As demand for wind turbines increase, blade manufacturers look toward automated production.
The world’s largest wind project will be completed this year, according to GE Energy. Stretching across 30 square miles in north-central Oregon, the Shepherds Flat wind farm will include 338 GE 2.5-100 wind turbines with a total capacity of 845 megawatts (MW). That’s enough clean energy for 235,000 households.
GE Energy built some of the largest components, including the nacelles and hubs, but turned to trusted suppliers for blades. GE Energy partners with about a half dozen suppliers to manufacture wind blades built to the company’s design specifications. In 2012, the company expects to ship more than 3,000 wind turbines, up approximately 50 percent from last year.
Industry demand from Atlanta-based GE Energy and other wind turbine suppliers is driving the need for wind blade automation. There are more than 8,300 MW of wind power currently under construction involving 100-plus separate projects spanning 31 states and Puerto Rico, according to the American Wind Energy Association (AWEA). “Blade production must become highly efficient and cost effective to keep up with demand,” says Randy Kappesser, vice president and general manager of MAG Composites Technologies, Hebron, Ky. “Automation is key.”
There are several factors compelling blade manufacturers to adopt automation. “There’s a general trend for wind turbine OEMs to get more energy out of each turbine,” says Kappesser. “One way to do that is make a larger area of wind capture.” Larger turbines result in larger blades, which may not be practical for hand layup. It can be difficult to access big blades by hand during manufacturing, says Kappesser.
The trend toward larger blades also leads to more use of carbon fiber, adds Kappesser. “Carbon fiber drives a higher set of standards for layup than glass,” he says. “The resulting part is more susceptible to wrinkles, for example, than glass.” Hand layup can be more challenging because of the need for exact tolerances.
Field failures also drive automation. One cause of blade damage on wind turbine installations is manufacturing errors. The labor-intensive production process can lead to problems such as poor bonding of internal blade components to each other or wrinkles from manual layup of fiber materials, leading to voids and disruption of the fiber path. “Automation is a repeatable process,” says Kappesser. “If you can get 100 percent acceptable out of an automated process, you’ll get it every time or with much less deviation.”