The latest episode in the American Chemical Society's (ACS') award-winning Global Challenges/Chemistry Solutions podcast series concludes that the larger the wind turbine, the greener the electricity it produces. The study could solidify the trend toward construction of gigantic windmills.

Based on a report by Marloes Caduff in ACS' journal Environmental Science and Technology, the podcast is available without charge at iTunes.

In the new episode, Caduff, a graduate student, and Stefanie Hellweg, Ph.D., her advisor, explain 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, to nearly 500 feet today. Although their study only investigated land-based wind turbines that were up to 300 feet in diameter, super-giant turbines approaching 1,000 feet in diameter might exist someday.

Caduff, Hellweg and colleagues 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, 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.

Second, over time and with more production, manufacturers gain knowledge on how to efficiently build big wind turbines. That means more clean power without large increases in the amount of material needed for construction or fuel needed for transportation.

Global Challenges/Chemistry Solutions is a series of podcasts describing some of the 21st century's most daunting problems, and how cutting-edge research in chemistry matters in the quest for solutions. Global Challenges is the centerpiece in an alliance on sustainability between ACS and the Royal Society of Chemistry.

Global Challenges is a sweeping panorama of global challenges that includes dilemmas such as providing a hungry, thirsty world with ample supplies of safe food and clean water; developing alternatives to petroleum to fuel society; preserving the environment and assuring a sustainable future for our children and improving human health.