Siemens Gamesa says it has developed the first offshore wind turbine blades that can be fully recycled, potentially saving hundreds of thousands of bulky objects from landfills and resolving an issue long highlighted by the industry’s critics.
Blades, which can be longer than a football pitch and are made of a mixture of materials including balsa wood, glass, and carbon fiber, are difficult and costly to reuse.
Skeptics of renewable energy have used images of blades piled in landfill sites to question the green credentials of wind power, which produces no emissions but requires materials such as steel and copper whose production remains carbon-intensive.
About 85 per cent of a turbine, including the steel towers, can already be recycled but the blades have proved more challenging. The materials are bound with a resin that ensures they are stiff enough to withstand typhoon conditions but makes it difficult to separate the components.
Although some blades have been used in imaginative ways such as in children’s playgrounds, Siemens Gamesa said the majority go to landfills when a project reaches the end of its life, typically after 25 years.
As many early projects now reach the end of their lives or are “rer powered” with new, more powerful turbines, about 6,650 blades will be removed each year in Europe until 2025, according to BloombergNEF. About 1,400 blades will be removed annually in the US over the same period.
Siemens Gamesa has produced its first six recyclable blades at a factory in Aalborg in Denmark using a different resin whose chemical structure ensures it can be more easily separated from the other components when heated in a mild acidic solution. The world’s biggest maker of offshore wind turbines is also evaluating the technology for use in onshore projects.