I managed to get ahold of the global wind map article we mentioned a few days ago. "Evaluation of Global Wind Power" by Cristina L. Archer and Mark Z. Jacobson is a detailed analysis of wind data from over 8,000 wind speed measurements around the world. The results are generally more conservative than other regional studies, but even so, nearly 13 percent of the stations recorded sustained wind speeds in the "Class 3" category (6.9-7.5 meters/second) or better, with some few locations topping out over "Class 7" (9.4 meters/second or greater). Generally speaking, with currently-deployed wind turbine technology, Class 3 winds or greater are required for economically useful generation.
Read on for more details from the Global Wind Power report, as well as a larger version of the global wind map.
One data point that didn't get much play in the press summaries was the relative lack of economically useful wind patterns in much of the world. Asia is the worst-positioned; as Archer and Jacobson put it, "The majority of this area is not suitable for wind power generation. Over the entire territories of India, Malaysia, Indonesia, and Philippines, for example, not a single station was in class 3 or higher!" China is not much better off, with higher-speed regions generally appearing only along the coastlines (fortunate, then, that China's wind plans involve off-shore turbines). Other regions with limited wind potential (as shown on the global map -- see below) include nearly all of Russia, most of South America, and Southern Europe. (Africa also shows only small amounts of power potential, but there are too few measuring stations to make an accurate estimate.)
Still, the big news remains the wind potential of the remaining 13%:
...total wind power potential over land from class ≥ 3 areas can be estimated roughly as 72 TW, corresponding to 6.27 x 10^14 kWh or, by assuming 100% primary energy equivalent and a conversion factor of 0.086 from TWh to Mtoe [IEA, 2003], 53898 Mtoe. [...] This value may appear large, but it applies only to that portion of the land (12.7%) with high average wind speeds (class 3 or greater). The global demand (or consumption) of electricity in 2001 was between 1.6 TW [EIA, 2004, Table 6.2] and 1.8 TW [IEA, 2003] (13.8 x 1012 -15.5 x 1012 kWh); the global demand of energy for all purposes in 2001 was between 6995 [IEA, 2003] and 10177 [EIA, 2004, Table E.1] Mtoe . As such, the amount of wind energy over land could potentially cover over five times the current global energy and about 40 times the current electricity uses with little incremental pollution.
Just to make the numbers clear on their own: the total wind power potential from economically usable (at current technology) locations amounts to 72 terawatts; the total global electricity use in 2001 was 1.6-1.8 terawatts; the total global energy use from all sources (according to the DOE) was just under 14 terawatts in 2002.
But as we know, technology isn't standing still. Innovations in wind turbine design may well make previously "uneconomical" wind speeds viable sources of power. Further, if we break out of the mind-set requiring a single power technology to replace all current sources, even "micropower" with small wind turbines -- built onto homes, for example, or along light fixtures -- becomes a useful way to add power to the grid. In any event, the science is clear: there's more than enough renewable power potential on the planet to handle all of our power needs well into the next century.
