Wind turbine blades have a life expectancy of around twenty years. As they are usually made from composites containing carbon fibre and can’t be recycled economically, used blades are typically buried in landfills. Apart from the environmental impact, this provides opponents of renewable energy with ammunition to attack wind farms.
Global expansion of wind farms is set to expected to reach 2,100 gigawatts by 2050, from the current capacity of 837 gigawatts. This means plenty of blades are currently destined for landfill with plenty of attaches from right-wing politicians expected to follow.
Addressing this challenge the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed blades made from bio-derived materials which is also chemically recyclable. A bio-based resin, PECAN (PolyEster Covalently Adaptable Network) has been created using biomass-derived sugars. At the end of their useful life blades can be broken down and chemically recycled in a process that takes just six hours.
The research team has demonstrated that the bio-based resin can match the performance standards of traditional virgin materials. In particular, they have proven that PECAN does not suffer from creep deformation during weatherization tests, unlike most recyclates. So far only a scale model about 10% the size of a commercial wind turbine has been built but there are plans to develop larger prototypes to further test the performance of the material.
Designers might want to explore this material for other applications where carbon fibre has been traditionally used.
PECAN has the potential to be an important part of the solution to the enormous waste being created in the transition to renewable energy. It is, for example, estimated that 78 million tonnes of solar panel waste will be generated by 2050 so the work of NREL and others in this research field is desperately needed. The PECAN project clearly demonstrates that solutions can be found and that the transition to renewable energy should not be hampered by these barriers.