It may sound like a scene from a climate-fiction movie, but polymer composites expert Valeria La Saponara, a professor in the UC Davis Department of Mechanical and Aerospace Engineering, has a vision to develop compostable, ecologically sound wind turbine blades from bamboo and mycelium, the fungal rootlike system that bears mushrooms.

La Saponara, co-principal investigator Michele Barbato in the Department of Civil and Environmental Engineering, and a diverse team of students and researchers in the Advanced Composites Research, Engineering and Science laboratory are testing a prototype on campus.

The environmental challenge of wind turbine blade disposal

Wind is one of the fastest growing sources of renewable energy in California and around the globe. It is a key part of California's path to carbon neutrality by 2045. China, which accounts for more than half of global wind power, is planning to build a wind farm that could power 13 million homes by 2025 as it works toward its 2060 net-zero goal.

The expanding role of wind is largely good news. But as this key source of renewable energy grows, an environmentally sound solution is needed for the exponentially growing number of wind blades bound for landfills. Wind turbine blades are huge: The average rotor diameter in the U.S. in 2021 was 418 feet, so a single blade is almost as big as a Boeing 747's wingspan. Designed to be resilient against heavy winds and weather conditions, the blades have a lifespan of about 20 years before they are retired or replaced. Most are constructed using a composite structure of fiberglass/epoxy built on top of balsa wood, which adds stability and flexibility. Recycling options are very limited, costly, and incur the additional carbon footprint impacts of transportation.