The NSF Sustainable Energy pathways (SEP) Program, under the umbrella of the NSF Science, Engineering and Education for Sustainability (SEES) initiative, will support the research program of Prof. Christopher Niezrecki and co-workers at the University of Massachusetts, Lowell, and Prof. Janet Twomey and co-workers at Wichita State University. The objective of this highly multidisciplinary study is the preparation of new forms of bio-derived materials for next generation wind turbine blades. These blades will be designed with the mechanical performance, economic viability, and environmental life cycle to enable sustainable wind energy pathways. Past research on biobased polymers has focused on thermoplastics that do not have the creep resistance and other properties necessary for significant structural applications. This project will focus on thermoset epoxies that are only a single reaction step from vegetable oil (a consistent, readily available feedstock), thus minimizing energy use and cost. Additionally, by developing an understanding of molecular-level thermal reworkability in composites through the inclusion of an appropriate catalyst, this work will enable a new end-of-life paradigm. Scaled test structures with mechanical and dynamic features comparable to utility-scale wind turbine blades will be constructed and their performance evaluated. Using these results new materials will be able to be quickly assessed without full scale tests. An environmental life cycle impact analysis will highlight areas for improved sustainability in the design of the biomaterials and end-of-life options for blades. An economic evaluation along with life cycle cost and toxic use analyses will provide a comparative economic evaluation of bio-derived alternatives to traditional petroleum-based thermosets along with the impact of converting to bio-based wind turbine manufacturing on job creation, education, and skills requirements.
With an expectation of growth in the U.S. to 170,000 turbines in 2030, wind energy represents a renewable resource to address 20% of the U.S. energy demand. From a systems point of view, this growth creates a need to dispose of well over 34,000 blades/year (each as large as 62 m long and weighing 18 tons) in the U.S. and approximately five times as many globally. Presently, nearly all of these blades are manufactured from glass fiber composites containing large amounts of petroleum-based epoxy resins and at their end of life they are very difficult to recycle. Spent blades are either land-filled, burned to extract heat for co-generation of electricity, or cut up and used as filler in construction. This project will determine how to effectively replace existing petroleum-based epoxy resins with bio-based materials that are reworkable so that they can be repaired and/or their materials can be reused at the end-of-life. Concurrently the impacts of the new blades on the economy, wind industry, environment, and society will be studied. Both graduate and undergraduate students will be exposed to technical and nontechnical problems important to industry, and a strong outreach effort will be implemented using demonstrations to motivate the interest of women and K-12 students in science and engineering. Wind Energy Research Workshops will be organized to serve a national audience of industry participants, scientists, and engineers.
This project will develop a transformative approach to the manufacturing of composites in general and wind turbine blades in particular. This work will lead to composite manufacturing that is more sustainable and less reliant on petroleum-based resins while enabling effective composite repair and recycling. The research will impact not only the wind industry, but many other areas of composite usage.
