Bigger Turbines, Greener Energy
June 22, 2012
In a study that could solidify the trend toward construction of gigantic windmills, scientists have concluded that the larger the wind turbine, the greener the electricity it produces. Their report appears in ACS’ journal Environmental Science & Technology.
Marloes Caduff and colleagues point out that wind power is an increasingly popular source of electricity. It provides almost 2 percent of global electricity worldwide, a figure expected to approach 10 percent by 2020. The size of the turbines also is increasing. One study shows that the average size of commercial turbines has grown 10-fold in the last 30 years, from diameters of 50 feet in 1980 to nearly 500 feet today. On the horizon: super-giant turbines approaching 1,000 feet in diameter. The authors wanted to determine whether building larger turbines makes wind energy more or less environmentally friendly.
Their study showed that bigger turbines do produce greener electricity — for two main reasons. First, manufacturers now have the knowledge, experience and technology to build big wind turbines with great efficiency. Second, advanced materials and designs permit the efficient construction of large turbine blades that harness more wind without proportional increases in their mass or the masses of the tower and the nacelle that houses the generator. That means more clean power without large increases in the amount of material needed for construction or fuel needed for transportation.
Bigger turbines, it turns out, not only are green, but save green, too. And will save even more in the near future. Better turbines perform better in lower wind speeds. That means more and more land area, that might have been uneconomical a few years ago for wind turbines, is now opening up and becoming useable.
In fact, the analysis found that the amount of U.S. land area with ideal siting conditions for wind power has increased by between 130 and 270 percent since 2002-2003 due to improvements in turbine technology. Similarly, land area that can produce wind power for less than 5 cents per kilowatt-hour — a price that makes wind competitive with natural gas — has increased by almost 50 percent over the same period.
“We’re opening a lot of new ground in the U.S., so to speak, that wasn’t available a decade ago,” Wiser said.