The trade publication Plastics Technology Online has an excellent technical article on the manufacturing of wind turbine blades. Awesome reading if you are a wind-industry insider. Or, if you have a degree in chemistry or chemical engineering. The scale of making turbine blades from fiberglass and carbon fiber is amazing, physically and financially. An industry expert interviewed for article stated that he "expects the global wind energy market for composites to be worth about $6 billion by 2012."
The manufacturing process has similarities to the manufacture of kayaks, truck fairings, bathtubs, shower stalls, bumpers, speed boats, trailers and RV bodies. Some key ingredients: epoxy and polyester resins, glass and carbon fiber, balsa wood, and PVC foam. Glass is the big one.
Typically composed of 70% to 75% glass by weight, these aerodynamically designed blades must meet very strict mechanical requirements such as high rigidity and resistance to torsion and fatigue. High static and dynamic loads over a wide temperature range are typical during a 20-yr service life. A standard 35- to 40-meter blade for a 1.5-MW turbine weighs 6 to 7 tons.Image credit:Turbine blade half removal, Siemens AGThe Danish company LM Glasfiber A/S uses robots to help produce
the industry’s longest wind blade. The 61.5-m (202-ft) blade, built for a 5-MW turbine from Germany’s REpower Systems, weighs 17.8 tons. The turbine has a rotor diameter of 126 m (413 ft) and the three blades cover an area almost the size of two football fields.Seeing one of these up close would be a good object lesson for those who argue that wind power can't be competitive because its' 'intermittent.' No one is going to invest in a technology at this scale to access an unreliable source of energy.
Via;:PTOnline,Composites, Wind Power Blades Energize Composites Manufacturing