A new study shows that wind energy is easily capable of supplying a full half of the world's electricity needs, given the political and social will.
How many wind turbines are needed? 4 million, 5-megawatt (MW) turbines would be an optimal number. After that, installing more turbines would have a diminishing return.
Those 4 million turbines would produce 7.5 terawatts a year - more than half the energy the world is expected to consume in 2030, report researchers at the University of Delaware and Stanford University in a study published in Nature.
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.
The data doesn't consider community or political barriers that often get in the way of siting wind farms.
The research shows what's physically possible, taking into account variables such as the exposure of each wind turbine to winds of varying velocities as well as global temperatures, moisture, clouds and other climate factors.
It also considers how the energy production of a given turbine might be affected by others around it, allowing developers to better determine when the optimum size of wind farms - when adding more turbines increases energy the most and when it would actually diminish the generating potential of a wind farm.
"We've seen some papers out there that have been somewhat annoying or confusing because they had very low estimates of the total potential of wind energy," Cristina Archer, associate professor of geography and physical ocean science and engineering with the University of Delaware, told US News & World Report. "We decided to run our own model and we found wind is very abundant -- we feel very strong these previous studies were incorrect."
"We're not saying, ‘Put turbines everywhere,' but we have shown that there is no fundamental barrier to obtaining half or even several times the world's all-purpose power from wind by 2030. The potential is there, if we can build enough turbines," Stanford engineering professor Mark Jacobson told Summit County Citizens Voice.
In the US, the 50 gigawatts (GW) installed supplies 3% of our energy, roughly the equivalent of 44 coal-fired power plants or 11 nuclear plants. By 2030, it could supply 20% of all energy, according to the Department of Energy (DOE).
What's more, it accounted for about one-third of all the new capacity added to the US grid in 2011, and the National Renewable Energy Laboratory (NREL) estimates that onshore and offshore wind projects could add another 15,200 GW in US wind capacity by 2050.
While the US led the world in wind investments in 2011, Scotland recently announced plans for what's being billed as the world's biggest wind farm - a multiphase, 1.5 GW offshore project with 339 turbines.
And this week, the Chinese government said it would seek to source up to 15% of the country's power from wind sources over the long term.
One drawback of wind, of course, is that it is intermittent – which is why more project developers are seeking to include energy storage components as part of project proposals.
Future developments will also meet with environmental objections, such as concerns over wildlife and endangered species impacts, noise pollution and aesthestics.
Here's the article in Nature: