The U.S. Department of Defense (DOE) is leading an initiative to produce aerodynamic rotor blades using 3D printed molds. This National Rotor Testbed (NRT) wind turbine blade, whose aerodynamic design has just been completed, will be used to help researchers better understand how wind turbines in close proximity to each other may influence one another (known as wake aerodynamics), and how they can be optimized to improve energy-producing efficiency.
At the same time, the additive manufactured molds will demonstrate that, thanks to 3D printing technology, it is possible to reduce the time and costs associated with manufacturing wind turbines—and thus the costs associated with wind energy more generally.
The wind industry in the United States is a major economic force, employing 73,000 people nationwide and expected to attract $35 billion in investment over the next five years. Finding faster and more cost-effective ways to manufacture wind turbines, as well as researching how to better harness the power of the wind, is therefore critical, and 3D printing technology has the potential to address both.
One major area in need of research is that of wake aerodynamics. Many wind turbines located in close proximity, such as on a wind farm, can negatively affect each other’s efficiency. But at the same time, the only way to manufacture wind energy on a large scale is to have many wind turbines working together.
To understand how this can be solved, the DOE, in collaboration with Sandia National Laboratory, Oak Ridge National Laboratory, TPI Composites, and Wetzel Engineering, will oversee the manufacturing of scaled-down turbine blades using 3D printed molds. This initiative is part of the DOE’s $1 million investment into 3D printing research to develop cheaper wind turbine blades.
The blades, measuring approximately 13 meters in length, will be tested at the DOE’s Scaled Wind Farm Technology (SWiFT) facility in Texas to help researchers better understand how turbines in close proximity can have an effect on each other’s efficiency.
3D printing the blade molds is also a major step forward in reducing the time and costs associated with manufacturing wind turbines. Current processes for manufacturing rotor blades—which can average over 150 feet and must be strong enough to withstand great loads—is energy, cost, and time-consuming.
First, a ‘plug’ is manufactured and used to create a mold, which in turn is used to fabricate the fiberglass blades. However, the first step could be entirely eliminated by applying 3D printing directly to the mold process, reducing manufacturing costs and giving researchers the time and freedom to experiment with new capabilities and improve design flexibility.
With the NRT rotor blade’s aerodynamic design complete, Oak Ridge National Laboratory, which previously 3D printed a clean-energy house and car system, has been put in charge of using the Cincinnati Inc. Big Area Additive Manufacturing (BAAM) machine to develop a 3D printed mold, incorporating features and capabilities not available through other methods. Blade manufacturer TPI Composites designed the molds, with Sandia consulting and Weztel Engineering providing crucial insight to the aerodynamic design. Manufacturing is set to be completed in summer 2016, followed by structural testing and flight testing, which will take place in 2017.
Though the current research is targeted at simplifying the manufacture of turbine blades, it could also help demonstrate that other wind turbine components could benefit from 3D printing as well, potentially bringing wind energy costs even lower. The DOE has stated that its coat is to reduce the cost of wind power to support development that could provide up to 20 percent of the nation’s energy from wind by 2030.
This is a particularly exciting time for wind energy, as Sandia and U.S. DOE are also involved in a project to manufacture enormous wind turbine blades for offshore energy production—that is, blades measuring up to 656 feet, or about 100 feet taller than the Empire State Building. Though there’s word yet on whether these giant exascale wind turbines will be 3D printed, the sky is truly the limit.