proves what many of us have thought for a while now; namely, that previous studies, which claimed that "adding more turbines would create diminishing returns to a point where wind power wasn't worth utilizing," are not correct. Instead, according to this study's authors, "4 million turbines would produce 7.5 terawatts a year - more than half the energy the world is expected to consume in 2030."
5 MW turbines are huge - about 100 meters tall - but half would be offshore. On land, they would cover one-half of one percent of the Earth's land - about half the area of the State of Alaska. However, virtually none of this area would be used solely for wind, but could serve other purposes such as open space, farmland, ranchland, or wildlife preserves.
And it would be most efficient to spread them across the globe, rather than all in one place, high wind areas like the Sahara and Gobi Deserts and the American plains.
Of course, the new study's authors point out, "we have a long way to go" to get to 4 million wind turbines, but we now know one thing for sure: "the saturation of wind power availability will not limit a clean-energy economy." Also worth emphasizing is that wind is only one form of clean energy; add in solar, which a recent study by NREL found could reach capacity of "just under 200,000 GW, which could generate around 399,700 TWh of energy annually," in the United States alone, and you get an idea of the enormous potential clean energy represents - for the economy and for the environment - in coming decades.