3D printing lowers costs, expands hydropower opportunities

Summary

Additive manufacturing enables rapid, customized and affordable production of components for low-head micro-hydropower systems, significantly reducing barriers to harnessing energy.

Problem

Of the approximately 90,000 dams in the United States, less than 3 percent currently generate electricity. About 51,000 dams are classified as having micro hydropower potential, capable of producing up to 100 kilowatts each. However, these small-scale units are often prohibitively expensive because of the need for custom designs suited to specific site conditions, particularly where conditions fluctuate seasonally. Approximately 29 gigawatts of untapped hydropower energy potential exists across thousands of U.S. sites. Without rapid cost reductions, few of these sites will be developed. Addressing this challenge could significantly boost energy independence, economic development and a more resilient energy grid.

Scientific challenge

Cadens, a startup based in Rome, Wisconsin, aimed to reduce the high manufacturing costs associated with low-head hydropower components. Their “Turbine Builder” software could specify hydropower components, but not solve the challenge of cost-effective manufacturing. Cadens partnered with the U.S. Department of Energy’s Manufacturing Demonstration Facility at Oak Ridge National Laboratory to explore additive manufacturing. Producing affordable yet robust components  was challenging, as parts needed durability for continuous decades-long exposure to water pressure but had to remain economically viable for small-scale energy output.

Innovation

Researchers identified balancing standardization and customization as key to reducing costs. A large polyvinyl chloride (PVC) pipe served as the primary waterway, complemented by specialized 3D-printed polymer components tailored to the pipe’s dimensions. 

The draft tube, essential for maximizing efficiency, was produced in two halves from 20 percent carbon-fiber reinforced acrylonitrile-butadiene-styrene (ABS) polymer, sealed to form a robust 688-pound unit. 

For the runner housing, which encloses the turbine, precise fabrication was critical. Researchers opted to 3D print a mold rather than directly printing the piece, then cast the housing in fiberglass. CNC machining and spray-coat sealing ensured accuracy and protection. 

Researchers used big area additive manufacturing, computer-aided design and a 3D Platform Workbench 400 Series System to print critical system components, including the draft tube, wall thimble, runner housing mold, PVC end fitting, pipe supports and a runner system for a Fixed-Kaplan S-turbine.

Results

This pioneering project revitalized small hydropower potential by demonstrating rapid, reliable and cost-effective manufacturing methods. The operational prototype installed at Cadens’ facility has operated continuously for more than six years, providing essential data, supporting further research and enabling enhancements in turbine design and energy conversion efficiency. 

This unique micro-hydro testbed has become a platform for industry-wide advancements in material and component testing, simulation model optimization and energy storage solutions.

Impact

The successful 3D-printed Fixed-Kaplan S-turbine marks progress in making small-scale hydropower viable. Additive manufacturing demonstrated the capacity to economically produce high-quality components matching traditional manufacturing performance. 

Cadens continues leveraging this success, focusing on scaling up, reducing costs and adapting designs for challenging field conditions, including debris management and biofouling resistance. 

Support

This research was sponsored by the U.S. Department of Energy Advanced Materials and Manufacturing Technologies Office. CRADA #NFE-18-07280