ORNL’s Manufacturing Demonstration Facility uses additive manufacturing to cut hydropower component costs
Collaboration with startup Cadens produced a 3D printed turbine prototype that has run continuously for more than six years
Fewer than 3% of the roughly 90,000 dams in the United States currently generate electricity, according to Oak Ridge National Laboratory (ORNL), and with around 51,000 of those classified as having micro hydropower capacity — each capable of producing up to 100 kilowatts – there is approximately 29 gigawatts of untapped energy across thousands of sites.
With a largely economic barrier to development that drives up per-unit costs and prevents small-scale units that require custom designs, something innovative needed to be done to unblock the issue.
Cadens, a startup based in Rome, Wisconsin, has developed “Turbine Builder” software capable of specifying hydropower components for low-head sites. The company had no solution for manufacturing those components affordably, though, so it partnered with the US Department of Energy’s Manufacturing Demonstration Facility (MDF) at ORNL to determine whether additive manufacturing could fill that gap.
Researchers at ORNL identified that balancing standardization with site-specific customization was the key cost lever. The design, therefore, centered on a large PVC pipe as the primary waterway, with specialized 3D printed polymer components built to match its dimensions.
The draft tube was printed in two halves from 20% carbon-fiber reinforced acrylonitrile-butadiene-styrene (ABS) polymer and sealed into a 688-pound unit. For the runner housing, researchers chose to 3D print a mold rather than the part itself, and then cast the housing in fiberglass, with CNC machining and spray-coat sealing applied for dimensional accuracy and water protection.
The team used big area additive manufacturing (BAAM) alongside CAD and a 3D Platform Workbench 400 Series System. Printed components included the draft tube, wall thimble, runner housing mold, PVC end fitting, pipe supports, and a runner system for a Fixed-Kaplan S-turbine.
The resulting prototype has operated continuously at Cadens’ test facility for more than six years, generating data that has supported further turbine design and energy conversion research. The 30-foot-long testbed has since become a platform for material and component testing, simulation work, and energy storage research across the industry.Â
ORNL reported the approach demonstrated a cost reduction of up to 40% per kilowatt compared to traditional manufacturing methods.
