Researchers studying the environmental life cycle of 2-megawatt wind turbines found they recoup the energy required to manufacture and install them, and begin making a net energy contribution, in a matter of months.
Writing in The International Journal of Sustainable Manufacturing, two authors from Oregon State University said there are virtually no carbon emissions associated with the energy that turbines produce. But there are environmental costs associated with manufacturing and installing the devices, as well as dealing with them at the end of their expected 20-year life span.
Researchers based their findings on a study of two turbines in the Pacific Northwest and calculated energy payback at 5.2 months and 6.4 months.
A life cycle assessment covers energy associated with procuring raw materials (such as steel, copper, fiberglass, and concrete), transportation, manufacturing, installation, two decades worth of maintenance and recycling and disposal when the turbines are worn out.
“It is likely that even in a worst-case scenario, lifetime energy requirements for each turbine will be subsumed by the first year of active use,” Sciencespot said. “Thus, for the 19 subsequent years, each turbine will, in effect, power over 500 households without consuming electricity generated using conventional energy sources.”
According to the website Windustry.org, the 2 MW capacity of the two turbines cited in the report is typical of today’s commercial-scale turbines. Such a turbine costs between $3 million and $4 million installed.