Abstract: Finding ways to manage the waste from the expected high number of wind turbine blades in need of disposal is crucial to harvest wind energy in a truly sustainable manner. Landfilling is the most cost-effective disposal method in the United States, but it imposes significant environmental impacts. Thermal, mechanical, and chemical processes allow for some energy and/or material recovery, but they also carry potential negative externalities. This article explores the main economic and environmental issues with various wind turbine blade disposal methods. We argue for the necessity of policy intervention that encourages industry to develop better technologies to make wind turbine blade disposal sustainable, both environmentally and economically. We present some of the technological initiatives being researched, such as the use of bio-derived resins and thermoplastic composites in the manufacturing process of the blades.
Globally, more than seventy thousand wind turbine blades were deployed in 2012 and there were 433 gigawatts (GW) of wind installed capacity worldwide at the end of 2015. Moreover, the United States’ installed wind power capacity will need to increase from 74GWto 300GW to achieve its 20% wind production goal by 2030. To meet the increasing demand, not only are more blades being manufactured, but also blades of up to 100 meters long are being designed and produced. The wind turbine blades are designed to have a lifespan of about twenty years, after which they would have to be dismantled due to physical degradation or damage beyond repair. Furthermore, constant development of more efficient blades with higher power generation capacity is resulting in blade replacement well before the twenty-year life span. Estimations have suggested that between 330,000 tons/year by 2028 and 418,000 tons/year by 2040 of composite material from blades will need to be disposed worldwide. That would be equivalent to the amount of plastics waste generated by four million people in the United States in 2013. This anticipated increase in blade manufacturing and disposal will likely lead to adverse environmental consequences, as well as potential occupational exposures, especially because available technologies and key economic constraints result in undesirable disposal methods as the only feasible options.
The material in the shells of the wind turbine blades is typically glass fiberreinforced polymer (GFRP), a resin-matrix material reinforced with fiberglass. In particular, the shells are commonly made from a combination of epoxy resin and glass fiber reinforcement. The blades also contain sandwiched core materials such as polyvinyl chloride foam, polyethylene terephthalate foam, or balsa wood, as well as bonded joints, coatings (polyurethane), and lightning conductors. Conventional epoxy resins are thermosetting materials usually produced by a reaction of epichlorohydrin and bisphenol A in the presence of sodium hydroxide. Both bisphenol A and epichlorohydrin are derived from petrochemicals. Contrary to other types, once cured, thermoset polymers cannot be melted and reshaped by applying heat at high temperatures. As a result, thermoset composites cannot be reformed by any means other than machining, which risks compromising the properties of the material through damage or destruction of the reinforcing fibers. Therefore, the GFRP found in the blades poses a challenge to find or develop more sustainable end-of-life alternatives. …
Katerin Ramirez-Tejeda, David A. Turcotte, Center for Wind Energy, University of Massachusetts Lowell, Mass.
Sarah Pike, Political Science and International Relations Department, University of San Diego, Cal.
NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy. Volume 26 issue 4 pages 581-598
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