CompositesWorld spent a couple of days at WINDPOWER 2009 (May 4-6, Chicago, Ill.) and filed this report on the the emerging trend, in evidence at the show, toward automation of wind blade manufacture.
For all of the positive attention wind blades have given the composites industry in the last few years, it was immediately apparent at the WINDPOWER show that blade manufacture has become the weak link in the wind turbine supply chain. It seems universally understood that manual placement of glass fiber fabrics, manual management of resin infusion and manual application of adhesives and bonding agents, while acceptable for many boat manufacturing applications, is not acceptable for long-term manufacture of a wind blade that must behave more like an aircraft wing.
This conundrum has not been lost on the composites industry. In the lead-up to the show, MAG Industrial Automation Systems (Hebron, Ky.) announced that it has developed the Rapid Material Placement System (RMPS) for the automated placement of gel coat, fabric (glass or carbon fiber) and adhesive in a wind blade mold. It offers 3m/sec layup speed for blade skin, spar cap and shear web molds and uses laser and vision-based systems to detect fabric wrinkles. The technology is based, in part, on MAG’s automated fiber and tape placement systems used to make aircraft fuselage and wing structures. Roger Cope, president Strategic Business Development Group at MAG, noted that a wind blade is more like a wing, and should be manufactured as such. The goal, he said, is to reduce blade weight and reduce warranty costs for blade manufacturers. Further, such a machine could bring consistent quality at high speed.
For its part, MAG has yet to actually build the RMPS, and to that end it’s pursuing a relationship with a U.S. blade manufacturer with whom to work to develop a functioning RMPS as part of a proof-of-concept program. Randy Kappesser, vice president and general manager Cincinnati Composites Technologies at MAG, said, “This industry is very manual and it’s begging for automation.”
When these new machines are built, there is a good chance that they will be tested and proved at the AEWC Advanced Structures and Composites Center at the University of Maine (Orono, Maine). Habib Dagher, director of the center, was at the show and announced the center’s planned expansion of its Advanced Wind Blade Prototyping Facility. Dagher says ground on the expansion will be broken this summer, with completion expected by year’s end. When finished, the facility will allow for prototyping, optimization and testing of wind blades up to 70m/230 ft in length in an ISO-certified lab environment. Manufacturing processes include vacuum-assisted resin transfer molding (VARTM), prepreg, hand layup, injection molding, compression molding, filament winding, tape layup and extrusion. Full-scale structural testing can apply multi-axis loads of up to 300,000 lb/136,363 kg.
More broadly, Dagher noted that for all of the activity in onshore wind energy development, he thinks there’s greater potential in offshore wind and discussed the need for floating towers and turbines that can be located in water depths greater than 200 ft/61m. “Europe is 10 years ahead of us in offshore projects,” Dagher said, and also noted that the North Sea water in which Europe is placing many of its offshore wind farms tends to be relatively shallow; prime wind locations offshore of the U.S. East Coast, he said, runs deeper and thus requires a fresh look at how turbines can be located and secured.
