Last year, nearly 200,000 wind turbines met 2.5 percent of global energy needs. These numbers are impressive, but wind energy has the potential to pack an even bigger punch — according to a new study, wind could power half the world with clean energy by 2030.

Wind power is now the fastest-growing (and one of the cheapest) renewable energy sources — a status that had brought more rigorous investigation of its potential. The industry is growing so rapidly that 40.5 gigawatts (GW) of new wind power was brought on line in 2011, bringing the global total capacity up to 238 GW and helping to offset over 600 million tons of CO2 annually.

Given this growth, the authors, who published their study in the Proceedings of the National Academy of Sciences, were curious about how much energy can wind produce?

A Wealth of Wind Energy

“More than we’ll ever need,” said Cristina Archer, co-author of the study and professor of geography and physical ocean science and engineering at the University of Delaware.

The study she worked on with Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford University, calculated the saturation potential of wind turbines, defined as the point at which adding new turbines becomes counterproductive because, by extracting power, each additional turbine decreases the overall average of every turbine.

For wind, the study found, that point is very high, around 250 terawatts (TW) of power, which is tens of times greater than the entire world’s average power use.

After getting the saturation point, the researchers focused their attention on a more realistic scenario: how many wind turbines would be enough to meet half of our energy needs, which the authors estimated at about 5.75 TW, in a clean economy by 2030?

Four Million Turbines

According to their results, 4 million five-megawatt (MW) turbines operating at a height of 100 meters could provide over 7.5 TW of power, at no risk to the environment. “With four million turbines, the climatic effects are negligible,” Archer said, “which means that wind power is very safe.”

“As climate scientists,” Archer continued, “we are concerned about the environmental impacts of anything. We want to know what the consequences are, and we are very confident that of all the sources of energy, wind is one of the sources of energy with the least environmental impact.”

The study concluded “there is no fundamental barrier to obtaining half or several times the world’s all-purpose power from wind in a 2030 clean-energy economy.”

The calculations were done without regard to societal or economic considerations, and with parameters representing a mixture of onshore and offshore wind turbines — the latter of which Archer sees becoming more important to the future of wind.

Offshore wind “has all these hidden benefits that we need to tap into, which will make it more common in the future,” she says.

Although it’s more expensive now, using more offshore wind will lower costs in the future, because “it’s right there on the coasts, where the people are. It also tends to correlate better with the demand: offshore wind tends to peak in the afternoon, which is when people peak with demand for electricity.” Offshore sites also tend to be windier than onshore sites, “and this extra wind is extra dollars that can come in.”

Top image courtesy of GE Energy Financial Services.