As wind turbines get bigger, so too do the blades. Blades on GE’s standard 1.5 megawatt wind turbines are about 120 feet long and are carved out from a single piece of fiberglass. Manufacturing these blades is tough, so researchers at GE and partner institutions have gone back to the origins of the windmill to find a material better suited to the challenge: fabric.
“We’re looking at the infrastructure to make these larger and larger blades,” says Wendy Lin, a GE Principal Engineer and leader of the project, which is funded by the U.S. Department of Energy’s Advanced Research Projects Agency, better known as ARPA-E. “Molds to make them are huge… Just the space to hold those become cumbersome,” she explains.
Unlike fiberglass, fabric is malleable and flexible. Simply stretching it over the metal skeleton of a blade could cut production costs by as much as 40 percent, the company says. That, in turn, would drive down wind energy costs, making wind power a more competitive source of energy.
“We’re after more automation in the manufacturing,” Lin says. “Some of these space frame parts will be made using more automated processes, leveraging some of the automotive techniques.”
The team on the $5.6-million, three-year project includes researchers from GE Global Research, Virginia Tech and the National Renewable Energy Laboratory
A New Fabric
The good news is that the fabric that could potentially canvas future turbines already exists. GE engineers are currently testing material used on the iconic roof of Denver International Airport (pictured above). GE now needs to customize this cloth so it withstand wear and tear and extreme weather conditions.
“We know what we like about [architectural fabric], but, we’re trying to develop it for a whole new application,” Lin explains. “We’re working with the fabric supplier to develop efficient ways to produce fabric we can use to make efficient wind blades.”
The idea takes windmills back to their beginnings.
Pre-industrail windmills throughout the world featured pieces of sailcloth stretched over a lattice framework.
Bigger Blades, Bigger Potential
Fabric blades could be significantly bigger than today’s fiberglass blades and capture more wind.
These expanded blades would open wind-challenged regions to the benefits of reliable and clean wind-powered electricity.
“Because wind is free, it’s all about the turbine cost for the cost of energy for wind. We need to drive the cost of the turbine down for large rotors to make wind energy more cost effective,” Lin explains.
Lin and her team anticipate launching ground testing of their large fabric blades sometime in the next three years. These tests will dictate whether GE launches production on fabric blades.
Top image: Denver International Airport, courtesy Flickr user Felix388