Aerial pictures of a municipal landfill in Casper, Wyoming, have put a spotlight on one of the less visible problems of the wind power boom: what happens to a turbine blade when it is taken out of service.
The Casper Regional Landfill has accepted at least 870 retired blades. They arrive in sections, are stacked in pits roughly 30 feet deep and are then covered over. Landfills in Lake Mills, Iowa, and Sioux Falls, South Dakota, have also taken blades, but few sites in the United States have the open space needed for such bulky waste.
Too tough to shred
A modern blade is a fiberglass and resin composite designed to keep turning through gales and heat for two decades or more. That strength is exactly what makes it hard to get rid of. Standard crushers cannot break it down, and there was no large-scale recycling route in the US at the time the pictures were taken.
When a wind farm is repowered or dismantled, crews cut each blade on site with heavy-duty saws into pieces short enough for a flatbed truck. Some blades are longer than the wing of a Boeing 747. Industry estimates reported by Bloomberg suggested that around 8,000 blades a year would be coming down in the US over the following years.
Once buried, the material stays as it is. Landfills are built to keep waste dry and sealed, so the composite does not rot or break down in any meaningful time frame.
Looking for a second life
A handful of companies have been working on alternatives. Texas-based Global Fiberglass Solutions grinds blades into pellets and panels that can be used for flooring, pallets and similar products. Waste management group Veolia was also testing ways to keep blades out of the ground, and in December 2020 GE Renewable Energy signed a multi-year deal with Veolia North America to shred blades from its US onshore fleet and use the material in cement kilns, where it replaces part of the coal, sand and clay normally fed into the process.
An industry under pressure
The pictures circulated as the renewable energy sector was dealing with the first wave of the coronavirus pandemic, which delayed parts deliveries and construction work. Even so, wind, solar and other renewable sources supplied close to a fifth of US electricity in 2019, according to the Energy Information Administration, and the agency still expected renewable generation to grow in 2020.
For a technology sold on its clean credentials, end-of-life waste remains an awkward question. The answer the industry settles on will shape how the next generation of blades is designed, made and eventually taken apart.
Sources: Bloomberg Green reporting (February 2020), Casper Regional Landfill, US Energy Information Administration, GE Renewable Energy and Veolia North America (December 2020).