There’s nothing to burn. No ore to mine. No coal trains snaking from Wyoming to Midwest power plants. But wind power has its own pollution problem looming.
Last year, one third of new electric capacity in the U.S. came from wind, reports the DOE, and it’s growing quickly. All of the new U.S. generating capacity in September 2012 came from wind and solar, says the Federal Energy Regulatory Committee, and the U.S. now relies on wind for 4.43% of its total generating potential. And there’s plenty of room to expand: Industrialized nations–Denmark (29%), Spain (19%), and Germany (11%)–are building heavily wind-driven energy grids.
The problem comes when all of those wind turbines need to be replaced. Scandinavia, among the first to adopt wind into its energy mix, is on the leading edge of this problem: “As the wind becomes a central part of energy supply, a huge waste problem is growing with similar speed,” reported Denmark’s major business newspaper Dagbladet Børsen in 2011.
While wind power looks self-contained–a field of towers, white fiberglass rotors, and the breeze–the massive fiberglass and carbon-composite blades eventually have to be decommissioned and replaced. Mechanical engineering Christopher Niezrecki of the University of Massachusetts Lowell’s Wind Energy Research Group estimates the U.S. will have as many as 170,000 wind turbines by 2030 (about 20% of the country’s installed capacity) translating into more than 34,000 trashed blades per year; globally, the figure may be as many as 170,000. Since each blade can stretch the length of a football field and weigh 18 tons, that’s a lot of unplanned waste.
To prevent this avalanche, the National Science Foundation (NSF) is funding Niezrecki and the University of Wichita to find biological-derived materials for biodegradable blade materials that replace carbon-fiber composites and petroleum-based epoxies, the current industry standard. As today’s materials cannot be easily recycled, most used blades are cut or ground up for incineration and burial in landfills and roads.
The next generation of blade material may come from natural cellulose fibers and bio-based plastics derived from soybean, linseed, and other vegetable oils, instead of oil-based polymers. The $1.9 million NSF grant will seek to understand how those may be applied to the wind industry, and any products made from fiberglass, says Niezrecki.
Even Texas, whose economy has ridden the energy boom for almost a century, is bullish on the potential for blades that can biodegrade or be easily recycled, reports the Houston Business Journal.
“Our turbines in Texas are less than 10 years old, and the average life span is 20 years old,” Roby Roberts, a spokesman for Madrid-based EDP Renewables, owner of Houston’s Horizon Wind Energy, told the Journal. But “we’re going to have to get rid of the blades in some fashion. The company who can come up with a process of recycling the blade is going to have a pretty good business plan.”