A compostable wind turbine is being developed that will eliminate the heavy environmental cost of recycling turbine blades.
The switch to renewable energy, especially wind power, has risen significantly in the US. Electricity generation from wind energy increased from about 6 billion kilowatt-hours in 2000 to about 380 billion kilowatt-hours in 2021. Over 10% of the United States’ energy is powered by wind.
While this is a great step to move away from fossil fuel energy, wind energy has its downsides, especially the wind turbines that provide the energy. Wind turbines, as you probably know, are huge. They are designed to be resilient against heavy winds and weather conditions. As a result, the blades on the wind turbines will wear out or, due to new designs, become obsolete. They generally have a lifespan of about 20 years before needing to be replaced. The used blades will typically end up in landfill as recycling options for the materials are limited and costly.
There might be a sustainable solution to these wasteful practices: compostable wind turbines. Students and researchers from the Advanced Composites Research, Engineering and Science laboratory at the University of California Davis are testing a prototype that could make this a reality.
Their compostable wind turbine project consists of creating a compostable wind turbine blade that would be built with woven bamboo, mycelium, and biomass from the agricultural waste from California’s Central Valley. These materials would replace the traditional fibreglass and balsa wood that is having a significant ecological impact and causing overlogging in the Ecuadorean Amazon rainforest.
The biodegradable and compostable wind turbine blades are made of bamboo, mycelium, and a mushroom root structure. The use of mycelium is a very good option for sustainable materials as it can be grown where it is going to be used and can thrive in waste streams from coffee grounds to discarded plastics. The team is investigating ways to build the blades, including structuring the bamboo layer. They are also looking to see if the material can regenerate itself in a form of self-healing, which would increase the lifespan.
As the team moves into the testing phase, they will replace the compostable wind turbine blades on a commercial 1-kilowatt turbine with mycelium-bamboo composite blades. They will test to see if the blades will generate energy and withstand 85-mile-per-hour winds. Once they find evidence that these compostable blades are viable, they will begin working with companies to commercialize this more sustainable option. They are also hoping that this compostable wind turbine project could help in areas that have been affected by natural disasters where energy solutions are needed quickly.
We’ve seen other evidence of engineers looking to make wind turbines more sustainable. In 2022, researchers at the University of Michigan announced they had made a new resin for blades by combining glass fibers with a plant-derived polymer and a synthetic one, which could be recycled into ingredients for products, including new turbine blades, laptop covers, power tools – and even gummy bear candies. The researchers found that removing the glass fibers and converting them into an alkaline solution could produce potassium lactate, which in turn could be purified and made into candy and sports drinks!
These examples show that wind turbines do not need to be thrown into the landfill at the end of their life. If they are made out of sustainable materials or if they are processed and remade into other materials, we could make renewable energy even more sustainable than it already is. These inventions do take time, resources, and testing, but if they are deemed useful, our future will look more environmentally friendly. And as old wind turbines get replaced, we will see new turbines made from more sustainable materials.