Turbine Blades Have Piled Up in Landfills. A Solution May Be Coming.

The blades on the newest wind turbines sweep an area longer than a football field and are nearly impossible to recycle.

At the end of their life span of around 20 years, they are chopped into pieces and buried in a handful of landfills across the Great Plains. Those few sites in Wyoming, Iowa and South Dakota have a spooky nickname: wind turbine graveyards.

But this waste problem from a growing source of low carbon energy could become a headache of the past.

Researchers at the National Renewable Energy Laboratory have developed what they say is a turbine blade made from plant material that can be recycled. The new substance is made from inedible sugar extracted from wood, plant remains, used cooking oil and agricultural waste.

They say the prototype they developed can perform as well as traditional blades that are made from a combination of fiberglass and plastic and which have been very difficult to reuse.

The new, recyclable material could be easily adopted by industry, said Robynne Murray, one of the researchers at the national laboratory.

Because the blades for wind turbines are shaped in large molds, which can take up entire warehouses and are expensive to build, it is critical for any new material to be compatible with existing molds and production facilities. And the substance developed by the national laboratory does exactly that, Dr. Murray said.

It’s “designed to be a drop-in replacement,” she said. “Manufacturers should be able to just take it and use it.”

Blades made from the new materials could be 3 to 8 percent more expensive than traditional blades, according to one estimate.

As more wind farms are built around the country, disposal of old or broken blades is a concern. Opponents of wind energy have seized on the problem as a reason to try to block new wind facilities.

More than 1,000 blades are buried at the Casper Regional Landfill in Wyoming, which does not accept blades from out of state. Wind blades do not exude toxic substances when buried in landfills but take up a great deal of space. Old turbine blades as long as 120 feet are cut into 40-foot sections before disposal. The landfill in Casper can accommodate around 9,000 more blades, according to a fact sheet provided by city officials.

Engineers expect more than 43 million tons of landfill waste will be generated by turbine blades globally by 2050, which is about three times as much total waste as New York City produces annually. The cost of discarding wind blades can be much higher in other nations with smaller land area and higher population density than the United States. Some European countries — including Germany, Austria, Finland and Netherlands — have banned turbine blades from landfills.

Recycling a turbine blade made from traditional materials is nearly impossible because it is very difficult to break its strong chemical bonds after the epoxy resin derived from petrochemicals gets poured into a mold and hardens into a blade.

Some old blades have been repurposed into utility poles and park benches and have been used in bridge construction. Blades can also be shredded into filler or added to cement production. A seven-ton blade that is ground and sent through a cement furnace can replace five tons of coal, resulting in fewer carbon emissions, according to the American Clean Power Association.

But the new material developed by the scientists at the national laboratory can be recycled by dumping it into a bath of methanol heated up to around 440 degrees Fahrenheit, which turns it into an elastic liquid that can be molded into a new shape.

Another researcher at the renewable energy laboratory, Nicholas Rorrer, compared the recyclable material to a cargo net in which engineers know a few specific knots that can be easily untied.

“It’s heat plus solvent,” Dr. Rorrer said. “That will break it apart.”

To test the durability of the new recyclable substance, researchers built a 30-foot wind blade prototype and placed it in a laboratory chamber designed to simulate 20 years of exposure to sunlight, varying temperature, humidity and other environmental factors. The material met the manufacturing requirements and endured stress better than traditional substances by some measures, Dr. Murray said.

The next step for this recyclable substance is creating a full-scale blade around 45-feet long and testing it, she said.

It is unclear if manufacturers would switch processes to use the recyclable material. It all depends on costs, said Ali Ghorashi, a senior vice president of energy infrastructure at DNV, an energy consulting firm.

The wind power industry is facing intense economic pressures, in part because of heavy up-front capital costs and high interest rates. Investing in more expensive recyclable materials might be difficult, Mr. Ghorashi said. The federal government should lead the effort in ensuring the entire industry to move toward recyclable materials, through regulations or subsidies, he said.

“I don’t see any major incentives to recycle the old ones,” Mr. Ghorashi said. “It’s not just the technological and engineering feasibility, but it’s about the production cost.”