Technology Review – GE hopes to make wind turbines far cheaper, and open up new ways to design them, by ditching the stiff fiberglass blades it uses now in favor of turbine blades made out of fabric. GE says the project, which recently received nearly $4 million from the U.S. Advanced Research Projects Agency for Energy, could lower wind turbine blade costs by 40 percent.
This illustration shows what a cross section of GE’s fabric blades might look like. The fabric will be stretched over a composite frame (light gray) and central spar (yellow and green).
GE intends to use a fabric that’s significantly different from the durable fabrics used now in architecture (such as for the roof of the Denver airport) or for gliders. Such projects use polyester, which wouldn’t be durable enough for wind turbines, Lin says. Instead, GE plans to use glass-based fabrics. Indeed, even current fiberglass wind turbine blades start with glass cloth. The blades are made stiff by cementing the fabric with stiff plastic resin. GE plans to use a soft, rubbery resin instead, allowing the fabric to retain some flexibility. That flexibility will make it more resilient than stiff fiberglass, which will in turn allow GE to use less material, reducing materials costs and weight.
The design calls for a frame that’s similar to the spars and ribs used in airplane wings. The fabric is stretched over that frame. This structure could be far cheaper to manufacture than fiberglass blades, which require forms that are so large that workers walk inside them to lay down layers of glass fiber.